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NOTICE OF FINAL RULEMAKING

TITLE 18. ENVIRONMENTAL QUALITY

CHAPTER 11. DEPARTMENT OF ENVIRONMENTAL QUALITY 

WATER QUALITY STANDARDS

PREAMBLE

1. Sections Affected Rulemaking Action

R18-11-101 Amend 

R18-11-102 Amend 

R18-11-107 Amend 

R18-11-107.01 New Section 

R18-11-108 Amend 

R18-11-108.01 New Section 

R18-11-108.02 New Section 

R18-11-108.03 New Section 

R18-11-109 Amend 

R18-11-110 Amend 

R18-11-111 Amend 

R18-11-112 Amend 

R18-11-113 Amend 

R18-11-114 Amend 

R18-11-115 New Section 

R18-11-116 Amend 

R18-11-117 Amend 

R18-11-118 Amend 

R18-11-121 Amend 

R18-11-122 Amend 

R18-11-123 Amend 

Appendix A Amend 

Table 1 Amend 

Table 2 Amend 

Table 3 Amend 

Table 4 Amend

Table 5 Amend

Table 6 Renumber 

Table 6 New Table 
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Table 7 Amend 

Table 8 Amend 

Table 9 Renumber 

Table 9 Amend 

Table 10 Renumber 

Table 10 Amend 

Table 11 Renumber

Table 11 Amend

Table 12 Renumber

Table 12 Amend

Table 13 Renumber

Table 13 Amend

Table 14 Renumber

Table 14 Amend

Table 15 Renumber 

Table 15 Amend 

Table 16 Amend

Table 17 Amend

Table 18 Repeal

Table 18 Renumber 

Table 18 Amend 

Table 19 Renumber 

Table 19 New Table

Table 20 Amend

Table 21 Renumber

Table 21 Amend

Table 22 Renumber

Table 22 Amend

Table 23 Renumber

Table 23 Amend

Table 24 Renumber

Table 24 Amend

Table 25 Renumber 

Table 25 Amend 

Table 26 Renumber

Table 26 Amend

Appendix B Amend 
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Appendix C New Appendix 

2. The specific authority for the rulemaking, including both the authorizing statute (general) and the statutes 

the rules are implementing (specific):

Authorizing statutes: A.R.S. §§ 49-202(A), 49-203(A)(1), 49-221, 49-222 

Implementing statutes: A.R.S. §§ 49-221, 49-222 

3. The effective date of the rules:

Sixty days after the rulemaking is submitted to the Secretary of State. 

4. A list of all previous notices appearing in the Register addressing the final rulemaking:

Notice of Rulemaking Docket Opening: 14 A.A.R. 897, March 28, 2008 

Notice of Proposed Rulemaking: 14 A.A.R. 1281, April 25, 2008 

5. The name and address of agency personnel with whom persons may communicate regarding the 

rulemaking:

Name: Shirley J. Conard 

Address: Arizona Department of Environmental Quality 

 1110 W. Washington Street, 5415A-1 

 Phoenix, Arizona 85007 

Telephone Number: (602) 771-4632 (Metro-Phoenix area) or 

 1-800-234-5677, 4632 (other areas) 

Fax Number: (602) 771-4528 

E-Mail: conard.shirley@azdeq.gov 

6. An explanation of the rules, including the agency=s reasons for initiating the rulemaking:

GENERAL EXPLANATION OF THIS RULEMAKING 

Section 303(c) of the Clean Water Act requires all states to, where appropriate, adopt and revise water 

quality standards at least once every three years. States must preserve and protect the quality of navigable waters 

and adopt surface water quality standards by considering the following factors: 

1. The protection of the public health and the environment; 

2. The uses that have been made, are being made, or with reasonable probability may be made of the 

waters; 

3. The provisions and requirements of the Clean Water Act, the Safe Drinking Water Act, and their 

implementing regulations; 

4. The degree to which standards for one category of water could cause violations of standards for 

other hydrologically-connected water categories (for example, the Department must consider the 
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degree to which surface water quality standards could cause violations of aquifer water quality 

standards); 

5. Guidelines, action levels, or numeric criteria adopted or recommended by the U.S. Environmental 

Protection Agency (EPA) or any other federal agency; and 

6. Any unique, physical, biological, or chemical properties of the waters. 

A.R.S. § 49-222 authorizes the Department to adopt surface water quality standards that assure water 

quality, if attainable, that provides for protecting the public health and welfare; to develop standards to enhance 

the quality of water in Arizona; and to take into consideration the use and value of water for public water supplies, 

the propagation of fish and wildlife, and recreational, agricultural, industrial, and other purposes. 

The Department is charged with adopting numeric surface water standards that establish numeric limits on 

the concentrations of each of the 126 toxic pollutants listed by EPA under § 307 of the Clean Water Act. In 

adopting numeric water quality standards, the Department may consider: 

1. The effect of local water quality characteristics on the toxicity of pollutants; 

2. The varying sensitivities of local affected aquatic populations to these pollutants; and 

3. The extent to which the natural flow of the stream is perennial, intermittent, effluent-dependent, or 

ephemeral. 

While the Department may consider these site-specific factors in establishing water quality standards for 

ephemeral waters and effluent-dependent waters, any water quality standard adopted must be consistent with the 

requirements of the Clean Water Act. 

Section 303(c) of the Clean Water Act provides the basis in federal law for Arizona’s surface water quality 

standards program. The key elements are: 

1. A water quality standard is defined as consisting of the designated beneficial uses of a water body 

and water quality criteria necessary to support the designated uses; 

2. The following minimum beneficial uses must be considered when establishing surface water quality 

standards under the Clean Water Act: 1) public water supply; 2) the propagation of fish, shellfish, 

and wildlife; 3) recreation; 4) agricultural uses; 5) industrial uses; and 6) navigation; 

3. Arizona’s water quality standards must protect public health and welfare, enhance the quality of 

water, and serve the purposes of the Clean Water Act; 

4. The surface water quality standards rules must be reviewed at least once every three years using a 

process that includes public participation; and 

5. A process exists for EPA review of the surface water quality standards adopted by the Department. 

EPA requires that the Department specify appropriate uses to be achieved and protected in Arizona’s 

surface waters. These designated uses include domestic water source (DWS), fish consumption (FC), full body 

contact recreation (FBC), partial body contact recreation (PBC), aquatic and wildlife (cold water) (A&Wc), 

aquatic and wildlife (warm water) (A&Ww), aquatic and wildlife (effluent-dependent water) (A&Wedw), aquatic 

and wildlife (ephemeral water) (A&We), agricultural irrigation (AgI), and agricultural livestock watering (AgL). 

Individual surface waters in Arizona and their respective designated uses are listed in Appendix B of this 
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rulemaking. 

The surface water quality standards for downstream surface waters must be considered when establishing 

designated uses for upstream waters. The Department must ensure that the water quality standards that are 

adopted for upstream water bodies also provide for the attainment and maintenance of the water quality standards 

for downstream waters. This concept is stated in R18-11-104(F). 

The Department must adopt water quality criteria that are sufficient to protect water quality for the 

designated uses of Arizona’s surface waters. Water quality criteria, numeric criteria, and narrative criteria must 

be based on a sound scientific rationale and must contain sufficient parameters or constituents to protect each 

designated use. 

The Department has discretionary authority under 40 CFR 131.13 to include general policies that affect the 

application and implementation of the surface water quality standards in the rules. The Department has used this 

authority to adopt a mixing zone rule at R18-11-114, a variance rule at R18-11-122, and site specific standards in 

R18-11-115. 

How Surface Water Quality Standards Impact Pollution Control in Arizona 

Surface water quality standards are essential elements of several important water quality management 

programs including: Arizona Pollutant Discharge Elimination System (AZPDES) permitting; the § 305(b) water 

quality assessment and § 303(d) impaired water listing; and total maximum daily load (TMDL) programs. 

AZPDES Permit Program 

Surface water quality standards are used to regulate point source discharges of pollutants under the 

AZPDES permit program authorized under § 402 of the Clean Water Act. When technology-based permit limits 

required by the Clean Water Act are not sufficiently stringent to meet the applicable water quality standards, the 

Clean Water Act requires the development of more stringent, water quality-based effluent limits (WQBELs) in 

the AZPDES permit that are designed to ensure that the applicable surface water quality standards are met. The 

surface water quality standards rules play a critical role in the development of every AZPDES permit and provide 

the regulatory basis for the development of WQBELs which affect the levels of treatment that a discharger may 

be required to provide to control the discharge of pollutants to surface waters in Arizona. 

Section 305(b) Water Quality Assessment and § 303(d) Impaired Water Listing 

Section 305(b) of the Clean Water Act establishes a process to develop and report information on the 

quality of Arizona’s surface waters. The Department developed a program to monitor surface waters within its 

boundaries, and a biennial report describing the status of water quality in Arizona rivers, streams, lakes, and 

reservoirs was prepared and submitted to EPA. The § 305(b) water quality assessment process is the primary 

means by which the Department evaluates whether water bodies in Arizona are meeting surface water quality 

standards, that progress has been made in maintaining and restoring surface water quality, and the extent of 

remaining water quality problems. The surface water quality standards play a central role in the § 305(b) water 
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quality assessment process by providing the benchmarks used to assess water quality status. The surface water 

quality standards also provide the basis for the identification of water quality-limited or impaired waters in 

Arizona. Under § 303(d) of the Clean Water Act, the Department identifies and lists impaired waters that do not 

meet one or more of the surface water quality standards. The Clean Water Act requires the Department to develop 

total maximum daily load analyses (TMDLs) to restore water quality in those impaired waters. 

Total Maximum Daily Load (TMDL) Program 

Under § 303(d) of the Clean Water Act, the Department is required to develop TMDL analyses for impaired 

water bodies that do not meet one or more surface water quality standards. A TMDL is a calculation of the 

maximum amount of a pollutant that a waterbody can receive and still meet surface water quality standards. The 

TMDL allocates that amount among the point and non-point sources in the watershed that discharge the pollutant 

of concern. A TMDL analysis starts with the identification of the pollutant(s) of concern and the surface water 

quality standards that must be attained to protect designated uses. A TMDL establishes a pollutant “budget” 

which is implemented through other Department water quality management programs such as the AZPDES 

permit program and the § 319 Non-Point Source Program. The ultimate goal of a TMDL is the restoration of 

water quality so that an impaired water attains applicable surface water quality standards. 

Other Department Water Quality Management Programs That Depend on Surface Water Quality Standards 

Section 319 of the Clean Water Act requires the Department to identify surface waters in Arizona that, 

without additional controls to control non-point sources of pollution cannot be reasonably expected to attain or 

maintain applicable water quality standards or the goals and requirements of the Clean Water Act. Management 

measures and best management practices (BMPs) are the primary mechanisms in § 319 of the Act to enable 

achievement of surface water quality standards. The Department administers the Water Quality Improvement 

Grant program that provides financial assistance to projects that control the discharge of pollutants to surface 

waters from non-point sources with a goal of achieving applicable water quality standards. 

Under § 401 of the Clean Water Act, the Department may grant, condition, or deny water quality 

certification for a federally permitted or licensed activity that may result in a discharge to a surface water in 

Arizona. Congress intended that states use the § 401 water quality certification process to ensure that no federal 

license or permit is issued that would violate state-adopted water quality standards. The surface water quality 

standards that are the subject of this rulemaking are the basis for the § 401 water quality certification process. If 

the Department grants water quality certification for a federal license or permit, it is in effect saying that the 

regulated activity will not result in a violation of a surface water quality standard. The Department also may place 

conditions on § 401 certification to ensure compliance with the surface water quality standards. The Department 

may deny certification if an applicant for a federal permit or license has not demonstrated that the regulated 

activity will be protective of applicable water quality standards. If the Department denies water quality 

certification, the federal permitting or licensing agency is prohibited from issuing the permit or license. The 

Department conducts § 401 water quality certifications for a variety of federal programs including the § 404 
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dredge-and-fill permit program administered by the U.S. Army Corps of Engineers, permits for construction of 

new or expanded airport facilities regulated by the Federal Aviation Administration, and some power plants 

regulated by the Federal Energy Regulatory Commission (e.g., hydroelectric power plants). 

Public Participation 

An important element of the surface water quality standards review process is the involvement of those 

who may be affected by water quality standards decisions. Section 303(c) of the Clean Water Act requires that 

the Department hold at least one public hearing during the rulemaking process to consider changes to the 

standards. A.R.S. § 49-208 requires that the Department ensure adequate public participation in the development 

of new or revised surface water quality standards. 

The Department invites the active involvement of citizens with an interest in surface water quality issues, 

the regulated community who may be affected by the state’s water quality standards decisions, and federal, state, 

and local agencies and governments, including Indian tribes, who may have a stake in the outcome of the 

rulemaking process. The Department has, over the last several years, gone well beyond the minimum 

requirements for public participation in this rulemaking, holding numerous workshops and public meetings to 

discuss water quality standards issues, including the following: 

June 4, 2008 Oral proceeding, Phoenix 

May 19, 2008: Oral proceeding, Tucson 

April 25, 2008 Notice of Proposed Rulemaking re-published in Arizona Administrative Register

April 4, 2008 Notice of Proposed Rulemaking Published in Arizona Administrative Register

September 21, 2007 Stakeholder Meeting on R18-11-113(E) in Phoenix 

September 13, 2007 Stakeholder meeting: Biocriteria 

August 30, 2007 Stakeholder meeting: Narrative nutrient standard IPs 

August 8, 2007 Stakeholder meeting in Phoenix to discuss final draft WQS rules 

June, 12, 2007 Discussion of the Pinto Creek site-specific standard, Miami area 

April 7, 2006 Meeting with PAG Environmental Protection Advisory Committee 

March 2006 Discussion of the Yuma East Wetlands project, Yuma, Arizona 

February 28, 2007 Informal stakeholder meeting 

February 8, 2006 Stakeholder meeting re: Permit Flexibility R18-11-113(E) 

November 29, 2005: Stakeholder meeting re: Permit Flexibility R18-11-113(E) 

November 16. 2005 Stakeholder meeting: Narrative Bottom Deposits Implementation Procedures 

November 10, 2005 Informal stakeholder meeting: Biocriteria & Narrative Nutrient Standard 

Implementation 

October-November, 2005 Informal stakeholder meetings on preliminary draft rules 

August, 2005 ADEQ published preliminary draft rules for informal comment 

July 18, 2005 Meeting with US Fish & Wildlife Service 

April 5, 2005 Kick-off meeting in Tucson 
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March 2005 Kick-off meeting in Phoenix 

December 17, 2004 Stakeholder meeting: Antidegradation Implementation 

July, 2004 Published request for input on rule issues 

June 29, 2004 Stakeholder meeting: Antidegradation Implementation 

November 25, 2003 Stakeholder meeting: Antidegradation Implementation 

EPA Review of Arizona’s Surface Water Quality Standards

The Department is required to submit new and revised water quality standards to the Region 9 

Administrator of the EPA for review. The Department must submit final surface water quality standards rules to 

the Regional Administrator within 30 days of the date of the filing of the final rules with the Office of the 

Secretary of State. At that time, EPA Region 9 will review the rules to determine whether they are consistent with 

the requirements of the Clean Water Act and EPA’s Water Quality Standards Regulation at 40 CFR 131. 

The EPA review of the surface water quality standards rules consists of the following determinations: 

1. Whether the designated uses are consistent with the requirements of the Clean Water Act; 

2. Whether Arizona’s surface water quality standards that do not include designated uses specified in § 

101(a)(2) of the Clean Water Act are based upon appropriate technical and scientific data and 

analyses; 

3. Whether the water quality criterion adequately maintains and protects water quality for the 

designated uses; 

4. Whether the legal procedures were followed for adopting the surface water quality standards rules; 

and 

5. Whether the surface water quality standards rules meet EPA minimum requirements specified in 40 

CFR 131.6. 

After completing the review, the EPA Regional Administrator may approve (in whole or in part), 

disapprove (in whole or in part), or conditionally approve (in whole or in part) Arizona’s surface water quality 

standards. If the Regional Administrator makes the decision to approve (in whole or in part) the rulemaking, the 

decision must be made within 60 days of the date of receiving a complete submittal of the surface water quality 

standards rules and supporting documentation. 

If the Regional Administrator determines that the surface water quality standards rules are inconsistent with 

the requirements of the Clean Water Act or federal water quality standards regulations, the Regional 

Administrator must disapprove the rules (in whole or in part) within 90 days of receiving the complete submittal 

of the surface water quality standards rules. 

If the Regional Administrator disapproves a water quality standard, EPA must notify the Department in a 

letter that includes a statement of the reasons for the disapproval and specify the revisions that must be adopted to 

obtain full EPA approval of the surface water quality standards. Under § 303(c)(4) of the Clean Water Act, EPA 

may federally promulgate water quality standards if the Regional Administrator disapproves a water quality 
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standard and the Department does not adopt the necessary revisions as specified by EPA. A state-adopted 

standard that EPA disapproves remains in effect until either: 1) The Department adopts the necessary revisions 

through the rulemaking process, or 2) EPA promulgates a federal water quality standard to supersede the 

disapproved water quality standard. 

SECTION BY SECTION EXPLANATION OF THE RULES 

R18-11-101. Definitions

This rulemaking makes minor, conforming, and editorial changes to the following definitions: “acute 

toxicity,” “agricultural irrigation,” “agricultural livestock watering,” “annual mean,” “aquatic and wildlife (cold 

water),” “Aquatic and wildlife (effluent-dependent water),” “Aquatic and wildlife (warm water),” “aquatic and 

wildlife (warm water),” “domestic water source,” “ephemeral water,” “existing use,” “full-body contact,” 

“intermittent water,” “mixing zone,” “oil,” “perennial water,” “pollutant,” “practical quantitation limit,” and 

“surface water.” 

The rulemaking combines all abbreviated terms (acronyms) with their defined counterparts. 

The following are new terms used within the rulemaking and have been added to this Section: “Arizona 

Pollutant Discharge Elimination System (AZPDES),” “assimilative capacity,” “critical flow condition,” “deep 

lake,” “reference condition,” “regulated discharge,” “riffle habitat,” “run-habitat,” “significant degradation,” and 

“wadeable.” 

The rulemaking adds the five lake categories, “deep lake,” “igneous lake,” “sedimentary lake,” “shallow 

lake,” and “urban lake,” identified in the narrative nutrient standard criteria rule at R18-11-108.03. 

The term “outstanding Arizona water (OAW),” replaces the term “unique waters.” 

The rulemaking revises the term “effluent-dependent water” to clarify that effluent-dependent water is 

surface water that consists of point source discharges of wastewater to ephemeral water. The current definition 

states that effluent-dependent water consists of “discharges of treated wastewater.” “Wastewater” is a broader 

term than “treated wastewater.” For example, the “point source discharge of wastewater” would include the point 

source discharge of untreated cooling water from a power plant to ephemeral water. The revision clarifies that 

“point source discharge of wastewater” does not mean a point source discharge of stormwater. 

The terms “National Pollutant Discharge Elimination System,” “recreational uses,” and “unique water” are 

no longer used and have been deleted from this Article. The term “ninetieth percentile” is still used within this 

Article, but only within R-18-11-109, therefore the term has been defined within that Section. 

R18-11-102. Applicability

This Section has been reorganized and revised for clarity. 

The following two new provisions in subsection (B) have been added to clarify the scope of the surface 

water quality standards rules: 

1. Subsection (B)(3) makes clear that surface water quality standards do not apply to man-made cooling 

ponds if they are created outside of what would otherwise be considered a “surface water” or a 
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“water of the United States.” 

2. Subsection (B)(4) makes clear that the surface water quality standards rules do not apply to surface 

waters located on Indian lands as Arizona does not have jurisdiction in Indian Country. 

R18-11-107. Antidegradation

Federal water quality standards regulations require the Department to adopt a statewide antidegradation 

policy and identify the methods for implementing the policy. Both federal and state antidegradation policies 

establish a three-tiered framework of antidegradation protection to maintain and protect existing water quality. 

This framework is established in this rulemaking. 

The basic purpose of the Tier 1 antidegradation policy is to maintain and protect existing water quality in 

Arizona’s surface waters and to ensure that applicable surface water quality standards are attained. 

Tier 2 maintains and protects existing water quality in Arizona’s “high quality” surface waters by allowing 

the degradation of existing water quality in high quality surface water only under certain circumstances. This rule 

language is modeled on the federal Tier 2 regulation that applies to “high quality” surface waters with water 

quality that exceeds levels necessary to support the propagation of fish, shellfish, wildlife, and recreation in and 

on the water. 

Tier 3 maintains and protects existing water quality in outstanding Arizona waters (OAWs). Currently, 

there are 20 OAWs that have been classified in rule. Two new OAWs have been added in this rulemaking. 

Editorial changes have been made to this Section for clarity. 

R18-11-107.01 Antidegradation Criteria

Federal water quality standards regulations require the Department to adopt a statewide antidegradation 

policy and to identify the methods for implementing the policy. Arizona’s first statewide antidegradation policy at 

R18-11-107 was adopted in 1985. Although Arizona has had a statewide antidegradation policy in rule for more 

than 20 years, the Department has not identified methods for implementing the policy in rule. R18-11-107.01 is a 

new Section that satisfies the federal mandate to identify methods for implementing antidegradation. R18-11-

107.01 is supported by a detailed guidance document entitled, “Antidegradation Implementation Procedures,” 

Arizona Department of Environmental Quality (July 2007). 

This Section contains the antidegradation criteria for each of the three tiers, and for reviews of general 

permits, § 404 dredge-and-fill permits, and AZPDES stormwater permits. 

The antidegradation implementation procedures rule applies to “regulated discharges,” defined at R18-11-

101(35). 

R18-11-108. Narrative Water Quality Standards

Narrative water quality standards are qualitative statements of desired water quality. The narrative water 

quality standards supplement the numeric water quality standards for specific pollutants and provide an important 

regulatory tool to maintain and protect the aesthetic qualities of Arizona’s surface waters. 
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This rulemaking adds a new narrative standard in subsection (D), which is a tool to prevent dumping in 

Arizona surface waters by making it an enforceable water quality standard; and a new narrative standard in 

subsection (E), which implements the third prong of the primary goal of the Clean Water Act, to restore and 

maintain the chemical, physical, and biological integrity of the nation’s waters. 

R18-11-108.01. Narrative Biological Criteria

This Section implements the new biocriterion in R18-11-108(E) by providing the objective criteria for 

determining if the narrative biocriterion standard is being met. In the past, the Department has implemented a 

chemically-based water quality standards program that has focused almost exclusively on the maintenance and 

protection of the chemical integrity of Arizona’s surface waters. However, a chemically-based water quality 

standards program alone cannot identify or adequately address all water quality problems that may result in 

impairment of the biological integrity of the state’s surface waters. Biocriteria can detect water quality problems 

that a chemically-based water quality standards program may miss or underestimate. Biocriteria are valuable 

tools because they directly measure the biological condition of surface waters. 

The biocriteria are based on the idea that the structure and function of aquatic biological communities 

provide important information about the overall quality of Arizona’s surface waters and attainment of aquatic life 

designated uses. Existing biological communities in relatively pristine or minimally impacted surface waters in 

Arizona that have been subjected to little or no anthropogenic disturbance provide the best available examples of 

biological integrity. Measurements of the attributes, structure and function of the biological communities in 

minimally impacted surface waters provide the basis for establishing reference conditions that can be used to 

evaluate the biological condition of surface waters that have been subjected to relatively greater amounts of 

disturbance. 

R18-11-108.02. Narrative Bottom-Deposits Criteria

This new Section implements R18-11-108(A)(1), which requires that surface waters “be free from 

pollutants in amounts or combinations that... settle to form bottom deposits that inhibit or prohibit the habitation, 

growth, or propagation of aquatic life.” This narrative standard, commonly referred to as the “narrative bottom 

deposits standard,” is intended to prevent excessive sedimentation and siltation in amounts that adversely affect 

aquatic life. Clean stream bottom substrates are essential for the health of many fish and benthic 

macroinvertebrate communities. Habitat degradation occurs when key stream habitat components such as 

spawning gravels and cobble surfaces are covered by fine sediment, decreasing inter-gravel oxygen transfer, and 

reducing or eliminating the quality and quantity of pool and interstitial habitat for fish, benthic 

macroinvertebrates, and algae. Excessive sediment and siltation adversely alters these habitats, suffocates fish 

eggs, and disrupts both aquatic communities and the food web dynamics. 

This Section prescribes the objective criteria that will be used to determine whether there is a violation of 

the narrative bottom-deposits standard. Using separate criteria for warm and cold water streams, the Department 

will use the percentage of fine sediments in the riffle habitats of wadeable, perennial cold-water streams and the 
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percentage of fine sediments in all stream habitats of wadeable, perennial warm-water streams to determine 

compliance with the narrative bottom deposits standard. The fine sediment thresholds are based on the scientific 

literature on sedimentation and siltation of streams. 

R18-11-108.03. Narrative Nutrients Criteria

R18-11-108(A)(6) states that surface waters shall not contain pollutants in amounts or concentrations that 

cause the growth of algae or aquatic plants that inhibit or prohibit the habitation, growth, or propagation of other 

aquatic life or that impair recreational uses. This subsection is often called the “narrative nutrients standard” 

because it is intended to regulate nutrients that cause excessive growth of algae and plants in surface waters (e.g., 

total nitrogen and total phosphorus). This narrative nutrient standard is intended to address water quality 

problems associated with nutrient over-enrichment and accelerated rates of eutrophication of Arizona’s lakes and 

reservoirs. 

The narrative nutrient criteria and matrix in this new section provide the objective criteria that will be used 

to determine whether there is a violation of the narrative nutrients standard at subsection (A)(6). The department 

will use the chlorophyll-a criterion as the primary endpoint in combination with the other matrix variables for 

assessing support of aquatic and wildlife designated use with regard to nutrients in lakes and reservoirs that are 

listed in Appendix B and classified for application of the matrix (e.g., urban lake, deep lake). 

R18-11-109. Numeric Water Quality Standards

This Section prescribes numeric water quality standards for bacteria, pH, temperature, suspended sediment 

concentration, dissolved oxygen, and nutrients. 

The single sample maximum nitrate criterion of 10 mg/L that applies to the San Pedro River from Curtiss to 

Benson prescribed in R18-11-109(F)(10) has been repealed. The site-specific criterion of 10 mg/L is the same as 

the National Primary Drinking Water Maximum Contaminant Level for nitrate promulgated by EPA under the 

Safe Drinking Water Act. It is also the numeric criterion that the Department adopts to maintain and protect water 

quality for the domestic water source (DWS) designated use. The designated uses for the San Pedro River from 

Curtiss to Benson do not include a DWS designated use. DWS is not an existing or designated use of this reach 

of the San Pedro River. The most stringent numeric water quality standard for nitrate that currently applies to this 

reach of the San Pedro River is the full body contact recreation (FBC) criterion. The numeric FBC criterion for 

nitrate is 2,240 mg/L. Department research on the origin of current site-specific criterion of 10 mg/L shows that 

the source of the current standard appears to be a report prepared in September, 1985 by the Arizona Department 

of Environmental Health Services (ADHS), “San Pedro and Santa Cruz Rivers: Nutrient Standards Review.” In 

this report, ADHS recommended that a single sample maximum nitrate standard of 10 mg/L be adopted for the 

San Pedro River because incidental ingestion of nitrate-enriched water during water-based recreation and 

consumption of alluvial groundwater further downstream could present a public health risk. The current FBC 

criterion of 2,240 mg/L in the surface water quality standards rules will protect public health from incidental 

ingestion of water associated with full body contact recreation. 
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The Department has repealed the numeric nutrient standards for four lakes (Roosevelt, Apache, Canyon, 

and Saguaro) under this Section and will apply the new narrative nutrient standard to protect these waterbodies. 

R18-11-110. Salinity Standards for the Colorado River

This Section contains the salinity standards for the Colorado River as approved by the Colorado River 

Salinity Control Forum, which was formed in 1973 by the seven Colorado river basin states to develop standards 

and a basin-wide plan of implementation. The rulemaking updates the incorporation by reference. 

R18-11-111. Analytical Methods

This Section contains the analytical methods that are necessary to determine compliance with a water 

quality standard. 

Minor editorial changes have been made to this Section and statutory citations have been updated and 

added to allow the use of EPA-approved methods for analysis of water and wastewater. 

R18-11-112. Outstanding Arizona Waters

This Section establishes the criteria for classifying a water as an outstanding Arizona water. The phrase 

“outstanding Arizona water” parallels EPA’s term and more adequately describes the type of surface water 

intended to be protected under the Tier 3 antidegradation policy. 

The reference to “unique waters” has been replaced throughout this rulemaking with “outstanding Arizona 

water (OAW)” to make the rule consistent with the terminology used in the federal antidegradation rule at 40 

CFR 131.12 when referring to Tier 3 waters. 40 CFR 131.12 refers to “outstanding national resource waters” in 

the Tier 3 federal antidegradation policy and provides the highest level of antidegradation protection to them. 

Davidson Canyon has been added to the list of OAWs. Davidson Canyon was nominated by the Pima 

County Regional Flood Control District and the Pima Association of Governments (PAG) Watershed Planning 

Department. Davidson Canyon contains perennial and intermittent reaches, is in a free-flowing condition, and the 

water quality data provided by PAG indicates that water quality is good. Davidson Canyon possesses attributes 

that make it of exceptional recreational and ecological significance. Davidson Canyon is one of the largest 

drainages in the Cienega Corridor and to Cienega Creek, which is already classified as an OAW. Davidson 

Canyon provides one of the most important wildlife migration corridors in Southern Arizona, linking the Santa 

Rita Mountains to the Rincon Mountains. The stream provides important riparian habitat for diverse flora and 

fauna, including priority vulnerable species listed under the Sonoran Desert Conservation Plan and threatened 

and endangered species or species of concern identified by the U.S. Fish & Wildlife Service, including the 

lowland leopard frog and the longfin dace. The Department notes that the nominated reach of Davidson Canyon, 

associated water rights, and surrounding lands are being acquired by Pima County as part of the Sonoran Desert 

Conservation Plan. The OAW classification of Davidson Canyon is consistent with and provides support for 

Pima County’s conservation management goals and policies for this important riparian area. 

Fossil Creek, a tributary of the Verde River, has been added to the list of OAWs. Fossil Creek was 
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nominated for OAW classification by the Grand Canyon Chapter of the Sierra Club and others. Fossil Creek is 

perennial, in a free-flowing condition, and the available water quality data indicates the creek has excellent water 

quality. Fossil Creek is of exceptional ecological significance, providing habitat for a diversity of plant and 

animal life. Of particular importance is the fact that Fossil Creek provides habitat for a diverse assemblage of 

native fishes, including the Sonora sucker, desert sucker, headwater chub, round tail chub, speckled dace, and 

longfin dace. The restoration and long-term protection of native fish in Fossil Creek provides an exceptional 

opportunity to restore Arizona’s declining native fish species and may increase the success of native fish 

restoration efforts in the Verde River watershed. The decision to classify Fossil Creek as an OAW is based 

largely on the information and data provide on current physical and biological conditions of Fossil Creek, which 

was provided in “Fossil Creek: State of the Watershed Report,” Northern Arizona University (July 2005). This 

rulemaking delays the effective date for the Fossil Creek OAW classification until June 30, 2010 to allow the 

Arizona Public Service company to complete de-commissioning activities in the Fossil Creek watershed. This 

date is the final deadline approved by the Federal Energy Regulatory Commission to complete all 

decommissioning activities. 

R18-11-113. Effluent-Dependent Waters

This Section establishes the effluent-dependent water standards. Effluent-dependent waters (EDWs) are a 

special category of surface waters created by the point source discharge of wastewater to an ephemeral water. An 

EDW is a surface water that, without a point source discharge of wastewater, would be an ephemeral water. 

Any person may request that a surface water be classified as an EDW. There are three basic information 

requirements that must be met to support an EDW classification by rule. First, a person must submit a map and a 

description of the EDW. Second, the person must submit information demonstrating that the EDW consists of a 

point source discharge of wastewater. Finally, a person must submit information demonstrating that the receiving 

water is an ephemeral water. The Department may also propose surface waters for EDW classification on its own 

initiative. 

The 36 EDWs currently listed in subsection (D) have been moved to Appendix B. 

A subcategory of the aquatic and wildlife designated use has been developed for effluent-dependent waters 

(A&Wedw) and apply to all surface waters that are classified as EDWs by rule. 

The phrase “discharge of treated wastewater” has been changed to “point source discharge of wastewater.” 

This change allows the Director to classify ephemeral waters that receive point source discharges of untreated 

cooling water and other industrial process waters as effluent-dependent waters in addition to discharges of 

municipal and domestic wastewater. 

New subsection (D) is subsection (E) in the current rule and requires that the permit-issuing authority use 

the water quality standards that apply to effluent-dependent waters to derive discharge limitations for a point 

source discharge from a wastewater treatment plant to an ephemeral water “that changes that ephemeral water 

into an effluent-dependent water.” This phrase has been deleted to clarify that EDW standards will be used to 

derive discharge limitations for all point source discharges of wastewater to an ephemeral water. A point source 
15 

discharge of wastewater to an ephemeral water changes the receiving ephemeral water into an effluent-dependent 

water. This position is based on the definitions of “effluent-dependent water” and “ephemeral water.” Subsection 

(D) clarifies which discharges are not considered “wastewater” for purposes of this Section, including stormwater 

and similar discharges approved under a general permit. 

In new subsection (E), language has been added to provide regulatory flexibility to apply only acute 

A&W(edw) standards to point source discharges of wastewater to ephemeral waters under certain circumstances. 

The Department recognizes that there may be infrequent, sporadic, or emergency point source discharges of 

wastewater to ephemeral waters where it is reasonable to conclude that chronic A&W(edw) standards are 

unnecessary. Acute and chronic A&W(edw) standards would be appropriate for continuous point source 

discharges of wastewater to an ephemeral water that create perennial EDWs or for intermittent point source 

discharges of wastewater that flow seasonally or regularly. Acute and chronic A&W(edw) standards are also 

appropriate to regulate a point source discharge to an ephemeral water where the water may reach a downstream 

surface water with chronic A&W standards. Also, chronic A&W(edw) standards are appropriate where the point 

source discharge of effluent creates an impoundment or semi-permanent ponds to permanent ponds within an 

ephemeral water. However, there may be point source discharges to ephemeral waters where the amount of flow, 

the frequency, or the duration of the discharge is such that it is unlikely that water may be present in the receiving 

ephemeral water for a sufficient period of time for organisms in the receiving water to be chronically exposed to 

pollutants. 

This Section has been revised to provide flexibility so that acute A&Wedw standards can be applied on a 

case-by-case basis in AZPDES permits. Language has been added that provides regulatory flexibility by 

clarifying that AZPDES permits may establish alternative discharge limits derived from acute A&W(edw) or 

chronic A&W(edw) standards based on seasonal variations in the discharge. 

R18-11-114. Mixing Zones

This Section lists the criteria for establishing a mixing zone and contains minor editorial and formatting 

changes. 

A provision has been added to subsection (H) that prohibits zones of initial dilution in a mixing zone that 

are so large that they cause lethality to drifting organisms that pass through. 

R18-11-115. Site-Specific Standards

State and federal laws authorize the adoption of site-specific standards that reflect local environmental 

conditions. The federal water quality standards at 40 CFR 131.11(b)(1)(ii) provide the Department with the 

authority to adopt water quality criteria that are “modified to reflect site-specific conditions.” Similarly, A.R.S. § 

49-221(C)(6) directs the Director to consider “[a]ny unique physical, biological, or chemical properties of the 

waters” when establishing surface water quality standards. Under A.R.S. § 49-222(C), the Department may 

consider the effect of local water quality characteristics on the toxicity of specific pollutants and the varying 

sensitivities of local, affected aquatic populations to pollutants when setting numeric water quality standards. 
16 

This Section provides specific authority for site-specific standards and identifies methods acceptable to the 

Department and EPA for their development. Site specific standards, like all surface water quality standards, must 

be based on a sound scientific rationale to protect the aquatic and wildlife designated use. This Section prescribes 

technically defensible methods for site-specific standard development. 

R18-11-116. Resource Management Agencies

This Section establishes how resource management agencies are affected by this Article and contains minor 

editorial changes. 

R18-11-117. Canals and Urban Park Lakes

This Section establishes standards for canals and urban park lakes and contains minor editorial changes. 

R18-11-118. Dams and Flood Control Structures

This Section establishes standards for dams and flood control structures and contains minor editorial 

changes. 

R18-11-121. Schedules of Compliance

This Section establishes schedules of compliance and contains minor editorial changes. 

R18-11-122. Variances

This Section establishes water quality standard variances for a point source discharge and contains minor 

editorial changes. 

R18-11-123. Discharge Prohibitions

This Section adds two new discharge prohibitions that prevent point source discharges of wastewater to 

listed ephemeral waters that flow onto the Ak Chin Indian Reservation. 

Appendix A. Numeric Water Quality Criteria

Appendix A lists the numeric water quality standards. Tables 1 and 2 have been deleted and the 

information contained in those two tables has been combined into a new Table 1. 

The numeric water quality criteria have been revised to reflect changes in criteria derivation 

methodologies, revised exposure assumptions, new information, and data on human health effects or new toxicity 

data that support a revision of aquatic life criteria. Specific revisions and the reasons for making the changes are 

indicated in the subsequent tables. Each table is organized by designated use, existing criteria, and adopted 

criteria for each parameter. 

Methodologies for Deriving Criteria for the Domestic Water Source Designated Use 
17 

Numeric criteria to maintain and protect water quality for the Domestic Water Source (DWS) designated 

use are either Maximum Contaminant Levels (MCLs) established by EPA under the National Primary Drinking 

Water Regulations or values derived using EPA methods to protect human health. Where an MCL has been 

established for a pollutant, the MCL has been adopted as a criterion to protect water quality for the DWS 

designated use. Where MCLs were not available, the criteria were derived for the DWS designated use using the 

following equations: 

For carcinogens: 70 kg * 10-6

 OCSF * 2 L/day 

For non-carcinogens: Rfd * RSC * 70 kg

 2 L/day 

In the carcinogen equation, 70 kg is the average weight of a human male in kilograms; 10-6 is the excess 

cancer risk level; OCSF is the oral cancer slope factor; and 2 L/day is the national average water consumption 

rate in liters per day. 

In the non-carcinogen equation, Rfd is the reference dose; RSC is the relative source contribution factor, 70 

kg is the average weight of a human male in kilograms and 2 L/day is the national average water consumption 

rate in liters per day. The relative source contribution factor is a way to account for other exposure pathways to a 

pollutant (e.g., food, inhalation, work exposure, etc.). There is little reliable information to assess the amount of 

exposure to a pollutant attributable to different exposure pathways. EPA uses a default RSC factor of 20 percent 

when developing MCLs. This assumes that 20 percent of a person’s exposure to a pollutant is estimated to be 

through the ingestion of water. The Department used the same default RSC factor in deriving criteria for the 

DWS designated use. 

Numeric criteria for the DWS designated use has been adopted using the following decision criteria: 

1. MCLs, where available; 

2. Where MCLs were not available, the DWS criterion was calculated using the appropriate procedure 

for carcinogens or non-carcinogens; 

3. For carcinogens where an OCSF was not available but an Rfd was available, the non-carcinogen 

procedure and the Rfd were used to calculate a criterion; 

4. For non-carcinogens, a criterion using available Rfds was used. If an Rfd was not available in the 

Integrated Risk Information System (IRIS) but a surrogate Rfd was available, such as a Minimum 

Risk Level (MRL) from the Agency for Toxic Substances Disease Registry (ATSDR), a criterion 

using the MRL as an Rfd was calculated; 

5. Where an MCL, OCSF, Rfd or MRL was not available, a criterion for the DWS designated use was 

not derived. 

The following table summarizes those pollutants where a change or repeal has been made to the numeric 

criteria for the DWS designated use. 
18 

Numeric Water Quality Standards for Domestic Water Source 

Pollutant Existing DWS 

Criterion (μg/L) 

Adopted DWS 

Criterion (μg/L) Reason for Change 

Acenaphthylene NNS None This pollutant has been removed from Appendix A because 

for any designated use. 

Acrylonitrile 0.07 0.06 The standard was calculated using the DWS method for carc

01). 

Arsenic 50 T 10 T A new MCL for arsenic has been adopted. Benz(a)anthracene 0.048 0.005 The standard was calculated using the DWS method for 

7.30E+00). 

3,4 Benzfluoranthene 0.048 0.005 The standard was calculated using the DWS method for 

7.30E+00). 

Benzo(k)fluoranthene 0.048 0.005 The standard was calculated using the DWS method for 

7.30E+00). 

Boron 630 T 1,400 T The standard was calculated using the DWS method for n

2.00E-01). 

Chlorine (total residual) 700 4,000 The maximum residual disinfection level (MRDL) for chl

from EPA’s 1998 Final Rule for Disinfectants and Disinfec

Chloropyrifos New parameter not in existing rules 21 The standard was calculated using the DWS method for n

3.00E-03). 

Chromium III 10,500 T None The rulemaking removes the speciated form and relies on 

criterion of 100. 

Chrysene 0.479 0.005 The standard was calculated using the DWS method for 

7.30E+00). 

Dibenz(ah)anthracene 0.048 0.005 The standard was calculated using the DWS method for 

7.30E+00). 
19 

Pollutant Existing DWS 

Criterion (μg/L) 

Adopted DWS 

Criterion (μg/L) Reason for Change 

p,p’-Dichlorodiphenyl dichloroethane (DDD) 

0.15 0.1 DDT and its metabolites, DDD & DDE have been consolid

The DWS criterion for DDT (0.1 μg/L) has been adopted f

1,1-Dichloroethane NNS None This pollutant has been removed from Appendix A because 

for any designated use. 

1,3-Dichloropropene 2 0.7 The standard was calculated using the DWS method for carc

02). 

Endosulfan sulfate NNS 42 The standard was calculated using the DWS method for n

6.00E-03). 

Hexachlorobutadiene 0.45 0.4 The DWS criteria have been adopted using the first signific

the decimal point. 

Malathion New parameter not 

in existing rules 

140 The standard was calculated using the DWS method for n

2.00E-02). 

o-Nitrophenol NNS None This pollutant has been removed from Appendix A because 

for any designated use. 

Paraquat New parameter not in existing rules 32 The standard was calculated using the DWS method for n

4.50E-03). 

Permethrin New parameter not 

in existing rules 

350 The standard was calculated using the DWS method for n

5.00E-02). 

Phenol 4,200 2,100 The standard was calculated using the DWS method for n

3.00E-01). 

2,3,7,8-Tetrachlorodibenzop-dioxin (2,3,7,8-TCDD) 0.01 0.00003 The new MCL has been adopted. Trihalomethanes (total) 100 80 The new MCL has been adopted. Uranium 35 D 30 D The new MCL has been adopted. 
20 

Methodologies for Deriving Criteria for the Fish Consumption Designated Use 

Numeric water quality criteria for the fish consumption (FC) designated use were derived using the 

following equations: 

For carcinogens: 70 kg * 10-6

 OCSF * 17.5 grams/day * BCF 

For non-carcinogens: Rfd * RSC * 70 kg

 17.5 grams/day * BCF 

In the carcinogen equation, 70 kg is the average weight of a human male in kilograms; 10-6 is the excess 

cancer risk level; OCSF is the oral cancer slope factor, 17.5 grams /day is the national average fish consumption 

rate, and BCF is a bioconcentration factor. 

In the non-carcinogen equation, Rfd is the reference dose, RSC is the relative source contribution factor, 70 

kg is the average weight of a human male in kilograms, 17.5 grams/day is the national average fish consumption 

rate, and BCF is the bioconcentration factor. 

These equations differ from those used to calculate the existing fish consumption criteria in two ways. 

First, the default fish consumption rate was changed from 6.5 grams/day to 17.5 grams/day. The default fish 

consumption rate was changed to 17.5 grams/day for several reasons. The previous rate of 6.5 grams/day was 

based upon the national average fish consumption value EPA used to calculate fish consumption criteria for the 

1980 ambient water quality criteria documents. EPA now recommends a fish consumption rate of 17.5 grams/day 

to adequately protect the general population of fish consumers. The 17.5 grams/day value is based on more recent 

fish consumption data obtained the U.S. Department of Agriculture 1994-1996 Continuing Survey of Food Intake 

by Individuals (CSFII). The CSFII is considered one of the best sources of current and unbiased information on 

the consumption of fish by the United States population. While 17.5 grams/day might be considered on the high 

end of national statistics for fish consumption, there is no reliable and statistically valid local or regional data on 

fish consumption to support the derivation of alternative fish consumption criteria for Arizona. 

Second, the relative source contribution factor (RSC) was used to calculate numeric fish consumption 

criteria for non-carcinogens. A default RSC factor of 20 percent was used when calculating numeric fish 

consumption criteria. This means that the Department assumes that 20 percent of a person’s exposure to a 

pollutant may come from the fish consumption exposure pathway. Previously, the Department had assumed that 

100 percent of a person’s exposure to a pollutant came through fish consumption. EPA recommends using the 20 

percent relative source contribution factor when routes of exposure to a pollutant other than fish consumption are 

anticipated, but adequate data to quantify those exposures are lacking. In a few instances, EPA has data 

suggesting a higher RSC for a particular pollutant. In those instances, the actual RSC was used rather than the 

default 20 percent (e.g., antimony, cadmium). The use of a higher fish consumption rate of 17.5 grams/day and an 

RSC factor resulted in more stringent numeric criteria for the fish consumption designated use. 

Third, EPA uses the 17.5 grams/day value when making its national criteria recommendations to protect 

human health. The following decision criterion is used to determine the numeric criteria for fish consumption 
21 

designated use: 

1. For carcinogens where an OCSF was available, a criterion was calculated using the procedure for 

carcinogens; 

2. For carcinogens where an OCSF was not available but an Rfd was available, the non-carcinogen 

procedure was used and a criterion was calculated for the carcinogen using the Rfd or an Rfd 

surrogate; 

3. For non-carcinogens, a criterion was calculated using available Rfd. If an Rfd was not available in 

the Integrated Risk Information System (IRIS) but a surrogate Rfd was available, such as a 

Minimum Risk Level (MRL) from the Agency for Toxic Substances Disease Registry (ATSDR), a 

criterion was calculated for the non-carcinogen using the MRL; 

4. Where an OCSF, Rfd, or MRL was not available, a criterion was not derived for the fish 

consumption designated use. If the Department did not have a bioconcentration factor for a 

pollutant, a FC criterion was not calculated. 

Methylmercury Fish Tissue Criterion 

This rulemaking adopts a fish tissue criterion for methylmercury of 0.3 mg methylmercury/kg fish tissue to 

protect human health. This criterion is based on EPA’s recommended national criterion for methylmercury in fish 

tissue, “Water Quality Criterion for the Protection of Human Health: Methylmercury,” EPA-823-R-01-001 

(January 2001). The criterion is expressed as a maximum concentration of methylmercury in fish and shellfish 

tissue to protect the consumers of fish and shellfish in the general population. It is not a water column value. 

To assess health risks, EPA derived a reference dose (Rfd) for methylmercury. A reference dose is an 

estimate (with uncertainty of perhaps an order of magnitude) of a daily exposure to the human population 

(including sensitive sub groups) that is likely to be without an appreciable risk of adverse health effects during a 

lifetime. To derive the Rfd, EPA established a no observed adverse effect level (NOAEL) for developmental 

neurotoxicity and then divided the NOAEL by a numerical uncertainty factor of 10 to account for areas of 

variability and uncertainty in the risk estimate. 

The consumption of contaminated fish and shellfish is the primary route of human exposure to 

methylmercury. 

Methylmercury is highly toxic to humans and causes a number of adverse health effects. Health studies 

have demonstrated that methylmercury is a potent neurotoxin, particularly in developing organisms. The brain is 

the most sensitive organ for which suitable health effects data are available to quantify a dose-response 

relationship. 

Mercury is found in the environment as a result of natural and human activities. During its movement 

among the atmosphere, land, and water, mercury undergoes a series of chemical transformations. One of these 

transformations is to an organic form of mercury called methylmercury. Methylmercury is easily absorbed into 

the living tissue of aquatic organisms and is not easily eliminated. Consequently, methylmercury accumulates in 

the tissues of predators as they age. The Department concluded that it is more appropriate to adopt a fish tissue 
22 

criterion for methylmercury instead of a water column-based water quality standard. A fish tissue criterion for 

methylmercury is more directly tied to the Clean Water Act goal of protecting public health because it is based 

directly on the primary route of human exposure to methylmercury (i.e., fish consumption). Second, the 

concentration of methylmercury in fish tissue is easier to quantify and is less variable over time. Third, a fish 

tissue criterion is consistent with how fish consumption advisories are issued. Fish consumption advisories for 

mercury are based on the amount of methylmercury in fish tissue that is considered acceptable. The adoption of a 

fish tissue standard directly supports Department issuance of fish consumption advisories. 

The following table presents the existing and amended criteria for the FC designated use. The table 

identifies the pollutant, the current FC criterion, the amended FC criterion, and the reasons for any changes. The 

table lists only those pollutants where a change or repeal has been made. 
23 

Numeric Water Quality Standards for Fish Consumption 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

Acenapthene 2,670 198 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; default Relative Source Contribpercent. Bioconcentration Factor (BCF = 242). 

Acenaphthylene NNS None This pollutant has been removed from Appendix A because 

designated use. 

Acrolein 25 1.9 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; default RSC = 20%; BCF = 2

Acrylonitrile 0.7 0.2 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 30. 

Aldrin 0.0001 0.00005 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 4,670. 

Anthracene 1,000 74 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; and default RSC = 20%; BCF 

Antimony 4,300 T 640 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 40%; BCF = 1. 

Arsenic 1,450 T 80 T The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 3. 

Benz(a)anthracene 0.49 0.02 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 30. 

Benzene 140 114 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 1. 

3,4 Benzfluroanthene 0.49 0.02 The standard was calculated using FC method for carcinoge
24 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

revised FC rate of 17.5 g/day; and BCF = 30. 

Benzidine 0.001 0.0002 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 87.5. 

Benzo(a)pyrene 0.05 0.02 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 30. 

Benzo(ghi)perylene NNS None This pollutant has been removed from Appendix A because 

designated use. 

Benzo(k)fluoranthene 0.49 0.02 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 30. 

Beryllium 1,130 T 84 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 19. 

Bis (2-chloroethoxy methane) NNS None This pollutant has been removed from Appendix A because 

designated use. 

Bis (2-chloroethyl) ether 1.4 0.5 The standard was calculated using FC meth

(OCSF = 1.10E+00); revised FC rate of 17.5 g/day; and Biocon6.9. 

Bis (2-chloroisopropyl) ether 174,400 3,441 The standard was calculated using FC method for non-carcino

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 9.3. 

Bromodichloromethane 46 17 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 3.8. 

Bromoform 360 133 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 3.8. 

Bromomethane 4,020 299 The standard was calculated using FC method for non-carcin
25 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 3.8. 

Butyl benzyl phthalate 5,200 386 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 414. 

Carbon tetrachloride 4 2 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 18.8. 

Chlordane 0.002 0.0008 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 14,100. 

Chlorobenzene 20,900 1,553 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 10.3. 

Chloroform 470 2,133 The standard was calculated using FC method for non-car

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 3.8. 

2-Chloronapthalene 4,300 317 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 202. 

2-Chlorophenol 400 30 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 134. 

Chromium III 1,010,000 T 75,000 T The standard was calculated using FC method for non-carcino

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 16. 

Chromium VI 2,000 T 150 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 16. 

Chrysene 4.92 0.02 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 30. 

Cyanide (as free cyanide) 215,000 T 16,000 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 1. 
26 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

Dalapon 161,500 8,000 The standard was calculated using FC method for non-carcino

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 3. 

Dibenz(ah)anthracene 0.20 0.02 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 30. 

Dibromochloromethane 34 13 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 3.80. 

Dibutyl phthalate 12,100 899 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 89. 

1,2-Dichlorobenzene 2,800 205 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%: and BCF = 351. 

1,4-Dichlorobenzene 77,500 5,755 The standard was calculated using FC method for non-carcino

FC rate of 17.5 g/day; RSC = 20%; and BCF = 55.6. 

3,3’-Dichlorobenzidine 0.08 0.03 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 312. 

P,p’-Dichlorodiphenyl dichloroethane (DDD) 

0.001 0.0002 The standard was calculated using FC method for carcinog

revised FC rate of 17.5 g/day; and BCF = 53,600. 

P,p’-Dichlorodiphenyl dichloroethylene (DDE) 

0.001 0.0002 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 53,600. 

P,p’-Dichlorodiphenyl trichloroethane (DDT) 

0.0006 0.0002 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 53,600. 

1,1-Dichloroethane NNS None This pollutant has been removed from Appendix A because 

designated use. 

1,2-Dichloroethane 100 37 The standard was calculated using FC method for carcinoge
27 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

revised FC rate of 17.5 g/day; and BCF = 1.2. 

1,1-Dichloroethylene 320 7,143 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 5.6. 

1,2-trans-Dichloroethylene 136,000 10,127 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 1.6. 

Dichloromethane 1,600 593 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 0.9. 

2,4-Dichlorophenol 800 59 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 40.7. 

1,2-Dichloropropane 236,000 17,518 The standard was calculated using FC method for non-car

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 4.1. 

1,3-Dichloropropene 1,700 42 The standard was calculated using FC method for carcino

revised FC rate of 17.5 g/day; and BCF = 1.9. 

Dieldrin 0.0001 0.00005 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 4,670. 

Diethyl phthalate 118,000 8,767 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 73. 

Di(2-ethylhexyl)phthalate 7.4 3 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 104. 

2,4-Dimethylphenol 2,300 171 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 93.8. 

4,6-Dinitro-o-cresol 7,800 582 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 5.5. 
28 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

2,4-Dinitrophenol 14,400 1,067 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 1.5. 

2,4-Dinitrotoluene 5,700 421 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 3.8. 

1,2-Diphenylhydrazine 0.5 0.2 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 24.9. 

Endosulfan sulfate NNS 18 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 270. 

Endosulfan (total) 240 18 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 270. 

Endrin 0.8 0.06 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 3,970

Ethylbenzene 28,700 2,133 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20% and BCF = 37.5. 

Ethyl chloride NNS None This pollutant has been removed from Appendix A because 

designated use. 

Fluoranthene 380 28 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 1,150

Fluorene 14,400 1,067 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; BCF = 30. 

Glyphosate 1,077,000 266,667 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 0.3. 

Heptachlor 0.0002 0.00008 The standard was calculated using FC method for carcinoge
29 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

revised FC rate of 17.5 g/day; and BCF = 11,200. 

Heptachlor epoxide 0.0001 0.00004 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 11,200. 

Hexachlorobenzene 0.001 0.0003 The standard was calculated using FC method for carcinogen

FC rate of 17.5 g/day; and BCF = 8,690. 

Hexachlorobutadiene 50 18 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 2.8. 

Hexachlorocyclohexane alpha 0.01 0.005 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 130. 

Hexachlorocyclohexane gamma (lindane) 

25 1.8 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 130. 

Hexachlorocyclopentadiene 580 74 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 40%; and BCF = 130. 

Hexachloroethane 9 3.3 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 86.9. 

Indeno (1,2,3-cd) pyrene 0.49 0.2 The standard was calculated using FC method for non-carcino

revised FC rate of 17.5 g/day; and BCF = 30. 

Isophorone 2,600 961 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 4.4. 

Mercury 0.6 T None Mrcury FC criterion was replaced with methylmercury fish tMethylmercury New parameter 

not in existing 

rules 

Fish tissue 

criterion 

0.3 mg/kg 

Based on EPA § 304(a) national criteria recommendation fotissue. 
30 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

Napthalene 20,500 1,524 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 10.5. 

Nickel 4,600 T 511 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 30%; and BCF = 47. 

Nitrobenzene 1,900 138 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 2.9. 

o-Nitrophenol NNS None This pollutant has been removed from Appendix A because 

designated use. 

N-Nitrosodimethylamine 8 3 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 0.026. 

N-Nitrosodi-n-phenylamine 16 6 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 136. 

N-Nitrosodi-n-propylamine 1.4 0.5 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 1.1. 

Pentachlorophenol 1,000 370 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 0.1. 

Phenol 1,000 37 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 6,462

Picloram 24,300 2,710 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 31. 

Polychlorinated biphenyls (PCBs) 

0.007 0.00006 The standard was calculated using FC method for carcinogens 

rate of 17.5 g/day; and BCF = 31,200. 

Pyrene 10,800 800 The standard was calculated using FC method for non-carcin
31 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

revised FC rate of 17.5 g/day; and RSC = 20%. BCF = 30. 

Selenium 9,000 T 667 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; and RSC = 20%. BCF = 6. 

Silver 107,700 T 8,000 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; and RSC = 20%. BCF = 0.5. 

Sulfides NNS None Sulfides was replaced with hydrogen sulfide. 2,3,7,8-Tetrachlorodibenzo-pdixoin 0.000000004 0.000000005 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 5,000. 

1,1,2,2-Tetrachloroethane 11 4 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 5. 

Tetrachloroethylene 3,500 261 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 30.6. 

Thallium 7.2 T 1 T The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 119. 

Toluene 201,000 29,907 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 40%; and BCF = 10.7. 

Toxaphene 0.001 0.0003 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 13,100. 

1,2,4-Trichlorobenzene 950 70 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 114. 

1,1,1 Trichloroethane NNS 428,571 The standard was calculated using FC method for non-carcin

revised FC rate of 17.5 g/day; RSC = 20%; and BCF = 5.6. 

1,1,2-Trichloroethane 42 16 The standard was calculated using FC method for carcinoge
32 

Pollutant 

Existing FC 

Criterion 

(μg/L) 

Adopted FC 

Criterion 

(μg/L) 

Reason for Change 

revised FC rate of 17.5 g/day; and BCF = 4.5. 

Trichloroethylene 203,200 29 The standard was calculated using FC method for carcinog

revised FC rate of 17.5 g/day; and BCF = 10.6. 

2,4,6-Trichlorophenol 6.5 2 The standard was calculated using FC method for carcinogens 

FC rate of 17.5 g/day; and BCF = 150. 

Vinyl Chloride 13 5 The standard was calculated using FC method for carcinoge

revised FC rate of 17.5 g/day; and BCF = 1.2. 

Zinc 69,000 T 5,106 T The standard was calculated using FC method for non-carcino

FC rate of 17.5 g/day; RSC = 20%; and BCF = 47. 
33 

Methodologies for Deriving Criteria for the Full Body Contact Designated Use 

The numeric water quality criteria for the full body contact (FBC) designated use was derived using the 

following equations: 

For carcinogens: 70 kg * 10-6

 OCSF * 15 ml/day 

For non-carcinogens: Rfd * RSC * 70 kg

 15 ml/day 

In the carcinogen equation, 70 kg is the average weight of a human male in kilograms; 10-6 is the excess 

cancer risk level; OCSF is the oral cancer slope factor, and 15 ml/day is the incidental water ingestion rate in 

milliliters per day. 

In the non-carcinogen equation, Rfd is the reference dose, RSC is the relative source contribution factor, 70 

kg is the average weight of a human male in kilograms, and 15 ml/day is the incidental water ingestion rate in 

milliliters per day. 

These equations differ from those used to calculate the existing full body contact criteria in two ways. First, 

the rulemaking changes the incidental water ingestion rate from 50 ml/day to 15 ml/day. The previous rate of 50 

ml/day was based upon 1989 EPA recommendations for incidental water ingestion rate associated with 

swimming contained in “Exposure Factors Handbook,” Exposure Assessment Group, EPA/600/8-89/043. (May, 

1989), U.S. Environmental Protection Agency, Office of Health and Environmental Assessment, Washington, 

D.C. In 2000, EPA published a new guidance document that addresses incidental ingestion of water from 

recreational uses in “Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human 

Health,” U.S. Environmental Protection Agency, Office of Water, Office of Science and Technology, EPA-822-

B-00-004, (October 2000). While EPA does not make national criteria recommendations for recreational uses like 

FBC, EPA does suggest approaches to estimating exposure to pollutants through incidental ingestion during 

recreation. Literature on recreational exposure combined with assumptions about the average mouthful of water 

ingested for every hour of total body contact can be used to determine an incidental water ingestion rate. EPA 

now recommends an incidental ingestion rate of 10 ml/day. This estimate is based on an assumption that an 

individual may be in full body contact with water for 123 hours a year (representing one hour exposure per day 

throughout four summer months) and may ingest 30 ml of water per hour of swimming. EPA calculated the 10 

ml/day value by multiplying 30 ml/hour by 123 hours per year and dividing the product by 365 days. Studies of 

recreational exposures suggest that there may be considerable variability in this incidental water ingestion rate. 

EPA notes that while the recommended value of 10 ml/day may be appropriate where full body contact 

recreational activities may occur daily during the summer months, states in warmer climates, like Arizona, may 

wish to use a higher incidental ingestion rate to protect their populations that may swim in surface waters for a 

greater portion of the year. The Department assumed that persons in Arizona could engage in full body contact 

recreational activities for more than 4 months in a year. The incidental water ingestion rate of 15 ml/day is based 

on the assumption that a person may engage in full body contact recreational activity for 180 hours per year 
34 

(representing one hour exposure per day throughout six warm-weather months) and ingest 30 ml of water per 

hour. The 15 ml/day value is calculated by multiplying 30 ml/hour by 180 hours per year and dividing by 365. 

Second, the relative source contribution factor (RSC) is used to calculate numeric full body contact criteria 

for non-carcinogens to account for other exposure pathways. A default RSC factor of 20 percent was used when 

calculating numeric FBC criteria unless EPA recommended a higher RSC (e.g., antimony, barium). The 

Department assumes that 20 percent of a person’s exposure to a pollutant may come from incidental water 

ingestion while engaged in water-based recreation. Previously, the Department had calculated criteria assuming 

that 100 percent of a person’s exposure to a pollutant came through a single exposure pathway, e.g., through full 

body contact recreation. 

This rulemaking adopts numeric criteria for the full body contact designated use using the following 

decision criteria: 

1. A criterion was calculated using the appropriate procedure for carcinogens or non-carcinogens; 

2. For carcinogens where an OCSF was not available but an Rfd was available, the non-carcinogen 

procedure was used and a criterion was calculated for the carcinogen using the Rfd or a surrogate 

Rfd; 

3. For non-carcinogens, a criterion was calculated using available Rfds. If an Rfd was not available in 

the Integrated Risk Information System (IRIS) but a surrogate Rfd was available, such as a 

Minimum Risk Level (MRL) from the Agency for Toxic Substances Disease Registry (ATSDR), a 

criterion for the non-carcinogen was calculated using the MRL; 

4. Where an OCSF, Rfd or MRL was unavailable, a criterion was not derived for the full body contact 

designated use. 

5. Where the calculated full body contact standard was more stringent than the Domestic Water 

Source standard for the same pollutant, the DWS value was used in place of the calculated PBC 

value. It is unlikely that an individual will be more at risk from incidental ingestion during 

recreational activities than through direct consumption. 

Full Body Contact Criterion for Arsenic 

Arsenic is categorized by the EPA as a Class A carcinogen (i.e., a demonstrated human carcinogen based 

on sufficient human epidemiological evidence (as opposed to animal studies)). Increased lung cancer mortality 

was observed in multiple human populations exposed primarily through inhalation. Also, increased mortality 

from multiple internal organ cancers (liver, kidney, lung, and bladder) and an increased incidence of skin cancer 

were observed in populations consuming drinking water high in inorganic arsenic. 

Calculation of the FBC criteria using the standard equation above would yield new FBC criteria of 3 μg/L. 

This concentration was more stringent than the new drinking water MCL for arsenic of 10 μg/L and the arsenic 

criterion that was being considered to maintain and protect water quality in surface waters with the domestic 

water source (DWS) designated use (also 10 μg/L). The Department did not think it was reasonable to adopt a 

FBC criterion for arsenic that was more stringent than the new drinking water MCL or the proposed DWS 
35 

criterion for arsenic, particularly when it was unlikely that persons engaged in full body contact recreational 

activity would be more highly exposed to arsenic through incidental ingestion of water than persons who are 

assumed to ingest 2 liters of drinking water each day. 

In the 2000 Human Health Methodology guidance document described earlier in this section, EPA provides 

that states may use alternate minimum risk levels in standards derivation. It states that 10-6 and 10-5 are 

appropriate risk levels for health protection of the general population provided more highly exposed 

subpopulations do not exceed the 10-4 risk level. EPA allows states to adopt a water quality criterion for a 

pollutant based on an excess cancer risk level of 10-5 provided that the chosen risk level is protective of the most 

highly exposed populations and there is adequate public participation in the decision to use a risk level other than 

10-6. As noted earlier, the Department made conservative assumptions when choosing the exposure parameters 

for deriving criteria for the FBC designated use regarding the amount of time a person may swim in an Arizona 

lake or stream and the estimated amount of incidental ingestion. The Department believes it is unlikely that there 

is a highly exposed subpopulation in Arizona that is engaged in full body contact recreational activities in 

Arizona lakes and reservoirs for more than an hour a day for more than 6 months out of the year. 

Based on EPA’s guidance on excess cancer risk levels and the conservative assumptions of exposure, this 

rulemaking adopts the full body contact water quality criterion for arsenic based on an excess cancer risk level of 

10-5. The new FBC criterion for arsenic is calculated as follows: 

 70 kg x 10-5

 1.5E+00 x 15 ml/day = 31 μg/L (The value has been rounded down to 30 μg/L) 

It should be noted that the FBC criterion of 30 μg/L, while not as stringent as the drinking water MCL or 

the DWS criterion (10 μg/L), it is more stringent than the currently effective FBC criterion of 50 μg/L in rule. 

The following table presents the existing and criteria for the FBC designated use. The table identifies the 

pollutant, the current FBC criterion, the FBC criterion, and the reasons for any changes. The use of a revised 

water ingestion rate and an RSC factor resulted in more stringent numeric criteria for the full body contact 

designated use. The table lists only those pollutants where a change or repeal has been made. 
36 

Numeric Water Quality Standards for Full Body Contact 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

Acenapthene 84,000 56,000 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and Relative So(RSC) = 20%. 

Acrolein 700 467 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

Alachlor 14,000 9,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

Anthracene 420,000 280,000 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

Antimony 560 T 747 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 40

Arsenic 50 T 30 T The standard was calculated using FBC method for carcinog

revised FBC water ingestion rate of 15 ml/day. The Departmen

Cancer Risk Level (ECRL) for arsenic. 

Atrazine 49,000 32,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

Benz(a)anthracene 1.9 0.2 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

Benzo(ghi)perylene NNS None This pollutant has been deleted from Appendix A because of 

designated use. 

Beryllium 2,800 T 1,867 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day; and RSC = 2
37 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

Bis(2-chloroethoxy) methane NNS None This pollutant has been deleted from Appendix A because 

designated use. 

Bis(2-chloroethyl) ether 1.3 1 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

Bis(2-chloroisopropyl) ether 56,000 37,333 The standard was calculated using FBC method for non-carcin

revised FBC rate of 15 ml/day; and RSC = 20%. 

Boron 126,000 T 186,667 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

Bromodichloromethane TTHM 18,667 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

Bromomethane 2,000 1,307 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day; and RSC = 2

Butyl benzyl phthalate 280,000 186,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day; and RSC = 2

Cadmium 700 T 700 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

Carbofuran 7,000 4,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day; and RSC = 2

Chlorine (total residual) 140,000 4,000 The maximum residual disinfection level (MRDL) from EP

Disinfectants and Disinfection-By-Products has been adopte

Chlorobenzene 28,000 18,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day; and RSC = 2

Chloroform 230 9,333 The standard was calculated using FBC method for non-ca
38 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

revised FBC water ingestion rate of 15 ml/day; and RSC = 2

2-Chloronapthalene 112,000 74,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

2-Chlorophenol 7,000 4,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day; and RSC = 2

Chloropyrifos Not in existing 

rules 

2,800 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day and RSC = 20

Chromium III 2,100,000 T 1,400,000 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day; and RSC = 2

Chromium VI 4,200 T 2,800 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, Relative Sou(RSC) = 20%. 

Chromium (total) 100 T None No OCSF or Rfd exists to calculate a FBC criterion. Cyanide (as free cyanide) 28,000 T 18,667 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Dalapon 42,000 28,000 The standard was calculated using FBC method for non-carcin

revised FBC rate of 15 ml/day; and RSC = 20%. 

Dibromochloromethane TTHM 18,667 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

1,2-Dibromo-3-chloropropane 2,800 None No OCSF or Rfd exists to calculate FBC criterion. 1,2-Dibromoethane 0.05 8,400 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Dibutyl phthalate 140,000 93,333 The standard was calculated using FBC method for non-carcin
39 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

1,2-Dichlorobenzene 126,000 84,000 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

1,4-Dichlorobenzene 560,000 373,333 The standard was calculated using FBC method for non-ca

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

p,p’-Dichlorodiphenyl dichloroethane (DDD) 

5.8 4 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

p,p’-Dichlorodiphenyl dichloroethylene (DDE) 

4.1 4 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

p,p’-Dichlorodiphenyl trichloroethane (DDT) 

4.1 4 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

1,1-Dichloroethylene 230 46,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

1,2-trans-Dichloroethylene 28,000 18,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

2,4-Dichlorophenol 4,200 2,800 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

2,4-Dichlorophenoxyacetic acid (2,4-D) 

14,000 9,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

1,2-Dichloropropane 126,000 84,000 The standard was calculated using FBC method for non-ca

revised FBC water injection rate of 15 ml/day; and RSC = 20

Diethyl phthalate 1,120,000 746,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2
40 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

Di(2-ethylhexyl) adipate 1,200 560,000 The standard was calculated using FBC method for non-carcin

revised FBC water injection rate of 15 ml/day; and RSC = 20

Di(2-ethylhexyl)phthalate 100 1,200 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

2,4-Dimethylphenol 28.000 18,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

4,6-Dinitro-o-cresol 5,600 3,733 The standard was calculated using FBC method for non-carcin

revised FBC water injection rate of 15 ml/day; and RSC = 20

2,4-Dinitrophenol 2,800 1,867 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, RSC = 20%. 

2,4-Dinitrotoluene 2,800 1,867 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Di-n-octyl phthalate 560,000 373,333 The standard was calculated using FBC method for non-ca

revised FBC water injection rate of 15 ml/day; and RSC = 20

Dinoseb 1,400 933 The standard was calculated using FBC method for non-carcin

revised FBC water injection rate of 15 ml/day; and RSC = 20

Diquat 3,080 2,053 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Endosulfan sulfate NNS 5,600 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Endosulfan (total) 8,400 5,600 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Endothall 28,000 18,667 The standard was calculated using FBC method for non-carcin
41 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

revised FBC water ingestion rate of 15 ml/day, RSC = 20%. 

Endrin 420 280 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Ethylbenzene 140,000 93,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Fluoranthene 56,000 37,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Fluorene 56,000 37,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Fluoride 84,000 140,000 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 5

Glyphosate 140,000 93,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Hexachlorocyclohexane gamma (lindane) 

420 280 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Hexachlorocyclopentadiene 9,800 11,200 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 4

Hexachloroethane 100 100 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. 

Malathion Not in existing 

rules 

18,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Manganese 196,000 T 130,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2
42 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

Mercury 420 T 280 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Methoxychlor 7,000 4,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Napthalene 28,000 18,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Nickel 28,000 T 28,000 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 3

Nitrate 2,240,000 3,733,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 5

Nitrite 140,000 233,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 5

Nitrobenzene 700 467 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Oxamyl 35,000 23,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Paraquat Not in existing 

rules 

4,200 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Permethrin Not in existing 

rules 

46,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Phenol 840,000 280,000 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Picloram 98,000 65,333 The standard was calculated using FBC method for non-carcin
43 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

revised FBC water injection rate of 15 ml/day; and RSC = 20

Polychlorinated biphenyls (PCBs) 

28 19 The standard was calculated using FBC method for non-carcin

revised FBC water injection rate of 15 ml/day; and RSC = 20

Pyrene 42,000 28,000 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Selenium 7,000 T 4,667 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Silver 7,000 T 4,667 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Simazine 7,000 4,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Styrene 280,000 186,667 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

2,3,7,8-Tetrachlorodibenzo-pdixoin 0.00009 0.00003 The standard was calculated using FBC method for carcinoge

revised FBC water ingestion rate of 15 ml/day. Resultant valuDWS so default to DWS. 

Tetrachloroethylene 14,000 9,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Thallium 112 T 75 T The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Toluene 280,000 373,333 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 4

1,2,4-Trichlorobenzene 14,000 9,333 The standard was calculated using FBC method for non-carcin
44 

Pollutant 

Existing FBC 

Criterion 

(μg/L) 

Adopted FBC 

Criterion 

(μg/L) 

Reason for Change 

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

1,1,1-Trichloroethane 200 1,866,667 The standard was calculated using FBC method for non-carcin

FBC water injection rate of 15 ml/day; and RSC = 20%. 

2,4,5-Trichlorophenoxy proprionic acid (2,4,5-TP) 

11,200 7,467 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Uranium NNS 2,800 The standard was calculated using FBC method for non-carcin

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Xylenes (total) 2,800,000 186,667 The standard was calculated using FBC method for non-c

revised FBC water ingestion rate of 15 ml/day, and RSC = 2

Zinc 420,000 T 280,000 T The standard was calculated using FBC method for non-ca

revised FBC water ingestion rate of 15 ml/day, and RSC = 2
45 

Methodologies for Deriving Criteria for the Partial Body Contact Designated Use 

The Department derived numeric water quality criteria for the partial body contact (PBC) designated use 

using the following equation: 

 Rfd * RSC * 70 kg

 15 ml/day 

In this equation, Rfd is the reference dose, RSC is the relative source contribution factor, 70 kg is the 

average weight of a human male in kilograms, and 15 ml/day is the incidental water ingestion rate in milliliters 

per day. The equation is the same equation used to derive numeric criteria for non-carcinogens for the full body 

contact designated use. 

This equation is different from the methods the Department has used in previous rulemakings to calculate 

PBC criteria. When PBC criteria were originally proposed in 1992, the Department followed recommendations 

for water quality criteria for the PBC designated use developed by members of the regulated community and 

published in “Proposed Human Health Ambient Water Quality Standards for Arizona” (EBASCO Environmental, 

et. al 1990). EBASCO recommended a criteria development method for PBC that included using reference doses 

and average weight of the human male of 70 kg but with an incidental water ingestion rate of 0.5 liter (500 ml). 

In 2002, the Department revised the EBASCO methodology because it used what the Department considered to 

be an unreasonable incidental water ingestion rate of 500 ml to derive the PBC criteria (a rate that was 10 times 

higher than the incidental water ingestion rate used to calculate the FBC criteria in 1992). In 2002, the 

Department used the following equation to derive PBC criteria: 

 Rfd x 70 kg

 50 ml/day 

This rulemaking revises the incidental water ingestion rate for both the FBC and PBC designated uses to 15 

ml/day. The incidental water ingestion rate for the PBC designated use should not be higher than the rate used for 

the FBC designated use. In the absence of reliable data to derive PBC criteria based on dermal exposures or 

another incidental ingestion rate, the rulemaking relies on incidental water ingestion rate used in the FBC 

methodology to derive criteria for the PBC designated use. 

The rulemaking adopts numeric criteria for the partial body contact designated use using the following 

decision criteria: 

1. Calculate a criterion using the PBC equation using available Rfds. If an Rfd is not available in the 

Integrated Risk Information System (IRIS) but a surrogate Rfd is available, such as a Minimum Risk 

Level (MRL) from the Agency for Toxic Substances and Disease Registry (ATSDR), a PBC 

criterion is calculated using the MRL; and 

2. A criterion for the partial body contact designated use was not derived if there was no Rfd or MRL. 

The following table presents the existing and proposed criteria for the PBC designated use. The table 

identifies the pollutant, the current PBC criterion, the proposed PBC criterion, and the reasons for any proposed 

changes. The use of a revised water ingestion rate and an RSC factor resulted in more stringent numeric criteria 

for the partial body contact designated use. The table lists only those pollutants where a change or repeal has 
46 

been made. 
47 

Numeric Water Quality Standards for Partial Body Contact 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

Acenapthene 84,000 56,000 The standard was calculated using PBC method (Rfd = 6.00E

ingestion rate of 15ml/day, and RSC = 20%. 

Acrolein 700 467 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15ml/day, and RSC = 20%. 

Acrylonitrile 56,000 37,333 The standard was calculated using PBC method (Rfd = 0.

ingestion rate of 15 ml/day, and RSC = 20%. 

Alachlor 14,000 9,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Aldrin 42 28 The standard was calculated using PBC method (Rfd 3.00E-

ingestion rate of 15 ml/day, and RSC = 20%. 

Anthracene 420,000 280,000 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Antimony 560 T 747 T The standard was calculated using PBC method (Rfd = 4.00E

ingestion rate of 15 ml/day, and RSC = 40%.

Arsenic 420 T 280 T The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%.

Atrazine 49,000 32,667 The standard was calculated using PBC method (Rfd = 3.50E

ingestion rate of 15 ml/day, and RSC = 20%. 

Benzene 93 3,733 The standard was calculated using PBC method (Rfd = 4.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Benzidine 4,200 2,800 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 
48 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

Beryllium 2,800 T 1,867 T The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Bis(2-chloroisopropyl) ether 56,000 37,333 The standard was calculated using PBC method (Rfd 4.00E-

ingestion rate of 15 ml/day, and RSC = 20%.

Boron 126,000 T 186,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%.

Bromodichloromethane 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day and RSC = 20%.

Bromoform 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Bromomethane 2,000 1,307 The standard was calculated using PBC method (Rfd = 1.40E

ingestion rate of 15 ml/day, and RSC = 20%. 

Butyl benzyl phthalate 280,000 186,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Cadmium 700 T 700 T The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Carbofuran 7,000 4,667 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Carbon tetrachloride 980 1,307 The standard was calculated using PBC method (Rfd = 7.00E

ingestion rate of 15 ml/day, and RSC = 40%. 

Chlordane 700 467 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Chlorine (total residual) 140,000 4,000 The maximum residual disinfection level (MRDL) has been ad
49 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

Final Rule for Disinfectants and Disinfection-By-Products. Prthe level to avoid eye and skin irritation. 

Chlorobenzene 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Chloroform 14,000 9,333 The standard was calculated using PBC method (Rfd = 0.

ingestion rate of 15 ml/day, and RSC = 20%. 

2-Chloronapthalene 112,000 74,667 The standard was calculated using PBC method (Rfd = 8.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

2-Chlorophenol 7,000 4,667 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Chloropyrifos Not in existing 

rules 

2,800 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Chromium III 2,100,000 T 1,400,000 T The standard was calculated using PBC method (Rfd = 1.50E

ingestion rate of 15 ml/day, and RSC = 20%. 

Chromium VI 4,200 T 2,800 T The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Chromium (total) 100 T None No Rfd or MRL exists to calculate a PBC criterion. Cyanide (as free cyanide) 28,000 T 18,667 T The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Dalapon 42,000 28,000 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day and RSC = 20%. 

Dibromochloromethane 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 
50 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

1,2-Dibromo-3-chloropropane 2,800 None No Rfd or MRL exists to calculate a PBC method or criterio1,2-Dibromoethane 0.05 8,400 The standard was calculated using PBC method (Rfd = 9.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Dibutyl phthalate 140,000 93,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

1,2-Dichlorobenzene 126,000 84,000 The standard was calculated using PBC method (Rfd = 9.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

1,4-Dichlorobenzene 560,000 373,333 The standard was calculated using PBC method (Rfd = 0

ingestion rate of 15 ml/day, and RSC = 20%. 

p,p’-Dichlorodiphenyl dichloroethane (DDD) 

5.8 467 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%.

p,p’-Dichlorodiphenyl dichloroethylene (DDE) 

4.1 467 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%.

p,p’-Dichlorodiphenyl trichloroethane (DDT) 

700 467 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%.

1,2-Dichloroethane 280,000 186,667 The standard was calculated using PBC method (MRL = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

1,1-Dichloroethylene 12,600 46,667 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

1,2-trans-Dichloroethylene 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Dichloromethane 84,000 56,000 The standard was calculated using PBC method (Rfd = 6.00E

ingestion rate of 15 ml/day, and RSC = 20%. 
51 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

2,4-Dichlorophenol 4,200 2,800 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

2,4-Dichlorophenoxyacetic acid (2,4-D) 

14,000 9,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

1,2-Dichloropropane 126,000 84,000 The standard was calculated using PBC method (Rfd = 0.

ingestion rate of 15 ml/day, and RSC = 20%. 

1,3-Dichloropropene 420 28,000 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Dieldrin 70 47 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Diethyl phthalate 1,120,000 746,667 The standard was calculated using PBC method (Rfd = 8.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Di(2-ethylhexyl) adipate 840,000 560,000 The standard was calculated using PBC method (Rfd = 6.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Di(2-ethylhexyl)phthalate 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

2,4-Dimethylphenol 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

4,6-Dinitro-o-cresol 5,600 3,733 The standard was calculated using PBC method (Rfd = 0.0

ingestion rate of 15 ml/day, and RSC = 20%. 

2,4-Dinitrophenol 2,800 1,867 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

2,4-Dinitrotoluene 2,800 1,867 The standard was calculated using PBC method (Rfd = 2.00E
52 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

ingestion rate of 15 ml/day, and RSC = 20%. 

2,6-Dinitrotoluene 5,600 3,733 The standard was calculated using PBC method (MRL = 4.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Di-n-octyl phthalate 560,000 373,333 The standard was calculated using PBC method (Rfd = 0

ingestion rate of 15 ml/day, and RSC = 20%. 

Dinoseb 1,400 933 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Diquat 3,080 2,053 The standard was calculated using PBC method (Rfd = 2.20E

ingestion rate of 15 ml/day, and RSC = 20%. 

Endosulfan sulfate NNS 5,600 The standard was calculated using PBC method (Rfd = 6.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Endosulfan (total) 8,400 5,600 The standard was calculated using PBC method (Rfd = 6.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Endothall 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Endrin 420 280 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Ethylbenzene 140,000 93,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Fluoranthene 56,000 37,333 The standard was calculated using PBC method (Rfd = 4.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Fluorene 56,000 37,333 The standard was calculated using PBC method (Rfd = 4.00E

ingestion rate of 15 ml/day, and RSC = 20%. 
53 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

Fluoride 84,000 140,000 The standard was calculated using PBC method (Rfd = 6.00E

ingestion rate of 15 ml/day, and RSC = 50%. 

Glyphosate 140,000 93,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%.

Heptachlor 700 467 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Heptachlor epoxide 18 12 The standard was calculated using PBC method (Rfd = 1.30E

ingestion rate of 15 ml/day, and RSC = 20%. 

Hexachlorobenzene 1,120 747 The standard was calculated using PBC method (Rfd = 8.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Hexachlorobutadiene 280 187 The standard was calculated using PBC method (MRL = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Hexachlorocyclohexane alpha 11,200 7,467 The standard was calculated using PBC method (MRL = 8.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Hexachlorocyclohexane beta 840 560 The standard was calculated using PBC method (MRL = 6.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Hexachlorocyclohexane gamma (lindane) 

420 280 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Hexachlorocyclopentadiene 9,800 11,200 The standard was calculated using PBC method (Rfd = 6.00E

ingestion rate of 15 ml/day, and RSC = 40%. 

Hexachloroethane 1,400 933 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Isophorone 280,000 186,667 The standard was calculated using PBC method (Rfd = 2.00E
54 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

ingestion rate of 15 ml/day, and RSC = 20%. 

Malathion Not in existing 

rules 

18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Manganese 196,000 T 130,667 The standard was calculated using PBC method (Rfd = 1.40E

ingestion rate of 15 ml/day, and RSC = 20%. 

Mercury 420 T 280 T The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Methoxychlor 7,000 4,667 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Napthalene 28,000 18,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Nickel 28,000 T 28,000 T The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 30%. 

Nitrate 2,240,000 3,733,333 The standard was calculated using PBC method (Rfd = 1.60E+

ingestion rate of 15 ml/day, and RSC = 50%. 

Nitrite 140,000 233,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 50%. 

Nitrobenzene 700 467 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

N-Nitrosodi-n-propylamine 133,000 88,667 The standard was calculated using PBC method (MRL = 9.5E

ingestion rate of 15 ml/day, and RSC = 20%. 

Oxamyl 35,000 23,333 The standard was calculated using PBC method (Rfd = 2.50E

ingestion rate of 15 ml/day, and RSC = 20%. 
55 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

Paraquat Not in existing 

rules 

4,200 The standard was calculated using PBC method (Rfd = 4.50E

ingestion rate of 15 ml/day, and RSC = 20%. 

Pentachlorophenol 42,000 28,000 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Permethrin Not in existing 

rules 

46,667 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Phenol 840,000 280,000 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Picloram 98,000 65,333 The standard was calculated using PBC method (Rfd = 0.

ingestion rate of 15 ml/day, and RSC = 20%. 

Polychlorinated biphenyls (PCBs) 

28 19 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Pyrene 42,000 28,000 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Selenium 7,000 T 4,667 T The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Silver 7,000 T 4,667 T The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Simazine 7,000 4,667 The standard was calculated using PBC method (Rfd = 5.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Styrene 280,000 186,667 The standard was calculated using PBC method (Rfd = 2.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

2,3,7,8-Tetrachlorodibenzo-p- 1.4 0.0009 The standard was calculated using PBC method (Rfd = 1.00E
56 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

dixoin ingestion rate of 15 ml/day, and RSC = 20%. 1,1,2,2-Tetrachloroethane 56,000 93,333 The standard was calculated using PBC method (MRL = 0.

ingestion rate of 15 ml/day, and RSC = 50%. 

Tetrachloroethylene 14,000 9,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%.) 

Thallium 112 T 75 T The standard was calculated using PBC method (Rfd = 8.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Toluene 280,000 373,333 The standard was calculated using PBC method (Rfd = 0

ingestion rate of 15 ml/day, and RSC = 40%. 

Toxaphene 1,400 933 The standard was calculated using PBC method (MRL = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

1,2,4-Trichlorobenzene 14,000 9,333 The standard was calculated using PBC method (Rfd = 1.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

1,1,1-Trichloroethane 200 1,866,667 The standard was calculated using PBC method (Rfd = 2), revi

rate of 15 ml/day, and RSC = 20%. 

1,1,2-Trichloroethane 5,600 3,733 The standard was calculated using PBC method (Rfd = 2), revi

rate of 15 ml/day, and RSC = 20%. 

Trichloroethylene 280,000 280 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

2,4,5-Trichlorophenoxy proprionic acid (2,4,5-TP) 

11,200 7,467 The standard was calculated using PBC method (Rfd = 8.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Uranium NNS 2,800 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 
57 

Pollutant 

Existing PBC 

Criterion 

(μg/L) 

Adopted PBC 

Criterion 

(μg/L) 

Reason for Change 

Vinyl Chloride 4,200 2,800 The standard was calculated using PBC method (Rfd = 3.00E

ingestion rate of 15 ml/day, and RSC = 20%. 

Xylenes (total) 2,800,000 186,667 The standard was calculated using PBC method (Rfd = 0

ingestion rate of 15 ml/day, and RSC = 20%. 

Zinc 420,000 T 280,000 T The standard was calculated using PBC method (Rfd = 0

ingestion rate of 15 ml/day, and RSC = 20%. 
58 

Numeric Water Quality Standards for Aquatic and Wildlife Designated Uses 

Currently, there are numeric criteria for 98 pollutants to maintain and protect water quality for the aquatic 

life and wildlife (A&W) designated uses. This rulemaking establishes new criteria or revisions, to existing 

numeric A&W criteria for 59 parameters. In most cases, the § 304(a) national criteria recommendations to protect 

freshwater aquatic life have been adopted. The national criteria for total residual chlorine have been adopted and 

will provide for slightly less restrictive criteria for both acute and chronic aquatic life. The current water quality 

standards are: acute = 11 μg/L and chronic = 5 μg/L. This rulemaking changes these values to: acute = 11 μg/L 

and chronic = 19 μg/L. 

New numeric water quality standards for previously unregulated pollutants include new A&W criteria for 

chloropyrifos, guthion, hydrogen sulfide, iron, malathion, mirex, paraquat, parathion, permethrin, and tributyltin. 

The numeric water quality criteria for “sulfides” have been repealed and replaced with numeric criteria for 

hydrogen sulfide. The current A&W criteria for beryllium has been repealed because EPA has withdrawn its 

national § 304(a) criteria recommendations for the pollutant. 

Several pollutants have been amended by rounding existing criteria to the nearest whole number or to the 

first significant figure to the right of a decimal point. 

No changes have been made to the current numeric water quality criteria for the aquatic and wildlife 

(ephemeral) (A&We) designated use. 

Criteria for hardness-dependent metals 

The numeric water quality standards for certain metals are expressed as a function of hardness because 

hardness can affect the toxicities of the metals to aquatic life. These “hardness-dependent” pollutants include 

cadmium, chromium III, copper, lead, nickel, silver, and zinc. Increasing hardness has the effect of decreasing the 

toxicity of the metals. 

Currently, the numeric water quality criteria for these pollutants include a lower hardness cap of 25 mg/L. 

This hardness cap is based on an earlier EPA national criteria recommendation that when the hardness of 

freshwater is less than 25 mg/L, a hardness-dependent metals criterion should be calculated as if the hardness is 

25 mg/L. EPA describes the available data for copper, zinc, and cadmium in the 1-25 mg/L range as “somewhat 

limited” and “quite limited” for silver, lead, chromium III, and nickel. EPA subsequently re-evaluated the limited 

available data in the current metals criteria documents and determined that the data were “inconclusive.” EPA 

expressed concern that capping hardness at 25 mg/L without additional data or justification could result in metals 

criteria that provided less protection than that intended by EPA’s “Guidelines for Deriving Numerical National 

Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses,” U.S. Environmental Protection 

Agency, Office of Research and Development, EPA 822/R-85-100, (1985). 

EPA now recommends that hardness not be capped at 25 mg/L or any other hardness value on the lower 

end. The rulemaking removes the lower hardness cap for the hardness-dependent pollutants to include numeric 

metals criteria in the 1-25 hardness range. 

The following table provides the dissolved acute and dissolved chronic criteria for the hardness-dependent 
59 

metals. Individual tables are shown by metal type and designated use, and are calculated using the equation and 

appropriate hardness criterion. 
60 

HARDNESS-DEPENDENT DISSOLVED METALS CRITERIA

STANDARDS

FR

A&Wc A&Ww A&Wedw A&We

Acute Chronic Acute Chronic Acute Chronic Acute

CHEMICAL

mA bA mC bC mA bA mC bC mA bA mC bC mA bA

AC

Cadmium 1.0166 -3.924 0.7409 -4.719 1.0166 -2.561 0.7409 -3.894 1.0166 -2.561 0.7409 -3.894 1.0166 -1.497 1.136

hardness

Chromium III 0.8190 3.7256 0.8190 0.6848 0.8190 3.7256 0.8190 0.6848 0.8190 3.7256 0.8190 0.6848 0.8190 4.9361 0Copper 0.9422 -1.7 0.8545 -1.702 0.9422 -1.7 0.8545 -1.702 0.9422 -1.7 0.8545 -1.702 0.9422 -1.1514 0Lead 1.273 -1.460 1.273 -4.705 1.273 -1.460 1.273 -4.705 1.273 -1.460 1.273 -4.705 1.273 -0.7131 1.46

hardness

Nickel 0.8460 2.255 0.8460 0.0584 0.8460 2.255 0.8460 0.0584 0.8460 2.255 0.8460 0.0584 0.8460 4.4389 0Silver 1.72 -6.59 − − 1.72 -6.59 − − 1.72 -6.59 − − 1.72 -6.59 Zinc 0.8473 0.884 0.8473 0.884 0.8473 0.884 0.8473 0.884 0.8473 0.884 0.8473 0.884 0.8473 3.1342 0

Hardness-dependent metals’ criteria may be calculated from the following:

Acute (dissolved) = exp {mA [ln(hardness)]+ bA} (CF)

Chronic (dissolved) = exp {mC [ln(hardness)]+ bC} (CF)
61 

Criteria for Pentachlorophenol 

The criterion equation for pentachlorophenol requires the insertion of receiving water pH to develop the 

applicable water quality standards. This rulemaking uses three tables to show for pentachlorophenol standards. 

The equations to develop the water quality standards and companion tables are: 

A&Wc acute standard: e (1.005 (pH) - 4.830)

A&Wc chronic standard: e (1.005 (pH) - 5.290)

A&Ww acute standard: e (1.005 (pH) - 4.830) 

A&Ww chronic standard: e (1.005 (pH) - 5.290)

A&Wedw acute standard: e (1.005 (pH) - 4.830)

A&Wedw chronic standard: e (1.005 (pH) - 5.290)

A&We acute standard: e (1.005 (pH) - 3.4306)

A&Wedw chronic criterion for dissolved mercury 

The rulemaking revises the A&W(edw) chronic standard for dissolved mercury from 0.2 μg/L to 0.01 

μg/L. The current A&W(edw) chronic criterion for dissolved mercury of 0.2 μg/L was adopted in 1992. The 

following documentation on the calculation of the A&W(edw) chronic criterion for mercury from 1992 explains 

how this criterion was derived: 

“The proposed standard was based on toxicity to aquatic life. However, mercury has a 

propensity to accumulate in tissues of aquatic life to levels that may be harmful to wildlife or 

human consumers. These routes of exposure should also be considered in developing A&W 

standards. The EPA publication “Ambient Water Quality Criteria for Mercury – 1984,” U.S. 

EPA, Office of Water, EPA 440/5-84-026 (January 1985) does not contain information 

regarding the effects of mercury on wildlife but does contain information on the effects of 

mercury on humans. Setting a standard based strictly on toxicity to aquatic life may not 

adequately protect wildlife. The rulemaking uses an FDA action level as a surrogate to protect 

wildlife. This seems appropriate because wildlife is more like humans than aquatic life. The 

mercury standard has been recalculated using the more appropriate Final Residue Value 

procedure. The equation used is: 

FDA action level

(Bioconcentration factor) 

Where the FDA action level for mercury is 1.0 mg/kg and the bioconcentration factor for 

mercury is 4,994 L/kg. (Criteria Document, p. 47), the recalculated A&Wedw chronic standard 

is 0.2 μg/L.” 

The methodology used in 1992 to recalculate the A&Wedw chronic criterion has been modified. An FDA 

action level as a surrogate value is no longer supported to protect aquatic life and wildlife in EDWs. The 

bioconcentration factor of 4,994 L/kg used in 1992 to calculate the chronic criterion significantly underestimates 

the bioaccumulation potential of mercury in the aquatic environment. More recent information indicates that 
62 

concentrations of total mercury in fish at the top of the food chain may be as much as 10,000 to 100,000 times 

higher than the concentrations of inorganic mercury found in surrounding waters (Source: EPA Fact Sheet, 

“Mercury Update: Impact on Fish Advisories,” EPA-823-F-99-016 (September, 1999). 

The rulemaking adopts the same chronic criterion for dissolved mercury that was adopted for the A&Wc 

and A&Ww designated uses. The Department employed the EPA methodology described in the national 

“Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and 

Their Uses,” U.S. Environmental Protection Agency, Office of Research and Development, EPA 822/R-85-100, 

(1985) to derive water quality criteria for mercury. The Guidelines methodology calls for the calculation of a 

Final Residue Value [FRV] if a maximum permissible tissue concentration and at least one acceptable 

bioconcentration factor determined from an aquatic species are available. The Department calculated a FRV for 

mercury using data from EPA’s National Ambient Water Quality Criteria Document for Mercury – 1984. The 

FRV of 0.012 μg/L became the A&Wc and the A&Ww criterion to protect against chronic toxicity from mercury. 

The Guidelines Methodology is a more appropriate method to derive A&Wedw chronic criteria than the use of 

FDA action levels to calculate the A&Wedw (chronic) criterion. 

Numeric Criteria for Total Ammonia for Effluent-Dependent Waters 

This rulemaking adopts numeric water quality criteria for total ammonia for the A&Wedw designated use. 

The Clean Water Act requires the Department to adopt water quality standards for all uses including effluentdependent waters that contain sufficient parameters or constituents to protect designated uses. Ammonia is a 

major toxicant of concern in Arizona’s effluent-dependent waters. There is a large body of scientific literature 

documenting ammonia toxicity to aquatic life, including toxicity to species that are known to inhabit effluentdependent waters. Therefore, the Department adopted numeric criteria to protect aquatic life in EDWs. The 

adoption of numeric water quality criteria for ammonia for the A&Wedw designated use is necessary to protect 

the use and will provide an objective basis for the establishment of water quality-based effluent limits in 

AZPDES permits to control toxic discharges of ammonia in wastewater to Arizona’s effluent-dependent waters. 

The U.S. Fish & Wildlife Service has repeatedly recommended that the Department include ammonia as a 

pollutant to be regulated in Arizona’s effluent-dependent waters, noting that Arizona’s EDWs are vital 

components of southwestern desert ecosystems, providing valuable replacement habitat for threatened and 

endangered species, including the Gila topminnow, Yuma clapper rail, and the Southwestern willow flycatcher, 

and other native and migratory birds. 

The ammonia criteria are based on “1999 Update of Ambient Water Quality Criteria for Ammonia,” U.S. 

Environmental Protection Agency, Office of Water, EPA-822-R-99-014 (December 1999), EPA’s most recent 

national § 304(a) criteria recommendations to protect freshwater aquatic life. The proposed ammonia criteria for 

A&Wedw, which consist of both acute and chronic criteria, are expressed as total ammonia concentrations (i.e., 

un-ionized ammonia (NH3) + ionized ammonia (NH4 

+

). 

Acute
63 

The § 304(a) criteria for total ammonia to protect against acute toxicity are dependent on pH and the 

presence or absence of salmonids (i.e., large trout). Where salmonids are present, EPA recommends that the acute 

criterion be calculated using the following equation: 

 Acute criterion = 0.275 + 39.0

 1+ 107.204-pH 1 + 107.204-pH 

The acute criterion for total ammonia was calculated for the A&Wc designated use using the equation 

recommended by EPA above. The results may be found in the first column of Table 25 in the current rules. There 

are no revisions of acute A&Wc criteria in this rulemaking. 

Where salmonid fish are not present, EPA recommends the calculation of acute criteria for total ammonia 

to protect aquatic life using the following equation: 

 Acute criterion = 0.411 + 58.4

 1 + 107.204-pH 1 + 107.204-pH 

The acute criterion for total ammonia was calculated for the A&Ww and the A&Wedw designated uses 

using this equation. The results may be found in the second column of Table 25 in the current rules. There are no 

revisions to the resulting numeric criteria for the A&Ww (acute) designated use in this rulemaking. 

This rulemaking applies the same numeric criteria for the A&Ww (acute) designated use to protect the 

A&Wedw (acute) designated use. The A&Wedw (acute) criteria has been recalculated using the EPA Guidelines 

methodology and adjusting the species toxicity datasets using representative species from effluent-dependent 

waters. The use of recalculation procedures did not result in any significant differences between A&Wedw and 

A&Ww acute criteria because the same species that are sensitive to ammonia toxicity that “drive” the criteria 

derivation are found in both warm surface waters and EDWs. The table below illustrates the minimal differences 

between the A&Ww(acute) criteria and the re-calculated A&Wedw (acute) criteria: 

pH 

Calculated 

A&Ww 

(in mg/L) 

Recalculated 

A&Wedw 

(in mg/L) 

6.5 47.6 48.9 

6.6 45.7 46.9 

6.7 43.5 44.6 

6.8 41.0 42.0 

6.9 38.2 39.2 

7.0 35.2 36.1 

7.1 32.0 32.9 

7.2 28.8 29.6 

7.3 25.6 26.2 

7.4 22.4 23.0 
64 

7.5 19.4 19.9 

7.6 16.6 17.0 

7.7 14.1 14.5 

7.8 11.8 12.2 

7.9 9.9 10.1 

8.0 8.2 8.4 

8.1 6.8 7.0 

8.2 5.6 5.7 

8.3 4.6 4.7 

8.4 3.8 3.9 

8.5 3.1 3.2 

8.6 2.6 2.7 

8.7 2.1 2.2 

8.8 1.8 1.8 

8.9 1.5 1.6 

9.0 1.3 1.3 

Chronic

The A&W(chronic) criteria for total ammonia are dependent on both pH and temperature. The national § 

304(a) recommendations for chronic toxicity for total ammonia that apply when early life stages of fish are 

expected to be present have been adopted because of the likelihood that early life stages of fish may be present in 

Arizona surface waters (including EDWs) at any time during the year. The following equation was used to 

calculate the chronic criteria for total ammonia for the A&Wc, A&Ww, and A&Wedw designated uses: 

Chronic criteria = ⎟

⎠

⎞ ⎜

⎝

⎛

+

+

+ 688.7 − − 688.7 101

487.2

101

0577.0

pH pH * MIN 2.85, 1.45 * 100.028 * (25-T) 

The results are found in Appendix A within Table 26. The chronic criteria are not species dependent and 

apply equally to the A&Wc, A&Ww, and A&Wedw designated uses. The chronic criteria for total ammonia 

become more stringent as temperature and pH values increase. 

The following table shows proposed changes to the aquatic and wildlife criteria. The table identifies the 

pollutant, the current A&W criteria, the proposed A&W criteria, and the reasons for any proposed changes. 
65 

Numeric Water Quality Standards for Aquatic and Wildlife Designated Uses

Pollutant Existing A&W Criteria 

(μg/L) 

Adopted A&W Criteria 

(μg/L) Reason for Chang

Aldrin A&W(c) acute: 2.0 

A&W(w) acute: 2.0 

A&Wedw acute: 2.0 

A&W(c) acute: 3 

A&W(w) acute: 3 

A&Wedw acute: 3 

Less stringent. The § 304(a) national critealdrin have been adopted. 

Ammonia A&Wedw acute: NNS 

A&Wedw chronic: NNS 

Acute and chronic 

A&Wedw criteria 

See Tables 25 and 26 

The ammonia criteria for A&Wedw have EPA’s § 304(a) national criteria recommeunder “Numeric Water Quality Standards Designated Uses” above. 

Arsenic A&Wc acute: 360 

A&Ww acute: 360 

A&Wedw acute: 360 

A&Wc chronic: 190 

A&Ww chronic: 190 

A&Wedw chronic: 190 

A&Wc acute: 340 

A&Ww acute: 340 

A&Wedw acute: 340 

A&Wc chronic: 150 

A&Ww chronic: 150 

A&Wedw chronic: 150 

More stringent. The § 304(a) national critearsenic have been adopted. 

Beryllium A&Wc acute: 65 

A&Ww acute: 65 

A&Wedw acute: 65 

A&Wc chronic: 5.3 

A&Ww chronic: 5.3 

A&Wedw chronic: 5.3 

None EPA has withdrawn its national § 304(a) c

to protect aquatic life for beryllium. 

Chlordane A&Wc acute: 2.4 

A&Ww acute 2.4 

&Wedw acute: 2.4 

A&Ww chronic: 0.21 

A&Wc acute: 2.4 

A&Ww acute: 2.4 

A&Wedw acute: 2.4 

A&Ww chronic: 0.2 

The standard has been rounded to the first right of the decimal point. 
66 

Pollutant Existing A&W Criteria 

(μg/L) 

Adopted A&W Criteria 

(μg/L) Reason for Chang

A&Wedw chronic: 0.21 A&Wedw chronic: 0.2 

Chlorine (total residual) A&Wc acute: 11 

A&Ww acute: 11 

A&Wedw acute: 11 

A&Wc chronic: 5 

A&Ww chronic: 5 

A&Wedw chronic: 5 

A&Wc acute: 19 

&Ww acute: 19 

A&Wedw acute: 19 

A&Wc chronic: 11 

A&Ww chronic: 11 

A&Wedw chronic: 11 

Less stringent. The § 304(a) national critechlorine have been adopted. 

Chloropyrifos None A&Wc acute: 0.08 

A&Ww acute: 0.08 

A&Wedw acute: 0.08 

A&Wc chronic: 0.04 

A&Ww chronic: 0.04 

A&Wedw chronic: 0.04 

New parameter. The § 304(a) national crfor chloropyrifos have been adopted. 

p,p’-Dichlorodiphenyl dichloroethane (DDD) 

A&Ww chronic: 0.02 

A&Wedw chronic: 0.02 

A&Ww chronic: 0.001 

A&Wedw chronic: 0.001 

More stringent. DDD and DDE have been The more stringent chronic criterion for adopted for DDD. DDD is a daughter criterion is based on EPA § 30recommendations. 

p,p’-Dichlorodiphenyl dichloroethylene (DDE) 

A&Ww chronic: 0.02 

A&Wedw chronic: 0.02 

A&Ww chronic: 0.001 

A&Wedw chronic: 0.001 

More stringent. DDD and DDE has been The more stringent chronic criterion for adopted for DDE. DDE is a daughter criterion is based on EPA § 30recommendations. 

Dieldrin A&Wc acute: 2.5 A&Wc acute: 0.2 The more stringent acute criteria and less 
67 

Pollutant Existing A&W Criteria 

(μg/L) 

Adopted A&W Criteria 

(μg/L) Reason for Chang

A&Ww acute: 2.5 

A&Wedw acute: 2.5 

A&Wc chronic: 0.002 

A&Ww chronic: 0.002 

A&Wedw chronic: 0.005 

A&Ww acute: 0.2 

A&Wedw acute: 0.2 

A&Wc chronic: 0.06 

A&Ww chronic: 0.06 

A&Wedw chronic: 0.06 

for dieldrin based on EPA § 30recommendations have been adopted. 

Endosulfan A&Wc acute: 0.22 

A&Ww acute: 0.22 

A&Wedw acute: 0.22 

A&Wc acute: 0.2 

A&Ww acute: 0.2 

A&Wedw acute: 0.2 

The standard has been rounded to first sigdecimal point. 

Endosulfan sulfate A&Wc acute: 0.22 

A&Ww acute: 0.22 

A&Wedw acute: 0.22 

A&Wc acute: 0.2 

A&Ww acute: 0.2 

A&Wedw acute: 0.2 

The standard has been rounded to first sigdecimal point. 

Endrin A&Wc acute: 0.18 

A&Ww acute: 0.18 

A&Wedw acute: 0.18 

A&Wc chronic: 0.002 

A&Ww chronic: 0.002 

A&Wedw chronic: 0.002 

A&Wc acute: 0.09 

A&Ww acute: 0.09 

A&Wedw acute: 0.09 

A&Wc chronic: 0.04 

A&Ww chronic: 0.04 

A&Wedw chronic: 0.04 

The more stringent acute criteria and less for endrin based on EPA § 30recommendations have been adopted. 

Endrin aldehyde A&Wc acute: 0.18 

A&Ww acute: 0.18 

A&Wedw acute: 0.18 

A&Wc chronic: 0.002 

A&Ww chronic: 0.002 

A&Wedw chronic: 0.002 

A&Wc acute: 0.09 

A&Ww acute: 0.09 

A&Wedw acute: 0.09 

A&Wc chronic: 0.04 

A&Ww chronic: 0.04 

A&Wedw chronic: 0.04 

The rulemaking adopts more stringent stringent chronic criteria for endrin aldehybased on EPA § 304(a) national criteria r

Guthion None A&Wc chronic: 0.01 New parameter. The criteria are based on 
68 

Pollutant Existing A&W Criteria 

(μg/L) 

Adopted A&W Criteria 

(μg/L) Reason for Chang

A&Ww chronic: 0.01 

A&Wedw chronic: 0.01 

criteria recommendations. 

Heptachlor A&Wc acute: 0.52 

A&Ww acute: 0.52 

A&Wedw acute: 0.58 

A&Wedw chronic: 0.013 

A&Wc acute: 0.5 

A&Ww acute: 0.5 

A&Wedw acute: 0.6 

A&Wedw chronic: 0.01 

The standard has been rounded to first sigdecimal point. 

Heptachlor epoxide A&Wc acute: 0.52 

A&Ww acute: 0.52 

A&Wedw acute: 0.58 

A&Wedw chronic: 0.013 

A&Wc acute: 0.5 

A&Ww acute: 0.5 

A&Wedw acute: 0.6 

A&Wedw chronic: 0.01 

The standard has been rounded to first sigdecimal point. 

Hexachlorobenzene A&Ww acute: NNS 

A&Wedw acute: NNS 

A&Ww chronic: NNS 

A&Wedw chronic: NNS 

A&Ww acute: 6 

A&Wedw acute: 6 

A&Ww chronic: 3.7 

A&Wedw chronic: 3.7 

The rulemaking adopts criteria for A&Ww EPA § 304(a) national criteria recommen

Hexaclorocyclohexane gamma (lindane) 

A&Wc acute: 2.0 

A&Ww acute: 3.4 

A&Wedw acute: 7.6 

A&Wc chronic: 0.08 

A&Ww chronic: 0.28 

A&Wedw chronic: 0.61 

A&Wc acute: 1 

A&Ww acute: 1 

A&Wedw acute: 1 

A&Wc chronic: None 

A&Ww chronic: None 

A&Wedw chronic: None 

Based on EPA § 304(a) national criteria more stringent acute criteria has been acriteria for lindane has been repealed. 

Hydrogen sulfide None A&Wc chronic: 2 

A&Ww chronic: 2 

A&Wedw chronic: 2 

New pollutant. Replaces “sulfides.” Propo

EPA § 304(a) national criteria recommen

Iron None A&Wc chronic: 1,000 New pollutant. The § 304(a) national cr
69 

Pollutant Existing A&W Criteria 

(μg/L) 

Adopted A&W Criteria 

(μg/L) Reason for Chang

A&Ww chronic: 1,000 

A&Wedw chronic: 1,000 

have been adopted. 

Malathion None A&Wc chronic: 0.1 

A&Ww chronic: 0.1 

A&Wedw chronic: 0.1 

New pollutant. The § 304(a) national crhave been adopted. 

Mercury A&Wedw acute: 2.6 

A&Wedw chronic: 0.2 

A&Wedw acute: 2.4 

A&Wedw chronic: 0.01 

See discussion under “Numeric Water Aquatic and Wildlife Designated Uses” a

Methoxychlor A&Wc chronic: NNS 

A&Ww chronic: NNS 

A&Wedw chronic: NNS 

A&Wc chronic: 0.03 

A&Ww chronic: 0.03 

A&Wedw chronic: 0.03 

The § 304(a) national criteria recomadopted. 

Mirex None A&Wc chronic: 0.001 

A&Ww chronic: 0.001 

A&Wedw chronic: 0.001 

Newly regulated pollutant. The § 3recommendations have been adopted. 

Parathion None A&Wc acute: 0.07 

A&Ww acute: 0.07 

A&Wedw acute: 0.07 

A&Wc chronic: 0.01 

A&Ww chronic: 0.01 

A&Wedw chronic: 0.01 

Newly regulated pollutant. The § 3recommendations have been adopted. 

Paraquat None A&Wc acute: 100 

A&Ww acute: 100 

A&Wedw acute: 100 

A&Wc chronic: 54 

A&Ww chronic: 54 

Newly regulated pollutant. The § 3recommendations have been adopted. 
70 

Pollutant Existing A&W Criteria 

(μg/L) 

Adopted A&W Criteria 

(μg/L) Reason for Chang

A&Wedw chronic: 54 

Permethrin None A&Wc acute: 0.3 

A&Ww acute: 0.3 

A&Wedw acute: 0.3 

A&Wc chronic: 0.2 

A&Ww chronic: 0.2 

A&Wedw chronic: 0.2 

Newly regulated pollutant. The § 3recommendations have been adopted. 

Phenanthrene A&Wedw acute: 54 A&Wedw acute: 30 The EPA § 304(a) national criteria recomm

acute criterion have been adopted. 

Selenium A&Wc acute: 20 T 

A&Ww acute: 20 T 

A&Wedw acute: 50 T 

A&Wc acute: None 

A&Ww acute: None 

A&Wedw acute: None 

The § 304(a) national criteria recommendexpressed as concentrations of selenate repealed. 

Sulfides A&Wc acute: 100 

A&Ww acute: 100 

A&Wedw acute: 100 

A&We: 100 

None “Sulfides” has been replaced with “hydro

2,3,7,8-Tetrachlorodibenzo-pdioxin (2,3,7,8-TCDD) A&Wedw acute: 0.12 A&Wedw chronic: 0.01 A&Wedw acute: 0.1 A&Wedw chronic: 0.005 The A&Wedw acute standard has bee

significant figure to right of decimal poA&Wedw chronic criterion has been adopEPA § 304(a) national criteria recommen

Toxaphene A&Wc acute: 0.73 

A&Ww acute: 0.73 

A&Wedw acute: 0.73 

A&Wc acute: 0.7 

A&Ww acute: 0.7 

A&Wedw acute: 0.7 

Acute criteria have been amended by significant figure to the right of the destringent A&Ww chronic and A&Wedw c
71 

Pollutant Existing A&W Criteria 

(μg/L) 

Adopted A&W Criteria 

(μg/L) Reason for Chang

A&Wc chronic: 0.0002 

A&Ww chronic: 0.02 

A&Wedw chronic: 0.02 

A&Wc chronic: 0.0002 

A&Ww chronic: 0.0002 

A&Wedw chronic: 0.0002 

adopted to be consistent with the § 3recommendations for toxaphene. 

Tributyltin None A&Wc acute: 0.5 

A&Ww acute: 0.5 

A&Wedw acute: 0.5 

A&Wc chronic: 0.07 

A&Ww chronic: 0.07 

A&Wedw chronic: 0.07 

Newly regulated pollutant. The § 3recommendations for A&Wc, A&Ww anadopted. 

1,2,4-Trichlorobenzene A&Wedw acute: NNS 

A&Wedw chronic: NNS 

A&Wedw acute: 1,700 

A&Wedw chronic: 300 

The current acute and chronic A&Ww cribeen adopted. 
72 

Appendix B. Surface Waters and Designated Uses

Appendix B lists surface waters and their designated uses. The geographic descriptions in Appendix B have 

been updated and reformatted. Lake categories have been added, when known. 

The following 29 new effluent-dependent waters have been classified using information provided to the 

Department in the context of AZPDES permitting. The new effluent-dependent waters are created by point source 

discharges of wastewater to ephemeral waters. Information from AZPDES permit applications, fact sheets, and 

discharge monitoring reports for each point source document discharges of wastewater to the ephemeral waters. 

1. Coconino Wash from the South Grand Canyon Sanitary District Tusayan WRF outfall to 1 km 

downstream. 

2. Unnamed wash from Grand Canyon National Park Desert View WWTP to Cedar Canyon. 

3. Unnamed wash from Valle Airpark WRF outfall to confluence with Spring Wash. 

4. Tyson Wash from Town of Quartzsite WWTP to 1 km downstream. 

5. Puerco River from Sanders Unified School District WWTP to 0.5 km downstream. 

6. Unnamed wash from High Country Pines II WWTP to Turkey Draw to confluence with Black 

Canyon Creek. 

7. Unnamed wash from Bison Ranch WWTP to Pierce Seep. 

8. Unnamed wash from Black Mesa Ranger Station WWTP to confluence with Pierce Wash. 

9. Bow and Arrow Wash and two unnamed washes, tributaries of the Rio de Flag from Estates at Pine 

Canyon Golf Course storage ponds 4I, 6E, and 10D. 

10. Agua Fria River from City of Avondale WWTP to Gila River. 

11. Andorra Wash from Town of Cave Creek WWTP outfall #1 to Cave Creek Wash. 

12. Galloway Wash from Town of Cave Creek WWTP outfall #2 to confluence with Andorra Wash. 

13. McMicken Wash from City of Peoria Jomax WWTP to Agua Fria River. 

14. Mountain Valley Park ponds from Town of Prescott Valley WWTP outfall #002 to Navajo Wash. 

15. Salt River from City of Mesa Northwest WWTP to Tempe Town Lake. 

16. Siphon Draw from Superstition Mountains Community Facilities District WWTP to 6 km 

downstream. 

17. Unnamed wash from City of Phoenix Cave Creek WRF to 0.5 km downstream. 

18. Unnamed wash from North Florence WWTP, tributary to Gila River. 

19. Wagner Wash from Town of Buckeye Festival Ranch WRF to 2 km downstream. 

20. Black Wash from Pima County WWMD Avra Valley WWTP to Brawley Wash. 

21. North Branch of Santa Cruz Wash from City of Casa Grande WRF to 1 km downstream. 

22. Santa Rosa Wash from Palo Verde Utilities WWTP to Gila River Indian Reservation. 

23. Unnamed wash from Arizona City Sanitary District WWTP to Santa Cruz Wash. 

24. Unnamed wash from Saddlebrooke WWTP to Canada del Oro. 

25. Unnamed wash from Fort Huachuca WWTP to Soldier Creek to Babocomari River. 

26. Pinal Creek from Lower Pinal Creek WTP to See Ranch Crossing. 

27. Unnamed wash from Cobre Valley Plaza WWTP to Russell Gulch. 
73 

28. Unnamed wash from Sedona Venture WWTP to confluence with Dry Creek and Dry Creek for 0.5 

km downstream. 

29. Unnamed wash from Flagstaff Meadows WWTP to Volunteer Wash. 

This rulemaking removes the Cholla Reservoir from Appendix B. In the early 1990s, the Cholla Reservoir, 

a manmade cooling pond for the Arizona Public Service Co. (APS) Cholla Power Plant near Joseph City, 

Arizona, was issued a National Pollutant Discharge Elimination System permit by EPA based on the agency’s 

understanding that the reservoir had been constructed in a water of the United States. As a result of this 

understanding, the Cholla Reservoir was added to the state’s list of surface waters in Appendix B. Recent 

investigation finds that the Cholla Reservoir is a 100 acre manmade impoundment constructed by APS in 1961. It 

is a terminal impoundment without any outflow to what would otherwise be considered a “water of the United 

States.” The source of water for the Cholla Reservoir is pumped groundwater. As the Cholla Reservoir was not 

created by impounding any “water of the United States,” nor was the reservoir created within a “water of the 

United States,” the reservoir has been removed from Appendix B based on a new exclusion at R18-11-102(B)(3). 

Appendix C. Site-Specific Standards

This new Appendix lists site-specific standards. 

Site-Specific Standards for Yuma East Wetlands 

The site-specific standards for total selenium and total residual chlorine for the Yuma East Wetlands 

Project are supported by a request by the City of Yuma to modify the two standards on grounds of net ecological 

benefit. The modification of the water quality standards for selenium and total residual chlorine will enable the 

City of Yuma to discharge spent filter backwash water from their Main Street Water Treatment Plant to the Yuma 

East Wetlands Project. The Yuma East Wetlands Project is a multi-million dollar river ecosystem restoration 

effort designed to restore, enhance, and augment riparian habitats for native and sensitive riparian plant and 

wildlife species, and to create natural history and cultural interpretation centers and recreational facilities along 

the Lower Colorado River. The restoration of these habitats depends upon the discharge of filter backwash water 

to maintain adequate flows of water in the wetlands, particularly during periods of low flow in the Colorado 

River. Without the discharge of the filter backwash water, the viability of a large portion of the Yuma Wetlands 

East Project would be jeopardized. 

Under R18-11-106, the Director may modify a water quality standard on the grounds that there is a net 

ecological benefit associated with the discharge of effluent to support or create a riparian and aquatic habitat in an 

area where water resources are limited. 

The Director has determined the conditions of R18-11-106 have been met to support modifications of the 

water quality standards for selenium and total residual chlorine and to allow the discharge of filter backwash 

water for flow augmentation in the Yuma East Wetlands on grounds of net ecological benefit 

The environmental benefits associated with the discharge of filter backwash water to support the restoration 

of the Yuma East Wetlands outweigh the environmental costs associated with eliminating the discharge. The 

discharge of filter backwash water for flow augmentation is essential to the maintenance and restoration of open 
74 

water and marshland habitats within the wetlands. Only the discharge of filter backwash water can assure the 

continual water flow necessary to maintain the marshes of the Yuma East Wetlands. 

The cost of treatment to achieve compliance with the selenium and total residual chlorine standards are 

prohibitive and it would be more cost-effective to eliminate the discharge of the filter backwash water to the 

wetlands instead of installing the necessary treatment processes. Achieving compliance with the total residual 

chlorine standard would require the installation and operation of a dechlorination facility at the water treatment 

plant. The City of Yuma estimates that the capital cost of a de-chlorination facility is in excess of $1 million. The 

estimated cost of compliance with the selenium standard would require the installation of reverse osmosis or a 

similar treatment process to remove dissolved solids from the spent filter backwash water. The City of Yuma 

estimates the capital cost of selenium treatment to be $8.2 million with estimated operation and maintenance 

costs of $1.3 million per year and further describes these costs as “economically impossible.” Moreover, it is 

feasible for the City of Yuma to completely eliminate the discharge of filter backwash to the Yuma East 

Wetlands. Spent filter backwash is currently recycled within the water treatment plant and is not discharged. 

There are no costs associated with maintaining the status quo of recycling the filter backwash water instead of 

discharging it to augment flows in the wetlands. The City of Yuma could avoid the compliance costs associated 

with meeting the selenium and chlorine standards by not discharging their filter backwash water to the wetlands. 

However, the success of the wetlands project would be jeopardized if the City of Yuma exercised that option. 

The discharge of filter backwash water that meets the site-specific standards will not cause or contribute to 

a violation of a water quality standard for a downstream surface water. The concentration of total residual 

chlorine in the filter backwash water is not anticipated to cause or contribute to a violation of the chlorine 

standard that applies to the adjacent Colorado River. Concentrations of chlorine are expected to dissipate in the 

filter backwash water pipeline, at the point of discharge to the wetlands, and by retention within the wetlands and 

marsh habitats. With regard to selenium, the City of Yuma does not add or remove selenium from the filter 

backwash water at its water treatment plant. The concentration of selenium in the filter backwash water is the 

same as the concentration of selenium in its raw intake water from the Colorado River. 

The City of Yuma demonstrated that it is implementing all practicable discharge control programs to 

reduce and limit the concentration of chlorine in its filter backwash water. The Department agrees with the City 

that there are no practicable discharge control programs that the City can implement to reduce selenium in its raw 

source water or in its filter backwash water. 

The discharge of filter backwash water does not produce or contribute to the concentration of a 

bioaccumulative pollutant that is likely to be harmful to humans or wildlife through food chain concentration. 

This condition is met with regard to chlorine because chlorine is not a bioaccumulative pollutant. While selenium 

is a bioaccumulative pollutant, the discharge of filter backwash water does not produce or contribute to selenium 

concentrations in either the Yuma East Wetlands or in the Colorado River. The concentration of selenium in the 

filter backwash water is the same as that found in the raw source water from the Colorado River. 

The rulemaking modifies the water quality standard applicable to this discharge for total residual chlorine 

to protect aquatic life from acute and chronic toxicity. The acute criterion is 33 μg/L and the chronic criterion is 

20 μg/L. These criteria are based on EPA recalculation procedures and the species list for chlorine toxicity, which 
75 

is located on the EPA website at www.epa.gov/region7/water/chlorine. The only adjustment made in the 

recalculation procedure was to remove the organism Daphnia magna from the toxicity dataset. The resulting 

chlorine criteria, calculated from the modified dataset, are the criteria of 33 μg/L and 20 μg/L. 

The rulemaking modifies chronic selenium criterion applicable to this discharge to protect aquatic life of 

2.2 μg/L. This concentration is based on the highest selenium concentration that has been measured in the 

receiving water within the Yuma East Wetlands. This concentration represents the observed background 

concentration in the lower Colorado River. The site-specific criterion is slightly less stringent than the default 

A&Ww chronic criterion for selenium of 2 μg/L in the current rules and it is more stringent than EPA’s 304(a) 

national recommended chronic criterion for selenium to protect freshwater aquatic life of 5 μg/L. The Department 

notes that the U.S. Fish & Wildlife Service has written a letter of support for the site-specific modifications of the 

selenium and chlorine standards for the Yuma East Wetlands project. 

Site-Specific Standard for Copper for Rio de Flag 

The site-specific dissolved copper standards for the Rio de Flag have been moved from R18-11-113(F) to 

Appendix C.

7. A reference to any study relevant to the rule that the agency reviewed and relied on in its evaluation of o r 

justification for the rule, where the public may obtain or review each study, all data underlying each study, 

and any analysis of each study and other supporting material:

“Antidegradation Implementation Procedures,” Arizona Department of Environmental Quality, Water 

Quality Division, (July 2008) 

Draft “Biocriteria Implementation Procedures,” Arizona Department of Environmental Quality, Water 

Quality Division, (April 2008) 

“Technical Support Documentation for the Narrative Biocriteria Standard,” Arizona Department of 

Environmental Quality, Water Quality Division, (April 2007) 

“Sediment in Streams: Sources, Biological Effects and Control,” American Fisheries Society Monograph 7, 

American Fisheries Society, Bethesda, Maryland (1995) 

Draft “Narrative Bottom Deposits Standard Implementation Procedures for Wadeable, Perennial Streams,” 

Arizona Department of Environmental Quality, Water Quality Division, (April 2008) 

Draft “Narrative Nutrient Standard Implementation Procedures for Lakes and Reservoirs (April 2008) 

“Ambient Water Quality Criteria for Bacteria – 1986,” U.S. Environmental Protection Agency, Office of 

Water, EPA 440/5-84-002 (January, 1986) 

“Fossil Creek: State of the Watershed Report,” Northern Arizona University (July 2005) 

“Water Quality Criterion for the Protection of Human Health: Methylmercury,” U.S. Environmental 

Protection Agency, Office of Water, Office of Science and Technology, EPA-823-R-01-001 (January 2001) 

“Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health,” U.S. 

Environmental Protection Agency, Office of Water, Office of Science and Technology, EPA-822-B-00-004, 

(October 2000) 
76 

“Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic 

Organisms and Their Uses,” U.S. Environmental Protection Agency, Office of Research and Development, EPA 

822/R-85-100, (1985) 

“Ambient Water Quality Criteria for Mercury – 1984,” U.S. Environmental Protection Agency, Office of 

Water, EPA 440/5-84-026 (January 1985) 

“1999 Update of Ambient Water Quality Criteria for Ammonia,” U.S. Environmental Protection Agency, 

Office of Water, EPA-822-R-99-014 (December 1999) 

“Pinto Creek Site-Specific Water Quality Standard for Dissolved Copper,” Arizona Department of 

Environmental Quality, Water Quality Division, (March 12, 2007) 

“Lakes and Reservoirs Statistical and Modeling Analysis Report,” Malcolm Pirnie, February 2005 

“Addendum to Lakes and Reservoirs Statistical and Modeling Analysis,” Malcolm Pirnie, February 2005 

“Potential Nutrient-related Targets for Arizona Lakes and Reservoirs,” Malcolm Pirnie, April 2005 

“San Pedro and Santa Cruz Rivers: Nutrient Standards Review,” Arizona Department of Environmental 

Health Services (ADHS) (September, 1985) 

“An Exploration of Nutrient and Community Variables in Effluent Dependent Streams in Arizona,” 

Arizona Department of Environmental Quality, OFR 05-09 

8. A showing of good cause why the rules are necessary to promote a statewide interest if the rules will 

diminish a previous grant of authority of a political subdivision of this state:

The proposed amendments do not diminish a previous grant of authority of a political subdivision of this 

state. 

9. The summary of the economic, small business, and consumer impact:

Water quality standards are provisions of state law required by the Clean Water Act, and require review 

and revision once every three years. These standards are implemented through various surface water programs at 

the Department, including the AZPDES permitting program, authorized under § 402 of the Clean Water Act for 

point source discharges of pollutants. Persons most affected by this rulemaking are AZPDES permittees. From an 

economic cost standpoint, permittees may experience costs through conditions established in future AZPDES 

permits to achieve the surface water quality standards of these rules. Some permittees, such as private and public 

wastewater utilities, mining operations, and electric utilities, may be required to make wastewater treatment 

changes to comply with new permit conditions to regulate their discharges. 

In addition to costs, there are benefits to these rules. These rules ensure that clean water will be available as 

a source for drinking water, bathing, cooking, washing clothes, and is safe for swimming, fishing, boating, 

wading, or other water-based recreation. The rules also protect aquatic and riparian ecosystems that are dependent 

on a surface water. It is, however, much more difficult to quantify these benefits in monetary terms. 

The Department does not require the costs of wastewater treatment to be submitted as part of the AZPDES 

permitting program, so any specific information on costs has been obtained from permittees or knowledgeable 

individuals in the area of wastewater treatment.
77 

For purpose of this analysis, the Department defines annual costs or revenues on a cost-revenue scale as 

follows:

Minimal  less than $10,000

Moderate  $10,000 to $1 million

Substantial  more than $1 million

A. Estimated Costs and Benefits to the Department of Environmental Quality. 

The Department may incur minimal costs in implementing this rulemaking. It is possible that new or 

revised water quality standards and new implementation procedures for narrative standards may lead to an 

increase in the number of surface waters that are identified as impaired waters. This may result in a 

corresponding increase in the number of Total Maximum Daily Loads (TMDLs) that the Department would 

be required to complete under the Clean Water Act. The Department does not anticipate any increase in 

FTEs or state funding to complete additional TMDLs.

There are some new costs for monitoring under narrative standards, but the Department expects these costs 

to reduce over time due to fewer sampling visits in the field. Narrative standard measurements provide a 

longer, more direct measure of the water quality and can show a recent history of the health of a surface 

water, instead of just a snapshot as with a chemical-based numeric standard. Accordingly, monitoring costs 

incurred by the Department may be reduced by this rulemaking. 

B. Estimated Costs and Benefits to Political Subdivisions. 

Political subdivisions are affected by the rules if they own or operate sewage treatment plants, and 

their costs are discussed below in section C. There may be additional costs for some political subdivisions 

that have a pretreatment program under the Clean Water Act. The pretreatment program requires political 

subdivisions to control industrial wastewater discharged to the sanitary sewer before it is mingled with 

domestic sewage and discharged at the treatment facility. These facilities, called publicly-owned treatment 

works (POTW), have the authority to establish water quality standards and issue permits to industrial 

facilities that discharge pollutants to the sanitary sewer to control the industrial wastewater and ensure that 

water quality standards are met. POTWs may incur minimal-to-moderate costs in reviewing the new 

surface water quality standards to ensure their own compliance and to evaluate the need to change limits 

and controls on local industrial wastewater to ensure compliance under their AZPDES permit. If changes 

are necessary, a POTW would make necessary changes to its future permits issued to industrial facilities or 

through its local regulations. 

Local industries generating industrial wastewater could indirectly be affected if the POTW requires 

changes in local limits in order to meet new surface water quality standards. Currently, 21 Arizona 

municipalities have pretreatment programs. 

C. Businesses Directly Affected By the Rulemaking 

Surface water quality standards are implemented through various general and individual permits 
78 

under the AZPDES permitting program, authorized under § 402 of the Clean Water Act and A.R.S. Title 

49, Chapter 2, Article 3.1 for point source discharges of pollutants. Businesses affected by this rulemaking 

are AZPDES permittees who discharge as a point source to a water of the United States.

Below are the numbers of authorizations for the current five-year AZPDES general permits. Most of these 

permits are held by businesses: 

AZPDES GENERAL PERMITS 

General Permit Category # Per Category 

Multi-Sector General Permit (MSGP) 1039 

Construction General Permit (CGP) 3800 

Municipal Separate Storm Sewer 

System (MS4) (Phase II permits) 

41 

De Minimus General Permit 472 

There are potential impacts to those discharging under an AZPDES general permit; however, the 

Department does not expect these rule changes to affect significantly large numbers of permittees. The De 

Minimus permit regulates minor discharges resulting from specified activities and is generally restricted to 

discharges containing minimum pollutant amounts. The other three general permits regulate stormwater 

discharges primarily by requiring the use of best management practices (BMPs) to lessen pollutants. These 

rules may impact a permittee if a surface water changes classification, such as ephemeral to effluentdependent, or if a numeric standard becomes stricter. The rules also may impact a permittee if under the 

new narrative standards criteria, a water is listed as impaired under 18 A.A.C. 11, Article 6. A project 

located near an impaired or water that seeks general permit coverage, especially the CGP and De Minimus, 

could see increased monitoring requirements or additional BMPs being required to protect water quality. 

For example, a small or medium MS4 is not typically required to monitor under the current general permit. 

This would change if the MS4 had to determine the source of a pollutant if its stormwater discharge 

contributed to an exceedance of a new water quality standard. Any facility permitted under a general permit 

with discharges that are above a new water quality standard could lose eligibility under the general permit 

and be required to seek an individual permit with more specific requirements. The Department expects only 

minimal, if any, impact to each permittee discharging under general permits. 

The outstanding Arizona water (OAW) classification can affect existing and potential facilities that 

discharge to an OAW. Tier 3 of the antidegradation rule prohibits a new or expanded point source directly 

discharging to an OAW. Antidegradation protection includes a tributary to, or upstream of, an OAW. An 

AZPDES applicant must demonstrate that the regulated discharge will not degrade existing water quality in 

the downstream OAW. OAW designation does not prohibit a discharge activity but it generally may make 

it more expensive in treatment costs or to divert a discharge. 
79 

The Department is designating two new surface waters as OAWs; Fossil Creek and Davidson 

Canyon. Fossil Creek is located on U.S. Forest Service land, with some of the area designated as a 

Wilderness Area. Arizona Public Service (APS) is discharging under an existing permit but will be ending 

its discharge activities in 2011. There are numerous closed mining claims along Fossil Creek  even 

though mining has not been a reported historical activity in this area. Any holder of a closed mining claim 

in this area that seeks to reactivate a claim to develop mining will not be able to discharge to Fossil Creek 

in a manner that would degrade the existing water quality. Land use in this area is mainly grazing and 

recreation. While Arizona does not have a regulatory program to directly control nonpoint sources of 

pollution such as grazing, the intention of the Tier 3 antidegradation policy is that best management 

practices be developed and implemented to prevent the degradation of existing water quality in an OAW. 

The Department is aware of a few mining claims in the area that would face limitations on 

discharging to Davidson Canyon or to any of its tributaries. The Department has no data that any sand and 

gravel or cement operation has been permitted in or around Davidson Canyon. 

It is unclear what economic costs a potential discharger to these new OAWs would bear. Any 

potential costs of discharging to a designated OAW should be weighed with the benefits that come from 

increased tourism of the area, as further discussed below. 

The Department believes that the changes in these rules will affect a relatively small number of 

existing AZPDES individual permittees, though costs may be moderate or substantial, depending on the 

specific case. Permit conditions are reviewed and revised as applicable when permittees apply for renewal, 

usually every five years. These permittees would incur costs if their discharge contains pollutants in a 

concentration that may result in an exceedance of a new surface water quality standard. 

The Department has reviewed the comments regarding the economic impact of this rulemaking. 

While the comments present an apparent “worst case scenario”, the Department assumes that permittees 

affected by this rulemaking actually will exercise every lawful option to delay, defray, and minimize any 

costs to their business and consumers. Two options to delay, defray, or minimize costs are offered in 

existing rules. One, there is the opportunity to request a compliance schedule in a permit when a facility 

cannot meet a new water quality standard. This allows the facility time to evaluate, design and construct 

treatment or other means of meeting the new standard. R18-11-121 (Schedules of Compliance). In addition, 

R18-11-122 (Variances) allow the Department flexibility in issuing AZPDES permits when there has been 

a change in water quality standards. The Department currently has 33 variances for a variety of pollutants, 

though some are multiples on the same permitted facility. There are 11 other permits with compliance 

schedules to meet water quality standards for a variety of pollutants. 

Under new provisions in R18-11-113(E) (Effluent-Dependent Waters), the Department has 

flexibility to conclude that acute-only standards are sufficiently protective for point source discharges of 

wastewater when the discharge is infrequent, sporadic, or an emergency. This will allow AZPDES permits 

to be written without chronic water quality standards when conditions are appropriate. If applicable, a 

discharger that provides adequate treatment will unlikely exceed acute standards, therefore this provision 

would likely result in cost savings to the discharger in not having to institute additional treatment measures 
80 

to meet chronic standards. Under this provision, the permittee will need to have sufficient discharge and 

storage options such that surface water discharge was infrequent, sporadic or on an emergency basis. 

The table below shows the number of AZPDES individual permits, broken down by category type. 

The individual permittees most likely to be affected by this rulemaking include owners of domestic 

wastewater treatment plants (sewage treatment plants), and some industries such as mining and electric 

power generation. Other industries could be impacted on a case-by-case basis, similar to how permittees of 

general permits could be impacted. 

AZPDES INDIVIDUAL PERMITS 

By Industry # of Permits 

Sewage treatment plants (municipal & private) 113 

Drinking water treatment plants & well discharges 7 

Power Generation 7 

Mining 12 

WQARF/Remediation projects 7 

Miscellaneous (EPNG, Lakeside, Rio Salado, FD) 4 

Fish hatcheries 4 

Truck Stops 3 

Marinas 2 

Industrial (other) 1 

Costs to Sewage Treatment Plants 

Rule changes may require some sewage treatment plants to incur costs to meet water quality-based 

discharge limitations established in an AZPDES permit. There are possible minimal increased monitoring 

costs based on a new numeric standard, but a number of variable factors make it difficult to quantify any 

increased costs for public and privately owned sewage treatment plants. 

Sewage treatment plants collect and treat wastewater, which is mostly sewage, and is as most people 

think, “untreated wastes from toilets, baths, sinks, lavatories, laundries, other plumbing fixtures, and waste 

pumped from septic tanks in places of human habitation, employment, or recreation.” R18-9-101(35). 

Federal and state laws require primary and secondary treatment before the sewage is discharged to a 

receiving water. Basic treatment processes are physical (removes solids), biological (uses bacteria to 

consume organic matter), and chemical (chemicals used to create changes in pollutants or kill harmful 

organisms). 

Compliance costs for a typical sewage treatment plant can be difficult to quantify because of the 

various contributing factors, including: 

● Capital costs of new equipment and land; 

● Operation and maintenance of new equipment; 
81 

● Waste capture and disposal, selling, or reuse; 

● Change in production processes or inputs; and 

● Maintenance changes in other equipment. 

Whether treated sewage may cause an exceedance of a surface water quality standard to the 

receiving water depends on such factors as: 

● Type or degree of treatment; 

● Size of flow from the treatment plant; 

● Characteristics of sewage from the treatment plant; 

● Amount and quality of flow from industrial contributors and the status of pretreatment plans; 

● Amount of flow in the receiving water that that can be used for dilution; 

● Quality of the receiving waters; 

● Amount of mixing between the discharged sewage and receiving waters; and 

● Uses of receiving waters. 

Assuming a sewage treatment plant is faced with a discharge that has a reasonable potential to cause 

an exceedance under the new standards, a number of options exist to achieve compliance. A sewage 

treatment plant would first consider the feasibility of low cost options, and only consider the more costly 

options if necessary. If adjusting existing operations would not be feasible or would not be sufficient to 

achieve the desired reductions, the next lowest cost option could be controlling the source of the 

wastewater, such as contributions from industrial users. The feasibility of source control efforts depends on 

the make-up of the influent. For example, industrial discharges can be regulated through pretreatment 

regulations, but residential sources would have to be targeted through public outreach and education, which 

may have low participation rates and may not result in adequate reductions. 

If the relatively low-cost options would not be sufficient for compliance, alternative discharge 

options or end-of-pipe treatment technologies may be necessary, such as diverting flow to recharge or 

reuse, land application, impoundments, or changing the outfall location to a different area with different 

water quality standards. The feasibility of each option would need to be considered; for example, an 

impoundment may not be feasible for a major facility with a large flow because the necessary amount of 

land may not be available. Remaining options come with greater capital expenditures, such as reducing the 

volume of discharge by reusing effluent, or installing treatment technology to reduce pollutants. 

An example of the cost of a sewage treatment plant is the expansion of the City of Casa Grande 

Water Reclamation Facility. Due to a 68 percent growth in population, the facility is planning to double its 

capacity from 6 to 12 million gallons per day, and increase the effluent quality. It is reported that the 

expansion will cost $67,129,710 and includes preliminary treatment, anoxic/aerobic basins, secondary 

clarification and return activated sludge/waste, tertiary treatment, effluent pumping and conveyance 

system, and solids stream expansion. Notably, this expansion was planned before and separate from this 

rulemaking, so these actual costs cannot necessarily be attributed to these rules. 

Another example is Pima County’s major renovation and expansion of its regional wastewater 

system due to aging infrastructure, population growth, and necessary environmental compliance. Pima 
82 

County is planning to construct a new water reclamation campus to replace its aging Roger Road water 

reclamation facility, which first operated in 1951. Costs of this new water reclamation facility are estimated 

at $235.2 million. Also, as discussed below, the costs of retrofitting a plant can be more than constructing a 

new one. Pima County plans to upgrade and expand its Ina Road water reclamation facility, designed in 

1973, and constructed from 1975 to 1977. These costs are estimated at $244 million. However, these are 

gross project costs; the fraction of these costs that may be required to meet new surface water quality 

standards is not specified by the project proponent. This plan was developed in large part for compliance 

with existing water quality standards in Pima County’s existing AZPDES permits for these facilities. 

If a publicly-owned sewage treatment plant must incur costs to achieve compliance with these rules, 

then options exist for financial assistance. The Water Infrastructure Finance Authority (WIFA) is an 

independent agency in Arizona and is authorized to finance the construction, rehabilitation, and/or 

improvement of drinking water, wastewater, wastewater reclamation, and other water quality 

facilities/projects. Generally, WIFA offers borrowers below-market interest on loans for 100 percent of 

eligible project costs. As a “bond bank,” WIFA is able to issue water quality bonds on behalf of 

communities for basic water infrastructure, providing significant savings due to lower interest rates and 

shared/reduced closing costs. WIFA is able to lower a borrower’s interest costs to between 70 and 100 

percent of WIFA’s tax-exempt cost of borrowing. WIFA’s principal tool for providing low-interest 

financial assistance for publicly and privately held sewer treatment plants is the Clean Water Revolving 

Fund, which is capitalized by contributions from the state and the U.S. Congress. In fiscal year 2007, 

WIFA executed loans in the amount of $133,448,342 to nine sewer treatment plants (or sewer-related 

projects). Three of the loans awarded were to communities with regulatory compliance issues. WIFA also 

manages a Technical Assistance (TA) program. The TA program offers pre-design and design grants to all 

eligible wastewater and drinking water systems. Both pre-design and design loans are available. The 

purpose of the TA program is to enhance project readiness to proceed with a WIFA project construction 

loan. In fiscal year 2007, WIFA provided $302,756 in grants for technical assistance to 11 sewer treatment 

plants. 

Ammonia Standard 

Based on comments received, the Department recognizes that changes in some rules will have more 

direct impact on sewage treatment plants than other rule changes. 

The new numeric water quality standard for ammonia in surface waters with the A&W(edw) 

designated use may result in new water quality-based discharge limitations in AZPDES permits for sewage 

treatment plants discharging to existing effluent-dependent waters (EDW) or ephemeral streams, with 

accompanying costs. Ammonia, a regulated pollutant, is a component of total nitrogen. Total nitrogen in 

sewage is typically composed of ammonia, nitrate, organic nitrogen, and soluble organic nitrogen. With 

only primary and secondary wastewater treatment, nitrogen usually is not removed to a sufficient level. 

Nitrogen discharged into surface waters can consume and deplete the oxygen in the water, damaging 

aquatic fauna, which also need the oxygen. Nitrogen in the form of ammonia is highly toxic to aquatic life. 
83 

For sewage treatment plants that have no other management options to achieve compliance with the 

ammonia standard, the most cost-effective method of ammonia removal is accomplished through the 

advanced treatment of biological nutrient removal (BNR) processes. The biological processes that remove 

the various forms of nitrogen from sewage are called nitrification and denitrification. 

BNR Systems Overview 

There are at least six common BNR treatment processes currently available to remove ammonia and 

nitrate from sewage. The BNR configuration that is appropriate for any particular sewage treatment plant 

depends on the target effluent quality (e.g., the applicable ammonia and nitrate criteria), sewage treatment 

plant operator experience, influent quality, and existing sewage treatment processes (if retrofitting an 

existing facility to meet the standards). In general, new sewage treatment plants have more flexibility and 

options when deciding which BNR system to implement because they are not constrained by existing 

treatment processes and sludge handling procedures. Retrofitting an existing sewage treatment plant to 

provide ammonia removal involves consideration of the following factors: 

● Aeration basin size and configuration, 

● Clarifier capacity, 

● Type of aeration system, 

● Sludge processing units, and 

● Operator experience. 

The aeration basin size and configuration of an existing sewage treatment plant dictates which BNR 

configurations are the most economical and feasible. If a sewage treatment plant has available excess 

capacity, it may reduce the need for construction of additional basins which may allow for a more complex 

BNR configuration. The need for additional basins may require the sewage treatment plant to purchase 

additional land if the space needed is not available. If land is not available, another BNR configuration will 

have to be considered. Clarifier capacity influences the effluent-suspended solids concentration, which 

affects effluent total nitrogen levels. Existing clarifiers may need to be modified to achieve target total 

nitrogen levels in the discharged effluent. Similarly, the sewage treatment plant will need to modify the 

existing aeration system to provide for aerobic and anaerobic zones in the sewage treatment train. The 

manner in which sludge is processed at an existing sewage treatment plant is important to the design of the 

BNR system. Sludge must be recycled within the sewage treatment process to provide the organisms and 

bacteria necessary for ammonia and nitrate removal and operators need to adjust treatment processes to 

compensate for changing conditions in the plant. BNR treatment processes are sensitive to influent 

conditions, including weather events and sludge processing. Sufficient operator skill and training are 

essential for achieving the target effluent concentrations of ammonia and total nitrogen. 

BNR Systems Costs 

BNR treatment systems will differ for new sewage treatment plants and retrofits. New plant BNR 

costs are based on estimated influent quality, target effluent quality, and available funding. Retrofit costs 
84 

are more site-specific and may vary considerably for any given size category of sewage treatment plant. No 

economic studies have been conducted in Arizona to estimate the costs of upgrading sewage treatment 

plants to provide BNR. However, EPA conducted studies in Maryland and Connecticut for BNR upgrade 

costs, Biological Nutrient Removal Processes and Costs, which provides guidance as to potential costs 

associated with retrofitting existing sewage treatment plants in Arizona as may be required on a case-bycase basis as a result of this rulemaking. The capital costs ranged from a low of $1,375,866 for a 2.5 mgd 

(million gallons per day) plant to a high of $138,305,987, for a 180 mgd sewage treatment plant, all in 2006 

dollars. The same EPA report provided costs for BNR upgrades to existing sewage treatment plants in 

Connecticut. The total costs of BNR retrofits ranged from $649,320 to $22,074,225. 

These figures appear on the low end of what the Department has seen in informal communications 

with municipalities in recent years. Based on conversations with various municipalities, new plant costs for 

BNR technology in Arizona likely range from $6-12 per gallon while retrofit facilities may cost as little as 

$2-4 per gallon but likely average in the $6-8 per gallon range, which is in keeping with EPA’s calculated 

average unit capital costs shown below. One example for which there are estimates for full nitrification and 

denitrification using the Modified Ludzack-Ettinger process, is the upgrade to the Nogales International 

Wastewater Treatment Plant. The project, currently 30 percent constructed, will cost over $62 million 

dollars for a 14.7 mgd facility. Costper-treatment gallon is approximately $4.40 and estimated annual 

operating costs are $5.3 million. Another example is the expansion of the Casa Grande Water Reclamation 

Facility, which as part of its $67 million costs, includes $4,239,724 for a nitrification/denitrification and 

BOD (biological oxygen demand) removal system. 

The EPA study underscores that site-specific factors such as existing treatment system layout and 

space availability may cause costs to vary significantly between treatment plants with the same design 

capacities that are implementing the same type of BNR treatment upgrade. The study shows that despite 

this variability in costs, the unit cost per million gallons per day generally decreases as the size of the 

sewage treatment plant increases due to economies of scale. EPA calculated the following average unit 

capital costs for BNR upgrades at the Maryland and Connecticut sewage treatment plants: 

Average Unit Capital Costs for BNR Upgrades at 

MD and CT Sewage Treatment Plants

Flow (in mgd) Cost/mgd (in $2006) 

> 0.1 – 1.0 $6,972,000 

> 1.0 – 10.0 $1,742,000 

> 10.0 $588,000 

The Department expects similar average unit capital costs for sewage treatment upgrades to provide 

ammonia and nitrate removal for existing facilities in Arizona that do not already meet the new standard 

with flows of 100,000 gpd (gallons per day) or more. Small BNR systems of less than 0.1 mgd are usually 

pre-engineered, factory or field-assembled package plant systems. Capital costs for package plants for new 
85 

small systems (<100,000 gpd) that can provide ammonia and nitrate removal will vary depending on the 

treatment process installed and the size of the package plant. Construction costs include all required 

facilities for a package plant on a new site and range from approximately $350,000 for a 4,000 gpd package 

plant to $1.5 million for a 100,000 gpd package plant. Annual operation and maintenance costs include 

labor, electricity, maintenance and repair, solids handling and disposal, administration, laboratory 

analytical costs, and chemical costs, and range from $25,000/year for the smallest plant (4,000 gpd) to over 

$160,000/year for the largest package plant (100,000 gpd). 

The EPA study of BNR costs for retrofitting sewage treatment plants in Maryland and Connecticut 

suggests that the cost of upgrading existing sewage treatment plants in Arizona to provide BNR treatment 

to remove ammonia and nitrate from effluents may be substantial for some communities. However most 

sewage treatment plants have already incurred the costs for denitrification treatment upgrades due to 

mandates under their required aquifer protection permits (APP). See A.R.S. § 49-241(B)(10); A.A.C. R18-

9-A202. As part of the APP process, a sewage treatment plant has to demonstrate that it will use Best 

Available Demonstrated Control Technology (BADCT). For sewage treatment plants, the treatment 

performance standards for BADCT are specified in rule at R18-9-B204 through B206. For most sewage 

treatment plants, BADCT requires nitrate removal to meet the aquifer water quality standard of 10 mg/L, 

which is the same as the surface water quality standard of 10,000 μg/L. See R18-11-406(B); 18 A.A.C. 11, 

Article 1, Appendix A, Table 1. 

There are 36 EDWs currently identified in the rules that will be affected by the new numeric 

ammonia criteria for EDW. This rulemaking adds 29 new EDWs. Most facilities discharging to these areas 

already provide biological nutrient removal treatment, including nitrification to transform ammonia to 

nitrate and denitrification to meet the current BADCT requirements for the APP permitting program. The 

Department estimates that as many as 18 sewage treatment plants may be required, over a period of time, to 

retrofit their existing facility and upgrade unit treatment processes to meet numeric ammonia standards if 

they choose to continue discharging to surface waters. The Department expects that the additional 

reductions necessary to meet surface water quality standards will not require capital expenditures to the 

same level as initial upgrades to install BNR systems. Independent of this rulemaking, discharges under 

AZPDES permits are prohibited from being toxic to aquatic life. See R18-11-108(A)(5). Several of these 

18 facilities have been discharging ammonia at a level showing toxicity to organisms. These facilities are 

required to consider the options discussed above, including additional treatment, despite the new ammonia 

standard. 

Between the new water reclamation facility and the upgrade to the Ina Road facility, Pima County 

estimates that the new ammonia standard will cost $9,400 in total additional energy costs, increased 

chemical costs of methanol treatment of $37,800 annually and $300,000 for new storage, pumping and fire 

safety equipment. The Department considers these estimated increased energy costs to be minimal to 

moderate, and notes that in documentation submitted for its existing AZPDES permit, Pima County plans 

to use methanol as part of treatment. It is unclear how much of the estimated costs for methanol is 

necessary to meet the requirements of Pima County’s existing AZPDES permit due to existing ammonia 
86 

toxicity and how much is needed to meet the new ammonia standard. 

Narrative Nutrient Standard Criteria in R18-11-108.03

A number of comments raised concerns about treatment requirements to use reclaimed water as 

source water in lakes and reservoirs, particularly in urban lakes. As noted in the response to comments, 

there is considerable misunderstanding about how the new narrative nutrient standard will be used to 

support AZPDES permitting. The matrix was not developed to be end-of-pipe limitations unless all 

other options fail. The standard will be applied in AZPDES permits, if necessary, once the assimilative 

capacity of the lake is determined and the target parameters chosen based on the in-lake water quality 

and the quality of the proposed discharge water. 

Most lakes and reservoirs in Arizona are terminal systems, meaning they receive little inflow or 

discharge little outflow, or both. Basically what enters the lake stays and accumulates over time. 

Nutrients, such as nitrogen and phosphorus, naturally occur in all surface waters. The natural balance 

of these nutrients in a lake can be disrupted due to a wastewater discharge from a sewage treatment 

plant, which contains high levels of nitrogen and phosphorus. Too many nutrients means algae 

overgrowth, leading to high pH, low dissolved oxygen, and periodic fish kills. The amount of algae 

growth also depends on lake size, configuration, age, retention time and sources of inputs including 

stormwater, irrigation runoff, and discharge. 

Nitrogen should be less of a concern in algae production because of the new ammonia standard 

for surface waters with the A&W(edw) designated use, as discussed above. However, phosphorus 

concentrations in reclaimed water tend to be higher than most lakes can assimilate without increased 

algae growth. A wastewater discharge with phosphorus concentrations in the 0.5 mg/l range allows the 

natural assimilation processes of a lake to better absorb this nutrient, allowing the lake to meet the 

target ranges in the rule matrix. 

If necessary, there are basically three options a sewage treatment plant can choose in order to 

achieve the 0.5 mg/l phosphorus range for effluent discharging into the lake: 

1. Retrofitting the existing sewage treatment plant to provide additional treatment; 

2. Constructing a smaller treatment facility to reduce phosphorus before discharging to the 

lake; or 

3. Treatment in the lake, such as chemicals or aeration. 

The treatment options depend on certain factors: 

1. How often will effluent be discharged into an urban lake? 

2. How much effluent will be discharged into an urban lake? 

3. What is the phosphorus level in the effluent? 

4. What is the phosphorus level in the lake? 

5. How much phosphorus needs to be reduced? 

Determining the costs to comply with the new narrative nutrient criteria will require permittees 

to answer these key questions first and then weigh the various options to decide which set of options is 
87 

the most cost-effective for its particular set of circumstances. Since each of these options is casespecific and dependent on factors such as volume of discharge, level of pollutants in the effluent, and 

quality of the receiving water, the Department presents a basic comparison of estimated costs by 

treatment option. 

Treatment Options

If the choice is to retrofit an existing sewage treatment plant, there are a number of treatment 

technologies capable of reducing phosphorus in effluent to satisfactory levels. Two common 

technologies are: 

● Chemical addition with filtration: This involves adding chemicals to wastewater with 

aluminum- or iron-based coagulants followed by tertiary filtration, which can reduce total 

phosphorus concentrations in the final effluent to very low levels. It requires a capital 

investment of chemical feed pumps, chemical storage and filters. Sludge production and 

disposal will increase. 

● Enhanced biological phosphorus removal (EBPR): This is a biological process that 

promotes growth of organisms that attract phosphorus. Sewage treatment plants which 

utilize EBPR in the secondary treatment process can often reduce total phosphorus 

concentrations to 0.3 mg/l or less, depending on the quality of wastewater influent. 

Below is a cost comparison of the two processes to upgrade flows at a 16 mgd sewage treatment 

plant. In this example, the plant upgrades for EBPR cost approximately $ 4.0 million, and reduce the 

phosphorus concentration in the effluent from 5 mg/L to 1.1 mg/L (an 80 percent reduction). A plant 

upgrade using chemical treatment alone can reduce phosphorus from 5 mg/l to 0.8 mg/l for $7.4 million 

in capital costs. These costs increase 600 percent, or to $44.4 million, in order to reduce phosphorus to 

0.4 mg/l. A combination of the two processes can produce effluent with a phosphorus concentration of 

0.8 mg/l for $11.4 million but reducing to 0.4 mg/l will cost nearly 4.5 times, or $45 million. The cost 

comparison underscores the importance of selecting the required phosphorus target reduction range. 

Treatment Process 

EBPR 

Only 

Chemical 

Treatment Only 

EPBR + 

Chemical Treatment 

Target Effluent Phosphorus 

(mg/L) 

1.1 0.8 0.4 0.8 0.4 

Total Capital Costs $4,000,000 $7,440,000 $44,440,000 $11,440,000 $48,440,000 

Annual O&M Costs $1,870,000 $20,000,000 $50,000,000 $9,600,000 $37,000,000 

Total Costs $5,870,000 $27,440,000 $94,440,000 $21,040,000 $85,440,000 

Instead of retrofitting the sewage treatment plant to treat the entire wastewater stream, a 

permittee may consider treating only that portion of the wastewater that will actually be discharged into 

the lake. The Department looked at the costs of treating 50,000 gallons per day of wastewater to a 
88 

phosphorus concentration range of 0.5 mg/L. This assumes an average urban lake, which is about 

fifteen acres, ten feet deep, requires approximately 50,000 gallons per day of makeup water during the 

summer months. The costs to build a 50,000 gpd wastewater treatment plant with chemical addition 

and sand filtration, capable of achieving a 96 percent removal of phosphorus to less than 0.5 mg/L 

would be $1.5 to $2 million. 

Alternatively, a small wetlands system also can be used to treat the effluent, assuming sufficient 

land resources are available. Wetlands are highly effective at removing nutrients. The costs to construct 

a small wetlands system to treat 50,000 gpd of wastewater would be $250,000 to $500,000. Wetlands 

are not difficult to operate but do require periodic maintenance. 

A final option to reducing phosphorus levels is in-lake treatment, which can be achieved with inlake alum application, allowing coagulated material to settle to the bottom. An average urban lake of 

fifteen acres, ten feet deep, would have a volume of 490 million gallons, and require approximately 

1000 liquid gallons of aluminum sulfate (liquid being the preferred method of application). At $3 per 

gallon, the cost per treatment would be $3000 for the chemicals in addition to labor and materials costs. 

The average urban lake might require alum application about three to four times in the summer in order 

to remove 80 percent of the available phosphorus from the water column. 

Power Generation and Mining 

Power plants and mines are also likely to be affected by surface water quality rule changes. As with 

sewage treatment plants, some of the rule changes may require a permittee to incur costs to meet water 

quality-based discharge limitations established in an AZPDES permit. There are possible minimal 

increased monitoring costs based on a new numeric standard. However, as with the sewage treatment 

plants, economic challenges associated with wastewater disposal present themselves with and without this 

rulemaking.

Based on public comments, the greatest economic impact will come from the change in the EDW 

definition, which will require some permittees to treat their discharges to meet the chronic aquatic life 

criteria for the first time, instead of the more lenient standards for discharges that meet ephemeral water 

standards. Under the previous rule, permittees that did not treat their wastewater had been allowed to 

discharge higher levels of pollutants at levels that were not protective of aquatic life. The Department 

estimates that there at least seven permitted industrial facilities that will be impacted by the change in EDW 

definition. These permitted facilities will be eligible to request a compliance schedule or variance, as 

discussed above, to delay or defray costs. 

This rulemaking clarifies that any discharge of “wastewater” to an ephemeral water will require use 

of EDW standards in the AZPDES permit and brings parity to all permitted discharges without 

distinguishing between treated and untreated discharges. With this change, all dischargers to the same 

waterbody will be held to the same water quality requirements. The Department acknowledges that some 

permittees may incur moderate to substantial costs to achieve compliance with the new surface water 

quality standards under the EDW definition, although it is difficult to quantify those costs. In general, 
89 

power plants have not been required to treat cooling tower discharges, which due to cycling of water 

through the cooling processes results in increasingly higher concentrations of metals, total dissolved solids 

(TDS), and other pollutants. Mining facilities have implemented varying degrees of treatment, depending 

on the wastewater generated whether it is stormwater, process wastewater or mine dewatering. Dewatering 

is a commonly used method of coping with groundwater seepage, mine excavations intersecting aquifers or 

excessive rainfall on mining operations. These waters contain concentrated levels of metals from the 

mineralized area and/or TDS.

To determine what costs a permittee would incur to meet new water quality-based discharge 

limitations established in an AZPDES permit at some appropriate time in the future, the following factors 

would have to be examined including:

● What are the pollutants for the facility? 

● Which pollutants present in the discharge have a reasonable potential to violate a new 

standard? 

● What is the effect of this rulemaking on the previous wasteload allocation (i.e., what are the 

revised AZPDES permit limits considering the revised chemical criteria, changes to the 

stream designation, and elimination of protected flow provisions?) 

● What are the existing effluent levels for each pollutant discharged under the current 

AZPDES permit? 

● Are the industrial wastewater streams for an individual facility segregated before discharge 

and if so, what are the flow rates for each wastewater stream? 

● Does the facility treat (or pre-treat) its wastewater and if so, what type of treatment 

technology is used? 

● Where a reasonable potential to exceed a new standard exists, is additional treatment 

necessary or are there alternatives available such as source reduction or recovery to reduce 

the existing levels in the wastewater stream? 

● What are the influent concentrations for each pollutant prior to any existing or anticipated 

treatment process? 

● Is eliminating all discharges a cost-effective option? 

Most permitted power plants and mining operations have some options as to where wastewater 

is discharged. Most power plants have more than one discharge location, with at least one location not 

being a water of the United States, where they can discharge at certain times of the year or under 

certain conditions. Mining operations generally are able to route waste streams to impoundments 

within the mine site, except maybe during storm weather events. Industries affected by this rulemaking 

will need to explore these options, as well as consider discharge volumes, duration of discharge, 

seasons, levels of pollutants, geography and other factors, in order to determine the most cos-effective, 

viable and environmentally protective option or combination of options. 

For purposes of this rulemaking, the Department has looked at several scenarios that a power 

plant or a mine operation might consider if circumstances require the facility either to not discharge or 
90 

to treat the waste stream to meet the new standards. Below is a brief description of the disposal and 

treatment options considered. Following each option is a discussion of how these options would impact 

each industry. While costs depend on the site and operation specifics, there are certain assumptions 

made to estimate impacts. For both mines and power plants, the Department assumes the pollutants of 

concern will be elevated metals and/or salts in the process water, dewatering water or cooling tower 

blowdown. The Department also assumes due to volume and quality of these waste streams, direct 

discharge to surface waters, injection into the aquifer, discharge to municipal sewers, or reusing the 

water within the facility are not viable options without treatment. These assumptions may or may not 

be accurate in all cases. 

Storage and Evaporation Options

In many cases, the simplest method for disposing of unusable wastewater is storage and 

evaporation in lined surface impoundments. Lined evaporation ponds are a well developed and 

common method for disposing of industrial wastewaters and work extremely well in Arizona’s arid 

climate. The costs associated with evaporation ponds are primarily the cost of land and necessary liners 

to protect the aquifer and facility security, such as fencing. Optimal depths are less than 40 inches, and 

operation and maintenance costs are relatively low. Periodic dredging and transport of sludge is an 

added, occasional cost. Ponds work well for small to moderate waste streams. Large ponds in an urban 

environment, especially where land prices are high, become less economically feasible. Cost modeling 

shows a rapid increase in costs with increases in the volume of wastewater and location. An 

evaporation pond sized to contain one million gallons per day of discharge for 30 days could cost 

upwards of $20 million if it were constructed today in the East Valley, given land prices estimated in 

excess of $200,000 per acre. 

Impoundments can be used with other techniques. A new technology called Wind Aided 

Intensified evaporation may eventually prove appropriate for use in the southwest. It reduces the 

overall surface area of the ponds by increasing evaporation through the use of netting. This technology 

would reduce the footprint of the ponds and therefore reduce land costs but would have some 

additional capital costs for piping, pumps and netting materials. Impoundments also can be combined 

with chemical additions to provide various types of primary treatment to drop out metals and other 

pollutants. The types, amounts and costs of the chemicals are directly related to the pollutants of 

concern in the waste stream, such as metals, nutrients, and TDS. 

Most mining operations are of such a scale that lined surface impoundments are generally the 

chosen method of disposal for excess process water that cannot be discharged under an AZPDES 

permit because of the low quality of the water. As most mines are in rural, undeveloped locations, land 

prices are generally not prohibitive. For mining operations with limited land for storage, especially in 

highly developed metropolitan areas or where discharges are too high, the wastewater may require 

treatment prior to disposal. Power plants in rural settings are able to utilize impoundments for 
91 

wastewater disposal, but for those facilities in the metropolitan area, land prices may make large 

surface impoundments economically infeasible. 

Treatment Options

The power plant industry, as well as municipalities, has been exploring zero liquid discharge 

systems, which use a variety of treatment techniques, often together with smaller surface 

impoundments, to treat, recycle and reuse all process wastewater leaving only the solids as a 

concentrate. Two technologies are discussed here, both of which are currently being used in the electric 

utility industry and could be transferred to other industries, including mining. 

Brine concentrators convert highly saturated industrial wastewater, such as process cooling 

water, into distilled water for reuse, and a waste stream. The waste stream is typically five to ten 

percent of the influent stream. For example, 100 gallons of highly saline wastewater would yield 90-95 

gallons of distilled water (with low TDS) and five to ten gallons of waste stream concentrate. The 

relatively small amount of waste stream concentrate can be disposed of in impoundments or, reduced to 

a dry solid through a process that makes solid crystal from the concentrate, which can then be disposed. 

The high quality water can be recycled within the plant or discharged under a permit. Brine 

concentrators can treat about 700 gallons per minute or 1.2 million gallons per day. A limiting factor is 

the cost of power to operate, which can range from 60-100 kilowatts per hour per 1,000 gallons of 

source water. These brine concentrators are reliable and not difficult to operate, but do require trained 

personnel to operate, as well as laboratory support. 

Standard reverse osmosis (RO) is a separation process that uses pressure to force a solution 

through a membrane that retains the concentrate on one side and allows the higher quality water to pass 

to the other side. The membranes are specific to the pollutants of concern. Depending on the quality of 

water needed, RO systems can be constructed for multiple passes or arranged in series to achieve the 

necessary water quality. The concentrate is then disposed of in impoundments or by other means. 

High Efficiency Reverse Osmosis (HERO) is a newer RO process that consists of three separate 

steps, but upon completion, the RO water (good water) is available for recycling within the plant as 

makeup water or can be discharged or injected into the aquifer under a permit. The concentrated RO 

water can be disposed of in impoundments or sent to a crystallizer to produce dry solid for landfilling. 

The HERO process has a lower energy requirement but does require specialized personnel to operate 

the system. The Griffith Energy Project near Kingman installed a HERO-based system in 2001. The 

plant is a 500 megawatt gas-fired, combined cycle unit. The Griffith facility is approximately the same 

size as the Salt River Project K-7 plant in South Tempe and half the size of the Salt River Project 

Santan plant in Gilbert. Initial findings at Griffith confirm the ability of the HERO system to reduce the 

volume of wastewater by nearly 90 percent. The system was designed to handle approximately 300 

gallons per minute. 

A cost comparison of the HERO with Evaporation Pond and Brine Concentrator with 

Evaporation Pond shows: 
92 

 HERO w/ Evaporation Pond 

$ x 1000 

Brine Concentrator w/ 

Evaporation Pond $ x 1000 

Total Direct Costs 6,450 7,375 

Total Installed Costs1 8,400 9,365 

Total Operating Costs 

(annual) 

430 978 

1

 includes direct and indirect costs 

D. Estimated Costs and Benefits to Private and Public Employment. 

Private and public employments are not affected directly by these rules. 

E. Estimated Costs and Benefits to Consumers and the Public. 

It is easy to describe qualitatively the benefits of clean water as a source for drinking water, bathing, 

cooking, washing clothes, and the inherent value of Arizona’s rivers and lakes that are safe for swimming, 

fishing, boating, wading, or other water-based recreation. There is also value in maintaining aquatic and 

riparian ecosystems that are dependent on surface water. However it is much more difficult to quantify 

these benefits in monetary terms. Because these are comprehensive rule changes, it would be next to 

impossible to separate the benefits derived from each rule change from the overall benefit that surface 

water quality standards have in achieving clean water. There are some monetary examples, however, that 

help to demonstrate the value and benefit of these rules for ensuring clean water. 

Recreation 

According to the Arizona Department of Tourism, some of the top Arizona attractions revolve 

around water. The following table shows the 2007 attendance for some of Arizona’s top water relatedattractions. 

ATTRACTION ATTENDANCE 

Tempe Town Lake 2,782,000 

Glen Canyon National Recreation Area 1,894,114 

Lake Mead National Recreation Area 1,824,297 

London Bridge 1,500,000 

Lake Pleasant Regional Park 697,479 

Lake Havasu State Park 329,529 

Slide Rock State Park 305,759 

Clean water is an essential component that clearly relates to these economically important 
93 

recreational activities. One example of the benefit of water quality standards for the designated use of full 

or partial body contact is the Ironman Marathon held in Tempe. The swimming portion of the marathon is a 

2.4 mile swim in Tempe Town Lake. The 2008 Ironman had just over 2,000 participants from all over the 

world, competing for a $75,000 prize. According to the Tempe Convention and Visitors Bureau, the 

Ironman competition generated approximately $5.1 million in 2007. 

Fishing 

A 2002 study on the economic importance of fishing and hunting, sponsored by Arizona Game and 

Fish (AZGFD), showed that more than 255,000 anglers spend an estimated $831.5 million on equipment 

and trip-related expenditures annually. This spending supports more than 17,000 jobs, provides residents 

with $314 million in salary and wages, and generates more than $58 million in state tax revenue. Based on 

AZGFD’s 2006-2007 Annual Report, 483,642 fishing licenses were purchased for 2006, generating part of 

the $14,740,686 revenue of hunting and fishing license sales for 2006. 

Part of AZGFD’s fishing program includes the Urban Fishing Program, which is supported by the 

sale of Urban Fishing Licenses and from fees from the city parks and recreation departments. During 2007, 

over $500,000 was spent on stocking over 200,000 pounds of keeper-size channel catfish, rainbow trout, 

and sunfish. Last year, over 55,000 urban anglers participated in fishing and accounted for over 650,000 

angler recreation days. The number of urban fishing licenses for 2006 was 32,837. A constant challenge in 

Arizona’s warm urban lakes is to monitor and manage pH levels and algae to ensure fish can be stocked. 

Out of the 21 urban lakes listed as part of the Urban Fishing Program, ten are surface waters protected 

under these rules. 

Other Monetary Benefits 

Agriculture is another measure where clean water is an absolute necessity for ensuring agricultural 

productivity. As noted by the Arizona Department of Agriculture, Arizona agriculture produces cotton, 

durum wheat, alfalfa, various produce like head lettuce, leaf lettuce, broccoli, cantaloupe, watermelon, and 

citrus. Livestock also plays a big role in Arizona, both with cattle and sheep. The Department of 

Agriculture reports that agricultural sales in Arizona generate $2.2 trillion annually, with Yuma County 

generating $1,303,492,000. Although a percentage of agricultural productivity depends on groundwater, 

surface water quality standards help maintain and protect surface water quality for irrigation and livestock 

watering. 

Another example of the value of clean water is the worth placed on Colorado River water, as 

demonstrated through the Central Arizona Project (CAP). One of Arizona’s main sources of water is the 

Colorado River, in which water is transported through the CAP. This 336 mile long canal provides, on 

average, 1.4 million acre-feet (one acre-foot roughly equals 326,000 gallons) of water each year to nearly 2 

million citizens and businesses in central and southern Arizona. In 2007, CAP delivered 1,700,203 acrefeet to its customers, generating $108.8 million in water operations and maintenance charges. Agricultural, 

and municipal and industrial water usage accounted for 975,635 acre-feet. CAP water rates for long-term 
94 

contract customers is at $91 per acre-foot. 

Quantifiable benefits also can be demonstrated as the cost avoided, such as for clean-up. The 

Department recently awarded a $54,978 grant to fund water quality improvement in Pima County for 

Lakeside Lake. This lake, filled mainly by reclaimed water, is a popular recreational and fishing location, 

but the lake has become increasingly eutrophic over the years. These conditions have resulted in noxious 

algal blooms, high pH, low dissolved oxygen, limited stocking, and periodic fish kills. A marked decline in 

water quality and several fish kills since the early 1990s led to citizen complaints and increased attention 

on the part of the City of Tucson, AZGFD, the University of Arizona, and the Department. The City of 

Tucson reports they spent $250,000 for installing an aeration system on the bottom of the lake, meant to 

improve water quality and alleviate stress on fishes. Declining conditions led AZGFD to stock trout only in 

the cooler months and catfish and other warm-water species in the summer months. Under the grant, 

Tucson will improve water quality in the lake by reducing drainage from surrounding park lands into the 

lake, providing bait disposal locations for people who fish, and occasionally treating the lake with alum, a 

chemical that will help reduce algae growth. Tucson will also remove debris from the lake and surrounding 

park. 

Deriving both full and partial body contact criteria for non-carcinogenic compounds, changing the 

relative source contribution from 100 percent exposure to 20 percent, also results in more protective 

standards. The benefit of water quality standards for the designated use of full or partial body contact can 

be demonstrated as revenue lost, for instance, when Slide Rock Park closes due to exceedances of E. coli, 

which has occurred on average of 12 times annually. 

Adding treatment, such as nitrification/denitrification, typically produces a better effluent quality, 

meaning lower level of pollutants, such as nitrates, but also other pollutants such as personal care products. 

Better effluent quality also allows more options for reuse, such as for irrigation purposes. Even though the 

Casa Grande Water Reclamation Facility expansion will cost $67,129,710, there is a recognized benefit of 

$14.5 million in total capital cost reduction in improving treatment for the overall liquids and solids process 

optimization. 

Health Benefits 

The most important benefit derived from the surface water quality standards is to the protection of 

humans for drinking water, swimming, and fish consumption. Deferred and avoided health care cost 

benefits associated with this rulemaking’s incremental human health protections are real but unquantified. 

One change to the methodology for deriving standards for non-carcinogens for each of the human health 

designated uses, is the use of a relative source contribution (RSC) of less than 100 percent. The RSC is the 

amount of exposure from various sources or routes, such as drinking, swimming, or fish consumption. 

Setting the RSC at less than 100 percent acknowledges there may be additional routes of exposure for a 

pollutant besides that particular designated use. For example, humans can be affected by arsenic from a 

variety of sources including oral, dermal and aerial. 
95 

For example, in deriving the fish consumption criteria, the Department has adopted EPA’s 

recommendations that resulted in two changes: 1) it increased the default fish consumption number from 

6.5 to 17.5 grams/day to more adequately protect the general population of fish consumer, and 2) it 

changed the relative source contribution from 100 percent to 20 percent, acknowledging there may be 

additional routes of exposure for a pollutant besides ingestion of fish. Part of the changes regarding fish 

consumption include a new fish tissue standard for methylmercury (MeHg), an organic compound of 

mercury that bioaccumulates in fish and is one of the most toxic substances known to man. While MeHg 

has been linked to a variety of health effects, the primary risk arises from its toxicity to the nervous system, 

including the brain. Numerous health studies have demonstrated that methylmercury is a potent neurotoxin, 

particularly in developing organisms [EPA, 1997; ATSDR, 1999; NAS, 2000.] 

Unborn children are as much as 10 times more susceptible than adults to its detrimental effects. The 

most common source of exposure to MeHg is from eating fish that contain the mercury. Upon ingestion by 

humans, MeHg is absorbed through the gastrointestinal tract and easily penetrates the blood-brain and 

placental barriers. Most at risk are infants and unborn children whose mothers consume fish containing 

MeHg during pregnancy or while nursing. If the tissues of a pregnant or breastfeeding woman are 

contaminated with mercury, a disproportionate amount of that mercury may be passed to the baby, where it 

can attack the developing nervous system. Chronic exposure to MeHg at elevated concentrations can cause 

developmental delays and learning disabilities and acute exposures may cause gross cranial defects, 

cerebral palsy, and a higher infant mortality rate. 

One example of costs of MeHg exposure is developmental impacts on children. Using national 

blood mercury prevalence data from the Center for Disease Control, it is estimated that between 316,588 

and 637,233 children each year have cord blood mercury levels greater than 5.8 μg/L, a level associated 

with loss of IQ. The resulting loss of intelligence causes diminished economic productivity that persists 

over the entire lifetime of these children. This lost productivity is the major cost of methylmercury toxicity, 

amounting to $8.7 billion annually, with a range of $2.2 to 43.8 billion (all costs are in 2000 US dollars) 

(Trasande et al, 2005). 

Adoption of the fish tissue standard is protective of human health and will aid the Department in 

notifying the public when it is not safe to consume fish from certain waterbodies. Costs avoided include 

reduced infant mortality and direct costs of medical care for exposure to mercury and MeHg, specifically 

neurological care for infants and children. Indirect costs of specialized education for children with learning 

disabilities may also be avoided. 

The Department has also adopted the new Safe Drinking Water MCL for arsenic of 10 ppb for the 

domestic water source designated use. Inorganic arsenic has been recognized as a human poison since 

ancient times and EPA has found it to be a Class A carcinogen. Arsenic ingestion has been linked to a 

multitude of health effects, including cancer of the bladder, lungs, skin, kidney, nasal passages, liver, and 

prostate. Nonlethal, but high doses, can cause non-cancerous health effects include gastroenterological 

effects, shock, continuous pain, and vascular effects in humans. Other effects that have been reported 

include alterations in gastrointestinal, cardiovascular, hematological (e.g., anemia), pulmonary, 
96 

neurological, immunological and reproductive/developmental function. High dosages of arsenic of 70 to 

280 mg for 50% of adults weighing 70 kg are lethal. Increased risks of lung and bladder cancer and of 

arsenic-associated skin lesions have been observed at drinking-water arsenic concentrations of less than 

0.05 mg/L. Children are exposed to arsenic in the same ways that adults are. Since children tend to eat or 

drink less of a variety of foods and beverages than do adults, ingestion of contaminated food, juice or infant 

formula made with arsenic-contaminated water may represent a significant source of exposure. There is 

some evidence that exposure to arsenic in early life (including gestation and early childhood) may increase 

mortality in young adults. 

The 1999 National Academy of Science report found that the lifetime risk of dying from cancer due 

to arsenic in drinking water is generally lower for people drinking low levels of arsenic in tap water (NAS, 

1999). A recent study from Finland (Kurttio et al., 1999) found that Finns who drank water containing low 

levels pf arsenic (<0.1 ppb) had about a 50 percent lower risk of getting bladder cancer than their 

countrymen who drank water containing higher levels (>0.1 ppb – 0.5 ppb). People who consumed water 

with 0.5 ppb arsenic had more than a 140 percent increase in bladder cancer rates, compared to those 

drinking at levels less and 0.1 ppb. Similar reductions in risk are found for other types of cancers and 

cardiovascular diseases at increasingly lower levels of arsenic (BEST, 2001). Costs avoided include direct 

costs of medical care for exposure to arsenic. EPA estimated the value of the benefits of adopting the 10 

ppb arsenic standard for drinking water to range from as high as $90 million for bladder cancer to $384 

million for lung cancer. 

These are two examples of human health and cost benefits that may be expected to result from more 

protective water quality standards like those adopted in this rulemaking. Though the standards in these 

rules are incrementally more protective of human heath then the previous standards, the Department 

believes the overall benefits of the rules outweighs the costs. 

Indirect Costs to Consumers and General Public

The Department recognizes that permittees, especially sewage treatment plants, may pass their direct 

costs onto their customers, taxpayers or both. If sewage treatment plant upgrades are required to comply 

with new or revised water quality standards, this can result in an indirect cost to some business, industry, 

and consumers paying higher utility bills for sewer services, or more for commodities. In particular, 

customers served by sewage treatment plants that discharge to effluent-dependent waters may be affected 

by the adoption of numeric water quality standards that will limit discharges of ammonia, but only if the 

discharge is not currently toxic, as described above. 

Sewage treatment plant upgrades are typically financed through rate increases or bonding. Publiclyowned sewage treatment plants also have a financing option of low-interest loans through WIFA. 

Consumers could see increased taxes and municipal debt financing due to public sewage treatment plant 

compliance with more stringent standards. Municipal operators of sewage treatment plants typically pay 

the debt service on bonds or WIFA loans through increases in sewer rates and sewer connection fees for 

customers in the local community. It is difficult to estimate the costs to consumers and the general public, 
97 

but cost of sewer services will increase for those sewage treatment plants that are required to upgrade 

treatment. 

An example of how a customer may be affected, the Nogales International Wastewater Treatment 

Plant projects a sewage treatment rate increase from $6.75 to $9.96 for the base fee over a period of 10 

years and an increase in the sewer rate from $1.17 to $1.71 for every 1,000 gallons over the same period. 

The City of Casa Grande has low sewer rates of $11.98 per month, but collects and uses development fees 

to help pay for new sewage treatment facilities. Pima County estimates that its customers’ monthly sewer 

bills will increase annually for a period of fifteen years, starting at $21.56 and projected to be $46.05. The 

annual percent change increase that a customer could see ranges from 16.9 to 1.7, with five years at zero. 

Pima County connection fees would also increase, with the annual percent change ranging from 19.9 to a 

low of 1.7, again with four years at zero. Connection fees start at $6,364 and are projected to climb to 

$12,494. 

F. Estimated Costs and Benefits to State Revenues. 

There are no fees associated with these rules. This rulemaking is expected to have no impact on state 

revenues. 

Requirements of A.R.S. § 41-1035.

The Department defines a small business as a privately-owned permitted facility that discharges less 

than 1 million gallons per day. The Department calculates that about 25 out of the 160 individual 

permittees would qualify as a small business. For a sewage treatment plant, this facility would serve a 

community of no more than 10,000. 

1. Establish less stringent compliance and reporting requirements for small businesses. 

The rules do not establish any reporting requirements. 

2. Establish less stringent compliance or reporting schedules or deadlines for small businesses. 

The rules authorize schedules of compliance in A.A.C. R18-11-121, which allows a facility 

time to evaluate, design, and construct treatment or other means of meeting a new standard. (The 

Department is prohibited by federal law from establishing less stringent compliance schedules for 

small businesses under 40 CFR 122.47.) The rules do not establish any reporting schedules or 

deadlines for small businesses. 

3. Consolidate or simplify the rule’s compliance and reporting requirements for small businesses 

The rulemaking does not prescribe reporting requirements. 

4. Establish performance standards for small businesses to replace design and operational standards. 

The rules do not establish design or operational standards for small businesses. 
98 

5. Exempt small businesses from any or all requirements of the rule. 

Water quality standards are provisions of state law required by the federal Clean Water Act. 

The Department has no authority to exempt small businesses from the requirement to comply with 

surface water quality standards. However, as explained in Section C above, the rules provide other 

methods for reducing the immediate impact for dischargers, including small businesses, such as the 

compliance schedules and variances. 

10. A description of the changes between the proposed rules, including supplemental notices, and final rules (if 

applicable):

Rulemaking changes made as a result of responses to comments are described in item #11. Conforming, 

grammatical, formatting, and other minor changes have been made throughout the rule package by the Department 

and as suggested by the Governor’s Regulatory Review Council (G.R.R.C.) staff and have not been addressed in 

items #10 or #11. 

The following changes are the result of Department review and are addressed in this section for the benefit 

of the reader. 

The proposed rulemaking used the term “municipal park” throughout the rulemaking when referring to 

specific lakes. This final rulemaking changed the terminology from “municipal park” lake to “urban” lake. 

The term “pollutant of concern” used in R18-11-107.01 refers to pollutants with either a numeric or 

narrative water quality standards and has been defined in R18-11-107.01(B)(4) and the remaining subsection has 

been renumbered. Because the term “pollutant of concern,” found in R18-11-114(D)(7) and R18-11-122(F)(3) 

does not pertain to antidegradation, it has been clarified is each case. 

R18-11-101. Definitions

The Department believes that by revising the language of the term “designated use” in the proposed 

rulemaking, the meaning of the term was changed  or could be understood in a different manner. The original 

definition has been retained. 

The term “wastewater,” used in this rulemaking, has the commonly understood meaning. The term is 

further clarified in this Section as to which types of discharge are not considered wastewater. 

R18-11-107.01. Antidegradation Criteria

The phrase “under an individual AZPDES permit” was added to subsections (B)(3) and (B)(3)(c) to 

clarify that the antidegradation review only applied to an individual AZPDES permit. 

The stem sentence in subsection (C)(3)(a) conflicts with the rest of the subsection. The actions required 

for an alternative analysis are covered within subsections (C)(3)(a)(i) through (iv). The following language 

has been removed from the rule: “The person shall demonstrate that there are no reasonable, cost-effective, 

less-degrading, or non-degrading alternatives to the regulated discharge” 
99 

R18-11-108.03. Narrative Nutrient Criteria For Lakes And Reservoirs

The Department believes that the term “lacustrine” (of or related to the lake”) is too general a term in 

this instance and that the term “limnetic” (of or occurring in the deeper, open waters of lakes or ponds, away 

from the shore) was more appropriate. Subsection (B) has been revised as follows: 

(B)(2)(c)(v) A nuisance algal bloom is present in the limnetic portion of the lake or reservoir; or

Appendix B

The name of the surface water proposed as “Unnamed Wash,” in the Colorado – Lower Gila (CL) 

watershed located at “Town of Quartzsite WWTP outfall at 33°42'30"/114°13'14" to1 km downstream at 

33°42'30"/114°13'45"” has been corrected to “Tyson Wash.” 

The location of the Gila River (EDW) in the Middle Gila watershed has been corrected as follows: 

From the confluence with the Salt River to the Gillespie Dam at 33°13'45"/112°46'07"

The location of the Unnamed Wash in the Middle Gila watershed has been corrected as follows; 

North Florence WWTP outfall at 33°03'49.54"/111°23'13.28" to confluence with Gila River at 

33°02'59"/111°23'15"

The name of the surface water segment proposed as “Santa Cruz Wash (EDW)” in the Santa Cruz – Rio 

Magdalena – Rio Sonoyta watershed, located at “Palo Verde Utilities WWTP outfall at 33°04'20"/112°01'47" to 

the Gila River Indian Reservation” has been corrected to the “Santa Rose Wash.” The surface water and 

designated use information about the corrected Santa Rose Wash has been positioned above the “Santa Rose 

Wash” located “Below Tohono O’odham Indian Reservation to the Ak Chin Indian Reservation.” 

11. A summary of the comments made regarding the rule and the agency response to them:

All comments in this section are, for the most part, presented as received. Extraneous or repetitive 

information has been omitted, as appropriate. 

GENERAL COMMENTS

Comment #1

Sandy Bahr, Sierra Club  Grand Canyon Chapter

While Pharmaceuticals and Personal Care Products (PPCPs) are not addressed in the proposed surface 

water quality standards, they are a significant public concern and should be addressed in the next Triennial 

Review. In the meantime, we recommend that the ADEQ implement testing for at least some of these products 

to begin to assess their occurrence in Arizona waters and that it continue to support research at the universities. 

These products are found in treated municipal wastewater that is discharged into Arizona waters, so it is 

something that should be considered and evaluated. 

J. Adrianne Settimo
100 

Pharmaceuticals and Person Care Products (PPCPs) have become a significant public concern. Trace levels 

of these products can be found in treated municipal wastewater that is being discharged into Arizona waters. 

Released wastewater “creates an aquatic environment that supports wetlands and streamside vegetation or may 

recharge the groundwater.” 

Although the issue of PPCPs is relatively new, “scientists have detected some of the chemicals at levels 

linked to adverse impacts on the reproductive systems of certain species of fish and frogs that depend on waters 

influenced by treated wastewater.” Id. 

The possibility that PPCPs may have adverse impacts on humans at higher levels, and water containing 

PPCPs may be recharging groundwater is cause for concern. Science has not yet determined what impact longterm exposure to low levels of pharmaceuticals will have on humans, let alone what impact this exposure will 

have on wildlife. 

The first step in assessing how big of an issue PPCPs are in Arizona’s water resources is to implement a 

testing program. Therefore, the testing of (at least) aquifer water should be added to the proposed rule. If levels of 

PPCPs are higher than trace amounts, action should then be taken to correct the situation. 

Response: PPCPs belong to a category of emerging pollutants that have recently come to the attention of 

scientists, federal and state regulators, and the public. The Department shares the commenter’s concerns about the 

potential impact of PPCPs that are making their way into Arizona’s rivers, streams, lakes, and reservoirs. 

Increased monitoring and better analytical test methods have increased awareness of the presence of PPCPs in 

surface water and highlighted the need for more information about their potential risks to human health and the 

environment. Research has just begun and little data currently exists about the consequences of PPCPs on human 

health or aquatic life. Currently, there is no basis for developing scientifically defensible water quality standards 

for PPCPs. The Department will follow the development of the regulation and science concerning these pollutants. 

Although the Department does not have detailed plans for where and when testing for these pollutants will occur, 

the Department has conceptual plans to conduct environmental testing over the coming years and will continue to 

support university research on this matter as resources allow. 

Comment #2

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ has failed to revise A.A.C. R18-11-106, net ecological benefit (NEB) to facilitate its intended use 

within Arizona. 

As Pima County and ADEQ staff have previously discussed and agreed, providing ADEQ with the 

information and demonstrations requested by this rule section, in order to provide the Department with grounds to 

modify an existing standard, may be impossible to achieve for many projects given the general and vague nature 

of the current rule language. It was obviously not the intent of the Department to create a rule that essentially 

could never be used for its intended purpose.

ADEQ staff has previously suggested that this rule could be used to allow a modification of standards to 

address the short comings of the current water quality standards, to properly regulate riparian habitat restoration 

projects such as the Kino Ecological Restoration Project (KERP). However, upon investigation by Pima County of 
101 

the demonstrations required by the rule, it became obvious that the rule was not written in a sufficiently clear and 

reasonable way, so that the information and demonstrations can actually be made. 

Pima County, at the invitation of ADEQ staff, has previously communicated with ADEQ on these issues in 

a letter dated January 26, 2006 (Attachment #6). This letter discusses the background of this rule language and 

makes suggestions for modifying the rule language consistent with EPA guidance, in a way that will make it 

usable for its intended purpose in Arizona. Pima County asks ADEQ to consider these issues and revise the NEB 

language to address these concerns. 

In addition we have attached comments from Dr. Ben Parkhurst (Attachment #2) discussing how the state 

of Wyoming has modified its water quality standards rules and produced implementation policies (Attachment #7) 

that have allowed the net ecological benefit concept to be used extensively is the state. We ask ADEQ to adopt 

similar rules and implementation policies for Arizona to address the problems with the Arizona NEB rule. 

Response: “Net Ecological Benefit” is a difficult determination for the very reasons the commenter points 

to: the comparison and evaluation of social value that a project may have versus the monetary costs of either not 

performing the project or meeting the current surface water quality standards required by the Clean Water Act and 

the rules. This is a complex issue that is not unique to Arizona and has been a point of discussion in other state 

and EPA water quality forums. As noted, the Department reviewed Pima County’s January 26, 2006 letter, other 

stakeholder comments, and held discussions with stakeholders, however the Department is not proposing changes 

to the Net Ecological Benefit rule at this time. The Department has approved modifications to water quality 

standards for the Yuma East Wetlands discharge in this rulemaking under R18-11-106, illustrating that the current 

rule can be used. 

JURISDICTION

Comment #3

Sydney Hay, Arizona Mining Association

As reflected in the existing and proposed definition of “surface water,” the standards in A.A.C. R18-11-101 

et seq. are intended to apply to waters of the United States as that term is defined pursuant to the CWA (“CWA”). 

As ADEQ is aware, the extent of CWA jurisdiction is uncertain after the decision of the United States Supreme 

Court in Rapanos v. United States, 547 U.S. 715 (2006). Subsequent to that decision, EPA and the Corps of 

Engineers issued guidance entitled “CWA Jurisdiction Following the U.S. Supreme Court’s decision in Rapanos 

v. United States & Carabell v. United States (June 2007) (the “Guidance”). Pursuant to the Guidance “traditional 

navigable waters” (“TNWs”), reasonably permanent tributaries of TNWs, and other tributaries with a “significant 

nexus” to TNWs remain regulated under the CWA. By contrast, swales or erosional features (e.g., small washes 

characterized by low volume, infrequent, or short duration flow) are generally not considered jurisdictional. 

In a state such as Arizona, where many “waters” are ephemeral washes, the Guidance may result in some 

waters previously considered jurisdictional no longer being so considered. At this point, it is simply too early to 

tell what the ultimate ramifications of the decision and the Guidance will be in Arizona. For example, the agencies 

have not yet fully identified the extent of TNWs within the state, nor clearly defined how the presence or absence 

of a “significant nexus” to such TNWs will be measured. 
102 

The AMA believes that the triennial review needs to account for this jurisdictional uncertainty. Currently, 

the definition of “surface water” is broader on its face than the corresponding EPA and Corps definitions (e.g., by 

specifically including “ephemeral” streams in the “other waters” category), and ADEQ has not proposed any 

changes to that definition. See A.A.C. R18-11-101(43)(c). The blanket inclusion of ephemeral streams is 

unwarranted, particularly after Rapanos. 

In light of the foregoing, the AMA suggests that the most efficient way to address the issue in the triennial 

review is as follows: (1) modify the definition of “surface water” to simply provide that a surface water means a 

“navigable water” as that is the term is defined in A.R.S. § 49-201(22), since “navigable water” is the term used in 

the governing statutes, specifically A.R.S. §§ 49-221(A) (authority to adopt surface water quality standards) & 49-

255(2) (definition of “discharge” for AZPDES program); and (2) add language clarifying that the designated uses 

in Appendix B apply “if and to the extent that each listed water or reach constitutes a surface water.” (The 

tributary rule (A.A.C.R. 18-11-105) already applies on its face only to a “surface water” and so would not need to 

be modified if the changes to the definition of “surface water” outlined above were adopted. Absent those or 

similar changes, however, the tributary rule would be subject to challenge by virtue of its apparent classification 

of every single tributary as a regulated “water of the United States” under the CWA.)

The AMA recognizes that ADEQ has authority to adopt surface water quality standards for non-navigable 

waters pursuant to A.R.S. § 49-221(B), but the Department has not proposed doing so and any such proposal 

would need to be accompanied by a separate analysis of the economic, social and environmental costs and benefits 

associated with any such standards. Absent such a proposal and accompanying analysis, the AMA believes that 

the approach suggested above is the most logical one given the current climate of uncertainty 

Response: The Department does not agree that the current rule language needs to be changed as a result of 

the Rapanos decision and federal guidance. The federal guidance document pertains to the Clean Water Act § 404 

program and is not rule. The Department is required to establish standards under section 303 of the Clean Water 

Act. Nothing in the Rapanos decision or the Guidance applies to section 303. 

The Department agrees that the proposed surface water quality standards are intended to apply to surface 

waters or waters of the United States. However, the Department disagrees that it should modify the current 

definition of surface water in response to the Rapanos decision and does not believe it is necessary to revise the 

definition of surface water to provide that a surface water is a navigable water. The term navigable water is 

defined in A.R.S. § 49-201(22). The current definition of surface water already states that it means a water of the 

United States, which defines navigable water under both state and federal law. 

The Department disagrees that language should be added to the definition of surface water to provide that 

the surface water quality standards apply “if and to the extent that each listed water or reach constitutes a surface 

water.” The suggested language is unnecessary because A.A.C. R18-11-102(A) already states that the water 

quality standards in 18 A.A.C. 11, Article 1 apply to surface waters. The listing of a water body in Appendix B of 

this rulemaking is a Department determination that the listed water body is a surface water as defined under 

A.A.C. R18-11-101(41). The water quality standards of 18 A.A.C. 11, Article 1 have applied to surface waters 

since 1992. No change has been made to the rule. 
103 

Comment #4

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

One of SMCFD’s primary concerns is based upon the U.S. Supreme Court’s ruling in Rapanos v. U.S., 126 

S.Ct. 2208 (2006). In Rapanos, the Supreme Court held that the jurisdictional term “navigable waters” under the 

CWA includes only relatively permanent, standing or flowing bodies of water, not intermittent or ephemeral flows 

of water lacking a significant nexus with waters of the United States. Although Rapanos involved consideration of 

the Army Corps of Engineers’ regulation of wetlands under section 404(a) of the CWA, the same definition of 

navigable waters applies to National Pollutant Discharge Elimination System (“NPDES”) permits under section 

402 of the CWA. See 33 U.S. §§ 1311(a), 1342(a), and 1362(7); see also A.R.S.§ 49-201(22) (“’Navigable 

waters’ means the water of the United States as defined by section 502(7) of the CWA.”). In addition, the Rapanos

decision makes clear that tributaries to waters of the United States that are not themselves waters of the United 

States, are viewed as “point sources” of discharge into waters of the United States only if the contaminant-laden 

waters in the tributary ultimately reach jurisdictional waters. Rapanos, 126 S.Ct. at 2228. 

Siphon Draw is not a Water of the United States

SMCFD operates a wastewater treatment plant that intermittently discharges treated wastewater (or 

“effluent”) to an unnamed wash that is tributary to “Siphon Draw.” A stretch of Siphon Draw is proposed in this 

rulemaking for listing as an “effluent-dependent water” simply because it receives drainage from SMCFD’s 

treatment plant. See Appendix B of the proposed rules. Siphon Draw is an ephemeral wash that historically 

drained precipitation from the Superstition Mountains. The historic drainage of Siphon Draw was significantly 

altered by the construction of the Central Arizona Project’s (“CAP’s”) canal, and intervening residential 

development and flood control structures. 

Historically, I understand ADEQ has taken the position that SMCFD’s discharge is jurisdictional because 

Siphon Draw is a tributary to Queen Creek, but this is incorrect. Siphon Draw was not historically, and is not 

today, a tributary of Queen Creek. See Exhibit C, January 16, 2001 letter from Tom Haws, P.E. to Ed Grabek. 

Even if we assume there were drainage patterns leading miles and miles from the SMCFD plant area to a 

navigable water (presumably the Gila River), which is not the case, the Rapanos decision makes clear that 

tributary status alone is not enough to invoke CWA jurisdiction – there must be proof that contaminant-laden 

waters ultimately reach covered waters. 

In the case of Siphon Draw, which even with development changes is at most a lengthy ephemeral wash, 

none of SMCFD’s discharges reach a water of the United States. Further, there is no evidence of a significant 

nexus of SMCFD’s discharge with any navigable water. 

Response: The Department received a number of comments concerning Clean Water Act (CWA) 

jurisdiction in the aftermath of the Rapanos decision. As noted in the comment, Rapanos was a plurality decision 

where the Supreme Court justices could not agree and as a result, issued five separate opinions, with no single 

opinion commanding a majority of the Court. Rapanos was a wetlands decision related to the provisions of section 

404, not the NPDES program under § 402 of the CWA. The Rapanos Guidance, which is not in rule, specifically 

states in footnote 17, that it “focuses only on those provisions of the agencies’ regulations at issue in Rapanos – 33 

CFR 328.3(a)(1), (a)(5), and (a)(7),” which are the federal regulations for the 404 permitting program 
104 

administered by the Army Corps of Engineers. Furthermore when EPA commented on this rulemaking, it did not 

note any concerns with jurisdiction issues. Irrespective of the Rapanos decision there are other factors of 

importance in Clean Water Act jurisdiction determination including a history of federal Clean Water Act case law 

that was not affected by Rapanos, including the tributary rule, commerce clauses, and interstate waters provisions. 

The Department appreciates that this is an important matter to stakeholders, as it is to the Department. In specific 

response to this comment, the Department does not concur that Siphon Draw has been removed from jurisdiction 

under the Clean Water Act. 

Under the tributary rule, R18-11-105, all ephemeral tributaries have applicable surface water quality 

standards and are subject to section 402 permitting requirements for point source dischargers. Under R18-11-113, 

the Director shall classify a surface water as an effluent-dependent water by rule, which the Department is doing 

with this rulemaking. R18-11-113(E) requires the Department to use A&Wedw standards for a point source 

discharge of wastewater to an ephemeral water. Superstition Mountains Community Facilities District (SMCFD) 

has an individual AZPDES permit that authorizes the discharge of 2.1 million gallons per day (mgd) of treated 

effluent to Siphon Draw. That permit is written to be protective of aquatic life and body contact uses. While 

SMCFD can direct discharges to underground storage basins, there is nothing restricting the District from 

discharging the full 2.1 mgd, 365 days a year to Siphon Draw. The SMCFD discharge has an effluent-dependent 

ecosystem. 

The Department disagrees with the commenter on the issue of Siphon Draw. The Department considers 

ephemeral waters to be surface waters as defined under R18-11-101(41). Siphon Draw is being classified as an 

effluent-dependent water and is listed in Appendix B in this rulemaking because it meets the definition of effluentdependent water. The identified reach of Siphon Draw that the Department proposes to classify as an effluentdependent water is from the SMCFD WWTP outfall to a location that is approximately 6 km downstream from the 

outfall. 

Comment #5

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

We understand from comments made at a previous stakeholder meeting that ADEQ believes it has authority 

under A.R.S. section 49-221(B) to expand the jurisdiction of the AZPDES program to apply to state waters that 

are not jurisdictional under the federal CWA. However, ADEQ also suggested that it does not intend to exercise 

this authority. ADEQ’s non-specific authority to create water quality standards for “waters of the State” in 49-

221(B), and even its specific authority to require persons otherwise covered by permit programs to conduct 

monitoring in state waters [see A.R.S. § 49-203(B)(2)], is not accompanied by any specific authority to implement 

those standards, and interpretation of section 49-221(B) in the manner suggested contravenes the limitations on 

ADEQ’s powers in section 49-203(A)(2) (permit program can be no more stringent that the requirements of the 

CWA). See also A.R.S. § 49-202 (section provides no specific authority to control discharges to state waters); 

A.R.S. § 49-231 (TMDL authorizing statutes define “surface water quality standard” to include only standards 

adopted for navigable waters); and A.R.S. § 49-201(41) (definition of “waters of the state”). Since it does not 

appear the Department can include waters of the state in the AZPDES program rules and permit, and since the 
105 

Department does not intend to exercise that jurisdiction anyway, then it is critical the Department conform its 

surface water quality rules to recognize only that jurisdiction permitted under the CWA for “navigable waters.” In 

SMCFD’s case, this will require that ADEQ amend the proposed Appendix B to remove Siphon Draw. 

Response: The Department disagrees that Siphon Draw should be removed from Appendix B for the 

reasons outlined in Response #4. The Department adopted the surface water quality standards in 18 A.A.C 11, 

Article 1 under the statutory authorities provided at A.R.S. §§ 49-221(A) and 49-222. These statutes provide 

authority for the Department to adopt water quality standards for navigable waters or waters of the United States 

as defined by the Clean Water Act. For nearly 30 years, the Department has considered, based on the Clean Water 

Act, its regulations and applicable law, tributary ephemeral and intermittent waters to be waters of the United 

States and thus navigable waters. The Department has adopted surface water quality standards for both categories 

of surface water. The Arizona Legislature considers ephemeral waters and intermittent waters to be navigable 

waters. The Legislature has specifically directed the Department to consider the effect of local water quality 

characteristics “...and the extent to which the natural flow of the stream is intermittent or ephemeral” when setting 

numeric standards for the quality of navigable waters. (A.R.S. § 49-221(C)). 

Comment #6

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

The Arizona Legislature in A.R.S. § 49-255.01(B) authorized the Department to promulgate rules for the 

AZPDES program consistent with the CWA, but the same provision prohibits the Department from adopting 

requirements more stringent than the CWA. If the Department applies AZPDES permit requirements to waters 

other than navigable waters as interpreted by the Supreme Court in Rapanos, then the Department is applying 

more stringent requirements than the CWA in violation of the prohibition in 49-255.01(B). The definition of 

“surface water” greatly exceeds the jurisdiction recognized in Rapanos, and exceeds the Department’s rulemaking 

mandate in A.R.S. § 49-255.01(B). 

Response: The Department disagrees with the commenter’s interpretation of the requirements of A.R.S. § 

49-255.01 or that the Department is violating its requirements by adopting the surface water quality standards in 

this rulemaking. A.R.S. § 49-255.01 governs the adoption of rules for the administration of the AZPDES permit 

program and does not apply to the adoption of the surface water quality standards rules that are the subject of this 

rulemaking. It is clear that A.R.S. § 49-255.01(B) prohibits the Department from adopting any AZPDES permit 

program rules that are more stringent or conflict with any requirement of the Clean Water Act. A.R.S. § 49-255.01 

does not apply to the adoption of surface water quality standards. See Response #5. 

 

Comment #7

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The proposed revisions to Arizona’s SWQS raise several substantial jurisdictional and other related issues. 

For example, notwithstanding recent U.S. Supreme Court decisions directly affecting the validity of the federal 

regulatory definition of “waters of the United States,” ADEQ nevertheless continues to use an expanded version 

of this regulatory definition to define the waters subject to the state’s SWQS. ADEQ continues to use this 
106 

expanded definition notwithstanding the statutory provisions in A.R.S. §§ 49-221(A) and 49-222 (giving ADEQ 

authority to adopt standards for “navigable waters”), in A.R.S. § 49-255.01(B) (prohibiting ADEQ from adopting 

any requirement associated with the AZPDES permit program that is more stringent than or conflicts with any 

requirement of the federal CWA), and in A.R.S. § 49-201(22) (defining “navigable waters” as “the waters of the 

United States as defined by section 502(7) of the Clean Water Cct (33 United States Code section 1362(7)).”). 

Jim F. DuBois, City of Tucson – Department of Transportation

This definition of surface water encompasses more than the waters governed by the CWA, i.e., navigable 

waters or waters of the U.S. 

Claire L. Zucker, Pima Association of Governments (PAG)

The definition for surface water should be consistent with federal definitions under the CWA. The 

definition in the rule for “surface water” includes as a Water of the U.S., all other waters such as rivers streams 

(intermittent or ephemeral), creeks, wash, draw etc. where the degradation or destruction of which could affect 

interstate or foreign commerce. It also includes all tributaries of these waters.

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ’s proposed definition of “surface waters” is inconsistent with the Rapanos decision because it goes 

beyond the scope of the CWA and therefore under Arizona law is beyond the statutory authority of ADEQ and 

must be revised (A.R.S. § 41-1052(C)(5)). ADEQ continues to use this expanded definition notwithstanding the 

statutory directives provided in A.R.S. §§ 49-221(A) and 49-222 (giving ADEQ authority to adopt standards for 

“navigable waters”), in A.R.S. § 49-255.01(B) (prohibiting ADEQ from adopting any requirement associated with 

the AZPDES permit program that is more stringent than or conflicts with any requirement of the federal CWA), 

and in A.R.S. § 49-201(22) (defining “navigable waters” as “the waters of the United States as defined by section 

502(7) of the CWA (33 United States Code section 1362(7)).”). ADEQ must revise its definition to apply only to 

those waters that are in fact “navigable waters” defined as “waters of the United States” within the CWA. 

In light of ADEQ’s failure to address these issues in this proposed rulemaking and the fact that a proper 

assessment of these issues by ADEQ would involve a significant amount of additional research and discussion 

with stakeholders, Pima County recommends that ADEQ withdraw those provisions of the rulemaking at this 

time. 

Response: The Department did not propose any substantive revisions to the definition of surface water in 

this rulemaking and disagrees that it is using an expanded regulatory definition of surface water to define water 

bodies subject to regulation under the surface water quality standards rules. On the contrary, the Department 

proposes to use the same definition for surface water that it has used since 1992. The Department’s decision not to 

revise the current definition of surface water is inaccurately characterized by the commenter as an expansion of 

the current regulatory definition. In fact, there has been no expansion of the regulatory definition of surface water 

and the agency’s interpretation of the definition remains the same. See Responses #5 and #6. The Department 

proposed only minor editorial revisions to the definition of surface water to conform internal cross-references and 

the rule numbering within the definition. The current definition of surface water at R18-11-101(41) is based on, 

and consistent with, the regulatory definition of water of the United States that may be found in current EPA 

NPDES regulations at 40 CFR §122.2. See Responses #3, #4, and #5. 
107 

Comment #8

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The recent 9th Circuit Court of Appeals decision in Friends of Pinto Creek v. EPA, 504 F.3d 1007 (9th Cir. 

2007) has potentially significant implications for the regulated community in Arizona, including municipalities, 

industrial dischargers, and construction and development companies. Under the court’s reasoning, new 

dischargers cannot be permitted unless and until they have demonstrated sufficient loading capacity for the 

constituent at issue and have developed compliance schedules designed to bring the waterbody into compliance 

with SWQS. The court further clarified its opinion that establishing a TMDL alone does not satisfy the 

requirement to demonstrate loading capacity. The result of this decision, assuming it is not overturned, is that it 

likely could ban new potential discharges to impaired waters, regardless of the nature of such discharges. The 

implications of the Friends of Pinto Creek case call for caution in proposing rules which could expand listings of 

impaired waters, particularly those noted below in this section. 

Response: See Responses #3, #4, 5, and #7 regarding the comments on jurisdictional issues. These rules 

will not, by definition, “expand listings of impaired waters.” Discussion of impaired waters listings and related 

permitting implications is beyond the scope of this rulemaking and is more appropriately raised in the context of 

the Impaired Water Identification rules at 18 A.A.C. 11, Article 6 or the AZPDES Program rules at 18 A.A.C. 9, 

Article 9. 

Comment #9

Claire L. Zucker, Pima Association of Governments (PAG)

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Many surface waters impacted by this rulemaking are excluded from CWA authority under Solid Waste 

Agency of Northern Cook County v. United States Corps of Engineers, 531 US 159 (2001) (“SWANCC”). In 

SWANCC, the Court held that non-navigable, intrastate and isolated (i.e., not adjacent to open water) waters are 

not “navigable waters” for CWA purposes, even though those ponds were arguably connected to interstate 

commerce. 531 U.S. at 168. Many urban lakes, and many surface waters, such as waters located within the closed 

Willcox Playa basin, qualify as isolated, non-navigable, intrastate waters, and thus should be non-jurisdictional in 

accordance with SWANCC. Importantly, the District of the District of Columbia recently interpreted a federal 

regulation defining “waters of the United States” which is even more limited than ADEQ’s proposed definition of 

“surface water” as an overly expansive interpretation of the applicability of the CWA. See American Petroleum 

Institute et al. v. Johnson, 2008 WL 834435 (D.C.Cir. 2008). The decision in Johnson emphasized the ruling in 

SWANCC – that the CWA does not extend to the full extent of Congress’ powers under the Commerce Clause of 

the U.S. Constitution, and thus a water may not be regulated under the CWA based only on its connection to 

interstate commerce. 

ADEQ’s proposed definition of “surface waters” is inconsistent with Rapanos and SWANCC, because it 

expands on the jurisdictional scope of regulations which those cases limited. ADEQ, to be consistent with law and 

not exceed its statutory authority, must refrain from establishing designated uses, SWQS or otherwise regulating 
108 

those waters which are either (i) not relatively permanent tributaries to traditional navigable waters or navigable 

waters; (ii) wetlands which do not directly abut traditional navigable waters; or (iii) waters which are nonnavigable, intrastate and isolated. ADEQ therefore should revise its definition of “surface water” proposed as 

R18-11-101(41), to apply only to navigable waters, defined as “waters of the United States” under the CWA. In 

the alternative, the Coalition requests that ADEQ explain its basis for asserting CWA jurisdiction over those 

waters affected by this rulemaking and remove the terms “ephemeral stream” and “wash” from its definition to be 

consistent with the federal regulatory definition, and remove all isolated urban lakes and all other isolated waters, 

including for example all surface waters in the closed Willcox Playa basin from regulation under this proposed 

rule. These suggested revisions would allow ADEQ to avoid extending its regulatory authority over waters 

deemed non-jurisdictional in light of Rapanos and SWANCC, and thus avoid violation of its obligations under 

A.R.S. § 41-1052(C)(5) to ensure that this rulemaking complies with applicable law and does not exceed its 

statutory authority.

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ is only authorized to adopt water quality standards for navigable waters. Given the jurisdictional 

uncertainty and other implications of the proposed revisions to Arizona’s SWQS, ADEQ should consider 

postponing portions of the proposed SWQS rule pending resolution and further discussions on these key issues. 

Matthew Oller, Flood Control District of Maricopa County

The District also adopts the Water Quality Coalition comments on the jurisdictional uncertainty after the 

Rapanos decision as it is unclear what Waters of the U.S. are. 

Robert S. Lynch, Irrigation & Electrical Districts Association of Arizona

The current definition of “surface water” in R18-11-101(41) does not comply with either the SWANNC or 

Rapanos decisions of the United State Supreme Court. The definition needs some clarification and revision for it 

to be consistent with this applicable case law. 

Response: The Department disagrees with the suggested changes to the rule and refers readers to 

Responses #3, #4, #5, #7, and #8, which deal with jurisdiction, surface waters, and case law. Both effluentdependent waters and ephemeral waters are included in Arizona’s definition of “surface water,” both have 

designated uses and numeric and narrative criteria developed to protect their designated uses and EPA has 

approved the Department’s water quality standards. These waters are subject to Clean Water Act section 305(b) 

assessments, 303(d) listing, and 402 permitting requirements. The Rapanos decision has limited applicability, and 

does not apply to the state’s adoption of surface water quality standards. 

R18-11-101. DEFINITIONS

R18-11-101(5) and- (8); Aquatic and wildlife (cold water) (A&Wc); Aquatic and wildlife (warm water) (A&Ww)

Comment #10

Sandy Bahr, Sierra Club  Grand Canyon Chapter

While we support the overall definitions of aquatic and wildlife (cold water) and aquatic and wildlife 
109 

(warm water), we remain concerned about using the 5000 foot elevation as an absolute cut off to distinguish 

these uses. As our comments indicated in the last Triennial Review, we recommend that the ADEQ also 

consider other mitigating factors, such as whether or not there is significant shading of a particular stream, 

water temperatures, and whether or not there is a cold-water macroinvertebrate community present. Under 

certain conditions, a lower elevation stream may support a cold water aquatic community. For example, our 

members have noted the presence of trout in Spring Creek, a tributary of Tonto Creek, at an elevation of 4200 

feet. A warm-water designation for this creek and others similar to it would be inappropriate. For those reasons, 

we again recommend some greater flexibility in these definitions. 

Response: The use of the 5000 foot elevation for applying the A&Ww and A&Wc designated uses was 

adopted in 2002. The 5000 foot elevation is applied as a general “rule of thumb” for the appropriate designation of 

the A&Wc and A&Ww uses. The Department agrees that there may be some exceptions to the use of the 5000 

foot elevation contour, which is why the Department used the phrase “generally occurring” in both definitions of 

the A&Wc and A&Ww designated uses. The Department believes the use of the phase, “generally occurring” in 

the definitions provides the needed flexibility to make appropriate use designations. For example, the Department 

adopted the A&Wc designated use for the Colorado River below Glen Canyon Dam even though it is at an 

elevation of approximately 3000 feet because it receives cold water discharged from Glen Canyon Dam and Lake 

Powell. 

Macroinvertebrates found in streams across Arizona contain cold water and warm water bioindicator 

species. The distribution of macroinvertebrate species and presence of cold water taxa in streams at various 

elevations led to the general conclusion that most cold water bioindicator species are found in streams at 

elevations greater than 5000 feet (Spindler, 1996). 

R18-11-101(5) - (8); Aquatic and wildlife (cold water) (A&Wc), Aquatic and wildlife (effluent-dependent water) 

(A&Wedw), Aquatic and wildlife (ephemeral) (A&We), Aquatic and wildlife (warm water) (A&Ww) 

Comment #11

Robert Hollander, City of Phoenix

The Water Services Department requests that the existing definitions be retained. The proposed definitions 

imply uses that may be put to the waters as the result of a single species. Section 5 of the Preamble on page 1283 

indicates, among other things, that “The Department may consider ... 2. The varying sensitivities of local affected 

aquatic populations to these pollutants;” [emphasis added]. Therefore, the designated use should be based on 

“aquatic populations” not a single species and that the species should be “local.” The existing definitions better 

articulate this requirement.

Response: The Department did not intend to substantively change the existing rule. The change had been 

proposed to conform to rule writing conventions. The Department agrees with the commenter and the Department 

will use the plural form rather than the singular form for “animal, plant, or other warm-water organism” in R18-

11-101(5) through (8): 

5. “Aquatic and wildlife (cold water) (A&Wc)” means the use of a surface water by animals, 

plants, or other cold-water organisms, generally occurring at elevations an elevation
110 

greater than 5000 feet, for habitation, growth, or propagation. 

6. “Aquatic and wildlife (effluent-dependent water) (A&Wedw)” means the use of an effluentdependent water by animals, plants, or organisms for habitation, growth, or propagation. 

7. “Aquatic and wildlife (ephemeral water) (A&We)” means the use of an ephemeral water 

by animals, plants, or organisms , excluding fish, for habitation, growth, or propagation. 

8. “Aquatic and wildlife (warm water) (A&Ww)” means the use of a surface water by 

animals, plants, or other warm-water organisms, generally occurring at elevations an 

elevation less than 5000 feet, for habitation, growth, or propagation. 

R18-11-101(6) & (7); Aquatic and wildlife (effluent-dependent water) (A&Wedw) and Aquatic and wildlife 

(ephemeral) (A&We) 

Comment #12

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

The definitions of “aquatic and wildlife (effluent-dependent water)” and “aquatic and wildlife (ephemeral)” 

are the same, except (1) one use is described as an “effluent-dependent water” and one is described as an 

“ephemeral water” and (2) the ephemeral definition specifically excludes fish. If an effluent-dependent water (as 

that term is defined in the current proposed rules) has insufficient volume and flow to sustain fish, does ADEQ 

intend to apply the aquatic and wildlife (effluent-dependent water) use to that water? If so, why? 

Response: The definitions of “aquatic and wildlife (ephemeral)” and “aquatic and wildlife (effluentdependent water”) designated uses are expressed in general terms that are intended to convey the idea that the two 

designated uses are established to maintain and protect water quality for the animals, plants, and other organisms 

that inhabit or could inhabit effluent-dependent waters and ephemeral waters. The definition of “aquatic and 

wildlife (effluent-dependent water)” does not include a reference to “fish” and the presence of fish is not 

necessary for the Department to classify a water body as an effluent-dependent water. The Department has 

adopted the aquatic and wildlife (effluent-dependent water) designated use for EDWs that have fish and those that 

do not. However, all EDWs have animals, plants, and other organisms that deserve water quality protection 

through the adoption of appropriate water quality standards. 

The commenter points out that the definition of “aquatic and wildlife (ephemeral)” includes the phrase, 

“excluding fish.” This phrase was included when the designated use was originally adopted in 1992 and is not 

changed in this rulemaking. The Department had included language in an attempt to clarify that the “aquatic and 

wildlife (ephemeral)” designated use was not intended to protect fish. The “excluding fish” language was intended 

to convey that the method and the toxicity datasets that the Department used to derive the numeric water quality 

criteria for the A&We designated use did not include fish species. 

R18-11-101(14); Deep lake 

Comment #13

Claire L. Zucker, Pima Association of Governments (PAG)

A deep lake is defined as a lake or reservoir with an average depth of over 6 meters, whereas a shallow lake 
111 

is defined as a lake or reservoir with an average depth of less than 3 meters. There is no definition for a lake with 

depths between that of a shallow and deep lake. 

Response: A lake that is neither “deep” nor “shallow,” nor located within an urban context, according to 

the definitions, will default to either “igneous” or “sedimentary” depending upon which geology and/or soils 

predominates. See Response #77. 

R18-11-101(17); Effluent-dependent water (EDW) 

Comment #14

Sydney Hay, Arizona Mining Association

The proposed revisions to the definition of “effluent-dependent water” (A.A.C. R18-11-101(17)) would 

delete the term "treated" before "wastewater," which is itself an undefined term. 

Response: The commenter is correct that the term “wastewater” is not a defined term in R18-11-101. Since 

it is not specifically defined in the surface water quality rules, it should be given its commonly understood 

meaning. Wastewater includes water that has been used for washing, flushing, or in a manufacturing process, and 

so contains waste materials, dissolved or suspended matter or other pollutants. Whether treated or not, wastewater 

discharges contain pollutants and must meet appropriate and protective water quality standards. 

Comment #15

Claire L. Zucker, Pima Association of Governments (PAG)

ADEQ removed the term treated as a modifier of wastewater in the definition for an effluent dependant 

water (EDW). Removing this term makes industrial discharges subject to Aquatic and Wildlife effluent dependant 

water (A&W edw) standards. The A&W edw water quality standards are specifically created for application to 

treated wastewater discharges, and may not be appropriate or intended for application to various industrial 

discharges. PAG asks if public outreach was conducted to inform industrial dischargers and to give them an 

opportunity to comment on the proposed regulations. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition:

ADEQ proposes to define an “effluent-dependent water” (“EDW”) as “a surface water, classified under 

R18-11-113, that consists of a point source discharge of wastewater. An effluent-dependent water is a surface 

water that, without the point source discharge of wastewater, would be an ephemeral water.” Proposed R18-11-

101(17). The proposed revision removes the word “treated” as a modifier of the word “wastewater” from the 

current EDW definition. This revision would effectively allow an ephemeral water which receives any discharge 

other than stormwater to be treated as an EDW. But ADEQ provides no explanation as to why such a “level 

playing field” is desirable or sensible. Effluent from a WWTP is quite different from many, if not most, industrial 

discharges. Effluent from a wastewater treatment plant is treated differently under the current EDW definition 

because it is different. Indeed, EDW criteria are based on assumptions of discharges from WWTPs. 

Response: The Department does not agree that the A&Wedw standards are “specifically created” to apply 

to domestic wastewater discharges. More accurately, these standards were created to be protective of aquatic life 

in intermittently or perennially wet environments. The term ‘treated’ was likely included because the vast majority 
112 

of dischargers under AZPDES permits are publicly owned treatment works (POTWs) or domestic wastewater 

treatment plants that are not allowed to discharge untreated wastewater. However, in applying the rule in permits, 

it is clear that some facilities may discharge water that is not sufficiently protective into waterbodies simply 

because of an artificial regulatory distinction. The purpose of having a surface water quality standards is to protect 

the waterbody for designated uses. This level of protection should not change depending on the source of the 

wastewater; either the standard is met or it is not. If water is supplied in any consistent basis in a desert 

environment, aquatic (and non-aquatic) life will use this critical resource. A discharge needs to be of adequate 

quality to protect that life and promote a healthy aquatic community. The term “treated” has been removed 

throughout the rulemaking. This revision will correct this inequity and will protect aquatic environments that 

should exist in waterbodies regardless of the source of the wastewater. 

Under the current rule, an effluent-dependent water may be created by the discharge of treated wastewater 

from a municipal or domestic wastewater treatment plant or by the discharge of treated wastewater from an 

industrial facility to an ephemeral water. The Department interprets both the current and the proposed definitions 

of “effluent-dependent water” as applying to point source discharges of wastewater from both sewage treatment 

plants and industrial facilities. 

Public notice and opportunity to comment on this issue was provided to the regulated community through 

the publication of the Notice of Proposed Rulemaking. The Department received numerous comments specifically 

addressing proposed revisions to the definition of effluent-dependent water from several persons representing 

industrial dischargers, including the Salt River Project and the Surface Water Quality Standards Coalition 

(representing over 5000 members of the Arizona Chamber of Commerce and Industry and the Greater Phoenix 

Chamber of Commerce). 

Comment #16

Jim F. DuBois, City of Tucson – Department of Transportation

The proposed definition drops “treated” as an adjective for “wastewater.” ADEQ states in their explanation 

of the rule that their intent is to expand the EDW approach to regulate industrial discharges in addition to treated 

domestic and municipal wastewater. The City of Tucson believes that ADEQ should continue with its traditional 

approach of using EDW provisions only for discharge of treated domestic and municipal wastewater effluent. 

Since “wastewater” is an undefined term and could be viewed as virtually any point source discharge, many 

surface waters become eligible to be regulated as EDWs under the proposed rule. Such an approach could, in 

effect, characterize many of the “receiving waters” of stormwater MS4s from ephemeral to EDW, merely by the 

presence of industrial, DeMinimus, or other types of point sources. If an MS4’s “receiving water” becomes 

regulated as an EDW, the standards used to assess BMP performance would change. While it doesn’t appear to be 

the intent of the rule to apply EDW standards generally to stormwater discharges, the rule could be applied in that 

manner. 

Claire L. Zucker, Pima Association of Governments (PAG)

The definition provided in the rule does not specify how much effluent, or for how long effluent is 

discharged before the stream reach is considered to be an EDW. Therefore, any amount of discharge could trigger 
113 

A&W edw water standards. The mere presence of an AZPDES industrial discharge on an ephemeral water body 

could be used by ADEQ to require all dischargers to that water body to comply with A&Wedw standards. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ failed to appropriately evaluate the application of these proposed rules to storm water discharges. It 

is generally recognized by the aquatic scientific community that storm water runoff events create a substantially 

unique eco-system in receiving waters in the arid West. The standards that have been developed for non arid West 

aquatic eco-systems may well be inappropriate during arid West storm water events. ADEQ should have, in this 

Triennial Review, rationally evaluated the appropriateness of applying these Standards to storm water discharges. 

Response: See Response #15 regarding deletion of the term “treated” from the definition. The changes 

proposed in R18-11-113 relating to the application of EDW standards to point source discharges of wastewater 

were not intended to encompass stormwater discharges or de minimus discharges. Stormwater flows are shortterm and in response only to precipitation events; this is consistent with the definition of ephemeral flow. This 

would cover certain ‘other allowable’ discharges that are permitted under the construction and the multi-sector 

general permit for stormwater. Likewise due to the unique nature of discharges authorized under the De Minimus 

General Permit (AZG2004-001) there may be instances where the use of ephemeral standards may continue to be 

adequate, and in response to comments to retain flexibility for this limited class. The following language has been 

added to R18-11-101 to clarify the Department’s original intent: 

48. “Wastewater” does not mean:

1. Stormwater;

2. Discharges authorized under the De Minimus General Permit;

3. Other allowable non-stormwater discharges permitted under the Construction General 

Permit or the Multi-sector General Permit; or

4. Stormwater discharges from a municipal storm sewer system (MS4) containing incidental 

amounts of non-stormwater that the MS4 is not required to prohibit.

Ephemeral waters that flow only in direct response to precipitation because they receive point source 

discharges of stormwater regulated under a MS4 permit are ephemeral waters as defined in R18-11-101(18) and 

the A&W(ephemeral) standards apply. The formal reclassification of an ephemeral water to an EDW that will 

affect an MS4 permit, will be done through rulemaking. Until or unless reclassified, those streams remain 

ephemeral for purposes of the MS4 program. The rule language has been revised to cover incidental amounts of 

other discharges that the MS4 is not required to prohibit in its illicit discharge detection and elimination program 

under 40 CFR 122.26(d)(2(iv)(B)(1). These include, but are not limited to, air conditioning condensate, foundation 

or footing drains not contaminated with process materials, irrigation, and street wash water. 

The commenter correctly notes that the MS4 permits tie assessment of BMP performance to the surface 

water quality standards and designated uses of the waters receiving the stormwater discharges. However, R18-11-

113(D) relates to the standard of protection for which individual discharge permits will be written and does not 

constitute a formal change in designation of a waterbody. Discharges of wastewater to an ephemeral wash may be 

required to meet EDW standards in permit limits, but the wash remains ephemeral until changed by rulemaking. 

An MS4 discharging stormwater to such a wash would only be responsible for evaluating discharges with respect 
114 

to ephemeral standards unless and until the receiving water is otherwise designated by rule. 

The Department does not have sufficient data to support the adoption of “wet-weather” standards that 

would apply to Arizona surface waters only during stormwater runoff events. Given the unavailability of wet 

weather standards, the default water quality standards apply to Arizona surface waters during storm events. 

AZPDES permitting staff will continue to work with all the MS4 permittees to develop renewal permits and work 

with the regulated community to clarify rules that are protective of the environment and reflective of local 

conditions. 

Comment #17

Kevin Wanttaja, Salt River Project

SRP is submitting comments regarding the proposed change to the definition of effluent-dependent water 

(EDW) and how implementation of the EDW rule under R18-11-113 will adversely impact SRP’s facilities. 

ADEQ proposes to define an effluent-dependent water (EDW) as “a surface water, classified under R18-

11-113, that consists of a point source discharge of wastewater. An effluent-dependent water is a surface water 

that, without the point source discharge of wastewater, would be an ephemeral water.” The proposed revision 

removes the word “treated” from the current EDW definition so that any industrial discharge to an ephemeral 

water, except stormwater, would be reclassified as a discharge to an effluent-dependent water. In the rulemaking 

preamble, ADEQ provides an example of how the revised definition would be applied. 

In each example, ADEQ identifies untreated cooling water from a power plant; untreated cooling water; 

and wastewater from a power plant as the regulatory triggers that would require the receiving water’s designated 

use to be reclassified from ephemeral to EDW. No other industries are specifically named in the proposed 

rulemaking. 

In reviewing a list of 181 Major/Minor AZPDES permits currently in service, only 6 permits were issued to 

steam-electric facilities (< 4% of the total). Of the 6 permits, SRP identified only 2 that currently discharge to an 

ephemeral water body: SRP’s Kyrene Unit K7 and Santan generating stations. Yet, ADEQ justifies the proposed 

rulemaking by stating, “changes in this rule making also level the playing field between businesses and 

municipalities that are point source dischargers.”

Furthermore, ADEQ states, “With this change, an industrial facility will be held to the same water quality 

requirements as the municipal discharger to the same waterbody.”

Municipal dischargers are different than other discharges. The initial EDW definition and rule were created 

because municipal effluents typically contain higher concentrations of conventional and non-conventional 

pollutants than other dischargers. (Conventional pollutants include biological oxygen demand, total suspended 

solids, fecal coliform, pH and oil and grease. Non-conventional pollutants include toxicity, chemical oxygen 

demand, metals and organic compounds not on the priority pollutant list, radioactivity and color.) Municipal 

effluents are also known to contain higher concentrations of ammonia, phosphate and often-times measurable 

concentrations of endocrine disruptors, pharmaceuticals, polybrominated diphenyl ethers (PBDE) and 

perfluorinaated acids (PFAs) — chemicals which are not commonly found in steam-electric effluents. 
115 

In comparison, permitted steam-electric facilities are required to meet stringent discharge requirements for 

pH, free available chlorine, total chromium and zinc and must be free from any of the 126 priority pollutants. 

ADEQ provides no other justification in the preamble for re-defining the EDW definition or R18-11-113 

rule change. Nor has ADEQ published the location of the administrative record or technical support document that 

provides the foundation or basis to support the proposed rulemaking 

If the proposed EDW definition and EDW rule is promulgated, and A&Wedw criteria applied, SRP’s 

Kyrene Unit K7 and Santan generating stations may lose their ability to discharge. If these facilities cannot 

discharge, they can not generate electrical energy needed by SRP’s 920,000 customers. This critical issue is not 

discussed anywhere in the rulemaking especially in the section titled, “The preliminary summary of the economic, 

small business, and consumer impact.”

For these reasons, SRP again requests ADEQ to postpone the proposed changes and continue to implement 

the EDW definition and rule promulgated on March 29, 2002. 

Response: See response #15. The effluent limitation guidelines (ELGs) referenced by the commenter, are 

industry standards promulgated by rule which in themselves, and are not necessarily protective of human health 

and aquatic life. For example, the ‘stringent’ ELGs for a steam electric power plant require pH to be between 6-9, 

similar to surface water quality standards; however, total chromium can be 200 ppm which is above all surface 

water quality standards, except possibly ephemeral standards depending on hardness and total to dissolved ratios; 

total zinc can be 1000 ppm which is above all aquatic and wildlife water quality standards except possibly 

ephemeral, depending on hardness and total to dissolved ratios; and Free Available Chlorine can range from 200-

500 ppm, which are levels that are toxic to aquatic life and significantly above total chlorine limits. The Clean 

Water Act requires permits to include discharge limits based on both ELGs and water quality standards, the lower 

of which drives discharge limits at the outfall. (40 CFR 122.44(d)) 

For qualifying dischargers, the rules provide for variances from certain standards if all provisions of R18-

11-122 are met. Another option would be the development of a use attainability analysis (UAA) to remove a 

designated use that is not an existing use, or to adopt a subcategory of a designated use if it can be demonstrated 

that the existing designated use can not be attained for one or more factors outlined in 40 CFR 131.10(g). These 

factors include controls that are more stringent than those required by § 301(b) and § 306 of the Clean Water Act 

are necessary to attain the use and that implementation of the controls would result in substantial and widespread 

economic and social impact. Considering all the options available to address SRP’s concerns, the Department 

anticipates that SRP will not be required to eliminate its discharge immediately, if at all, and will continue to 

provide reliable electricity to its customers from its Kyrene and San Tan generating stations. 

Comment #18

Claire L. Zucker, Pima Association of Governments (PAG)

In March 2004, the State issued a De Minimus General Permit (No. AZG2004-001), which permits 

discharge of pollutants associated with potable and reclaimed water systems. The permit also allows ADEQ to 

review and approve other case-by-case short-term and/or low volume discharges that are considered De Minimus. 

Under the currently proposed rule, all discharges of wastewater, including some of those clearly considered 
116 

acceptable under the De Minimus permit would trigger A&W edw water quality standards. Therefore the 

proposed rules appear to conflict with the intent of the De Minimus permit and language should be added to 

clarify that the De Minimus discharges do not invoke EDW status. 

PAG recommends leaving the word treated in the rule to avoid some of the complications stated above. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

This proposed revision of the EDW definition also runs counter to current and long-standing ADEQ 

permitting practices. For example, ADEQ currently makes available a De Minimis General Permit under its 

AZPDES program (Permit No. AZG2004-001) for de minimis discharges with low pollutant levels. Under the 

proposed EDW definition, such permitted discharges, no matter how insignificant in amount or environmental 

impact, would result in transforming a water otherwise classified as ephemeral into an EDW for SWQS and 

AZPDES permitting purposes. Permittees would have no incentive to seek de minimis permit authorization, 

because by so doing they would effectively convert their receiving water into an EDW under the proposed 

definition. 

Response: See Response #16. 

Comment #19

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

The definition of “effluent-dependent water” consists of a point source discharge of “wastewater.” It 

appears from ADEQ’s explanation of the use of the term “wastewater” that it is intended to apply to any liquid 

discharge, of any type, volume, and frequency. The definition fails to provide rational criteria distinguishing 

effluent-dependent waters from ephemeral waters at the point stream flow enters a water of the United States. 

Although ADEQ proposes to add flow criteria in rule section R18-11-113(E) that would authorize, but not require, 

ADEQ to apply acute effluent-dependent water standards to “sporadic, infrequent, or emergency point source 

discharges,” this new definition language in R18-11-101(17) fails to recognize that ephemeral waters receiving 

point source discharges may not, in fact, be “effluent-dependent” at the point they enter a water of the United 

States. 

Since the definition of “effluent-dependent water” is to be used by ADEQ to apply more stringent surface 

water quality standards to point source discharges to ephemeral waters because those waters with the addition of 

discharges gain characteristics of intermittent or perennial flows and may have little or no dilution at the point 

where they contribute to a water of the United States, this definition needs to provide criteria for volume, 

frequency, and dilution of flow at the point where the tributary joins a water of the United States. 

Response: The Department disagrees that the proposed definition of effluent-dependent water fails to 

provide rational criteria for distinguishing between effluent-dependent waters and ephemeral water, both of which 

are waters of the United States. The proposed definition provides a bright-line criterion that clearly distinguishes 

the two categories of surface water. The defining characteristic that distinguishes an EDW from an ephemeral 

water is the presence of a point source discharge of wastewater to an ephemeral water. 

The difference between ephemeral waters and effluent-dependent waters is best understood by reading the 

regulatory definitions of ephemeral water and effluent-dependent water together. A comparison highlights the 
117 

distinguishing characteristic between the two categories. Ephemeral waters and effluent-dependent waters are 

defined primarily by their flow characteristics. An ephemeral water is defined as a surface water that has a channel 

that is at all times above the water table (i.e., a normally dry watercourse such as a wash), and that flows only in 

direct response to precipitation (See R18-11-101(18)). By contrast, an effluent-dependent water is a normally dry 

watercourse that contains flow that is the result of a point source discharge of wastewater to the normally dry 

channel. The difference between the two types of surface water is the source of flow; i.e., the presence or absence 

of wastewater or effluent. Since the distinction between the two is based on hydrology, the Department disagrees 

that the definition of effluent-dependent water needs to provide criteria for a minimum volume of treated 

wastewater, a minimum frequency of discharge, or the availability of receiving water for dilution. 

Comment #20

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

A similar issue arises with respect to stormwater permitting. ADEQ has represented in stakeholder 

meetings that it will interpret the proposed EDW definition such that any ephemeral water receiving any 

discharge, other than stormwater, will be treated as an EDW for SWQS purposes. However, stormwater permits 

authorize certain non-stormwater discharges. For example, the current Small MS4 General Permit authorizes 

certain “occasional incidental non-stormwater discharges,” such as water line flushing, pumped groundwater, 

discharges from potable water sources, foundation drains, air conditioning condensate, and other discharges not 

identified as “significant contributors of pollutants.” (Permit No. AZG2002-002). Similarly, the Construction 

General permit allows for certain non-stormwater discharges, including discharges from firefighting activities, air 

conditioning or compressor condensate, and water used in drilling, coring or compacting soil. (Permit No. 

AZG2008-001). In light of the proposed EDW definition, it is unclear how such permitted non-stormwater 

discharges would be treated. 

The Coalition, in light of the above discussion offers a suggested definition: 

Effluent-dependent water” means a surface water that consists of discharges of treated 

wastewater that the Director determines create a significant aquatic ecosystem in terms of size and 

location that would otherwise not exist due to flows from precipitation events alone. An effluentdependent water is a surface water that, without the discharge of treated wastewater creating a 

significant aquatic ecosystem that would otherwise not exist due to flows from precipitation events alone, 

would be an ephemeral water. 

Response: The Department cannot support the Coalition’s recommended definition of effluent-dependent 

water (EDW) because it requires a subjective determination of the significance of an aquatic ecosystem created by 

the discharge of “treated” wastewater before the Department could designate a surface water as an EDW. A 

definition of EDW that relies on a determination of a “significant aquatic ecosystem” cannot be practically 

implemented. In the absence of clearly defined and objective significance tests, the determination of significance 

becomes little more than a subjective value judgment raising a danger of inconsistent decision-making when 

classifying EDWs. 

The Department has reviewed the comments regarding the incidental authorized discharges under several of 
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the general permits and individual MS4 permits and has modified the rule language in R18-11-113(D). See 

Response #16. 

Comment #21

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ should similarly revise R18-11-113(C) by either inserting the modifier “treated” before the term 

“wastewater,” or by defining the term “wastewater” in that section to mean effluent discharges from a WWTP. 

Additionally, ADEQ could simply replace the term “wastewater” in the proposed definition with the term 

“reclaimed water” as defined in A.R.S. § 49-201(31), which would make EDW regulation more consistent with 

Aquifer Protection Permit and reclaimed water use regulations. 

Response: The Department disagrees with the comment that the application of these standards should be 

only to municipal sewage plants. See Responses #15 and #16. 

The Department disagrees with the suggestion that the term “wastewater” be replaced with the term 

“reclaimed water.” Reclaimed water quality standards were not intended to be protective of surface water or 

aquatic and wildlife. In particular, reclaimed water often contains residual disinfection byproducts, such as 

chlorine and metals, which are toxic to aquatic life. 

Comment #22

J Adrianne Settimo

Substituting the term “wastewater” for “discharges of treated wastewater,” under R18-11-113, is too 

broad and fails to adequately protect surface water quality. The term “wastewater,” as stated by the ADEQ 

indicates that “untreated cooling water and other industrial process waters” and “discharges of municipal and 

domestic wastewater,” will be allowed to enter ephemeral waters, classifying them as effluent-dependent 

waters. See, R18-11-113. Making standards more flexible to allow untreated wastewater into ephemeral waters,

proposed rule at R18-11-113, only puts public health and welfare and “water quality for the protection and 

propagation of fish, shellfish and wildlife and for recreation in and on the water,” in jeopardy. Water Quality 

Standards, 40 C.F.R. § 131.2 (2007). Broadening the term allows waters possibly containing chemicals, 

including potential carcinogens and other pollutants to enter waterways. The proposed rule should not be 

adopted as it would potentially degrade the quality of water downstream of these ephemeral waters. 

Response: The comment suggests a misunderstanding of the rule proposal. Under the current regulations, 

untreated wastewaters may discharge and are being discharged into waters under ephemeral water quality 

standards that are not appropriate or protective for these discharges. The current regulations are flawed precisely 

because they allow more pollutants to be discharged and less protective standards to be met simply because they 

are untreated. This rulemaking rectifies this by regulating these discharges in the same manner as treated 

discharges — thus they would need to meet a higher level of protection under these new rules. See Response #17. 

In some cases, dischargers may have to treat their wastewater or find other disposal options besides discharge to a 

surface water. 

The proposed revisions are intended to clarify how A&Wedw standards are applied to any point source 
119 

discharges of wastewater (except stormwater) to ephemeral waters that create effluent-dependent waters. Point 

source discharges of “wastewater,” “treated wastewater,” “untreated cooling water,” and “other industrial process 

waters” to ephemeral waters, and to EDWs remain subject to regulation under the AZPDES permit program which 

controls the discharge of pollutants to Arizona’s surface waters. 

R18-11-101(20); Fish consumption 

Comment #23

Janet Hashimoto, Chief; EPA Monitoring & Assessment Office

The proposed rule would narrow the definition of Fish Consumption (FC) as a beneficial use (section R18-

11-101.20). The current FC definition broadly includes “harvesting aquatic organisms for consumption,” such as 

“fish, clams, turtles, crayfish, and frogs” whereas the proposed new definition would pertain strictly to fish. The 

FC definition affects which water bodies can qualify for protection under ADEQ standards for human 

consumption of aquatic organisms. By narrowing the definition, ADEQ would preclude determination of water 

body impairment on the basis of human consumption of pollutant-contaminated aquatic organisms other than fish. 

Even if ADEQ currently only relies on consumption of fish to designate water bodies for FC, the proposed 

rule does not provide a rationale as to why narrowing the definition is warranted. In the future, ADEQ or other 

interested parties may identify water bodies in which humans are consuming aquatic organisms other than fish. A 

broad definition of fish consumption is not without precedent in other areas; for example, several California 

Regional boards have established a commercial or sport fishing (CMM) beneficial use that pertains not only to 

fish but to shellfish and other organisms intended for human consumption or bait purposes. 

Response: The Department agrees. While fish are the only organisms that are currently being sampled in 

support of the fish consumption designated use, it is important to address the possibility that other aquatic 

organisms are being harvested and consumed or may be in the future. Except for the added acronym of the term, 

“fish consumption,” the original definition will remain unchanged. 

R18-11-101(24); Igneous lake 

Comment #24

Claire L. Zucker, Pima Association of Governments (PAG)

An igneous lake would be one that is floored by igneous geology and soils including volcanic or plutonic 

igneous materials. 

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

The definition in rule of “igneous lake” uses the criteria of “volcanic or basaltic,” whereas the guidance 

document says “volcanic/granitic lithology.” ADEQ shouldn’t use conflicting definitions and should get the 

geologic terms straight. If the important factor is the permeability of the rock beneath the lake, the rule should just 

distinguish between hard rock substrate and soft rock/alluvial substrate. 

Response: The Department agrees there is need for clarification and the definition has been revised as 

follows: 
120 

24. “Igneous lake” means a lake located in volcanic, basaltic, or granitic geology and soils.”

R18-11-101(28); Outstanding Arizona Water 

Comment #25

Claire L. Zucker, Pima Association of Governments (PAG)

The definition for “Outstanding Arizona Water” should match the previous definition of a Unique Water 

and be written as follows “Outstanding Arizona Water means a surface water that is classified as an outstanding 

state resource water by the Director under R18-11-112.” This clear definition removes any ambiguity about which 

waters are designated as OAW. By including some explanatory information in the definitions section, but not all 

of the information in R18-11-112, contradicting interpretations about what constitutes an OAW might be 

introduced. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ proposes to use the term “Outstanding Arizona Water” (“OAW”) in lieu of the term “unique water” 

in its proposed SWQS. This definition fails to address the most important characteristic of an OAW – that the 

water has been designated an OAW by ADEQ pursuant to the proposed R18-11-112. The criteria (a) – (c) in the 

proposed OAW definition are already adequately addressed under the OAW designation criteria in R18-11-112. 

The current definition suggests that a water could qualify as an OAW without being designated as such, which 

would eliminate essential public participation in making such designations. The OAW definition would also 

confuse permittees as to particular permit conditions that would apply only to OAWs, and give rise to potential 

conflicts with the language in R18-11-112. ADEQ should revise the definition of OAW to mean “a surface water 

that is classified as an outstanding state resource water by the Director under R18-11-112.” 

Sydney Hay, Arizona Mining Association

The AMA concurs with the Coalition's comment that the proposed new definition of outstanding Arizona 

water ("OAW") at A.A.C. R18-11-101(28) suggests that waters may qualify as OAWs even without being 

classified by rule, which is inconsistent with the text of A.A.C. R18-11-112(A). The AMA supports the Coalition's 

suggested revision to that definition. 

Response: The Department agrees that an OAW must be classified by the Director through formal 

rulemaking and has revised the definition of OAW as follows: 

28. “Outstanding Arizona Water (OAW)” means a surface water that is classified as an 

outstanding state resource water by the Director under R18-11-112.

Comment #26

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We are supportive of the name change for “Unique Water” to “Outstanding Arizona Water” as it does 

accurately describe the nature of the waters listed. 

Response: The Department appreciates the Sierra Club’s support for the Department’s proposed change in 

terminology from “unique water” to “Outstanding Arizona Water.” The Department agrees that it more accurately 

describes the nature of surface waters that are classified as outstanding state resource waters and the term is more 
121 

consistent with the terminology used in federal regulations to describe waters that are protected under Tier 3 of the 

federal antidegradation policy. 

R18-11-101(29); Partial-body contact (PBC) 

Comment #27

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We remain concerned about the Partial Body Contact designation and continue to support a Full Body 

Contact designation for all water bodies in which people recreate. Especially for children, there is no real 

practical difference between Partial and Full Body Contact. Our designated uses and standards should be set to 

protect the most vulnerable. 

To simplify the standards and to promote better understanding of the rule and better water quality 

overall, we suggest designating all of Arizona's surface water for full body contact (FBC) recreation use and to 

eliminate the partial body contact (PBC) designated use and standards, unless it is clear that children do not 

have access to the area. Because there is almost no difference between partial body contact and full body 

contact when it comes to children, we think the most protective standards possible should apply to all of these 

surface waters in order to adequately protect the health of young children. We would like the department to 

build in some kind of safety factor in determining these limits and would rather see it default to the higher 

standards. Unfortunately, most of the standards are established based on the average weight of a human adult 

male (70 kilograms).

Response: The Department did not make a substantive change to the definition of “partial body contact 

recreation” in this rulemaking nor did the Department adopt the full body contact designated use for all surface 

waters in Arizona where people may recreate. To derive PBC criteria, the methodology for non-carcinogenic 

pollutants was used. This results in few differences between the two sets of numeric water quality criteria for the 

two designated uses. 

The Department appreciates the commenter’s concerns but believes there is sufficient evidence that a PBC 

standard is warranted, especially in Arizona where many of our streams are intermittent or ephemeral and many 

urban lakes are managed for incidental contact. 

While the functional differences between full body contact and partial body contact have narrowed due to 

the adoption of more realistic exposure assumptions, the Department believes it is important to continue to 

differentiate between the two uses due to the influence of flow on the overall probability of exposure. For created 

waterbodies such as listed canals and most effluent-dependent streams, full body contact is not considered an 

appropriate use. In ephemeral waterbodies, the random and episodic nature of the flow precludes “chronic” 

consumption (small amounts over a long period of time) and severely limits the likelihood for carcinogenic 

exposure. It is only in perennial rivers, streams, and lakes that recreational full body contact is likely to occur. See 

Response #145 for more discussion on how standards are derived for these two designated uses. See Response 

#127 for discussion on safety factors in risk analysis. 

R18-11-101(31); Pollutant 
122 

Comment #28

Jim F. DuBois, City of Tucson – Department of Transportation

The ADEQ should not diverge from the statutory wording for this term [pollutant]. In doing so, it seems 

that “substances and chemicals” was dropped. The terms “other agricultural chemicals,” “munitions” and 

“petroleum products” are awkward when converted to the singular. ADEQ should consider deleting this definition 

and simply relying on the statutory definition of A.R.S. § 49-201(29). 

Response: The current definition mirrors statutory language. The Department has restated the current 

definition using italics and the statutory citation, following rule writing guidelines. No change has been made to 

the rule. 

R18-11-101(35); Regulated discharge; R18-11-107.01 

Comment #29

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Under proposed R18-11-101(35), ADEQ defines a “regulated discharge” triggering antidegradation review 

as a “point source discharge regulated under an AZPDES permit, a discharge regulated by a § 404 permit, and any 

discharge authorized by a federal permit or license that is subject to state water quality certification under § 401 of 

the CWA.” The proposed definition of “regulated discharge” violates the statutory restriction on ADEQ authority 

to impose more stringent requirements than the CWA and related federal regulations. See A.R.S. § 49-255.01(B). 

This definition is also inconsistent with EPA guidance entitled “Tier 2 Antidegradation Reviews and Significance 

Thresholds,” (August 10, 2005) (copy enclosed as Attachment A). The Coalition recommends that ADEQ revise 

this definition to be consistent with EPA’s approach – that only new or expanded point source discharges under 

AZPDES or new or expanded discharges under sections 401 and 404 of the CWA qualify as “regulated 

discharges” for purposes of antidegradation review. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ’s proposed antidegradation definition is inconsistent with Arizona law. 

The proposed definition of “regulated discharge” found at A.A.C. R18-11-101(35) is more restrictive than 

the CWA and therefore violates A.R.S. § 49-255.01(B) that limits ADEQ authority to those requirements found 

within the CWA. The proposed definition is also inconsistent with the EPA guidance entitled Tier 2 

Antidegradation Reviews and Significance Thresholds, August 10, 2005 (Attachment #10). Pima County requests 

that ADEQ revise its proposed definition to be consistent with EPA guidance which stipulates that only new or 

expanded point source discharges under AZPES or new or expanded discharges under sections 401 and 404 of the 

CWA qualify as “regulated discharges” for purposes of antidegradation review. 

David E McNeil, City of Tempe

ADEQ has indicated in stakeholder meetings that antidegradation review applies to all facility seeking 

permit coverage. Tempe is unaware of any other state that extends antidegradation review beyond new or 

expanded facilities and ADEQ has not clearly explained how antidegradation review would apply to existing 

facilities seeking permit renewal. The only suggestion made by ADEQ staff during the stakeholder process in 

response to questions regarding how and when antidegradation review would apply to existing facilities was that it 
123 

could be applied when standards were changed. Tempe is very concerned with the suggestion implying that if 

20% of assimilative capacity for a pollutant is consumed for a Tier 2 water body, and a standard becomes more 

stringent, that a discharger might be forced to completely redesign and rebuild a treatment facility in order to 

accommodate the reduction in assimilative capacity resulting from the standards change. There is no way for a 

municipality to anticipate all future changes in a standard when designing a treatment facility to meet current and 

future antidegradation requirements. Tempe requests a clear explanation of how and when antidegradation will be 

applied to existing facilities, and recommends limiting this rule to new, expanded, or reconstructed facilities. 

Sydney Hay, Arizona Mining Association

The AMA fully supports the Coalition comments on antidegradation, particularly the comment that 

antidegradation review should apply only to new or modified discharges (i.e., increased or new pollutant 

loadings), not to renewals of existing permits with no changes (or to aspects of an existing discharge that will not 

be changed). To the best of the AMA’s knowledge, that is how EPA and neighboring states implement 

antidegradation reviews. The AMA does not even understand how an antidegradation review of an existing 

discharge would be conducted, especially given that applicable standards likely would have changed over the life 

of the discharge (making analysis of assimilative capacity in the past a moving target). 

Response: The Department disagrees that the proposed definition of “regulated discharge” in the surface 

water quality standards rules violates any statutory restriction found in A.R.S. § 49-255.01(B). A.R.S. § 49-

255.01(B) does not apply to the adoption of the surface water quality standards rules under § 303(c) of the Clean 

Water Act (CWA). Rather, it applies to the Department adoption of rules regarding the AZPDES permit program. 

The Department disagrees that the proposed definition of “regulated discharge” is more stringent than, or 

conflicts with, any requirement of the Clean Water Act. There is nothing in the Clean Water Act that defines 

“regulated discharges” and the Department’s definition simply summarizes applicable CWA regulations. 

The Department has reviewed the comments and revisited EPA guidance document titled Tier 2 

Antidegradation Reviews and Significance Thresholds and has changed the rule to limit the Tier 2 antidegradation 

tier to “new or expanded” point source discharges. R18-11-107.01(B)(3) has been revised as follows to modify 

when the Tier 2 antidegradation review is triggered: 

3. Antidegradation review. Any person proposing a new or expanded regulated discharge 

under an individual AZPDES permit that causes significant degradation shall provide the 

Department with the following information:

R18-11-101(40); Significant degradation; R18-11-107.01(B)(2) 

Comment #30

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Additionally, ADEQ’s proposed definition of “significant degradation” under R18-11-101(40) ties the 

calculation of significant degradation of Tier 2 waters to the “critical flow conditions,” which is defined as “the 

lowest flow over seven consecutive days that has a probability of occurring once in 10 years.” This definition also 

provides that significant degradation includes (a) the consumption of 20 percent or more of the available 

assimilative capacity for a pollutant of concern at critical flow conditions, or (b) any consumption of assimilative 
124 

capacity beyond the cumulative cap of 50 percent of assimilative capacity. This language is redundant with, and 

arguably inconsistent with, the provision proposed in R18-11-107.01(B)(2) regarding significant degradation. The 

Coalition recommends that the definition of “significant degradation” be deleted or that ADEQ simply reference 

the language in R18-11-107.01(B)(2) as the definition. 

Response: The Department disagrees that the proposed definition of “significant degradation” should be 

deleted and that it is redundant or inconsistent with the provisions of A.A.C. R18-11-107.01(B)(2). The term 

“significant degradation” is an essential term used in the proposed antidegradation implementation rule at R18-11-

107.01. Since it is actually used in the rules relating to Tier 2 antidegradation implementation procedures, a 

definition is useful to help the regulated community and the general public read and understand the rules. The term 

“significant degradation” has a specific meaning outside the normal, common meanings of the words that make up 

the phrase. No change has been made. 

The Department agrees that “critical flow condition” is an important concept for significant degradation and 

has revised R18-11-107.01(B)(2) as follows: 

2. A regulated discharge that meets the following criteria, at critical flow conditions, does 

not cause significant degradation:

Comment #31

Sandy Bahr, Sierra Club  Grand Canyon Chapter

The definition of “Significant degradation” is troublesome in that it allows one discharge to consume as 

much as 20 percent of the assimilative capacity for a pollutant under conditions in which only 50 percent of the 

assimilative capacity is remaining. This definition is not protective of the surface water quality standards or the 

designated uses, especially in light of the rapid growth in Arizona. We strongly recommend that the ADEQ 

reconsider this proposal and instead implement the original definition the agency proposed which defined 

significant degradation as less than 10 percent of the assimilative capacity for a pollutant.

Response: The comment appears to reflect a misunderstanding of the Department’s proposals regarding the 

significant degradation thresholds that trigger comprehensive Tier 2 antidegradation review procedures. The intent 

of the Tier 2 antidegradation policy is to maintain and protect existing water quality in Arizona’s high quality 

surface waters. The Tier 2 antidegradation policy does not allow significant degradation of existing water quality 

without making demonstrations that: 1) there are no reasonable, cost-effective alternatives to lowering water 

quality, and 2) that allowing degradation is necessary to accommodate important social and economic 

development. The purpose of the Tier 2 antidegradation policy is to limit degradation of high quality surface 

waters and the consumption of available assimilative capacity in those waters. 

The Department chose to target Arizona’s Tier 2 antidegradation policy on regulated discharges that result 

in significant degradation of high quality surface waters. The Department has some discretion in determining what 

constitutes significant degradation that triggers detailed antidegradation review procedures. The Department 

followed EPA guidance and defined significant degradation in terms of the percent consumption of available 

assimilative capacity for pollutants in high quality surface waters. The Department proposed to define significant 

degradation as either: 1) the consumption of 20 percent of the assimilative capacity for a pollutant by a regulated 
125 

discharge, or 2) the consumption of any percentage of assimilative capacity by a regulated discharge once 50 

permit of the assimilative capacity for a pollutant has been used. The second significance threshold is often called 

a cumulative cap on the use of the total assimilative capacity of a surface water. Once 50 percent of the total 

assimilative capacity has been consumed in a high quality surface water, any use of available assimilative capacity 

constitutes significant degradation. On the other hand, if more than 50 percent of the total assimilative capacity for 

a pollutant is available in a high quality surface water, then a regulated discharge may consume up to 20 percent 

of the available assimilative capacity for a pollutant before the lowering of water quality is considered significant 

degradation. The allowable consumption of up to 20 percent of available assimilative capacity only applies when 

more than 50 percent of the total assimilative capacity remains available in the surface water. The adopted 20 

percent significant degradation threshold coupled with a cumulative cap represents a reasonable approach that 

maintains and protects existing water quality in high quality surface waters without unnecessarily triggering 

detailed Tier 2 antidegradation review requirements on regulated discharges. 

EPA has recognized that states may adopt significance thresholds as part of their Tier 2 antidegradation 

implementation policies [See EPA policy memorandum by Ephraim S. King, Tier 2 Antidegradation Reviews and 

Significance Thresholds, U.S. Environmental Protection Agency, Office of Water (August 10, 2005)]. EPA has 

afforded states discretion in determining what constitutes significant degradation for purposes of Tier 2 

antidegradation reviews. EPA has accepted a number of approaches to defining significance thresholds that trigger 

comprehensive Tier 2 antidegradation reviews. States have adopted significance thresholds that range from 5 

percent of assimilative capacity to as much as 33 percent of assimilative capacity. The adopted significance 

thresholds are well within ranges that have been approved by EPA. Moreover, the Department’s approach of 

combining the 20 percent significance threshold with a cumulative cap of 50 percent is an approach that has been 

recommended by EPA. 

R18-11-101(42); Total nitrogen 

Comment #32

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

The proposed definition of Total Nitrogen is inaccurate and should be revised to eliminate a reference to 

ammonia (NH 3). 

Response: The Department did not propose any revisions to the definition of “total nitrogen” in this 

rulemaking. The Department disagrees that the definition should be revised to eliminate ammonia. Total nitrogen 

includes the following forms of nitrogen that are of greatest interest in water and wastewater. These forms are, in 

order of decreasing oxidation state, nitrate, nitrite, ammonia and organic ammonia. All of these forms of nitrogen, 

as well as nitrogen gas, are biochemically interconvertible and are components of the nitrogen cycle. They are all 

elements of total nitrogen. 

R18-11-101(45); Urban lake 

Comment #33

Jim F. DuBois, City of Tucson – Department of Transportation
126 

The use of the term “small” renders this definition subjective. ADEQ’s guidance document for narrative 

nutrients in lakes doesn’t seem to restrict this category by size. ADEQ should delete or quantify this modifier. 

Response: The Department agrees that urban lakes are defined by their location, not by their size. The 

definition as been modified as follows. 

45. “Urban lake” means a manmade lake within an urban landscape.

R18-11-101(47); Wadeable stream 

Comment #34

Robert S. Lynch, Irrigation & Electrical Districts Association of Arizona:

“Wadeable stream” is new, but according to the definition, a wadeable stream could be 8.5 feet deep (8.5’ x 

1 c.f.s. = 8.5). Later, in R18-11-118.01, the rule refers to a wadeable perennial stream. Are these streams 

different? If so, the definitions should be clarified. 

Robert A. Hollander, City of Phoenix

Wherever the term “wadeable stream” is used throughout the rules (e.g. R18-11-108.01, R18-11-108.02, 

R18-11-108.03) it is always linked to “perennial.” Therefore, the definition should include the term “perennial,” 

such as “’Wadeable stream’ means a perennial stream where the product of the water depth in feet multiplied by 

the velocity of the water in feet per second is less than nine.” 

Response: The Department agrees that the definition of “wadeable stream” should be clarified. The 

proposed definition of “wadeable” was based on a “rule of thumb” that Department water quality monitoring staff 

used to determine whether a stream could be safely waded. However, the rule of thumb was not helpful to the 

general public. 

The term “wadeable” has been defined rather than the phrase “wadeable stream.” The word “stream” has 

been removed from the phrase to avoid any potential confusion over whether there is a difference between 

“wadeable stream” and “wadeable, perennial stream.” By removing the word, “stream,” the separate modifiers, 

“wadeable” and “perennial” are each defined in the definition section. These separate definitions help the public 

understand where the proposed biocriteria and narrative bottom deposits standards apply. The definition, which 

had been proposed as: “[w]adeable stream means a stream where the product of the water depth in feet multiplied 

by the velocity of the water in feet per second is less than nine,” has been revised as follows:

47. “Wadeable” means a surface water can be safely crossed on foot and sampled without a 

boat.

R18-11-102. APPLICABILITY

Comment #35

Fred H. Gray, City of Tucson – Parks and Recreation Department

ADEQ has removed from applicability certain types of manmade impoundments. However, another type of 

manmade impoundment that should not be governed by these rules is impoundments storing reclaimed water for 

beneficial use. ADEQ should include storage impoundments used for reclaimed water. 
127 

Claire L. Zucker, Pima Association of Governments (PAG)

ADEQ has removed from applicability certain types of manmade impoundments; however, impoundments 

storing reclaimed water for beneficial use should also be exempted from these rules. Storage impoundments used 

for reclaimed water are comparable to impoundments that are part of the waste treatment system. Reclaimed water 

permits cover reclaimed storage ponds and require discharge to them to meet reclaimed water quality standards, 

making surface water quality standards inappropriate for these facilities.

Jim F. DuBois, City of Tucson – Department of Transportation

ADEQ has removed from applicability certain types of manmade impoundments. However, one significant 

type of manmade impoundment, which should not be regulated by this rule, has not been included in R18-11-

101(A) – impoundments storing reclaimed water for beneficial use. ADEQ should list reclaimed water storage 

impoundments in this subsection among the instances in which the proposed rule does not apply. This type of 

facility is comparable to impoundments that are part of the waste treatment system, which are currently excluded 

under R18-11-102(B)(1). Reclaimed water permits already cover reclaimed storage ponds and require discharge 

into them to meet reclaimed water quality standards. Surface water quality standards are inappropriate for these 

facilities, and ADEQ should exclude them from applicability. 

Response: The Department disagrees. The exemption in R18-11-102 is patterned after language in 40 CFR 

122.2. Discharges to reclaimed ponds that are built in a water of the United States (WUS) are not exempt, and will 

continue to be regulated according to the provisions of the Clean Water Act. Reclaimed standards are not, and 

were not intended to be, protective of surface waters or aquatic life. In particular, reclaimed water often contains 

residual disinfectants, such as chlorine, that are incompatible with aquatic life. Reclaimed waters may contain high 

concentrations of metals and other pollutants above the standards and that may be toxic to aquatic life. 

Comment #36

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ provides in its proposed R18-11-102(B)(2) to exempt from the SWQS rule any “man-made surface 

impoundment and associated ditches and conveyances used in the extraction, beneficiation, or processing of 

metallic ores that is not a surface water or is located in an area that once was a surface water but no longer 

remains a surface water because it has been and remains legally converted.” [emphasis added]. This exemption is 

circular – its suggests that an impoundment used for mineral processing is not a surface water unless it is a surface 

water. ADEQ should therefore remove from this section the following language: “is not a surface water or” to 

avoid confusion as to which surface impoundments are exempt from SWQS regulation. ADEQ should also 

include storage impoundments used for reclaimed water among the instances in which the proposed rule does not 

apply. This type of facility is comparable to impoundments that are part of the waste treatment system. Reclaimed 

water permits cover reclaimed storage ponds and require discharge to them to meet reclaimed water quality 

standards. Surface water quality standards are therefore inappropriate for these facilities, and only serve to 

frustrate water conservation efforts relying on reclaimed water.

Response: The Department adopted editorial revisions only to the current exclusion for mining 

impoundments and associated ditches and conveyances at R18-11-102(B) in this rulemaking. While the 
128 

Department agrees that the cited phrase “that is not a surface water or is located in an area that once was a surface 

water but no longer remains a surface water because it has been and remains legally converted” is somewhat 

circular, the Department disagrees that it should be removed from the final rules. A review of the history of the 

mining impoundment exclusion is necessary to understand the reasons for not revising the circular language cited 

in the comment. 

The Department originally proposed the mining impoundments exclusion in the 1992 rulemaking of surface 

water quality standards. The original language of the mining impoundments exclusion was similar to the current 

R18-11-102(B)(2) with one important difference. As originally proposed and adopted, the mining impoundment 

exclusion exempted certain mining impoundments from water quality standards provided discharges from those 

impoundments were permitted under the NPDES permit program. The mining impoundments exclusion did not 

include language limiting the excluded mining impoundments to those that were created outside what would 

otherwise be considered waters of the United States. 

In September 1993, EPA disapproved the mining impoundments exclusion as proposed by the Department. 

EPA disapproved the exclusion on the ground that it excluded entire categories of mining-related impoundments 

without any regard as to whether specific impoundments were waters of the United States. In disapproving the 

exclusion, EPA Region 9 stated in its disapproval letter that Arizona must either repeal the mining impoundment 

exclusion or “otherwise revise its regulations in order that those impoundments which are waters of the United 

States are governed by appropriate water quality standards.” 

The Department subsequently proposed the repeal of the mining impoundments exclusion to resolve EPA’s 

disapproval of that provision. The proposed repeal was strongly opposed by the Arizona Mining Association and 

led to a stakeholder effort to explore the second alternative offered by EPA Region 9 to resolve the disapproval; 

i.e., the appropriate revision of the language of the mining impoundments exclusion. There was an extensive 

stakeholder effort in 1995-1996 to come up with acceptable language that would appropriately limit the mining 

impoundments exclusion. The language that the commenter states is circular is the revised language that was 

acceptable to EPA and resolved its concerns. EPA approved the current language of the mining impoundments 

exclusion by letter to the Department dated April 26, 1996. No change has been made to the rule. 

R18-11-107.01 ANTIDEGRADATION CRITERIA

Comment #37

Claire L. Zucker, Pima Association of Governments (PAG)

Several of our member jurisdictions are concerned that the Antidegradation Implementation Procedures are 

not yet ready for inclusion in the rule. They feel that the previously released guidance document is much better 

and should continue to be used rather than putting new language into rule. The term “baseline water quality” aptly 

describes the water quality of streams for the purposes of applying antidegradation rules, and should be used 

instead of the term “existing water quality” throughout this section. 

Response: The Department is required by federal regulation to develop and adopt a statewide 

antidegradation policy and to identify methods for implementing the antidegradation policy (See 40 CFR 131.12). 
129 

The statewide antidegradation policy for Arizona is prescribed in the surface water quality standards rules at 

A.A.C. R18-11-107. Versions of the antidegradation policy have been in Arizona’s water quality standards rules 

since 1968 [See Section 6-2-5, Water Quality Standards for Surface Waters in Arizona, State Department of 

Health, Water Quality Control Council, July, 1968.] While Arizona has had an antidegradation policy in rule for 

40 years, the Department has not identified methods for implementing Arizona’s antidegradation policy in rule. 

EPA has recommended since 1986 that the Department identify methods for implementing the statewide 

antidegradation policy. The Department has produced several antidegradation implementation procedures 

guidance documents over the last twenty years. This rulemaking adopts antidegradation policy implementation 

criteria based on the updated guidance document (Antidegradation Implementation Procedures (April, 2008)). 

The lack of antidegradation implementation procedures in rule was identified by EPA as a deficiency of the 

water quality standards rules during the 1992 rulemaking. The U.S. Fish & Wildlife Service notified the 

Department through the consultation process under § 7 of the Endangered Species Act that the lack of 

antidegradation implementation procedures for the antidegradation rule could result in an incidental take of 

threatened and endangered species. Other stakeholders in the 1992 rulemaking expressed concern that the 

preparation and adoption of the Department Implementation Guidelines for the State of Arizona Antidegradation 

Standard should be subject to formal rulemaking procedures because they believed that the guidelines qualified as 

rules under the Arizona Administrative Procedures Act. The Department agrees that antidegradation 

implementation procedures are necessary elements of the water quality standards program and that they are 

required by EPA regulations implementing the Clean Water Act. 

The Department responded to comments received in the 1992 rulemaking that antidegradation 

implementation procedures should initially be contained in guidance documents and that the Department could 

subsequently make decisions regarding which procedures should be incorporated into rule after gaining some 

practical experience. Sixteen years later, the Department has written a comprehensive Antidegradation 

Implementation Procedures guidance document and, for the first time, proposes to adopt elements of the guidance 

document as objective bases for determining compliance with the Antidegradation Rule (R18-11-107.01). The 

Department disagrees that the antidegradation criteria are not ready for inclusion in rule after more than twenty 

years of development. 

The Department received numerous comments on the Implementation Procedures for the Narrative 

Standards which are outside the context of this rulemaking. The implementation procedures will be adopted as 

policy when finalized. The Department has provided responses to those comments directly to the authors and will 

contact them to participate in upcoming worksessions for the Impaired Waters Identification rule and AZPDES 

permit program rulemakings, as appropriate. To avoid any confusion, the Department is modifying the title of the 

rule to read: Antidegradation Criteria.

R18-11-107.01(A) 

Comment #38

Karlene Martorana, (Ryley Carlock & Applewhite) Irrigation Districts

The Proposed Rules appear to attempt to regulate all canals through Tier 1 of the antidegradation rules, 
130 

Proposed Rules R18-11-107 and R18-11-107.01, and the Antidegradation Implementation Procedures. 

By law, these regulations can only regulate water in canals to the extent that the canal otherwise qualifies as 

“surface water.” However, the Tier 1 protection appears to attempt to directly regulate water in canals by 

prohibiting degradation of the water quality and by requiring that water quality standards be achieved. The 

Antidegradation Implementation Procedures state that Tier 1 protection constitutes the “default protection level” 

for all surface waters, including canals. Through the Antidegradation Implementation Procedures and the 

antidegradation rules, it appears that ADEQ is attempting to exercise jurisdiction over the water in all canals. 

However, ADEQ does not have jurisdictional authority to regulate water in all canals. Pursuant to A.R.S. § 

49-221, ADEQ can implement water quality standards only for “navigable waters.” The Arizona Revised Statutes 

incorporate the definition of “navigable waters” from the CWA. A.R.S. § 49-201. The CWA defines “navigable 

waters” as “waters of the United States, including the territorial seas.” 33 USC § 1362(7). The Proposed Rules 

define “surface water” as a “water of the United States.” 

The definition does not contain any changes from the current definition, and it is very similar to the 

definition of “waters of the United States” found at 33 CFR § 328.3 and 40 CFR § 230.3. Most canals do not fit 

into this definition of surface water. Most canals are not used for interstate or foreign commerce or recreational 

purposes, nor are they an interstate water, a river or stream, an impoundment or a tributary to a surface water. 

When a canal does not fit into ADEQ’s definition of “surface water” or the definition of “water of the United 

States,” that canal is not a “navigable water” and ADEQ does not have authority to regulate the water in such 

canals. 

For the reasons stated above, we request that ADEQ clarify the Proposed Rules to only apply to canals that 

otherwise qualify as “surface water.” 

Robert S. Lynch, Irrigation & Electrical Districts Association of Arizona

R18-11-107.01 attempts to redefine “surface water,” and includes “canals” despite the definition of 

“surface water” in R18-11-101 (which doesn’t mention canals). Only those canals listed in Appendix B have been 

treated as surface waters and the provision of “canal” in R18-11-107.01 should include a limitation to “as listed in 

Appendix B.” 

Response: The Department does not intend to expand the regulation of canals through this anti-degradation 

provision. The Department agrees that not all canals are regulated and would not be subject to this provision. 

Canals that are not listed specifically in Appendix B of the standards rule will continue to be evaluated on a caseby-case basis as issues arise to determine if they otherwise qualify as a surface water. 

The Department agrees to clarify the references to a canal in R18-11-107.01(A)(1)(e) and R18-11-

107.01(A)(3) by adding the phrase, “listed in Appendix B” after “a canal” to each of the cited references. There 

was no intent to regulate water quality in all canals or to exercise jurisdiction over the water in all canals by 

including the reference to canals in R18-11-107.01(A)(1)(e). The Department’s intent was to clarify how 

antidegradation is implemented for those canals that are regulated as surface waters and identified in Appendix B 

of the surface water quality standards rules. The following subsections have been revised as follows: 

R18-11-107.01(A)(1)(e)

A canal listed in Appendix B.
131 

R18-11-107.01(A)(3) 

Except as provided in subsections (E) and (F), Tier 1 antidegradation review requirements are 

satisfied for a point source discharge regulated under an individual AZPDES permit to an 

ephemeral water, effluent-dependent water, intermittent water, or a canal listed in Appendix B, 

provided water quality-based effluent limitations designed to achieve compliance with applicable 

surface water quality standards are established in the permit and technology-based requirements 

of the Clean Water Act for the point source discharge are met.

Comment #39

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

The proposed antidegradation rule appears to apply to all “intermittent waters,” “ephemeral waters,” and 

“canals” regardless of their connection to a water of the United States. The rule should clarify that antidegradation 

protection applies only to intermittent waters, ephemeral waters, and canals that are waters of the United States. 

Response: The Department disagrees that the antidegradation rules should include additional language to 

clarify where the antidegradation rule applies. The Department addresses applicability of the surface water quality 

standards rules, including the antidegradation rules, in R18-11-102 (A), which clearly states that the surface water 

quality standards (including antidegradation) apply to “surface waters” (defined in R18-11-101(41)). 

R18-11-107.01(A)(2) 

Comment #40

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ provides in proposed R18-11-107.01(A)(2) that a “regulated discharge shall not cause a violation of 

a surface water quality standard or a wasteload allocation established in a total maximum daily load under 11 

A.A.C. 6.” It is not clear what is meant by causing a violation of a wasteload allocation established in a total 

maximum daily load. In other relevant contexts, regulations and/or permits refer to a discharge being “consistent” 

with a wasteload allocation and associated total maximum daily load (see Arizona’s Construction General Permit 

(Part I.D.4.b); EPA’s Construction General Permit (Part 1.3(C)(5)(a)); and EPA’s 2000 Multi-Sector General 

Permit (Part 1.2.3.8.2). Also, the reference to 11 A.A.C. 6 appears to be mistaken. Based on these observations, 

the language in proposed R18-11-107.01(A)(2) should read instead as follows: “A regulated discharge shall not 

cause a violation of a surface water quality standard and shall be consistent with any applicable wasteload 

allocation established in a total maximum daily load under Arizona Administrative Code, 18 A.A.C 18, Article 6.” 

ADEQ provides in proposed R18-11-107.01(A)(3) that “Tier 1 antidegradation review requirements are 

satisfied for a point source discharge regulated under an AZPDES permit” to certain waters as long as “water 

quality-based effluent limitations designed to achieve compliance with applicable surface water quality standards 

are established in the permit.” The language suggests that any point source discharge regulated under an AZPDES 

permit would have to include water quality-based effluent limitations in order to satisfy Tier 1 antidegradation 

requirements. The Coalition does not believe that this is the intent of this language especially given the competing 
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language in proposed R18-11-107.01(E) and R18-11-107.01(F) addressing certain individual and general 

stormwater permits. Accordingly, to clarify the scope of the language in proposed R18-11-107.01(A)(3), this 

subsection should be revised as follows: “Except as provided in subsections (E) and (F), Tier 1 antidegradation 

review requirements are satisfied for a point source discharge of wastewater regulated under an individual

AZPDES permit to an ephemeral water, effluent-dependent water, or a canal provided water quality-based effluent 

limitations designed to achieve compliance with applicable surface water quality standards are established in the 

permit and technology-based requirements of the CWA for the point source discharge are met.” 

Response: The Department agrees the language in R18-11-107.01(A)(2) needs clarification to account for 

TMDLs authored by either the Department or EPA. The language has been revised as follows: 

2. A regulated discharge shall not cause a violation of a surface water quality standard or a 

wasteload allocation in a total maximum daily load approved by EPA.

The Department agrees that the language of R18-11-107.01(A)(3) should be revised to clarify that the 

provision applies to point source discharges regulated under individual AZPDES permits and does not apply to 

AZPDES general permits and storm water permits. The commenter is correct that the Department intends to take a 

different approach to antidegradation implementation for AZPDES storm water permits and general permits and a 

clarification is necessary. The Department made the revisions to R18-11-107.01(A)(3) as recommended by the 

commenter with two differences. The Department did not add the unnecessary modifying phrase, “of wastewater” 

after point source discharge and retained “intermittent water” as one of surface waters specified in R18-11-

107.01(A)(3). The rule has been revised s follows: 

3. Except as provided in subsections (E) and (F), Tier 1 antidegradation review requirements 

are satisfied for a point source discharge regulated under an individual AZPDES permit to 

an ephemeral water, effluent-dependent water, intermittent water, or a canal listed in 

Appendix B provided water quality-based effluent limitations designed to achieve 

compliance with applicable surface water quality standards are established in the permit 

and technology-based requirements of the Clean Water Act for the point source discharge 

are met. 

R18-11-107.01(B) 

Comment #41

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We are concerned about how the baseline water quality will be established by a person seeking to 

discharge into any perennial water. How will this be accomplished, and how will the agency ensure that the 

entity seeking to degrade the water will provide the most accurate information? There should be strong quality 

control requirements on this. 

We support the public participation requirements in this section, although, considering that this section 

allows for degradation of water quality, a public hearing should also be required. 

Response: The Department addresses how baseline water quality will be established in Chapter 4 of the 

associated Antidegradation Implementation Procedures (April 2008) guidance document. Chapter 4 contains a 
133 

summary of the Department’s approach to determining baseline water quality, a description of the baseline water 

quality assessment procedures, sampling locations and protocols, pollutants of concern, and how the Department 

will interpret data to establish baseline water quality. The Department believes it is more appropriate to place the 

procedures related to determining baseline water quality in guidance document versus rule. 

The Department appreciates the Sierra Club’s support for the public participation procedures that the 

Department proposed for Tier 2 antidegradation reviews. The Department does not agree that a public hearing 

should be required for all Tier 2 antidegradation reviews. The proposed rule provides for public notice and an 

opportunity to comment on Tier 2 antidegradation reviews of regulated discharges that cause significant 

degradation. The proposed rule gives persons an opportunity to request a public hearing, but does not require a 

public hearing in all cases. 

Comment #42

Robert S. Lynch, Irrigation & Electrical Districts Association of Arizona

Under R18-11-107.01(B), a person may explain that degradation of water has occurred because of 

environmental justice or social issues. Although vague as to what that means, is the converse true -- that a person 

may oppose the Director’s finding of allowable degradation based upon environmental justice issues? 

Response: Persons may comment in support or opposition to a regulated discharge and the Department 

antidegradation review. R18-11-107(B)(4) does not limit public comments, so persons may oppose a Tier 2 

antidegradation review on environmental justice grounds. 

R18-11-107.01(C)(1) 

Comment #43

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Also in connection with general permits, proposed R18-11-107.01(C)(1), establishing Tier 3 protection, 

should be narrowed in its application from a “direct tributary” to an OAW to 1/4 mile of an OAW, to be consistent 

with the Department’s recently issued Construction General Stormwater Permit (see Part I.D.4).

Sydney Hay, Arizona Mining Association

The AMA also agrees with the Coalition that the language in proposed A.A.C. R18-11-107.01(C)(1), 

applying Tier 3 antidegradation protection to any tributary to an OAW, is overbroad. This provision potentially 

greatly expands the universe of Tier 3 protection, since a single OAW may have numerous direct tributaries and 

those tributaries may not possess the characteristics of the OAW. Moreover, not every activity in a direct tributary 

will affect an OAW. The expansion of Tier 3 protection, and the requirement to demonstrate no impact on the 

OAW as a result of activities occurring in a direct tributary (proposed A.A.C. R18-11-107.01(C)(3)), should apply 

only to activities occurring within a reasonable proximity of the nearest reach designated as an OAW. 

Claire L. Zucker, Pima Association of Governments (PAG)

The Tier 3 protection applies to a surface water that is an OAW or is a direct tributary to an OAW. 

However, the rule does not define how far upstream that protection should extend or what constitutes a direct 

tributary. 
134 

Response: The Department disagrees that the scope of Tier 3 antidegradation protection for individual 

permits should be narrowed to only those tributaries within 1/4 mile of an OAW. The purpose of Tier 3 

antidegradation protection is to maintain and protect existing water quality in OAWs. The establishment of a limit 

in terms of a specified distance to an OAW would be arbitrary and inconsistent with the general purpose of 

protecting existing water quality in OAWs and prohibiting degradation. 

The Department agrees that the meaning of “direct tributary” is open to interpretation. A person who 

proposes a regulated discharge to a tributary of an OAW must demonstrate that the regulated discharge will not 

degrade existing water quality in the downstream OAW. This distance will vary depending on the specifics of a 

discharge scenario. Any discharge that is determined to affect the quality of water in an OAW must be reviewed 

under Tier 3. If the Department determines the discharge to the tributary will not affect the OAW, antidegradation 

review will proceed based on the appropriate tier of the tributary. 

The Department deleted the word “direct tributary” in both R18-11-107.01(C)(1) and (C)(3) and revised the 

rule as follows:

1. Tier 3 antidegradation protection applies only to an OAW listed in R18-11-112(G).

3. A person seeking authorization for a regulated discharge to a tributary to, or upstream of, 

an OAW shall demonstrate in a permit application or in other documentation submitted to 

the Department that the regulated discharge will not degrade existing water quality in the 

downstream OAW.

R18-11-107.01(D) 

Comment #44

Sydney Hay, Arizona Mining Association

Antidegradation review for Section 404 permits involving the discharge of fill material should focus on the 

effect of the fill on water quality in surface waters outside the area of fill. In one sense, the fill itself could be 

considered degradation, but such activities have been explicitly authorized under Section 404 of the CWA if the 

relevant regulations are complied with (Corps regulations, EPA’s Section 404(b)(1) guidelines). This is how 

antidegradation reviews have been conducted in the past, but with the significantly expanded rule language on this 

topic, this point should be explicitly stated in the rule language itself. 

Response: The Department agrees that an antidegradation review of § 404 permits involving the discharge 

of fill to a surface water should focus on a review of the effect on surface water quality outside of the area of fill. 

The Department agrees that any discharge of fill could be considered degradation per se if the Department literally 

applied the requirements of the antidegradation rule; however, such a position is illogical because fill activities are 

clearly authorized by the Clean Water Act. EPA specifically addressed the applicability of antidegradation 

requirements to dredge-and-fill activities authorized under § 404 of the Clean Water Act in a guidance document 

called Questions and Answers on Antidegradation (EPA, 1985). The Department agrees with the following 

statement in the guidance document: 

“Since a literal interpretation of the antidegradation policy could result in preventing the issuance of any 

wetland fill permit under Section 404 of the Clean Water Act, and it is logical to assume that Congress intended 
135 

some such permits to be granted within the framework of the Act, EPA interprets 40 CFR 131.12(a)(1) of the 

antidegradation policy to be satisfied with regard to fills in wetlands if the discharge did not result in “significant 

degradation” to the aquatic ecosystem as defined under Section 230.10(c) of the Section 404(b)(1) guidelines.” 

Arizona’s antidegradation policy does not prohibit dredge-and-fill activities that are authorized by a permit 

issued under § 404 of the Clean Water Act. Like EPA, the Department interprets its state antidegradation policy to 

be satisfied with regard to activities authorized by a § 404 permit provided the discharge of fill to a surface water 

does not result in “significant degradation” to the aquatic ecosystem as defined by § 230.1(c) of the § 404(b)(1) 

Guidelines. 

The Department disagrees that the details of how the Department will conduct an antidegradation review of 

§ 404 permits should be explicitly stated in R18-11-107.01. The proposed rule states, at R18-11-107.01(D), that 

the Department will conduct the antidegradation review of a § 404 permit as part of the § 401 water quality 

certification process. Reviews of individual § 404 permits will be conducted on a case-by-case basis. The 

Department’s Antidegradation Implementation Procedures guidance document, dated April 2008, provides some 

of the requested detail on how the Department will conduct antidegradation reviews of individual and nationwide 

§ 404 permits. 

R18-11-107.01(D) has been revised as follows to clarify how antidegradation reviews of § 404 permits will 

be conducted: 

D. Antidegradation review of a § 404 permit. The Director shall conduct the antidegradation review of 

any discharge authorized under a nationwide or regional § 404 permit as part of the § 401 water 

quality certification prior to issuance of the nationwide or regional permit. A regulated discharge 

authorized by a § 404 permit does not require an individual antidegradation review unless the 

discharge may degrade existing water quality in an OAW or a water listed on the 303(d) List of 

impaired waters. For regulated discharges that may degrade water quality in an OAW or a water 

listed on the 303(d) List of impaired waters, the Director shall conduct the antidegradation review 

as part of the § 401 water quality certification process.

R18-11-107.01(E) 

Comment #45

Claire L. Zucker, Pima Association of Governments (PAG)

For AZPDES stormwater permits, the permittee is in compliance with their MS4 permit if they develop a 

Stormwater Management Plan that contains Best Management Practices to reduce pollutant levels to the 

Maximum Extent Practicable (MEP). The additional requirement stated in this rule “conducting monitoring 

activities of discharge water quality” should be deleted because it is more stringent than the AZPDES permit 

program requirements and not all MS4 permittees are required to monitor. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Under proposed R18-11-107.01(E), ADEQ provides that an individual MS4 general stormwater permittee 

meets antidegradation requirements “if the permittee complies with the permit, including developing a stormwater 
136 

management plan containing controls that reduce the level of pollutants in stormwater discharges to the maximum 

extent practicable and conducting monitoring activities of discharge water quality.” All language following 

“maximum extent practicable” in that section should be deleted, as certain permits may not require monitoring, 

and compliance with the MS4 stormwater permit should be adequate to meet antidegradation requirements. 

Additionally, that language violates the statutory limit that the AZPDES program be no more stringent than the 

federal NPDES permit program. A.R.S. § 49-255.01(B). Furthermore, this section should provide that it 

establishes all applicable antidegradation review for individual MS4s notwithstanding any other potentially 

applicable language elsewhere in the proposed rule. The title of this section should also be revised to clarify that it 

applies only to individual MS4 permits, not to all AZPDES stormwater permits. 

Response: Though the Department will continue to require municipal stormwater monitoring to determine 

BMP effectiveness and progress towards attaining standards, the Department has removed this requirement from 

the rule to meet antidegradation criteria. Monitoring in and of itself does not achieve water quality protection. 

R18-11-107.01(E) has been revised as follows: 

(E) Antidegradation review of an AZPDES stormwater permit. An individual stormwater 

permit for a municipal separate storm sewer system (MS4) meets antidegradation 

requirements if the permittee complies with the permit, including developing a stormwater 

management plan containing controls that reduce the level of pollutants in stormwater 

discharges to the maximum extent practicable.

R18-11-107.01(F) 

Comment #46

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Also in connection with antidegradation review for AZPDES stormwater permitting, ADEQ proposed that a 

person seeking authorization to discharge under a general permit is not required to undergo an individual 

antidegradation review at the time the Notice of Intent (“NOI”) is submitted unless the discharge may affect an 

OAW or an impaired water under CWA § 303(d). See proposed R18-11-107.01(F). If antidegradation review is 

conducted after issuance of the permit, such review may impose additional conditions which are more 

appropriately imposed on a general permit through the initial issuance process. ADEQ should therefore revise this 

section so that antidegradation review occurs only at the time of issuance of the general permit, and never at the 

time of submittal of an NOI, including for discharges to an OAW or impaired water. This approach would be 

consistent with ADEQ’s recently reissued Construction General Permit (see Parts I.D.4 & 5), which simply inserts 

additional provisions in the permit (not individual antidegradation review requirements) in the event of potential 

discharges to impaired or unique waters. 

Sydney Hay, Arizona Mining Association

The provision requiring individual antidegradation review of general permit authorizations for activities 

that “may affect” an OAW or an impaired water (proposed A.A.C. R18-11-107.01(F)) is vague and overly broad 

(e.g., for impaired waters, the provision should be limited to activities discharging the pollutant for which the 

water is listed). 
137 

Anti-degradation evaluations are made on a pollutant- by-pollutant basis and are not limited to pollutants 

that are causing impairments. As such, a limitation of this provision as proposed would be inappropriate.

Response: The Department disagrees that the language of R18-11-107.01(F) should be limited with regard 

to antidegradation review of discharges authorized by general permit to OAWs or impaired waters. While general 

permits are typically written for a class of discharger (e.g., facility) that involves the same or substantially similar 

types of operations or pollutants, it is difficult to develop a general permit that is adequately protective for 

impaired waters, waters meeting standards, and waters of exceptional quality. 

It is the Department’s intention to review only individual Notices of Intent (NOIs) that may degrade OAWs 

or impaired waters, and condition them, if appropriate, to protect these waters and satisfy antidegradation similar 

to how the Department has written the Construction Stormwater General Permit and the De Minimus General 

Permit. Other alternatives might be to exclude these discharges from coverage under general permits, however, the 

Department generally considers this ‘blended’ approach to be adequately protective and of benefit to both the 

permittee and the agency in terms of process. 

The Department agrees that “may affect” may be overly broad. The Department revised R18-11-107.01(F) 

and replaced “may affect an OAW” with the phrase “may degrade existing water quality in an OAW.” 

F. Antidegradation review of a general permit. The Director shall conduct the 

antidegradation review of a regulated discharge authorized by a general permit at the time 

the general permit is issued or renewed. A person seeking authorization to discharge 

under a general permit is not required to undergo an individual antidegradation review at 

the time the Notice of Intent is submitted unless the discharge may degrade existing water 

quality in an OAW or a water listed on the 303(d) List of impaired waters.

R18-11-108. NARRATIVE WATER QUALITY STANDARDS

R18-11-108(A)(1) 

Comment #47

Robert A. Hollander, City of Phoenix

This Section requires that surface waters “be free from pollutants in amounts or combinations that...settle 

to form bottom deposits that inhibit or prohibit the habitation, growth, or propagation of aquatic life.” This 

standard is intended to prevent excessive sedimentation and siltation in amounts that may adversely affect aquatic 

life. 

If the standard is directed at solids, and to be consistent with R18-11-108.02.B, R18-11-108.A.1, it should 

state “be free from sedimentation and siltation in amounts...” As proposed it could include toxics, which is not the 

intent of this standard. 

Response: The Department believes that the current standard, as written, is clear, understandable and 

accomplishes this intent. There is little risk of R18-11-108(A)(1) being inappropriately applied to regulate toxic 
138 

pollutants in surface waters because a different narrative standard specifically requires that surface waters be free 

from pollutants in amounts or combinations that are toxic to humans, animals, plants, or other organisms [See

R18-11-108(A)(5)]. 

R18-11-108(D) 

Comment #48

Sydney Hay, Arizona Mining Association

The proposed new standard prohibiting refuse and similar materials being placed in surface waters or on 

their banks (proposed A.A.C. R18-11-108(D)) suffers from numerous problems. (1) The proposed standard is 

awkwardly worded, starting out as a “free from” standard but ending with the words “or onto its banks,” which do 

not fit with anything preceding that phrase. (2) ADEQ admits that this is intended as a “tool to prevent dumping,” 

see 14 A.A.R. at 1287. As such, it is best addressed in the solid waste rules currently in process at ADEQ, not the 

water quality standards. (3) To the extent the standard applies to the “banks” of surface waters, such areas are 

likely outside the jurisdictional surface waters and thus are not subject to surface water quality standards. (4) Such 

a provision is unnecessary, as dumping of refuse or solid waste today is likely in violation not only of the 

AZPDES program, but also the APP program and the existing solid waste rules. There is no “gap” that needs to be 

filled by adopting a new standard. (5) The standard, if adopted, could have unintended (and undesirable) 

consequences; for example, it could be construed to prohibit the use of waste rock or overburden from a mine site 

in any capacity in bank stabilization efforts. For all these reasons, this proposed new standard should not be 

adopted. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

This narrative standard violates ADEQ’s obligations under A.R.S. § 41-1052 to ensure that this rulemaking 

complies with applicable law and does not exceed its statutory authority. As noted above, and as ADEQ 

acknowledged in its rulemaking, ADEQ’s derives its authority to establish SWQS pursuant to the CWA, which 

scope is limited only to navigable waters. However, this narrative standard expressly applies to the “banks” of 

streams, which do not form part of a navigable water. Indeed, the term “banks” is itself vague and ambiguous. 

This standard is unnecessary. ADEQ already prohibits wildcat dumping and regulates disposal of solid 

wastes. See A.R.S. § 49-701 et seq. Additionally most municipalities in the state prohibit littering and unpermitted 

dumping of refuse or rubbish. As such, this proposed narrative standard provides no additional protection, but is 

simply unnecessarily redundant with other well-established programs accomplishing the same effect. 

Matthew Oller, Flood Control District of Maricopa County

The District has an interest in the “rubbish” provision proposes in R18-11-108(D). The District tends to 

believe that it is beyond the jurisdiction of ADEQ to adopt a rule that applies to the “banks” of watercourses, as 

opposed to the waters. This could be a problem with projects that are using native material for bank stabilization. 

It is not clear who would have the responsibility to clean it up. The terms are not defined, and there are other 

programs to govern trash (as opposed to floatables, which are in SWQS).

Response: The Department believes that the dumping of trash in Arizona’s surface waters is a significant 

water quality problem that is appropriately addressed by the surface water quality standards rules. It is true that 
139 

there may be other regulatory programs that address the problem of illegal dumping (e.g., solid waste rules). 

However, the existence of other authorities that provide regulatory tools to address illegal dumping (i.e., by the 

solid waste program) is not an argument for not using the authority provided under the water quality standards 

program to maintain and protect the biological, chemical and physical integrity of Arizona’s surface waters. 

The Department disagrees that regulation of the banks of surface waters is “outside...jurisdictional surface 

waters” and not subject to regulation under the water quality standards program. Improperly placed or managed 

waste on stream banks has the potential to impact surface water quality and therefore the Department believes it 

can be regulated under this Article. The Department agrees that last phrase in R18-11-108(D), “...into a surface 

water or onto its banks,” is inconsistent with the construction of the other narratives. The last phrase of subsection 

(D) has been stricken and reworded for clarity as follows:

D. A surface water shall not contain solid waste such as refuse, rubbish, demolition or 

construction debris, trash, garbage, motor vehicles, appliances, or tires.

The Department disagrees that the narrative standard is unnecessary because it may be addressed by the 

AZPDES permit or APP programs. The AZPDES permit program regulates point source discharges to surface 

waters in Arizona and not non-point source discharges of trash and garbage. The APP program regulates 

discharges of pollutants to ground water. Neither regulatory program addresses illegal dumping of trash and 

garbage in or adjacent to surface waters that may affect water quality. While the Department may agree that solid 

waste program rules address illegal dumping, the existence of solid waste program regulations does not preclude 

the Department from addressing the problem through appropriate water quality regulation. The proposed narrative 

water quality standard supplements Department solid waste regulations and other local ordinances that prohibit 

illegal dumping and littering. The adoption of R18-11-108(D) supports implementation of other Department water 

quality management programs such as the § 319 grant program to address the problem. 

The proposed narrative water quality standard is clearly intended to address the significant problem of 

using Arizona surface waters as illegal dumpsites for trash, garbage, and other refuse or the illegal use of tires, 

abandoned cars, or old and discarded appliances for bank stabilization efforts. The new narrative standard is not 

intended to prohibit or prevent properly authorized bank stabilization efforts (e.g. such as those authorized by a § 

404 permit).

The Department disagrees that the new narrative standard will create any barriers to properly authorized 

bank stabilization projects using native materials. The plain language of the proposed narrative standard states that 

it is intended keep surface waters free from “solid waste such as refuse, rubbish, demolition or construction debris, 

trash, garbage, motor vehicles, appliances, or tires.” This language cannot reasonably be interpreted to preclude 

the use of native materials for bank stabilization projects. It is not a deficiency for the proposed narrative standard 

to be silent regarding who has responsibility for cleaning up the trash in a surface water. The Department’s 

enforcement statutes for water quality control, at A.R.S. §§ 49-261 through 49-263, assign responsibility for the 

violation of the proposed “free from” trash standard to the person who violates the standard. The person who 

places refuse, rubbish, etc. into a surface water would be responsible under R18-11-120.

Comment # 49
140 

Claire L. Zucker, Pima Association of Governments (PAG)

Wildcat dumping and trash accumulation along waterways is a widespread problem that is very difficult, if 

not impossible, to correct completely. If the occurrence of trash and debris on the banks of a stream were used to 

indicate impairment of that stream, then most, if not all, streams in Arizona would probably be considered 

impaired. Jurisdictions do not have the resources to ensure that all refuse stays out of the waterways at all times, 

so this rule should be changed to indicate that refuse (and other stated materials) should be reduced to the 

Maximum Extent Practicable. In addition, the CWA regulates water quality and it does not have jurisdiction over 

areas adjacent to waterways such as stream banks. Furthermore, the term “banks” is not defined and it is unclear 

what constitutes a “bank” and therefore how far outside of the waterway, this rule would apply. This rule would 

be particularly difficult to implement in the urban park environment. 

Jim F. DuBois, City of Tucson – Department of Transportation

This proposed section establishes a narrative standard for refuse, rubbish, demolition or construction debris, 

trash, garbage, etc., which is so stringent that virtually every watercourse in the state will not meet it. For example, 

park areas that comprise the banks of urban lakes and watercourses would be out of compliance with this standard, 

if any littering were to occur. The standard does not recognize that many of these areas are already managed for 

public use with BMPs to control trash. Also, there are already solid waste regulations that apply. ADEQ should 

delete this provision. If ADEQ insists on this type of narrative, the agency should establish some specific measure 

of the presence of the listed solid wastes that protects against an impairment of human health or aquatic and 

wildlife use, rather than simply using the proposed “shall not contain” prescription. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ proposes a new and unprecedented narrative water quality standard in R18-11-108(D). In that 

section, ADEQ provides that a surface water “shall not contain refuse, rubbish, demolition or construction debris, 

trash, garbage, motor vehicles, appliances, tires, or other solid waste into a surface water or onto its banks.” This 

proposed standard is problematic for several reasons. First, ADEQ provides no definition of “refuse, rubbish, 

demolition or construction debris.” The regulation is therefore vague, ambiguous, and subject to an overly broad 

application. For instance, many projects, pursuant to state or federal permits, utilize construction material or other 

materials for bank stabilization. Presumably these measures would violate SWQS, despite having the effect of 

preserving the integrity and quality of the stream. Furthermore, this new narrative standard would prove 

unworkable, in that nearly every watercourse in the state would be out of compliance to some degree.

Response: The Department appreciates the recognition that wildcat dumping and trash accumulation along 

Arizona’s waterways are a widespread problem. The fact that wildcat dumping is a widespread problem that will 

be difficult to correct is not reason to ignore the problem. The Department does not intend to hold local 

jurisdictions responsible for ensuring that trash and refuse stay out of surface waters. A person who causes a 

violation of proposed “free from” trash narrative standard is the person who will be held responsible for a 

violation. The Department disagrees that the standard should be expressed as the commenter recommends (i.e., 

that refuse and trash should be reduced “to the maximum extent practicable.”) The water quality goal for Arizona 

surface waters should be that they be maintained free from trash and rubbish. The Department does not believe it 

is appropriate to set a lesser water quality standard that accepts levels of trash accumulation based on a reduction 
141 

to the maximum extent practicable. The standard needs to be protective of water quality. How it is implemented 

depends on the requirements of each water quality permitting program. The adoption of a narrative water quality 

standard that addresses wildcat dumping will allow the Department to focus water quality management programs, 

other than just enforcement, on the problem. For example, the Department could better direct Clean Water Act § 

319 grant funds to fund nonpoint source pollution control and watershed clean-up projects to address this problem. 

See Response #48. 

The Department has adopted other narrative and numeric water quality standards to protect human health 

and aquatic life. Narrative standards such as R18-11-108(D) supplement the numeric water quality standards to 

protect human health (DWS, FC, FBC and PBC) and aquatic life (A&Wc, A&Ww, A&Wedw and A&We). It is 

similar in nature to other narrative water quality standards that describe general water quality goals such as surface 

waters shall be free from objectionable odors, or cause off-flavor in drinking water or aquatic organisms, or 

change the color of a surface water from natural background color. The narrative standard is intended primarily to 

protect the aesthetic qualities of Arizona surface waters. While it is not the intent of this new narrative to be used 

for waterbody assessment, before the Department could use this narrative standard in determining a waterbody as 

impaired for solid waste, it must develop implementation procedures that identify the specific basis for 

determining that a violation of R18-11-108(D) exists under A.R.S § 49-232(F). 

R18-11-108(D) has been revised to clarify that ‘refuse, rubbish, demolition or construction debris, trash, 

garbage, motor vehicles, appliances, and tires” are components of solid waste. 

Comment #50

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

This narrative standard is unwieldy in its application. How would ADEQ establish TMDLs for “refuse, 

rubbish, demolition, or construction debris”? How would such “discharges” be treated in permits? How would this 

standard be enforced, as storm events frequently result in debris and rubbish being washed up to banks or into 

rivers? How would such storm events resulting in “exceedances” of this narrative standard comport with 

stormwater permits? This narrative standard is inconsistent with the purpose and history of the CWA and ADEQ 

surface water quality regulation, and would prove unworkable in its application in the TMDL and permitting 

contexts. For this reason, and for those discussed above, the Coalition recommends that ADEQ delete R18-11-

108(D) from its proposed SWQS.

Response: The Department disagrees that the proposed narrative standard should be withdrawn because 

there are questions about how the standard will be implemented in the Department water quality management 

programs. The proposed “free from” narrative standard at R18-11-108(D) is no different than other narrative 

standards. AZPDES-permitted discharges will be required to comply with applicable water quality standards. This 

means that an AZPDES-permitted point source discharge will not be allowed to discharge solid waste including 

refuse, rubbish, demolition or construction debris, trash, garbage, motor vehicles, or appliances into a surface 

water. AZPDES MS4 permits will be written to control the discharges of solid waste... to the “maximum extent 

practicable.” Before the Department can list a water as impaired based on that new narrative standard, a 

prerequisite to a TMDL, the Department must develop implementation procedures that identify the specific basis 
142 

for determining that a violation of R18-11-108(D) exists. Aspects of the implementation procedures may then be 

promulgated in a future rulemaking. 

The Department disagrees that the R18-11-108(D) is inconsistent with the history of the Clean Water Act 

or the Department’s surface water quality regulations. On the contrary, there is a long history of this type of 

regulation by EPA and at the state level. Similar “free-from” narrative standards to address the aesthetic qualities 

of surface waters have been a part of water quality standards regulations since the enactment of the modern Clean 

Water Act (See Quality Criteria for Water, U.S. Environmental Protection Agency (July, 1976)(the “Red Book”). 

See Response #49. No change has been made to the rule. 

R18-11-108(D) and (E) 

Comment #51

Sandy Bahr, Sierra Club  Grand Canyon Chapter

The Sierra Club supports the changes in the Narrative Water Quality Standards including the addition of 

Subsection (D), which prevents dumping of trash and debris in Arizona’s surface waters, and the addition of 

Subsection (E), establishing that a wadeable perennial stream support and maintain a community of organisms 

having a taxa richness. This will help further the goal of the Clean Water Act to restore the biological integrity 

of the nation’s waters. Preventing trash in the standards is also appropriate. Recently, we learned of a total 

maximum daily load (TMDL) that was developed relative to trash in California. This may be something that the 

ADEQ would consider for the future in order to help address this growing problem. 

Response: The Department appreciates the support of the Sierra Club for the proposed adoption of the 

narrative standards at R18-11-108(D) and (E).

R18-11-108(E) 

Comment #52

Robert A. Hollander, City of Phoenix

Insert “...with A&Wc or A&Ww designated uses...” after “A wadeable, perennial stream...” to 

communicate that the narrative biological standard applies to wadeable, perennial streams with those designated 

uses as proposed at R18-11-108.01(A). 

Response: The Department does not believe that including the phrase “with the A&Wc or A&Ww 

designated uses” in R18-11-108(E) is necessary. The proposed standard at R18-11-108(E) is already limited in its 

application to wadeable, perennial streams and R18-11-108.01(A)(1) explicitly states that R18-11-108(E) applies 

to “a wadeable perennial stream with either an aquatic and wildlife (cold water) or an aquatic and wildlife (warm 

water) designated use.” No change has been made to the rule. 

NARRATIVE WATER QUALITY CRITERIA

The Department is adopting a new narrative standard for biological integrity and narrative criteria for three 

narrative standards: biological integrity (R18-11-108(E)); bottom deposits (R18-11-108(A)(1)); and nutrients 
143 

(R18-11-108(A)(6)). The criteria translate the narrative standard into objective bases that the Department can use 

for determining if the standard is being met. 

With the proposed rule, the Department disseminated draft Implementation Procedures to explain the 

derivation of each criterion and the use of the criterion in assessment, listing, and development of water-quality 

based limits for AZPDES permits. A.R.S. § 49-232(F) requires the Department to adopt implementation 

procedures that specifically identify the basis for determining that a violation of the narrative or biological criteria 

exists. The procedures, when finalized, will provide this guidance and will be adopted as substantive policy. 

The Department received numerous comments on the Implementation Procedures for the Narrative 

Standards, which are outside the context of this rulemaking. The Department has provided responses to those 

comments directly to the authors and will contact them to participate in upcoming work sessions for the Impaired 

Waters Identification rule and AZPDES permit program rulemakings, as appropriate. 

Comment #53

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ has drastically revised its approach to the narrative bottom deposits, biocriteria, and nutrient 

standards by establishing proposed objective criteria for determining compliance with each. Indeed, ADEQ’s 

proposed changes to the narrative standard are so revolutionary in their reliance on objective criteria that the 

Coalition questions whether these proposed standards still qualify as “narrative.” The proposed adoption of 

objective criteria would overturn years of operating under a more subjective approach and make obsolete agency 

guidance upon which the regulated community has relied for some time. 

The proposed narrative standards represent such a drastic and significant change, and require such detailed 

technical investigation in order to understand their potential ramifications, that the Coalition requests that the 

narrative biocriteria, bottom deposits, and nutrient standard concepts (proposed R18-11-108.01, R18-11-108.02, & 

R18-11-108.03) be (1) removed from the current triennial review package, and (2) addressed in the standards as 

appropriate during the next triennial review period based on implementation through the draft narrative standard 

guidance documents. 

However, if ADEQ proceeds with this planned approach to narrative standards, the Coalition requests that 

ADEQ delete from its narrative water quality standard sections (proposed R18-11-108.01 through R18-11-108.03) 

any reference to “implementation procedures.” These proposed regulations provide objective criteria for 

determining compliance with narrative SWQS. They do not provide “implementation procedures” for purposes of 

TMDLs as required in A.R.S. § 49-232(F). Referring to these criteria as “implementation procedures” serves only 

to confuse the regulated community as to these criteria versus true TMDL implementation procedures 

promulgated pursuant to statute.

Response:. The Department disagrees that the new biocriteria and narrative bottom deposits and nutrient 

standards rules should be withdrawn. The Department agrees that the proposed narrative bottom deposits, 

biocriteria and narrative nutrient standards and their associated criteria rules at R18-11-108.01, R18-11-108.02 
144 

and R18-11-108.03 represent a new hybrid approach to surface water quality standards regulation because it 

combines narrative water quality standards with objective criteria that translate the narrative water quality 

standards that the Department can use for compliance and assessment purposes. The Department believes that the 

development of the narrative translators for these three narrative standards is an improvement over the more 

subjective approach. The lack of objective criteria for determining whether a violation of a narrative standard 

exists has been an obstacle to consistent Department implementation of the narrative water quality standards in the 

past. The adoption of objective criteria will provide greater regulatory certainty to the regulated community 

regarding whether or not the narrative standards are violated and they will provide more specific and objective 

criteria that the Department staff can use to fairly and consistently apply the standards. The Department proposed 

R18-11-101.01, R18-11-108.02 and R18-11-108.03 to specifically identify the objective bases for determining 

that the narrative biocriterion at R18-11-108(E), the narrative bottom deposits standard at R18-11-108(A)(1) or the 

narrative nutrient standard at R18-11-108(A)(6) are being met. 

The Department agrees that the references to implementation procedures in R18-11-108.01, R18-11-108.02 

and R18-11-108.03 may be confusing. The rules are more appropriately titled with the term “criteria,” which 

establish the objective bases for determining if the water quality standard is being met. The narrative standards 

Section titles have been revised as follows: 

R18-11-108.01 Narrative Biological Criteria for Wadeable, Perennial Streams

R18-11-108.02 Narrative Bottom Deposit Criteria for Wadeable, Perennial Streams

R18-11-108.03 Narrative Nutrient Criteria for Lakes and Reservoirs

R18-11-108.01. NARRATIVE BIOLOGICAL CRITERIA FOR WADEABLE, PERENNIAL STREAMS

Comment #54

Robert R. Ressler, Pinal Creek Group (PCG)

The proposed narrative biocriteria standard and associated implementation procedures in A.A.C. R18-11-

108(E) and R18-11-108.01 are key issues for the PCG. PCG believes that the threshold for compliance is 

inappropriate. 

Response: The thresholds for compliance with the proposed biocriteria have been developed following the 

EPA Rapid Bioassessment Protocols guidance document (Barbour et al, 1999) and are based on empirical data. 

The 25th and 10th percentiles of the reference macroinvertebrate community were selected based on the ability of 

the Arizona warm and cold water Indexes of Biological Integrity (IBI) to detect differences between prior selected 

reference sites and stressed stream sites and biological communities. 

These biological indexes or biocriteria encompass spatial and temporal variability of aquatic life in Arizona 

perennial, wadeable stream habitats. The IBIs were based on a robust dataset of macroinvertebrate samples 

collected from every major watershed across Arizona over a five-year period (1992-97). Approximately 400 

samples were collected statewide to develop the warm water and cold water Indexes (WW IBI 221 samples from 

112 sites with 61 reference sites; CW IBI 180 samples from 79 sites with 43 reference sites). These IBIs were 

developed and tested using EPA methodology in two biocriteria technical reports (Gerritsen & Leppo, 1998; 
145 

Leppo & Gerritsen, 2000) and were updated in the technical support documentation for the narrative biocriteria 

standard (ADEQ, 2007). See Responses #55 and 56. 

Comment #55

Benjamin R. Parkhurst, HAF, Inc., on behalf of the Pinal Creek Group

The language in the narrative biocriterion is clear and unambiguous, and effective and logical given the 

associated implementation guidance. 

The major issue I have with the accuracy of the indices is with the use of the 25th percentile as the 

threshold for identifying impairment. No evidence has been presented that shows that the 25th percentile is the 

threshold for impairment. Otherwise, I believe the indices are technically sound and accurately defined. 

I also don’t agree that the methods will distinguish well between impacted and non-impacted sites. This is 

because setting the criterion at the 25th percentile of reference sites largely is arbitrary and most likely will result 

in about 25% of unimpaired sites being identified as impaired. By definition, reference sites are unimpaired. 

Joseph S. Volosin, Parametrix, on behalf on the Pinal Creek Group

The selection of the 25th percentile as the biocriteria threshold for warmwater streams does not seem 

justified based on the Biocriteria TSD (ADEQ 2007a). Selection of this threshold is critical because it has the 

potential to identify any type of reach (reference or stressed) as impaired 25 percent of the time thus resulting in 

incorrect assessments. In fact, as stated in the Biocriteria TSD, 23 percent (77 percent, n = 98/128 attained) of the 

a-priori warmwater reference site streams did not attain the 25 percentile (ADEQ 2007a). This is an acceptance of 

a relatively high Type 1 error rate when the 25th percentile is used to describe a significant difference (Newman 

1995). Would it be acceptable to have a chemical analysis be incorrect 25 percent of the time? A lower Type I 

error rate exists when the accepted percentile is smaller, such as the 10th percentile (Newman 1995). 

Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

On a technical front, ADEQ provides no explanation for the election of the 25th percentile as its threshold 

standard in this narrative standard. Indeed, using the 25th percentile of reference streams as the threshold means 

that 25% of all “unimpacted” reference streams would be classified as violating the proposed biocriteria standard 

and, by inference, at least 25% of unimpacted, non-reference streams will be similarly classified as violating the 

standard. A reference stream with a low percentile (i.e., < 25th percentile) score could be impacted from unknown 

sources. Also, ADEQ states in its draft guidance document (dated April 2008) on the narrative biocritiera standard 

that the odds of making a Type 1 false positive error are “very low.” However, the odds of a false positive are 

25%, a scientifically unacceptable error rate. The use of the 25th percentile of reference streams, particularly in 

light of a proposed reliance on a single bioassessment sample, is therefore fundamentally flawed. 

Response: The macroinvertebrate indexes of biological integrity are composed of several metrics or 

characteristics of the stream bottom dwelling macroinvertebrate community. These metrics are tested for ability to 

discriminate between a-priori reference (undisturbed waterbodies) and stressed (disturbed waterbodies) samples. 

Reference macroinvertebrate samples are collected from pre-screened sites that meet landscape and reach scale 

physico-chemical parameters for reference condition. The most powerful metrics in four categories (richness, 

composition, tolerance, and trophic status) are selected for inclusion in a multi-metric index. A threshold is then 
146 

selected which best represents the statistical difference between reference and stressed samples and which is based 

on the reference distribution of IBI scores. A box and whisker plot of the distribution of reference versus stressed 

samples is typically used to display the distribution of IBI scores and determine a reference threshold which best 

discriminates reference samples from stressed (Barbour et al., 1999). The initial development and testing of the 

IBIs was conducted by TetraTech for the Department in a rigorous analysis using approximately 100 reference 

samples each for the cold water and warm water indexes. The statistic that best represented the separation of 

reference and stressed Arizona samples was the 25th percentile of the reference distribution. 

The 25th percentile of the reference IBI distribution distinguishes well between 75 percent of the reference 

samples and 75 percent of the stressed samples in our dataset. While it is true that the Department is accepting up 

to a 25 percent Type I error rate in the initial reference dataset, there are reasons why this rate is acceptable. The 

EPA has recommended a quartile/percentile scoring approach for biocritiera thresholds since the 1999 EPA Rapid 

Bioassessment Protocols manual (Barbour et al, 1999). The 25th percentile value is often found to be the lowest 

quartile at which good discrimination between a-priori designated reference and stressed sites can be determined. 

According to the EPA Summary of States’ Bioassessment Programs, eleven other states have selected the 25th 

percentile of reference condition as their IBI threshold. 

While a 25 percent error rate seems high, biologists recognize that there is more inherent variability in 

stream ecosystems and biological communities than in water chemistry. The Department acknowledges that many 

of the reference sites in the lower quartile were only the best available stream sites in a region and not the least 

impaired reference sites, because pristine sampling sites were non-existent. There were many reference samples in 

the lower quartile that were initially used in IBI development which will now be exempted from application of 

biocriteria for various reasons. There were samples in the dataset from streams which were collected from bedrock 

or travertine dominated habitats, for which biocriteria are now not applicable. There were samples which are now 

thought to have been impaired due to collection following the extreme floods of 1993. These samples (10 of 13 

impaired warm water reference samples and 8 of 12 cold water impaired reference samples) were stressed due to 

natural conditions and will be exempted from application of the narrative biocriterion. 

The variability in reference quality in the lower quartile of reference condition is acceptable as natural 

variation in the reference sample population and selection of a lower percentile target would increase the Type II 

error rate. Setting the biocriterion at a lower percentile (such as the 5th percentile) would result in more false 

negatives. At the 10th percentile, an estimated false negative rate of 48 percent occurs among the warm water 

samples in the Department’s dataset. The Department must balance the risk of false positive (Type I) errors as 

well as false negatives (Type II). The thresholds established balance those risks most effectively, with the 10th 

percentile as the absolute lowest threshold for a violation, the 25th percentile as the minimum threshold for 

protecting the aquatic life use, and 10-25th percentile as inconclusive when a verification sample is required. 

Comment #56

Joseph S. Volosin, Parametrix, on behalf on the Pinal Creek Group

Some reference sites could be defined as violating the new biocriteria standard, if after a single sample 

collection event, the ADEQ Warmwater IBI score is below the 10 percentile (i.e., 39 for ADEQ Warmwater sites). 
147 

Based on spring collected samples from 1992 to 2003, 10 percent of reference sites were determined to 

have scores less than the ADEQ Warmwater IBI score. Therefore, about 13 reference sites could have been 

determined to be violating the new biocriteria standard. Determining that a reference site exceeds the new 

biocriteria standard does not seem appropriate. Therefore, what is the justification for the 10th percentile as the 

absolute threshold for determining whether the new biocriteria standard is violated? As this is equivalent to saying 

that the reference sites (which represent sites minimally affected by human activity) are violating applicable 

standards 10 percent of the time, there needs to be a more complete explanation of what the biocriterion seeks to 

protect, what constitutes an actual violation of the standard, and how to differentiate impacts from human activity 

from natural variability. As discussed in the IP, “The naturally occurring biological diversity becomes the primary 

reference condition used to measure and assess attainment of aquatic life goals.” In as much reference sites define 

the range of naturally occurring biological diversity, there is no logical rationale for a site within the range for the 

reference condition to be considered in violation for attainment of aquatic life goals. Why should not the entire 

ADEQ Warmwater IBI range for reference streams be considered attaining and anything below that range not 

attaining? 

Response: The rationale for using the 10th percentile as the threshold for determining that the biocriterion 

is violated is that the majority of stressed samples in a box and whisker plot analysis fell below the 10th percentile 

of reference condition. This suggests that samples with IBI scores in this range (<10th percentile) are equivalent to 

samples that are a-priori known stressed sites, thus they do not achieve biointegrity and are violating the 

biocriterion. For discussion of why some of the “reference samples” are violating the biocriterion, see Response 

#55. 

Comment #57

Joseph S. Volosin, Parametrix, on behalf on the Pinal Creek Group

ADEQ Warmwater IBI scores for reference sites are compared to those for stressed sites in Figure 5 of the 

Technical Support Documentation for the Narrative Biocriteria Standard (ADEQ 2006c). The comparison is for 

the 1992 to 2003 data. What is the sample number for each of the site class categories compared? Should there not 

be a similar number of stressed sites to compare to reference sites so that the sample numbers are balanced? 

Similar sample sizes would support a more robust statistical comparison than in the present situation with unequal 

sample sizes for un-paired samples (Steel and Torrie 1960). A larger sample size may be needed to support the 

conclusions that the 10th percentile is the absolute threshold for a standard violation determination and that the 

25th percentile is the minimum threshold for a standard violation determination for Arizona warmwater sites. 

As there was not a significant difference between sites designated as reference and those as non-reference, 

why not combine the data to derive the ADEQ Warmwater IBI scores? 

Response: The table below provides the number of samples in each of the site class categories shown in 

Figure 5 of the technical support documentation for the Narrative Biocriteria Standard. The number of a-priori 

identified reference sites is greater than the number of stressed sites and samples, due to the concentration of effort 

to develop reference sites during the first few years of biocriteria research effort. The concentrated effort on 

“reference condition” was necessary because the Indexes of Biological Integrity are ultimately based on robust 
148 

reference conditions, not stressed conditions. While a larger number of stressed samples would be ideal, 30 

samples are generally considered a large enough sample size to make inferences about stream conditions. A larger 

sample size is not needed to support the use of the 10th percentile as the threshold for a standards violation 

determination because this quantile reflects such a low percentage of reference conditions and approximates the 

median of stressed samples in the warm water distribution and approximates the 75th percentile in the cold water 

distribution of stressed samples. 

Number of sites Warm water 

Reference (a-priori) 131 

Non-reference + unknown 189 

Stressed (a-priori) 30 

Total number of sites 350 

Figure X. Box plot distribution of reference and stressed Arizona Index of Biological Integrity scores for 

warm water and cold water, with proposed biocriteria thresholds (ADEQ, 2007). 

The suggestion to use non-reference condition as the basis for the biocriterion is not valid. Non-reference is 

not a scientifically defensible approach to setting biocriteria thresholds. Developing reference condition is critical 

to the interpretation of biological surveys. EPA guidance states the “the reference condition establishes the basis 

for making comparisons and for detecting use impairment...” Following EPA guidance in the Rapid 

Bioassessment Protocols (Barbour et al., 1999), the Department dedicated three years of data collection effort into 

developing a dataset of reference site macroinvertebrate samples by which to create indexes of biological integrity 

to make biological assessments. Using non-reference sites to establish thresholds is not a technically valid 

approach. 

Comment #58

Joseph S. Volosin, Parametrix, on behalf on the Pinal Creek Group

Because streams have a fair amount of variability over time and space, a single sample event is 

inappropriate to evaluate the biological integrity of the entire site. Between-year and within-riffle differences can 
149 

be fairly high for some sites. The condition of the macroinvertebrate community may not necessarily be reflected 

in the results of a single sample. More than one sample is needed to evaluate the initial and verification sample (if 

needed). For any particular site, multiple samples should be collected over time and for each sample collection 

event. Therefore, multiple samples in each of two seasons should be the minimal sample number collected to 

evaluate biotic integrity. 

An understanding of this variability is especially needed when a site is scored near the threshold (Barbour 

et al. 1999). Furthermore, the variability around a single sample should be known and taken in to account even for 

reference samples by understanding the standard deviation of repeated measures for streams (Barbour et al. 1999). 

Therefore, single sample variability should be taken into account as described in Parametrix (2006). 

Response: Streams do have natural variability over space and time. The Department methods and the IBIs 

have encompassed that variation by sampling more than 100 cold and warm water reference sites statewide and 

over a 5-year period for inclusion in the Indexes of biological integrity. In addition, a large amount of natural 

variation is controlled by the sampling protocols (specified sampling habitat, collecting season, standardized 

methods), and lab taxonomy protocols (genus level standard taxonomy and standardized lab protocols). The 

Department has found low variability in repeat reference samples collected during the early 1990s, with a standard 

deviation of the reference site IBI scores of 7 percent (Gerritsen & Leppo, 1998). However, some year-to-year 

variation in IBI scores is natural because of flooding or drought conditions. When these conditions result in an 

impaired bioassessment score, the assessment process will evaluate the cause as natural. Riffle-to-riffle variability 

is not an issue because the Department sampling method specifically calls for compositing within the available 

riffle habitats in the reach. Compositing over 9m2

 (a much larger area than most state bioassessment methods) of 

stream bottom maximizes the taxa richness estimate for the study reach and reduces the amount of variability 

between samples. 

The Department made a large investment in developing robust IBIs that encompass spatial and temporal 

variability in reference stream macroinvertebrates and represent a composite condition by which to measure single 

samples from study sites. A single sample is sufficient for determining whether the biological integrity standard 

has been met for the following reasons: 1) a single macroinvertebrate sample represents long term, ongoing 

conditions because they reside in streams year-round, 2) Department sampling protocols limit variability by 

targeting specific habitat, collection period, and sampling conditions, 3) the Department Indexes of Biological 

Integrity are robust tools, including metrics from four categories of structural and functional measures that limits 

variability associated with a single metric approach; 4) a large, statewide reference dataset collected over a 6-year 

period was used to develop the reference thresholds; and 5) the 10th percentile of reference will be used as the 

threshold for identifying impairment for a single macroinvertebrate sample. This is a very low threshold at which 

there is a high certainty of correctly identified impairment. 

The supporting documents that describe the development of the IBIs include references to two different 

time periods. The abstract for the “Development and Testing of a Biological Index for Warmwater Streams of 

Arizona” states that the warm water IBI is based on the analysis of benthic macroinvertebrate data collected from 

1992-1997 (5 years). The abstract for the “Development and Testing of A Biological Index for Coldwater Streams 

of Arizona” states that the coldwater IBI is based on the analysis of macroinvertebrate data collected by ADEQ 
150 

from 1992-1998 (a 6-year period). See Response #55. 

Comment #59

Joseph S. Volosin, Parametrix, on behalf on the Pinal Creek Group

In Table 1 of the Biocriteria TSD, the discriminatory power of the separate metrics are evaluated by 

comparing “ref” (reference) and “edw” (effluent dominated) streams. If effluent dominated streams are not to be 

evaluated under the implementation of the narrative biocriteria standard, then why are effluent dominated streams 

used to evaluate the discriminatory power of the separate metrics? Should not a-priori stressed sites be used to 

evaluate the discriminatory power of the separate metrics? 

Response: Macroinvertebrate samples from effluent-dependent waters were used in the IBI analysis 

because they were known to be stressed from high nutrient concentrations and possibly other contaminants. 

Samples from known stressed sites and multiple stressors are a necessary dataset for testing the discriminatory 

ability of the IBI to detect impairment of biological integrity. The effluent-dependent streams in the Department’s 

dataset fit the stream class the IBI was designed for: perennial, wadeable streams. Samples from sediment stressed 

sites in wadeable, perennial streams were used in the stressed sample dataset. The proposed biocriteria do not 

apply to effluent-dependent streams because the Department does not know what the attainable biological 

integrity of these water bodies is.

Comment #60

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The draft guidance document (dated April 2008) for the narrative biocriteria standard includes application 

elements that are not specified in R18-11-108.01, but are critical components of the proposed biological standard. 

These additional application elements include that wadeable, perennial streams must contain fast-flowing riffle or 

run habitat, not be dominated by bedrock or travertine, and be sampled during the spring index period. These 

additional elements should be included in the rule to clarify that if these elements are not present the narrative 

biological standard is not applicable. Further, the inclusion of these additional elements will help to ensure that the 

narrative biological standard proposed by ADEQ in R18-11-108(E) applies only to wadeable, perennial streams 

capable of supporting the type of fauna intended to be protected by the proposed rule 

Response: The language in the biocriteria rule is clear and concise. The language regarding wadeable and 

perennial is included in the rule to specify the appropriate stream type to which one of the IBIs will apply. 

However, the other application elements are part of the broader sampling methodology that is discussed in the 

Implementation Plan guidance document and the sampling procedures are fully disclosed in the appendix of the 

guidance document. It is unnecessary to address all the sampling methodology in rule, especially when it is 

provided in an approved QAPP (ADEQ, 2006). No change has been made to the rule. 

Comment #61

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ should revise proposed R18-11-108.01 as follows: 
151 

R18-11-108.01 Narrative Biological Standard Implementation Procedures

A. The narrative biological standard implementation procedures in R18-11-108(E) this Section apply

applies only during the spring index period (April-May for warm water streams and May-June for cold water 

streams) to a wadeable, perennial stream with fast-flowing riffle or run habitat with a heterogeneous substrate 

that is not dominated by bedrock or travertine and the wadeable, perennial stream has either an aquatic and 

wildlife (cold water) or an aquatic and wildlife (warm water) designated use. 

B. The biological standard in R18-11-108(E) is met when a bioassessment result, as measured by the 

Arizona Index of Biological Integrity (IBI) for cold or warm water is: 

1. Greater than or equal to the 25th percentile of reference condition, or 

2. Greater than the 10th percentile of reference condition and less than the 25th percentile of reference 

condition and a verification bioassessment result is greater than or equal to the 25th percentile of reference 

condition. 

C. Arizona Index of Biological Integrity (IBI) scores. 

Index of Biological Integrity Scores

Bioassessment Result A&We A&Ww 

Greater than or equal to the 25th 

percentile of reference conditions 

≥52 ≥50 

Greater than the 10th and less than the 

25th percentile of reference condition 

46 - 51 40 - 49 

D. A violation of the biological standard in R18-11-108(E) shall be determined based on the IBI goal in 

subsection (B) and the biocriteria implementation procedures adopted by the Department in accordance with 

A.R.S. § 49-232(F). 

E. Application or use of the biological standard in any AZPDES permit shall be as described in the 

biocriteria implementation procedures adopted by the Department in accordance with A.R.S. § 49-232(F). 

Response: The Department disagrees that R18-11-108.01 should be revised as recommended by the 

Coalition. The objective criteria for determining whether the narrative biocriteria standard is met are prescribed in 

the rule at R18-11-108.01(B) and (C). The Department agrees that compliance with the proposed biocriteria 

standard is determined from bioassessment results as measured by the Arizona Indexes of Biological Integrity for 

cold or warm water streams. However, the Department does not agree that this compliance determination is 

dependent on the adoption of “biocriteria implementation procedures adopted by the Department in accordance 

with A.R.S.§ 49-232(F).” The proposed rule already states how the Department will determine compliance with 

the narrative biocriteria standard. There is no need to refer to other implementation procedures adopted under 

A.R.S. § 49-232(F). 

The Department disagrees with the commenter’s addition of new subsection (E). The Department is 

adopting surface water quality standards rules, not rules for the AZPDES permit program. The appropriate place 

for rules addressing implementation of biocriteria in AZPDES permits are the AZPDES permit rules found in 18 

A.A.C. 9, Article 9. 
152 

Comment #62

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ also fails to disclose whether it performed a truly independent analysis of its methods in selecting 

data sets providing the basis of its biocriteria standard. A data set should be comprised of a priori unclassified, 

impacted and no-impacted, non-reference sites, and ADEQ should have then determined how well its methods 

correctly identified sites that would be meeting or not meeting the proposed biocriteria standard. 

The Coalition therefore recommends that ADEQ explain its methods for selecting data sets.

Response: A complete discussion of how the Indexes of Biological Integrity for macroinvertebrates were 

developed is provided in the “Technical Support Documentation for the Narrative Biocriteria Standard” (ADEQ, 

2007). The analytical methodology for developing the reference condition dataset is provided as well as the 

rationale for testing and development of the Indexes. The statistical analysis was conducted by TetraTech Inc., for 

the Department and followed standard EPA statistical approaches for development and testing of IBIs. This 

included development of the Indexes using one dataset (statewide), then independently testing the resulting Index 

using a separate and independent dataset (Verde River basin). 

Comment #63

Sandy Bahr, Sierra Club  Grand Canyon Chapter

This provision adds a new important aspect to the surface water quality standards and will aid the ADEQ 

substantially in working toward the goal of restoring biological integrity to our surface waters. The health and 

diversity of the biological community can provide important information on how the surface water system is 

functioning. 

Response: The Department appreciates the comment. 

Comment #64

Sydney Hay, Arizona Mining Association

On their face, the new implementation procedures (“IPs”) associated with the narrative biological integrity 

criterion apply to any wadeable perennial stream with a cold water or warm water aquatic life use designation 

(i.e., any water that is not ephemeral or EDW). See proposed A.A.C. R18-11-108.01(A). However, the draft 

implementation procedures themselves (p. 3) include additional applicability factors that are not, but should be, 

specified in the rule. These criteria are: (1) presence of fast-flowing riffle or run habitat; (2) water is not 

dominated by bedrock or travertine; and (3) sampling occurs during the spring index period. The rule should make 

clear that these factors must be present in order to assess compliance with the biological criterion.

Response: The Department disagrees that the proposed R18-11-108.01(A) should include additional 

applicability factors based on the sampling protocols described in the draft implementation procedures document. 

The proposed rule clearly states that the narrative biocriteria standard applies to wadeable, perennial streams with 

the A&Wc or A&Ww designated use. No change has been made to the rule.
153 

R18-11-108.02. NARRATIVE BOTTOM DEPOSIT CRITERIA FOR WADEABLE, PERENNIAL 

STREAMS

Comment #65

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Similar to the proposed narrative biocriteria standard language, ADEQ should clarify that the proposed 

narrative bottom deposits criteria apply only to wadeable, perennial streams, and that they do not constitute 

“implementation procedures” as that term is understood in the TMDL context. As such, the Coalition recommends 

that ADEQ revise its proposed R18-11-108.02 as follows: 

R18-11-108.02. Narrative Bottom Deposits Standard Implementation Procedures

A. The narrative bottom deposit implementation procedures standard in this Section applies only apply

to wadeable, perennial streams with an aquatic and wildlife (cold water) or an aquatic and wildlife (warm water) 

designated use. 

B. The narrative water quality standard for bottom deposits at R18-11-108(A)(1) is met when: 

1. The percentage of fine sediments in the riffle habitats of a wadeable, perennial stream with an 

A&Wc designated use, as determined by a riffle pebble count, is less than or equal to 30 percent. 

2. The percentage of fine sediments in the riffle and run habitats of a wadeable, perennial stream with 

an A&Ww designated use, as determined by a reach level pebble count, is equal to or less than 50 percent. 

C. A violation of the narrative bottom deposits standard at R18-11-108(A)(1) shall be determined 

based on the criteria in subsection (B) and the narrative bottom deposits standard implementation procedures 

adopted by the Department in accordance with A.R.S. § 49-232(F).

D. Application or use of the narrative bottom deposits standard criteria in any AZPDES permit shall be 

as described in the narrative bottom deposits standard implementation procedures adopted by the Department in 

accordance with A.R.S. § 49-232(F).

Response: The Department will change the Section title to be clear that this rule is not the implementation 

procedure that will be adopted as agency guidance and that this rule applies only to wadeable, perennial streams. 

See Response #53. The language for A&Ww streams has been revised to eliminate the reference to “riffle and 

run” and replaced with “all stream habitats.” The Department does not agree that the language proposed to be 

added in subsections (C) and (D) is necessary for the clarity or implementation of the rule for the same reasons 

stated in Response #61. The Department has revised the rule as follows: 

R18-11-108.02. Narrative Bottom Deposit Criteria for Wadeable, Perennial Streams

A. The narrative bottom deposit criteria in this Section apply to wadeable, perennial 

streams with an aquatic and wildlife (cold water) or an aquatic and wildlife (warm 

water) designated use.

B. The narrative water quality standard for bottom deposits at R18-11-108(A)(1) is 

met in perennial waters when:

1. The percentage of fine sediments in the riffle habitats of a wadeable, 

perennial stream with an A&Wc designated use, as determined by a riffle 

pebble count, is less than or equal to 30 percent.
154 

2. The percentage of fine sediments in all stream habitats of a wadeable, 

perennial stream with an A&Ww designated use, as determined by a reach

level pebble count, is equal to or less than 50 percent.

Comment #66

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We are supportive of this change in the standards as it again helps to implement the goal of restoring 

biological integrity to our surface waters. Sedimentation of our streams and rivers can adversely affect the benthic 

macroinvertebrate community, a key component of a healthy surface water, and greater sedimentation can 

adversely affect species of trout. The Sierra Club has participated in one training and has also done at least one 

field trip using the procedures outlined in the Narrative Bottom Deposits Standard Implementation Procedures for 

Wadeable, Perennial Streams, April 2008. These procedures are clear and relatively easy to implement in the 

field. They will help to determine the biological condition of our state’s wadeable streams. 

Response: The Department appreciates the comment. 

Comment #67

Sydney Hay, Arizona Mining Association

The standard applies on its face to any wadeable, perennial stream. See proposed A.A.C. R18-11-

108.02(A). The draft IPs make clear that the standard only makes sense in the context of riffle and run habitat, as 

that is the environment in which high sediment can adversely affect benthic macroinvertebrates and other 

organisms using stream bottoms (e.g., fish laying eggs). This should be made explicit clear in the applicability 

section of the rule (R18-11-108.02(A)). Absent such clarification, the procedures could be applied to a “water” 

such as the tunnel and lined channel at the Asarco Ray Mine (which as noted above carry an aquatic life 

designation), even though those areas lack riffle or run habitat and thus logically should not be subject to these 

IPs. 

Response: The Department disagrees with the suggestion that language relating to riffle and run habitats be 

added to the applicability subsection in R18-11-108.02(A). The Department believes that the recommended 

language limiting the applicability of the narrative bottom standard is unnecessary because the target sampling 

habitats are specified in R18-11-108.02(B). See Response #65. The narrative bottom deposits standard applies to 

wadeable, perennial streams with natural substrates and not to concrete-lined tunnels and channels such as those 

constructed at the Asarco Ray Mine. The Department could not follow either the riffle pebble count or the reach 

level sampling protocol in such a highly modified system. 

R18-11-108.03. NARRATIVE NUTRIENT CRITERIA FOR LAKES AND RESERVOIRS

Comment #68

Janet Hashimoto, Chief; EPA Monitoring & Assessment Office

We commend ADEQ’s development of implementation procedures for narrative nutrient standards for 
155 

lakes and reservoirs as an important step to advance the quality of nutrient assessments. The implementation 

procedures proposed in section R18-11-108.03 follow EPA’s national guidance and include a weight-of-evidence 

matrix providing the basis for interpreting the narrative nutrient standards. ADEQ has created five functional lake 

classes, along with nutrient threshold values expressed as ranges of chlorophyll-a, Secchi depth, total nitrogen, 

total Kjeldahl nitrogen (TKN), total phosphorus, percent blue-green algae, and total count of blue-green algae. 

To accompany the proposed rule text, ADEQ developed draft guidance titled “Narrative Nutrient Standard 

Implementation Procedures for Lakes and Reservoirs,” April 2007 to be used for both ambient water quality 

assessment and permit compliance purposes. The guidance does not specify the method by which to translate 

narrative nutrient standards into numeric limits for inclusion in National Pollutant Discharge Elimination System 

(NPDES) permits. 

Because ADEQ has concurrently proposed to eliminate numeric nutrient limits for some water bodies 

(Theodore Roosevelt, Apache, Canyon, Saguaro, and San Pedro River from Curtiss to Benson) per section R18-

11-109.E, permit writers would need to rely on the narrative nutrient guidance to set numeric limits for NPDES 

permitted facilities located in these watersheds. We are concerned with the elimination of numeric standards 

absent a detailed procedure for translating the proposed narrative nutrient standards into permit limits. 

The rule should include the frequency of nutrient exposure, e.g., average peak season value, which is 

currently only specified in the guidance. 

Response: The Department appreciates EPA’s support for developing the narrative nutrient standard but 

disagrees that these permitting details should be included in the standard. They are appropriately included in the 

implementation procedures and ultimately in the AZPDES permit program rules. The narrative standard guidance 

documents are still being developed for the assessment, listing, and permitting program. Those processes are 

independent of surface water quality standards and should not affect adoption of this standard. 

The Department received a number of comments concerning use of the narrative nutrient matrix in 

AZPDES permits. While the implementation procedures guidance documents are not being adopted as part of this 

rulemaking, it is clear from the comments that the Department has not adequately described in the draft guidance 

document how it envisions use of the matrix in AZPDES permits. A review of the latest version of the guidance 

documents released in April 2008, finds several inconsistencies in the permitting section that no doubt caused 

reader confusion. While the guidance document is not being adopted as rule, a brief discussion of the permitting 

process is outlined in this response. The Department continues to refine its initial approach outlined in the April 

2008 draft IP and intends to develop a loading approach tailored to meet a lake-specific biomass target. The 

Department does not envision application of the narrative nutrient matrix (Numeric Targets Table) as end-of-pipe 

limits in AZPDES permits, at least initially. Proposed nutrient discharges will involve a number of steps including 

determining: the receiving water assimilative capacity, existing nutrient loads, and proposed loads (including any 

necessary lake management activities). This information would be used to determine the appropriate size of the 

mixing zone and to develop an appropriate monitoring plan to determine if the narrative nutrient standard is being 

attained in a lake or reservoir. 

As noted earlier, the Department has provided detailed responses to comments about the implementation 

guidance to the authors and will encourage those commenters to participate in future work sessions to finalize 
156 

those documents. 

Since this narrative nutrient standard only applies to lakes and reservoirs, removal of the nitrate standard on 

the San Pedro River is not at issue (see Response #87). If a permit for discharge to one of the four lakes identified 

by the commenter is submitted to the Department before the implementation procedures are finalized, the 

Department standards and permitting staff will work with the permittee to obtain the needed data to determine if 

the narrative nutrient standard is being met and to develop the appropriate permit conditions, including in-lake 

monitoring if needed, to ensure the standard is being attained in the lake. Currently there are three AZPDES 

permits for discharges to lakes. Two permits are small wastewater treatment plants (WWTP) at the marinas at 

Roosevelt and Canyon Lakes and the third permit is the discharge of reclaimed water to Lakeside Lake in Tucson. 

The Department will incorporate the provision of the narrative nutrient criteria in the renewal permits as 

appropriate. 

While the rule currently has the frequency of exposure, the Department agrees that the language should be 

clarified and has revised the first paragraph of R18-11-108.03(B) as follows: 

B. The narrative water quality standard for nutrients at R18-11-108(A)(6) is met if, based on 

a minimum of two sample events conducted during the peak season for lake productivity, 

the results show an average chlorophyll-a value below the applicable threshold for

designated use and lake category in subsection (D).

Comment #69

David E McNeil, City of Tempe

The Department has proposed to establish numeric criteria for implementation of the existing narrative 

water quality standard requiring surface waters to “not contain pollutants in amounts or combinations that cause 

the growth of algae or aquatic plants that inhibit or prohibit the habitation, growth, or propagation of other aquatic 

life or that impair recreational uses” (R18-11-108.A(6)), also known as the “narrative nutrient standard.” The City 

of Tempe opposes the establishment of the numeric criteria, as proposed, for several reasons: 

Many states have had challenges implementing the narrative nutrient standard due to the relationships 

between causal and response variables that are unique to each water body. Accordingly, EPA has responded to 

recent correspondence from both the Association of State and Interstate Water Pollution Control Administrators 

(ASIWPCA) and the National Resources Defense Council (NRDC) urging EPA to establish technology-based 

nutrient criteria by initiating the development of guidance on nutrient removal technology. Pending completion 

and distribution of this guidance to the states, which is expected in August, proceeding with the promulgation of 

nutrient criteria in Arizona is premature. The upcoming guidance should provide valuable information regarding 

the costs and feasibility of implementing nutrient removal technology, and may even suggest the use of 

technology-based criteria in lieu of numeric translators for the narrative standard. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

For example, many states have struggled to implement narrative nutrient standards due to the relationship 

between the causal and response variables unique to each waterbody. As such, the Association of State and 

Interstate Water Pollution Control Administrators (“ASIWPCA”) and the National Resources Defense Council 
157 

(“NRDC”) have urged EPA to establish technology-based nutrient criteria through the development of guidance 

on nutrient removal technology. EPA has responded that it intends to provide such guidance. ADEQ therefore 

should delay finalization of any narrative nutrient standard pending issuance of EPA’s guidance on 

implementation of nutrient removal technology. 

Response: The Department agrees that it has been challenging to develop criteria that translate the 

narrative nutrient standard into objective criteria that can be measured to determine whether the narrative standard 

is met. However, the Department disagrees that it is “premature” for the Department to propose numeric 

translators for Arizona lakes and reservoirs in this rulemaking. 

The Department will follow efforts by EPA, ASIWPCA and the NRDC to develop technology-based 

standards to control the discharge of nutrients. However, the potential future development of technology-based 

nutrient standards is not a substitute for the water quality-based approach developed by the Department to protect 

Arizona’s lakes and reservoirs with this new standard.

Comment #70

David E McNeil, City of Tempe

The proposed approach establishes chlorophyll-a as the primary criteria which, in concentrations below the 

numeric target range established in subsection D, indicates attainment of the nutrient standard. Weight-ofevidence criteria such as nitrogen and phosphorous are only evaluated for assessment purposes if chlorophyll-a is 

above the lower end of the target range. This approach to the narrative standard concludes that the response 

variable of chlorophyll-a is, by itself, a good indicator of attainment. 

The complex relationship between different causal variables and chlorophyll-a makes such a demonstration 

of assimilative capacity implausible. In addition, a limitation on the extent of chlorophyll-a response amounts to 

the inappropriate establishment of an antidegradation requirement for the narrative standard. Any attempt to 

preempt impairment by requiring dischargers to meet target thresholds for causal variables also ignores a lake 

manager’s authority and ability to attain the standard by managing the response variables using physical, 

biological, or chemical control of weeds and algae as established in A.A.C. R18-11-117. Accordingly, the 

proposed rule should specify that it is to be used for lake assessment only, and shall not be used to establish 

effluent limitations in the absence of a TMDL. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The determination of assimilative capacity is nearly impossible due to the complex relationship between 

causal variables. Also, ADEQ’s limitation on the degree of chlorophyll-a response amounts to an inappropriate 

establishment of an antidegradation standard through the draft guidance document. Furthermore, ADEQ’s efforts 

to prevent impairment by requiring permittees to meet target thresholds for causal variables fails to consider a lake 

manager’s ability, under A.A.C. R18-11-117, to manage response variables using physical, biological, or chemical 

controls to attain SWQS. 

ADEQ should clarify that the proposed narrative nutrient standard applies only to lake assessment, and is 

not relied upon in promulgating discharge limits absents ADEQ’s establishment of a total maximum daily load 

(“TMDL”) for the lake in question. 
158 

Response: The Department is adopting the chlorophyll-a criterion as the primary endpoint for meeting the 

narrative nutrient standard (except when the lake is designated as a shallow lake outside of the urban context – see 

rule clarification below). Chlorophyll-a is an EPA-approved surrogate for aquatic plant biomass and is included in 

the National Nutrient Criteria established for Lakes and Reservoirs in 2001/2002. The Department disagrees that 

the limitation on the degree of chlorophyll-a response is an antidegradation standard. It is a primary end-point for 

meeting the standard as established in EPA documents and scientific literature. Although the causal-response 

relationship is complex and always in flux, chlorophyll-a, in combination with the standards for dissolved oxygen 

(DO), pH, and ammonia, is considered to be the most feasible alternative in assessing support of aquatic and 

wildlife designated use with regard to nutrients. The Department disagrees that determination of assimilative 

capacity is impossible. It is similar to determining standards attainment at the edge of a mixing zone. The mixing 

zone rule has been in the standards since 1992 and a number of permits have been written with them. See 

Response #68. 

The Department disagrees that the proposed narrative nutrient standard applies only to assessments and 

cannot be used to establish effluent limitations in the absence of a TMDL. Narrative standards are independently 

applicable in determining whether a waterbody is meeting its designated uses. However, how the narrative 

nutrient standard and matrix is to be used in assessments, impaired waters listings and in discharge permits is still 

under development and will be discussed in the context of guidance documents and in the appropriate 

rulemakings. 

To clarify the standard for shallow lakes outside of an urban context, the the following minor revisions to 

R18-11-108.03(B)(3) have been made: 

3. For a shallow lake. In addition to meeting the mean chlorophyll-a concentrations in (B)(1) 

or (2) above, submerged aquatic vegetation covers 50 percent or less of the lake bottom 

and there is less than a 5 mg/L swing in diel dissolved oxygen concentration measured 

within the photic zone. 

Comment #71

David E McNeil, City of Tempe

The establishment of Total Nitrogen as supporting criteria for chlorophyll-a concentrations to assess 

compliance with the narrative nutrient criteria is not supported by the 2005 Statistical Modeling and Analysis 

Report. While the data supports a strong positive correlation between TKN and chlorophyll-a, the data also 

establishes that the correlation between Total Nitrogen and chlorophyll-a is only moderate (Report, p. 4-13; p. 4-

28;) and that the correlation between chlorophyll-a and nitrate as well as nitrate-plus-nitrite is weak (Report, p. 4-

4; p. 5-1). The data also indicates that TKN generally comprises upwards of 70% of Total Nitrogen (Report, Table 

B-2) and that the correlation between TKN and Total Nitrogen is one of the strongest observed correlations 

(Report, Table 4-2). This demonstrates that the moderate correlation between Total Nitrogen and chlorophyll-a is 

incidental to the TKN/chlorophyll-a correlation, and not demonstrative of a causal relationship. Concentrations of 

Nitrogen species other than TKN are not statistically correlated with nutrient impairment, making the use of Total 

Nitrogen as supporting criteria arbitrary. 
159 

The use of the remaining nutrient targets independently as supporting criteria for chlorophyll-a

concentrations to assess compliance with the narrative nutrient criteria is also not supported by the Statistical and 

Modeling Analysis Report. As described above, any correlation between Total Nitrogen and chlorophyll-a appears 

to be incidental to the TKN/chlorophyll-a correlation, making the use of Total Nitrogen as supporting criteria for 

chlorophyll-a arbitrary in the absence of elevated TKN. The report also concludes that the strong correlation 

between TKN and chlorophyll-a is partially derived from (TKN’s) correlation with Total Phosphorous (Report, p. 

4-14). In addition, Total Phosphorous becomes much more of a causal factor when TKN (and accordingly Total 

Nitrogen) concentrations decrease (Report, p. 4-4). This information demonstrates that TKN and Total 

Phosphorous have a synergistic rather than independent effect on chlorophyll-a. Accordingly, the use of TKN and 

Total Phosphorous target ranges independently as supporting factors in assessing compliance with the narrative 

nutrient criteria is arbitrary. The language in proposed A.A.C. R18-11-108.03(B)(2)(c)(vi) should exclude Total 

Nitrogen, and the word “or” should be replaced with “and.” 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ’s establishment of target criteria for Total Nitrogen is erroneous, because the correlation between 

Total Nitrogen and chlorophyll-a established in ADEQ’s statistical modeling report is incidental to the TKNchlorophyll-a concentration. 

Response: The Statistical and Modeling Analysis Report by Malcolm Pirnie is comprised of various data 

analysis techniques applied to Arizona lake and reservoir data. The goal was three-fold: 1) develop a 

lake/reservoir classification system to support nutrient-related initiatives, 2) derive numeric and non-numeric 

endpoints for assessment, and 3) incorporate these elements into formal implementation procedures for assessment 

of lake conditions and determination of compliance with the narrative nutrient standard. The analyses discussed in 

this report laid the empirical foundation for the second document, Potential Nutrient-related Targets for Arizona 

Lakes and Reservoir, which culminated in the matrix of threshold values proposed in this rulemaking. It is 

important to understand that the threshold ranges for specific nutrients were derived from empirical relationships 

found in Arizona lake data. The ranges for total P, total N, TKN, and secchi depth are not intended to be 

predictive of chlorophyll-a, but are used as corollary information in a weight-of evidence evaluation for 

determining evidence of nutrient-related impairment (see R18-11-108.03(B)(2)). These supporting thresholds are 

there for the reviewer/evaluator so that if/when future data do not reflect these ranges, it may be a trigger for 

further investigation. Regardless, comparison of future data to these threshold ranges will be used to solidify or 

possibly to refine our understanding of lake classes and/or how a lake that falls in multiple classes may respond.

The inclusion of total nitrogen in the matrix is intentional. The commenter is correct in saying that TKN 

was found to have the most powerful correlation to chlorophyll-a, but this may or may not be equally predictive. 

Including total nitrogen and TKN allows the evaluation of nitrate+nitrite-N by subtraction when comparing 

assessment data with matrix thresholds. In addition, along with TKN, the Department will evaluate ammonia 

values in combination with TKN values and other event-related lake data to track relationships between physical, 

chemical and biological conditions. No change has been made to the rule. 

Comment #72
160 

David E McNeil, City of Tempe

The use of DO and pH standards as supporting criteria for chlorophyll-a concentrations to assess 

compliance with the narrative nutrient criteria is not supported by ADEQ’s February 2005 Statistical and 

Modeling Analysis Report. Specifically, the Summary and Conclusions section of this report indicate that 

“dissolved oxygen and pH concentrations were also largely independent of other parameters, and did not even 

correlate strongly with algal chlorophyll-a.” The DO and pH standards are stand-alone criteria, exceedances of 

which constitute an exceedance of numeric standards. There is no reason or basis for establishing these criteria as 

supporting criteria for the response variable of chlorophyll-a, especially when causality has not been established. 

There are many issues regarding the proposed narrative nutrient standard that warrant removal of the 

standard from the current revision of water quality standards. Alternatively, Tempe requests that chlorophyll-a be 

established as stand-alone criteria with a standard at the upper end of the target thresholds presented in the rule. If 

a lake is listed for narrative nutrients based on chlorophyll-a, a study of the causal factors specific to a water body 

could then be undertaken through the TMDL process. 

Response: The Department disagrees that the proposed narrative nutrient standard should be removed or 

reduced to a stand-alone chlorophyll-a criterion. While the Department agrees that an exceedance of the upper end 

of the target thresholds for chlorophyll-a represents an exceedance of the narrative nutrient standard, an 

exceedance of the narrative nutrient standard is also demonstrated when chlorophyll-a concentrations are within 

the range of thresholds presented in the matrix and there is other evidence of nutrient-related impairments such as 

exceedances of target thresholds for dissolved oxygen, pH, Secchi depth, total nitrogen, total phosphorus, and 

blue-green algae. 

While the standards for dissolved oxygen (DO) and pH do stand alone, they are also relevant to aquatic 

ecosystem function and nutrient cycling. DO and pH are related to productivity (rate of biomass production and 

are therefore relevant to biomass and to the narrative nutrient standard. The matrix includes these parameters in 

the weight of evidence (see R18-11-108.03(B)(2) and (B)(3)) used to determine whether a chlorophyll-a value 

within the target range may or may not be correlated with exceedances of DO and/or pH, secchi depth, blue-green 

algae, TKN, TP, or TN above the corresponding ranges. The ammonia standard is not cited specifically, but 

ammonia also is relevant, as it is the preferred nitrogen form over nitrate for uptake, as is orthophospate. So 

correlation is not causation, but is used to inform further investigation. 

Comment #73

Robert A. Hollander, City of Phoenix

The Water Services Department requests that park lakes that include reclaimed water should be excluded 

from meeting the proposed nutrient criteria. There should be no public health impact using reclaimed water in park 

lakes with a partial body contact (PBC) designated use especially since reclaimed water used for these purposes in 

Arizona must meet the restricted use pathogen requirements under an Aquifer Protection Permit. Many golf 

courses that use reclaimed water for irrigation store excess reclaimed water for future use in those lakes. The 

nutrients in reclaimed water are essential for adequate irrigation and one of the benefits of using reclaimed water. 

This could have a major capital and operation and maintenance cost impact on water utilities for further treatment 
161 

facilities and on water resources if the lakes have to be filled with potable water. Please see the comments, to the 

Preamble above, regarding the use of reclaimed water. The proposed rule could eliminate the option of using 

reclaimed water in park lakes. 

Response: The narrative nutrient standard for urban lakes will only apply to those lakes classified in 

Appendix B of the surface water quality standards, not to every impoundment storing reclaimed water. The lakes 

listed in Appendix B have met the criteria for waters of the United States and must be protected for aquatic life 

support and, at a minimum, for partial body contact. The list of lakes to which the narrative nutrient standard 

applies is further limited to those lakes that have been “classified” according to the controlling lake characteristic 

(e.g., igneous, sedimentary, urban). The commenter is correct in that many golf courses store excess irrigation 

water in golf course lakes but the Department believes the vast majority of these lakes are not waters of the United 

States and this new narrative nutrient standard would not apply to these impoundments. See Response #77.

Comment #74

David E McNeil, City of Tempe

Because nutrient removal to the target ranges established in the proposed narrative nutrient standard is 

unachievable without employing reverse osmosis or other similar technology, the rule in conjunction with the 

April 2008 draft IP creates an effective prohibition on the beneficial reuse of reclaimed water in Arizona’s lakes. 

The rule and IP are inconsiderate of the challenges that Arizona faces in ensuring a sustainable water supply into 

the future. As water stewards, it is our responsibility to prepare for cyclical droughts as well as reductions in water 

supply induced by climate change. The effective prohibition on the use of reclaimed water in lakes is contrary to 

EPA’s March 2008 draft “National Water Program Strategy: Response to Climate Change,” which outlines the 

need to consider water sustainability in making regulatory decisions such as changes in standards or more 

stringent permit limits, and emphasizes the need to promote the recycling and reuse of water. Establishing 

discharge-prohibitive permit limits for causal variables despite every indication of a healthy water body based on 

an assessment of the response variable is not true to EPA’s Climate Change Strategy, lacks foresight, and fails our 

commitment to water stewardship. 

Response: The Clean Water Act requires criteria that are protective of the waterbody’s highest and best 

designated uses. That is why the proposed chlorophyll-a criteria have been tiered from Domestic Water Source 

(DWS) down through full body contact to Aquatic and Wildlife (A&W) endpoints. Use of lakes as reclaimed 

storage impoundments is an ancillary use that may not be compatible with the lake’s ability to handle nutrient 

inputs and still meet the appropriate standards for the designated uses of the lake. As long as a lake carries (at a 

minimum) A&W designated use, the impact of nutrient loading must be considered because the narrative standard 

at R18-11-108(A)(6) was adopted to ensure the protection of aquatic life and recreational uses. 

Most reclaimed water impoundments that are created in a waters of the United States would likely be 

classified as A&W urban. This matrix category has the least stringent range for protection allowing up to 50 ug/L 

for chlorophyll-a. An upper threshold of 50 ug/L for chlorophyll-a is designed to keep the lake from becoming 

hyper-eutrophic while meeting DO and pH standards. Lakeside Lake in Tucson, is the only lake that received 

reclaimed water that had a sufficiently robust data set for use in the statistical analysis. For the time period 
162 

modeled, Lakeside Lake was found to be marginally attaining its designated uses but required active in-lake 

treatment to greatly reduce phosphorus. 

The matrix does not require attainment of target values at end of pipe. Rather, it is an assessment of the 

lake’s ability to assimilate nutrient inputs. Use of reclaimed water as source water for a lake may be considered on 

a case-by-case basis, however, current levels of nutrients in reclaimed water are orders of magnitude higher than 

those found in surface water. The case-by-case determination will, to the degree possible, recognize that impacts 

of a reclaimed water discharge may vary with factors including size of the impoundment, quality of other source 

water, retention time, surface area, prevailing wind direction or currents, depth as well as the volume, setting, 

climatic conditions, suspended particulate matter, nutrient species present and total load, and timing of the 

proposed reclaimed water discharge. It is expected that lakes proposed for use of reclaimed water as source water 

will require moderate-to-intensive management to meet A&W and contact recreation standards. Even without 

reclaimed water, many of these systems require chemical, physical, or biological management on some level. The 

narrative nutrient matrix is an active and pre-emptive approach to ensuring attainment of the designated uses to 

protect human health, aquatic life, and wildlife. See Response #68.

Comment #75

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ’s proposed narrative nutrient standard implementation procedures at R18-11-108.03 establishes 

unnecessarily strict nitrogen and phosphorus targets for Arizona lakes and reservoirs. 

Pima County believes for the reasons detailed in our attached letter the proposed nitrogen and phosphorus 

target levels, which create a strict numeric prohibition, are not scientifically defensible. This proposed rule would 

effectively create a prohibition of use of reclaimed water into Arizona lakes due to the incorporation of the 

proposed nitrogen and phosphorus limits into discharge permits. These limits would be imposed even if a true 

measure of lake impairment could not be verified with chlorophyll-a measurements. In light of the number of 

waters in Arizona that are being created as part of ecological restoration projects, that need sources of water such 

as reclaimed water to allow them to remain viable and healthily without the wasteful use of scarce groundwater, 

ADEQ should carefully consider the recommendations of our attached letter and modify its implementation 

procedure to accommodate the use of reclaimed water in Arizona lakes under certain circumstances. Most Arizona 

constructed wastewater treatment facilities cannot treat effluent to meet the nitrogen and phosphorus limits 

proposed in this rule and therefore valuable ecological restoration projects in Arizona will potentially not be 

accomplished as a result. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ’s proposed narrative nutrient criteria creates an effective prohibition on the use of reclaimed water 

in Arizona’s lakes by mandating the use of nitrogen and phosphorus targets to establish permit limits for all 

discharges, even if the response variable (chlorophyll-a) concentrations are not indicative of impairment. Without 

costly treatment processes, no reclaimed water plant can meet the nutrient limits that will be established for all 

plants in the state based on the proposed procedure (i.e., 1.2 to 1.5 ppm for Total Nitrogen; 0.07 to 0.1 ppm for 

Total Phosphorus). ADEQ’s proposal therefore has potentially paralyzing consequences with regard to future 
163 

water management and water conservation methods in recycling water in Arizona, particularly for municipalities 

which operate WWTPs. 

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

ADEQ’s proposed narrative nutrient criteria make it nearly impossible to use reclaimed water in Arizona’s 

lakes and are contrary to the State’s drought management and sustainable water management objectives for 

replacing groundwater and other sources with reclaimed. The rule could be used by permit writers to require 

nitrogen and phosphorus targets as permit discharge limits, even if the response variable (chlorophyll-a) 

concentrations are not indicative of impairment. Without more costly treatment than most denitrifying wastewater 

plants achieve, reclaimed water cannot generally meet the nutrient limits that would be based on the proposed 

procedure (i.e., 1.2 to 1.5 ppm for Total Nitrogen; 0.07 to 0.1 ppm for Total Phosphorus). The proposed rule, 

therefore, has downside impacts on both cost and water conservation that have not been considered in ADEQ’s 

estimated costs and benefits. 

Response: The Department disagrees that the numeric thresholds for total nitrogen and total phosphorus 

are unnecessarily strict and scientifically indefensible. The thresholds are based on the statistical analysis of 

empirical data obtained from Arizona lakes and reservoirs and summarized in the Lakes and Reservoirs Statistical 

and Modeling Analysis Report, which provided the technical supports for the adopted rule. The analyses discussed 

in this report laid the empirical foundation for the second document, Potential Nutrient-related Targets for 

Arizona Lakes and Reservoir, which culminated in the matrix of threshold values adopted in this rulemaking. 

The Department also disagrees that the translator procedures for the narrative nutrient standard will make it 

nearly impossible to discharge reclaimed water into an Arizona lake regulated under the proposed surface water 

quality standards or to a lake and reservoir that is part of ecological restoration project. See response #74. The 

proposed numeric targets for total nitrogen and total phosphorus in the table at R18-11-108.03(D) do not create a 

strict numeric prohibitions as they are not independently enforceable numeric water quality standards. Rather, they 

represent secondary criteria that are intended to be used in combination with the primary response variable, 

chlorophyll-a, to determine whether the narrative nutrient standard is attained or not. The numeric targets for total 

nitrogen and total phosphorus in the matrix in R18-11-108.03(D) will be applied using a weight-of-evidence 

approach to determine the “sufficient assimilative capacity,” as increasing nutrient load will trigger increased 

productivity, change in biomass, and possible negative shifts in aquatic community structure and function. 

Weight-of-evidence (see R18-11-108.03(B)(2) and (B)(3)) in this context refers to the application of matrix 

thresholds taken together as a set of parameters that inform the Department’s determination as to whether there is 

excessive plant and algae growth that inhibits or prohibits the habitation, growth, or propagation of aquatic life or 

that impairs recreational uses proscribed under R18-11-108(A)(6). It is clear from the language of the adopted rule 

and the Department guidance that the numeric target levels were never meant to be stand-alone nutrient standards. 

A point source discharge of reclaimed water into a lake regulated as a surface water may require higher 

levels of treatment to reduce nutrient loads before the reclaimed water can be used as a source of water in a lake. 

For some lakes, a higher level of treatment may be necessary to maintain and protect water quality for the lake’s 

designated uses. This may be the case where reclaimed water is a sole source or a significant percentage of the 
164 

water for an urban lake. For example, a small point source discharge of treated wastewater to a large lake such as 

Lake Roosevelt presents a very different set of facts from an urban lake that is created entirely of reclaimed water 

(e.g. Lakeside Lake in Tucson) or one where the use of reclaimed water is being considered (e.g. Tempe Town 

Lake). 

The Department supports the reuse of reclaimed water for beneficial use. As the commenters are aware, the 

Department has adopted reclaimed water quality standards for the direct reuse of reclaimed water and has 

established a reuse permit program to regulate the direct reuse of reclaimed water for recreational and landscape 

impoundments and for other reuse applications. The Department designed the reclaimed water quality standards 

and the reuse permit program to encourage the direct reuse of reclaimed water. However, the existence of 

Department programs to regulate the direct reuse of reclaimed water does not replace or substitute for the surface 

water quality standards program and the AZPDES permit program which regulates the discharge of pollutants to 

waters of the United States under the Clean Water Act. 

Comment #76

David E McNeil, City of Tempe

The establishment of standards that will result in extreme nutrient limits in AZPDES should be further 

scrutinized in the context of carbon footprint, greenhouse gas emissions, and sustainability. EPA’s March 2008 

draft “National Water Program Strategy: Response to Climate Change” points out that energy use by drinking 

water and wastewater facilities accounts for three percent of energy consumption in the United States, resulting in 

emissions of approximately 116 billion pounds of CO2 per year. The technology necessary to reduce nutrients to 

unrealistic and unnecessary levels will undoubtedly increase energy usage and greenhouse gas contributions from 

wastewater utilities. ADEQ’s “General Explanation of This Rulemaking” in section 5 of the rule states that ADEQ 

is required to “adopt surface water quality standards by considering (certain) factors,” including “the provisions 

and requirements of the Clean Air Act.” In developing proposed standards and implementation procedures for 

narrative nutrients, ADEQ has not satisfied this mandate, and has failed to consider the full costs associated with 

the proposed rulemaking. ADEQ’s proposal also falls contrary to Arizona’s Climate Change Action Plan 

developed by Governor Napolitano’s Climate Change Advisory Group in 2006. 

Response: The Department appreciates the commenter’s reference to state and federal efforts to address 

climate change. However, the comment relates only very generally to impacts of nutrient removal technology and 

not to state, local and facility specific impacts of this rule. In fact, as climate change impacts the southwestern 

United States, the Department expects longer term and higher impact droughts and higher temperatures, both of 

which may impact lake and reservoir quality, especially with respect to nutrient impacts. This rule will help 

protect Arizona’s lakes and reservoirs from these impacts. 

Comment #77

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department
165 

Distinctions between lake categories are unclear, and a lake could fall into multiple categories. ADEQ 

should clarify how to identify the single controlling lake characteristic that will define each lake for narrative 

nutrient standard purposes, i.e., depth, substrate, or urban setting. Alternatively, identifying the lake type could be 

left subjective, if ADEQ only relied upon their guidance document without rule criteria. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

First, in establishing the criteria, ADEQ differentiates between deep, shallow, urban, igneous and 

sedimentary lakes. However, the definitions of these types of lakes are not mutually exclusive – for example, an 

igneous lake can be shallow or deep. ADEQ must establish in the rules or by guidance some way of establishing 

what the controlling lake characteristic is that will define the lake for narrative nutrient standard purposes. 

Response: R18-11-108.03(A) states that the criteria in the rule apply only to lakes and reservoirs that are 

categorized in Appendix B. Appendix B includes a column that specifically identifies each lake or reservoir and 

its corresponding lake category. The lake category in Appendix B establishes the controlling lake characteristic 

that the Department will use for implementing the narrative nutrient standard. Not all lakes and reservoirs in 

Appendix B are classified. The Department cannot use the criteria in R18-11-108.03 for any unlisted or 

unclassified lake. 

The lake classification system does account for multiple categories; however, each lake in Appendix B is 

assigned its primary category for assessment purposes. Any non-urban lake with an average depth > 18 ft is 

classified as a “deep” lake. Any lake created in an urban environment is classified as “urban.” Any non-urban lake 

with an average depth < 12 feet is classified as a “shallow” lake. The remaining lakes are classified based on the 

parent geology in which they are situated. The deep, shallow, and urban classifications are the primary drivers for 

lake character; igneous and sedimentary are actually secondary, but if the lake does not fall into one of the primary 

categories, the default assignation is geology and soils based. See Response #13. 

Comment #78

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

There is a statement in the guidance document about lakes with reclaimed water that says, “Lakes with 

reclaimed water carry only the partial body contact (PBC) designated use.” However, there is no separate category 

of lakes (in the matrix) with reclaimed water and no mention of PBC for the nutrient standard in the proposed rule. 

Response: The adopted rulemaking accidentally omitted the PBC category from the Numeric Targets for 

the Lakes and Reserviors Table. A lake having either full body contact (FBC) or partial body contact (PBC) as a 

designated use will have to meet the same target endpoints. See Response #68. 

There are few lakes listed in Appendix B with reclaimed water as a source water component, let alone 

effluent-dependent. These waters carry both A&Wedw and PBC designated uses. The matrix driver for these 

effluent dependent waterbodies will be the A&Wedw category; lakes that use reclaimed water as part of the 

source water, would use the A&Ww urban category. Because of the relatively high nutrient content of reclaimed 

water, it is generally less suited as source water for impoundments designated as fisheries. The increase in lake 

productivity would require aggressive treatment and lake management. The FBC use is contraindicated for 
166 

reclaimed source water for several reasons: high biomass, high turbidity, high pH, algal toxins or irritants, and 

growth of bacteria. To date, all waters listed as A&Wedw also carry PBC use. Lakes created in waters of the 

United States that receive reclaimed water will have to meet A&W Urban chlorophyll targets as those are more 

stringent than the PBC targets. 

As a result of the above comment, the following two typographical errors and three omissions were 

discovered in the matrix table and have been corrected. 

NUMERIC TARGETS FOR LAKES AND RESERVOIRS

Designated

Use

Lake

Category

Chl-a

(μg/L)

Secchi

Depth

(m)

Total

Phosphorus

(μg/L)

Total

Nitrogen

(mg/L)

Total

Kjehldal

Nitrogen

(TKN)

BlueGreen

Algae

(per ml)

BlueGreen

Algae

(% of total 

Dissolved 

Oxygen

(mg/L)

pH

(SU)

FBC and

PBC Deep 10-15 1.5-2.5 70-90 1.2-1.4 1.0-1.1 20,000 6.5-9.0

 

A&Wedw All 30-50 0.7-1.0 125-165160 1.7-1.9 1.4-1.7 <50

6.0

(top m)

6.5-6.0

9.0

Comment #79

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

In the table of subsection D, there appears to be no reason for establishing ranges for Secchi depth, 

phosphorus, and the two forms of nitrogen. The proposed rule makes no use of this “middle ground,” and it adds 

confusion to express a range in the table. 

Response: The commenter appears to misunderstand how the matrix works. See more detailed explanation 

on how the matrix will be used in Responses #70, #71 and #72. Inclusion of the nutrient and secchi ranges in the 

matrix is warranted as they inform the weight-of-evidence decision of potential nutrient-related impairment when 

the chlorophyll-a concentration is within the target range. R18-11-108.03(B)(2)(c) cites conditions that, if 

violated, inform that the narrative nutrient standard is not being met.

Comment #80

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

In the table of subsection D, the very restrictive values (in some cases even more stringent than the aquatic 

and wildlife protected uses) for nitrogen under DWS and FBC uses do not seem to be justified by the drinking 

water standard of 10 mg/l for nitrate. If the limits for these uses are meant to protect human health, they should be 

set based upon the drinking water standard. 
167 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The nitrogen values proposed in the table under R18-11-108.03 are overly stringent; in particular for the 

drinking water source designated use, because the safe drinking water standard for nitrate (10 mg/L) is a much 

more relaxed standard than that being applied to the untreated source water. 

Response: The nutrient ranges in the matrix represent ambient surface water values that correspond to the 

chlorophyll-a targets and can still support the specific designated uses. In the case of Domestic Water Source 

(DWS) use, drinking water is only part of the potential use, but the ranges conservatively reflect those levels of 

nitrogen that would impact formation of total trihalomethane compounds. Typical nitrate levels in surface water 

are three orders of magnitude less than the 10 mg/L specified to protect human health. Further, 10 mg/L of nitrate 

in surface water would greatly exacerbate lake productivity and increased biomass and would likely result in the 

surface water being unsuitable for drinking.

Comment #81

Claire L. Zucker, Pima Association of Governments (PAG)

PAG’s jurisdictional members feel that it is premature to incorporate the Narrative Nutrient Standard 

Implementation Procedures into the rule at this time. The draft implementation procedures were released in midApril leaving very little time for jurisdictions to work with ADEQ by reviewing and potentially appealing the 

procedures before the final rules were issued on April 25, 2008. There are also many inconsistencies between the 

rule and the guidance document. For example, the table shown in R18-11-108.03 D may be interpreted as 

containing numeric, not narrative, standards, because it loses the subjective approach laid out in ADEQ’s 

guidance document. In addition, the statement in R18-11-108.03(B)(2)(c) that there shall be “no evidence” of 

various nutrient related impairments, contrasts with the language in Subsection 4.4, Applicability of Matrix, in 

ADEQ’s guidance document that recommends applying a “weight of evidence” approach to these various factors. 

Rather than including this section in the rule at this time, it would be more appropriate to use the guidance for a 

period of time, to solicit stakeholder input, and then, if appropriate, elevate the procedures into rule. 

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department

The table of subsection D becomes a numeric, not a narrative, standard, because it loses the subjective 

approach of ADEQ’s guidance document. R18-11-108.03(B)(2)(c) states that there shall be no evidence of 

nutrient related impairment. However, in subsection 4.4 of ADEQ’s guidance document, it says to apply a weightof-the-evidence approach to these various factors of the matrix. ADEQ’s guidance is set up for lake managers to 

use best professional judgment, an approach that is lost in translation to the rule. 

Response: The Department disagrees that it is premature to propose R18-11-108.03 to implement the 

narrative nutrient standard for lakes and reservoirs. The adopted rule and the associated guidance document have 

been in development for several years. Similar preliminary draft rules and guidance documents have been 

informally discussed in public meetings going back to the spring of 2004. Lake program staff and the contractor, 

Malcolm Pirnie, presented several project updates on development of the lake classification system and narrative 

nutrient targets in meetings held at ADEQ: March 2004; November 2004; April 2005; and September 2006. 
168 

Additional meeting were held where working drafts of the Implementation Procedures were made available during 

review sessions of the adopted rule. 

To the extent there are any inconsistencies between the adopted rule and the associated Department 

guidance document titled “Draft Narrative Nutrient Standard Implementation Procedures for Lakes and Reservoirs 

(April 2008), the rule controls. The associated guidance document explains the rationale and approach to the 

development of the provisions in R18-11-108.03. See Responses #71, #72, #75 and #79 regarding the weight-ofevidence approach.

Comment #82

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We support addition of these implementation procedures as they will help with implementation of this 

standard and better ensure protection of lakes and reservoirs in Appendix B by limiting the nutrients that 

contribute to the excessive growth of algae. Including rivers and streams in future standards is also an important 

consideration. 

Response: The Department appreciates the comment and agrees that the development of the adopted 

procedures to translate the narrative nutrient standard for lakes and reservoirs is both timely and necessary to 

maintain and protect Arizona’s lakes’ and reservoirs’ water quality and to prevent accelerated eutrophication 

(excessive algae and weeds) and nutrient-related impairments in Arizona’s lakes and reservoirs. 

R18-11-109. NUMERIC WATER QUALITY STANDARDS

R18-11-109(A) 

Comment #83

Jim F. DuBois, City of Tucson – Department of Transportation

ADEQ has adjusted the partial body contact standard for E. coli in R18-11-109(A), without explanation. It 

appears that FBC and PBC standards for E. coli listed in R18-11-109(A) are not based on the same ingestion 

criteria used for the constituents listed in Appendix A, creating inconsistency in the rule. 

E. coli standards for PBC will be applied in MS4 stormwater permits. Because of widespread natural 

wildlife impacts on stormwater, these levels could be exceeded quite frequently. ADEQ has not factored such 

likely costs into the rule’s cost-benefit evaluation. In the past, these E coli standards may have been appropriate to 

gauge the impact of domestic and municipal wastewater, but they do not reflect the natural variability seen in 

stormwater sources. ADEQ should clarify that these standards only apply when there is a direct human source of 

pathogens. Also, ADEQ should consider revising the description of the geometric mean to reflect the frequency of 

sampling expected for stormwater flows of four samples over a period of two years. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The definition of partial body contact proposed in this rulemaking states that the exposure is such that 

“ingestion of the water is not likely.” In fact, ADEQ, in this proposed rule, has adjusted the partial body contact 

standard for E. coli without explanation. It appears that the full body contact and partial body contact standards for 
169 

E. coli are not based on the same ingestion criteria used for the constituents listed in Appendix A of the proposed 

rule, evidencing an inconsistency in ADEQ’s application of ingestion rates between these two designated uses. 

ADEQ should eliminate the ingestion rate criteria for partial body contact, or at the very least, ADEQ should 

adopt the same assumptions for partial body contact incidental ingestion rate as those relied upon by EPA. 

Response: The E. coli criteria in R18-11-109(A) were not derived, and never have been derived, using the 

same criteria derivation methodologies and water ingestion exposure assumptions used to derive numeric criteria 

for pollutants listed in Appendix A. The E. coli criteria are based on EPA’s national criteria recommendations for 

bacteria (See Ambient Water Quality Criteria for Bacteria – 1986, U.S. Environmental Protection Agency, Office 

of Water, EPA 440/5-84-002, January 1986), which are based on an estimate of bacterial indicator counts and an 

acceptable swimming-related rate of gastrointestinal illness obtained from EPA human health effects studies. The 

E. coli standards are not ingestion-based standards. The proposed changes are minor modifications to comport 

with national criteria. 

The Department disagrees that the change to the E. coli standards will result in any significant increased 

costs to Phase I MS4s as the Department is adopting only minor revisions to the currently effective standards for 

E. coli. that have been effective since 2002. The Department adopts the E. coli standards to protect human health 

no matter the potential source of the E. coli. Water quality criteria, including the E. coli criteria, are adopted to 

maintain and protect water quality for designated uses. 

The Department disagrees with the suggestion to revise the averaging period for the calculation of the 

geometric mean to reflect the frequency of sampling expected for stormwater flows of four samples over a period 

of two years. The proposed sampling period of four samples in 30 days is based on EPA recommendations 

regarding the appropriate averaging period for calculating the geometric mean. There is no technical or statistical 

basis for using a 2-year averaging period. There is flexibility within the permitting program to tailor sampling 

frequency to the needs of the situation, but the Department disagrees that the standard should be restricted as the 

commenter suggests. 

R18-11-109(C)(1)

Comment #84

Claire L. Zucker, Pima Association of Governments (PAG)

Our region is concerned about the suspended sediment concentration limits for surface waters. Arid streams 

naturally carry large sediment loads during storm events. The state has struck the provision that the standard only 

applies to surface water that is at, or near, base flow conditions and does not apply to surface water during or soon 

after a precipitation event. We feel this should be placed back in the rule. Sediment transport is a necessary part of 

our ecological balance in our natural alluvial systems and should be allowed in stormflow, which may extend 

beyond the 48 hours of a local stormflow event as stipulated in the rule. 

Also, changing the way in which the standard is expressed to a median value, instead of a geometric mean, 

precludes an allowance for natural variation in the system. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department
170 

ADEQ has removed the provision that the standard only applies to surface water that is at, or near base 

flow conditions and does not apply to surface water during or soon after a precipitation event. This provision 

should be included in the rule. Streams in Pima County have suffered significant erosion, sometimes causing 

severe undercutting of flood control structures. This phenomenon has been linked to clear water scour, which 

occurs when flowing waters are deprived of sediment and as a result they pick up fine-grained materials along the 

watercourse. This occurrence is aggravated by standards that impose limits on suspended sediments in naturally 

flowing waters. Sediment transport is a necessary part of our ecological balance in natural alluvial systems and 

should be allowed in storm flow, which may extend beyond the 48 hours of a local storm flow event as provided 

in the rule.

Jim F. DuBois, City of Tucson – Department of Transportation

ADEQ has provided no technical justification for the change in this standard. ADEQ should not change 

from a geometric mean to a median value, because there is a need to allow for the natural variability of Arizona’s 

alluvial stream systems. Also, ADEQ should retain the current rule language about the standard only applying to a 

stream that is “at or near its base flow.” Furthermore, ADEQ should clarify that this standard does not apply to 

ephemeral water under any circumstance, because there is no such thing as base flow in ephemeral waters as 

defined in the rule. 

Response: Suspended sediment is an important water quality parameter, and the control of excessive 

sediment and siltation is critically important to the maintenance and protection of water quality for the growth and 

propagation of aquatic life. The Department adopted the SSC criteria for the A&Wc and A&Ww designated uses 

primarily to protect aquatic life in perennial and intermittent streams. The SSC standards do not apply to 

ephemeral waters that flow only in direct response to storm events and transport large amounts of sediment. The 

Department did provide a technical justification for revision of the SSC during the informal rulemaking process 

and expands on it here. The current SSC standard is intended to control excessive levels of suspended sediment in 

surface waters to protect aquatic life (i.e., A&Wc and A&Ww). 

The Department disagrees that the expression of the standard as a median concentration precludes 

consideration of natural variability of SSC concentrations in surface waters. The median and the geometric mean 

are both ways of expressing the central tendency of a dataset. The median value is actually a better measure of the 

center of a numerical dataset because it is not influenced by outliers (i.e., very large or very small values in the 

data set that may be atypical). A median is the point at which there are an equal number of data points whose 

values lie above and below the median value. The median represents the actual middle of any data set. 

The Department has proposed revisions to the current SSC standard for several reasons. First, the U.S. Fish 

& Wildlife Service had questioned whether the current SSC numeric criterion of 80 mg/L adequately protected 

aquatic life in cold water streams. Second, the current SSC standard was expressed as a geometric mean calculated 

from a minimum of four sample results. The expression as a geometric mean raised questions regarding what 

averaging period should be used when calculating the geometric mean. The current SSC standard is silent on this 

point. Finally, the applicability of the current SSC standard is unclear. The current standard applies only “at or 

near base flow” and does not apply “soon after a precipitation event.” The Department does not have operational 

definitions of at or near base flow or soon after a precipitation event to interpret the current standard. For most 
171 

surface waters, there are no long-term flow data or gage data that can be used to reliably determine base flow 

conditions. For all of these reasons, the Department revised the SSC standard in this rulemaking. 

The Department expressed the SSC criterion as a chronic criterion to protect aquatic organisms from longterm (i.e., chronic) exposures to suspended sediment. Most of the published reports on the biological effects of 

suspended sediment on aquatic organisms address chronic exposures. The scientific literature the Department 

reviewed did not support the proposal of an acute SSC criterion. The literature suggests that fish can tolerate 

exposures to very high concentrations of suspended sediment (e.g., > 100,000 mg /L) for short periods of time). 

There is little or no data or information on acute or short-term effects of suspended sediment on aquatic 

organisms. For these reasons, the Department adopted a SSC criterion expressed as a median value. A median is a 

better way to express the central tendency of the data, particularly when working with relatively small datasets. 

Neither the current nor the adopted suspended sediment concentration standards apply to ephemeral or 

effluent-dependent waters. Only the A&Wc and A&Ww designated uses have criteria for suspended sediment. 

Comment #85

David E McNeil, City of Tempe

Suspended sediment concentration is an antiquated term and laboratory analysis that has been replaced with 

total suspended solids (TSS). ADHS has confirmed there is a method for “Determining Sediment Concentration in 

Water Samples” that is different from residue non-filterable methods. Determining Sediment Concentration in 

Water Samples is ASTM method D 3977-97 and does not contain the term “suspended” sediment. It should be 

noted that ADEQ has replaced the term “suspended sediment concentration” with “total suspended solids” in the 

newly proposed MS4 permits. Accordingly, this change should be made to the water quality standards. 

Response:. The Department does not agree that SSC is an antiquated term that has been replaced by TSS. 

SSC remains the most accurate way to measure sediments in water. The inclusion of TSS in MS4 stormwater 

permits was made to allow permittees to use a quicker and easier method that can serve as an indicator of 

sediment pollution. However, permit conditions do not drive water quality standards, rather the opposite is true. 

The presence of an alternative monitoring approach within an AZPDES permit is not justification for a standards 

change. 

The Department expressed the standards as suspended sediment concentration (SSC) for several reasons. 

First, the analytical method for measuring SSC, ASTM D3977-97, “Standard Test Method for Determining 

Sediment Concentration in Water Samples,” is the U.S. Geological Survey (USGS) standard method for 

determining the concentration of suspended sediment in surface water samples. Second, the measurement of SSC 

is the most accurate way to measure the total amount of suspended sediment in an ambient surface water sample. 

Studies on the accuracy of the SSC analytical method by ASTM and the USGS Survey Branch of Quality Systems 

(Gordon, et. al 2000) have shown that SSC analysis represents a more accurate and reliable measure of suspended 

sediment than the measurement of total suspended solids or turbidity. 

Differences between total suspended solids (TSS) and suspended sediment concentration analyses have 

been investigated by the USGS (See Gray, John R., et. al, “Comparability of Suspended Sediment Concentration 

and Total Suspended Solids Data,” Water Resources Investigation Report 00-4191, U.S. Dept. of Interior, U.S. 
172 

Geological Survey (August, 2000)). The USGS investigated differences in the data produced by TSS and SSC 

analyses by studying 3,235 paired TSS and SSC samples and 14,466 data pairs from the USGS NWIS database. 

The USGS concluded from the statistical analyses of the paired samples that the data produced by the SSC 

technique is more reliable than data produced by TSS analysis. 

For these reasons, the Department expressed the standard as suspended sediment concentration and not as 

total suspended solids. 

Comment #86

Steven L. Spangle, Field Supervisor, US Fish And Wildlife Service

We are encouraged to see ADEQ propose the revision of its suspended sediment concentration (SSC) 

standard. The SSC standard replaced the turbidity standard during the 2002 triennial review. We concluded this 

change was likely to adversely affect fishes in Arizona (USFWS 2004), particularly salmonids. The SSC standard 

in A&Wc and A&Ww was 80 mg/L. ADEQ has proposed to lower the SSC standard in A&Wc from 80 mg/L to 

25 mg/L. The newly adopted narrative bottom deposits standard implementation procedures will augment the SSC 

standard and should help strengthen the protection of the aquatic environment against the harmful effects of 

excessive sediment. Hopefully, after several years of data collection, the narrative bottom deposit standard will be 

expanded for use in ephemeral and intermittent streams and will be added in future triennial reviews. 

Response: The Department appreciates the comment.

R18-11-109(F) 

Comment #87

J. Adrianne Settimo

The fast growing city of Benson is highly dependent on groundwater sources for drinking, agriculture, 

industrial use and riparian habitat. Benson is located in the San Pedro watershed basin. Lowering the numeric 

water quality standards from 10mg/L of nitrate, to Full Body Contact (“FBC”) criterion, under proposed rule R18-

11-109, would put water used for drinking at risk as well as public health. Not only could “incidental ingestion of 

nitrate-enriched water during water-based recreation” occur, ingestion could also take place through the 

consumption of alluvial groundwater located downstream. ADEQ fails to show that lower standards will not 

adversely affect the public through FBC and the consumption of alluvial groundwater affected by lowered 

numeric water quality standards. The proposed rule should not be adopted by the ADEQ.

Janet Hashimoto, Chief; EPA Monitoring & Assessment Office

ADEQ has proposed to eliminate the existing site-specific nitrate standard of 10 mg/L for the San Pedro 

River from Curtiss to Benson (section R18-11-109). The justification cited is that this stretch of the San Pedro is 

not designated as a domestic water source (DWS). ADEQ’s proposed Full Body Contact standard for nitrate of 

3,733 mg/L, orders of magnitude higher than 10 mg/L, would apply in the alternative. 

The proposed rule should describe available information supporting that the San Pedro River from Curtiss 

to Benson is not being used as a DWS. Also, ADEQ should assess whether any downstream water bodies 
173 

potentially have a DWS use not identified which could be adversely impacted by a higher nitrate allowance in the 

San Pedro River segment in question. 

Response: The Department repealed the site-specific criterion at A.A.C. R18-11-109(F)(10) for total nitrate 

as N that applies to the San Pedro River from Curtiss to Benson. This site-specific criterion is expressed as a 

single sample maximum concentration of 10 mg/L, which is the same as the drinking water MCL. The numeric 

criterion has been adopted for nitrate to maintain and protect water quality for the domestic water source 

designated use. 

This segment of the San Pedro River carries designated uses of Aquatic & Wildlife, Fish Consumption, Full 

Body Contact, Agricultural Livestock Watering and Agricultural Irrigation. It is not and never has been designated 

for Domestic Water Source, which would have a nitrate standard of 10 mg/L. 

The Department researched the origin of the current site-specific criterion of 10 mg/L for the cited reach of 

the San Pedro River. The Department found that the source of the site-specific criterion appears to be a report 

prepared by the Water Assessment Section of the Arizona Department of Health Services titled San Pedro and 

Santa Cruz Rivers: Nutrient Standards Review (September, 1985). The purpose of this report was to summarize 

water quality data for the San Pedro River and Santa Cruz River to evaluate the need for nitrogen and phosphorus 

standards to protect beneficial uses and to determine whether federally-promulgated nutrient standards should be 

repealed and replaced by state-adopted standards. 

The report stated, in relevant part, that nitrogen additions in the San Pedro River were occurring in the St. 

David area as a result of the inflow of nitrate-contaminated groundwater from the Apache Nitrogen site. The final 

recommendation of the report was to promulgate a nitrate standard of 10 mg/L for the San Pedro River, from onemile upstream of the U.S. 80 bridge near St. David to Benson, investigate the source of the nitrate contamination, 

and implement a corrective action program. 

The Department has concluded that the site-specific criterion of 10 mg/L for nitrate for the San Pedro River 

from Curtiss to Benson should be repealed. The 1985 criterion appears to be based on drinking water protection 

but the identified reach of the San Pedro River was not used as a domestic water source in 1985 and this reach of 

the river is not used as a drinking water source today. Moreover, if the intention in 1985 was to protect the full 

body contact recreation designated use, the site-specific criterion of 10 mg/L is overprotective. The Department’s 

current water quality criteria for nitrate to maintain and protect water quality for the full body contact recreation 

designated use is 2,240 mg/L, over 200 times the 1985 site-specific criterion. The current criterion for nitrate for 

the full body contact designated use is derived using an incidental water ingestion exposure assumption. Finally, 

the Department has adopted an aquifer water quality standard of 10 mg/L for nitrate to maintain and protect 

ground water for drinking water purposes (See R18-11-406(B)). An active corrective action plan is in place at 

Apache Nitrogen Products and is addressing the source of the high nitrates. 

In October 2005, the Department placed a public notice in the newspapers serving Benson and Tombstone, 

seeking public comment on the proposal to repeal the site-specific nitrate (NO3) standard that currently applies to 

the San Pedro River from Curtiss to Benson. The notice indicated that the Department was seeking information on 

whether the public is obtaining drinking water from groundwater wells that are hydrologically connected to the 

shallow aquifer and whether local wells have been impacted by nitrates in this area. No comments were received. 
174 

Based on the available hydrologic data for the area, the Department staff determined there is no hydrologic 

connection between the public water system wells in the St. David area and the San Pedro River. Since the river is 

not designated for domestic water source uses and there appears to be no hydrologic connection to the river from 

area wells, removal of the site-specific nitrate standard is justified. The existing full body contact standard is 

protective of humans that may recreate in the water in this area. 

 

R18-11-112. OUTSTANDING ARIZONA WATERS

Comment #88

Claire L. Zucker, Pima Association of Governments (PAG)

Some of the criteria listed as the basis for the Director’s designation of an OAW are new as of this rule. The 

rule should state that these criteria are the basis for all new designations made by the Director and that they will 

not be retroactively applied to any of the OAWs listed in R18-11-112(G) and Appendix B. 

Response: The Department disagrees that clarification is needed; there is nothing in the rule that suggests 

OAWs are to be re-examined after designation. New criteria would affect future designations.

Comment #89

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We also support adding the clarification that an intermittent water can be considered for Outstanding 

Arizona Water designation. Intermittent waters in Arizona provide significant and important wildlife habitat. 

Response: The Department appreciates the comment. 

R18-11-112(A) 

Comment #90

Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Furthermore, the proposed language in R18-11-112(D)(1), extends the potential scope of the OAW 

designation to intermittent waters. ADEQ provides no justification for this extension in the rules. Such a drastic 

extension of protection intended for unique, ecologically valuable surface waters to features that may only contain 

water on an infrequent basis unnecessarily broadens the scope of this protection. Because of the potentially 

significant restrictions on land use activities resulting from OAW designations, this designation is best preserved 

for perennial waters which support critical habitats and provide recreation, instead of diluting scarce state 

resources by extending OAW protection to anywhere in the state that water may be present. ADEQ should revise 

the proposed definition of OAW and the OAW regulations at R18-11-112 to clarify that the OAW designation is 

limited to free-flowing perennial waters with good water quality that exhibit the characteristics specified in R18-

11-112(D)(4). 

Sydney Hay, Arizona Mining Association

ADEQ has proposed extending potential OAW status to intermittent waters, not just perennial waters. 

ADEQ has provided no explanation or rationale whatsoever for this change, and in fact does not even note the 

change in the preamble discussion of the rules. Given that the Department in the last triennial review adopted the 
175 

requirement that OAWs must be perennial waters and emphasized repeatedly that intermittent waters were not 

eligible for listing, this unexplained change in course is puzzling. 

The lack of explanation makes it very difficult to comment on this aspect of the proposal. Nevertheless, 

given the broad and vague definition of "intermittent" waters found in the rules (those flowing continuously at 

certain times of the year), and the fact that intermittent waters, unlike ephemeral and effluent-dependent waters, 

are not specifically identified in Appendix B, the AMA is concerned that this proposal potentially dramatically 

expands the universe of OAWs in Arizona. Rather than protecting only the truly unique and rare waters in the 

State, this proposal moves toward allowing OAW status to be conferred anywhere water is sometimes present, 

even if infrequently. This is not, and never has been, the intent of the unique water (now OAW) program. 

Response: The Department is not drastically extending the scope of eligibility for Outstanding Arizona 

Water classification in this rulemaking. The Department is correcting a fairly recent limitation on the eligibility of 

surface waters for OAW classification and restoring the universe of surface waters eligible for OAW classification 

to pre-2002 conditions. The limited eligibility for unique water classification to perennial waters was established 

in 2002. Prior to 2002, there were no eligibility requirements for unique water classification based on flow regime 

and no limitation only to perennial waters. A person could nominate any surface water for unique water 

classification and the Director could classify any surface water as a unique water provided the Director made the 

requisite findings that the surface water met the criteria for unique water classification prescribed in R18-11-112. 

The Department has concluded that there should be no prior restrictions on the eligibility of a surface water 

for consideration as a Outstanding Arizona Water based on flow regime. All surface waters should be eligible for 

nomination for Outstanding Arizona Water classification and a nomination for OAW classification should be 

considered on its merits. The Department is persuaded that prior restrictions of OAW eligibility based on flow 

may restrict consideration of intermittent waters that may qualify as OAWs because they are of exceptional 

recreational or ecological significance, essential to the maintenance and propagation of a threatened or endangered 

species, or provide critical habitat for a T&E species. 

R18-11-112(D) 

Comment #91

Kim S Wilson

The proposed changes to the surface water standards are needed to identify, nominate, and regulate OAWs 

in ways that are critical for maintaining their ecological resource values. The inclusion of intermittent waters as 

OAWs is especially important because the significant role intermittent waters play in providing wildlife habitat 

and watershed resources is often overlooked. The water quality of intermittent waters needs to be maintained in 

consistency with federal and state antidegradation policies, especially as the water resources of Arizona come 

under ever increasing pressure due to development and climate change. Some will argue against the inclusion of 

intermittent waters as OAWs by indicating that intermittent waters lack value. However, a rational society would 

not categorically exclude these important water sources from OAW protection without consideration of their 

unique roles in local ecosystems and their intrinsic value given Arizona’s ever-shrinking inventory of intermittent 

waters. 
176 

Response: The Department appreciates the comment. 

Comment #92

Claire L. Zucker, Pima Association of Governments (PAG)

PAG, and its jurisdictions, strongly support the addition of intermittent waters to the criteria, allowing 

intermittent waters to be protected as long as other OAW classification requirements are met. In our region, 

perennial and intermittent stream reaches are often intermixed. OAW water quality protections are needed on the 

intermittent reaches because both intermittent and perennial reaches support critical habitats and provide 

recreation for Arizona’s citizenry. 

Response: The Department appreciates the comment. 

R18-11-113G(G)(21) 

Comment #93

Sydney Hay, Arizona Mining Association

Davidson Canyon is subdivided into four reaches in Appendix B. It appears that the lower three reaches are 

intended for designation as an OAW (although there is some uncertainty over the scope of the proposed 

designation, as noted below). However, it has not been adequately demonstrated that these segments qualify for 

listing even under the revised criteria set forth in the proposed rule. 

The proposed listing of Davidson Canyon is confusing. As noted above, Davidson Canyon is subdivided 

into four reaches in Appendix B. The first reach is defined as "headwaters to unnamed spring at 

31°59'00"/110°38'46.” However, the proposed listing in A.A.C. R18-11-112(G)(22) reads as follows: “Davidson 

Canyon, from its headwaters at the unnamed spring at 31°59'00"/110°38'46" to its confluence with Cienega 

Creek." The specified latitude and longitude mark the end of the first (headwater) segment, not its commencement. 

The nominating petition sought OAW designation only for the lower three reaches and not the upper (headwater) 

reach. We presume ADEQ intended to propose the same thing. If any OAW listing is finalized for Davidson 

Canyon, which the AMA does not believe is appropriate for the reasons outlined below, ADEQ needs to be more 

clear in identifying the delineated segment. 

Response: The commenter is correct that Davidson Canyon is divided into four separate reaches in 

Appendix B of the surface water quality standards rules and that the lower three reaches from the unnamed spring 

at 31°59' 00” / 110° 38' 46" to the confluence of Davidson Canyon and Cienega Creek are intended for 

Outstanding Arizona Water (OAW) classification. The Department agrees that the Department may have 

inadvertently created confusion over which reaches of Davidson Canyon were proposed for OAW classification 

because the Department incorrectly included the phrase, “from its headwaters” in the description of the proposed 

listing at R18-11-112(G)(21). The ephemeral reach of Davidson Canyon from its headwaters to the unnamed 

spring at 31°59' 00"/ 110° 38' 46” is not included in the proposed OAW classification and the phrase “from its 

headwaters” has been removed. 

 

Comment #94
177 

Sydney Hay, Arizona Mining Association

The second (uppermost) segment proposed for OAW designation (from the unnamed spring at 

31°59'00"/110° 38' 46" to confluence with unnamed tributary at 31°59'32.5"/110°38'43.5") may not possess the 

requisite "good water quality" required under proposed A.A.C. R18-11-112(D)(3). Designated uses for that reach 

are A&W (warm water), fish consumption, full body contact and agricultural livestock watering. 

Data is insufficient to demonstrate with any certainty that the uppermost stretch of Davidson Canyon 

proposed for OAW classification possesses the “good water quality” necessary for such designation. The 

lowermost reach proposed for OAW designation (from the unnamed spring at 32°00'54"/110°38'54" to Cienega 

Creek) likewise lacks sufficient data to accurately assess water quality. Although none of the data provided in 

support of the nomination does demonstrate the existence of water quality problems, it is insufficient to allow an 

evaluation of overall existing water quality. 

Response: The Department disagrees that Davidson Canyon lacks the requisite good water quality required 

by R18-11-112(D)(3) for an Outstanding Arizona Water classification. Under R18-11-112(D)(3), the Director 

may classify a surface water as an Outstanding Arizona Water if the surface water has water quality that meets or 

is better than applicable water quality standards. The Pima Association of Governments provided sufficient water 

quality data to the Department from samples collected in Davidson Canyon from 2002 to 2005 for the Department 

to find that Davidson Canyon possesses good water quality. None of the available water quality data indicates the 

existence of any water quality problems or exceedances of applicable water quality standards. 

Comment #95

Sydney Hay, Arizona Mining Association

The middle reach of Davidson Canyon proposed for OAW designation (the third of four delineated in 

Appendix B) extends from the confluence with the unnamed tributary at 31°59'32.5"/110°38'43.5" to the unnamed 

spring at 32°00'54"/110°38'54.” No water quality results appear to have been provided for this reach of the Creek. 

However, the reach is listed in Appendix B of both the current and proposed rules as ephemeral. As an ephemeral 

reach, it cannot qualify for OAW designation under the current or proposed rules. It therefore should be removed 

from the proposal. 

Response: The Department agrees that the identified middle reach of Davidson Canyon is listed in 

Appendix B of the surface water quality rules as an ephemeral water. However, the existence of this ephemeral 

reach does not disqualify Davidson Canyon from OAW classification. Davidson Canyon from the unnamed spring 

at 31°59' 00” / 110° 38' 46" to the confluence of Davidson Canyon and Cienega Creek is more correctly described 

as a spatially intermittent stream with reaches of the stream above and below the ephemeral middle reach that 

have perennial and intermittent stream flow. The segment of Davidson Canyon nominated for OAW classification 

is 3.2 miles in length with approximately 0.75 miles of perennial stream flow and 1.25 miles of intermittent stream 

flow. The nomination document for Davidson Canyon provides sufficient information for the Department to find 

that the nominated segment of Davidson Canyon, considered as a whole, is an intermittent stream that was eligible 

for OAW classification under the proposed rule at R18-11-112(D)(1). The Department has previously classified 

surface waters as unique waters (or OAWs) that have perennial, intermittent, and ephemeral reaches. It should be 
178 

noted that Davidson Canyon is tributary to Cienega Creek which the Department has already classified as an 

OAW and it has a similar hydrology to Cienega Creek. The existence of ephemeral reaches in Cienega Creek did 

not disqualify Cienega Creek from being classified as a unique water and does not disqualify Davidson Canyon. 

Comment #96

Sydney Hay, Arizona Mining Association

The listing criteria for OAW designation make clear that it is the attributes of the surface water that should 

determine whether listing is appropriate. As noted above, the water quality data regarding Davidson Canyon is not 

conclusive. Moreover, the preamble (as well as the nomination and supporting letters) focuses heavily on 

preservation of the area as a local corridor for wildlife migration, particularly as a means for wildlife to cross I-10. 

The AMA does not question this characterization, but believes it is irrelevant with respect to the question of 

classifying Davidson Canyon as an OAW. The areas adjacent to the surface water presumably provide that 

migration corridor today, even without OAW status, and there is no suggestion that the wildlife corridor functions 

of these areas would be diminished by any change in water quality. It is not clear why Tier II antidegradation 

protection would be insufficient to protect the functioning of the existing migration corridor. In short, 

classification of Davidson Canyon as an OAW is not essential to one of the primary stated purported benefits of 

the designation. 

Similarly, the recreation benefits cited in the nominating petition are hiking, biking and birdwatching in the 

vicinity of the surface water. These are benefits of the surrounding land, not the surface water itself – no mention 

is made of boating, swimming, fishing or other water-based recreation. It is therefore unclear why these 

recreational uses require imposition of Tier 3 antidegradation protection for the nearby surface water, or why Tier 

2 protection would not be sufficient to allow those uses to continue. 

The preamble also states that the stream provides habitat for “threatened and endangered species or species 

of concern identified by the U.S. Fish and Wildlife Service, including the lowland leopard frog and the long fin 

dace.” These species are not listed as threatened or endangered, nor are they candidates for listing. The phrase 

“species of concern” does not appear to have any legal significance or definition. The two species identified are 

priority vulnerable species under the Sonoran Desert Conservation Plan, but that County-specific plan should not 

alone be sufficient to elevate a water to status as an outstanding Arizona resource water. (One of the stated goals 

of the Sonoran Desert Conservation Plan is to “maintain or improve the status of unlisted species whose existence 

in Pima County is vulnerable” (italics added). This highlights the County-specific nature of the Plan. )

For all the foregoing reasons, the AMA questions whether Davidson Canyon meets the criteria for listing 

set forth in A.A.C. R18-11-112(D). 

Response: The Department agrees that it is the attributes of a surface water that determine whether a 

surface water should be classified as an OAW and has concluded that Davidson Canyon possesses those attributes 

and meets the criteria for OAW classification in R18-11-112(D). The nominated segment of Davidson Canyon is a 

spatially intermittent stream with perennially flowing reaches, is in a free-flowing condition, has good water 

quality that meets applicable water quality standards and it is of exceptional ecological significance. 

The U.S. Fish & Wildlife Service (USFWS), the lead federal agency charged with implementation of the 
179 

Endangered Species Act, wrote a letter of support for the OAW classification of Davidson Canyon. In their letter, 

the USFWS states that Davidson Canyon provides habitat for listed species. Davidson Canyon is an outstanding 

example of a lowland desert stream with perennial water that provides habitat for a number of listed and 

vulnerable species of concern and that its importance as a wildlife migration corridor qualifies it as an OAW as a 

surface water of exceptional ecological significance under R18-11-112(D)(4)(a). The designation as an OAW is 

not based on R18-11-112(D)(4)(b), which requires endangered or threatened species. 

Comment #97

Sydney Hay, Arizona Mining Association

More generally, the AMA is concerned that the proposed OAW designation may be driven more by a desire 

to limit land use in the vicinity (even if not directly adjacent to the reaches proposed for OAW designation) than 

by anything else. 

OAW designations unquestionably have a limiting effect on land use in the area of the designation (because 

of Tier 3 antidegradation protections, limits on use of some general permits, etc.), and such designations should be 

judiciously made and limited to situations where the truly unique characteristics of a surface water require it. 

Land use decisions are best made at the local level, not indirectly via state rulemaking. In fact, in this case, 

such decisions are being made at the local level. Pima County already controls much land around the reaches 

proposed for designation, and is purchasing private lands and trust land grazing leases in the area in order to 

augment the Cienega Valley Reserve system. Thus, the nomination of the Creek as an OAW is unnecessary to 

prevent the “fragmentation” of the area and its loss of function as a wildlife corridor. 

Moreover, if the designation were to be used in an attempt to block a mining operation from ever opening, 

as is clearly the intent of at least some of the proponents of the designation, then the costs imposed by the 

designation are potentially enormous. In short, if ADEQ proceeds with the proposed designation, it must make a 

good faith effort to assess the probable costs of the designation in light of potential limits on activity in the 

watershed, as required by A.R.S. § 41-1052(C). See also 8 A.A.R. at 1303 (identifying as a factor that ADEQ can 

use in exercising its discretion concerning whether to designate a qualifying water as unique the social and 

economic impact of Tier 3 antidegradation protection, such as: limits on existing or new point sources, restrictions 

on land use in the watershed (including possible limits on mining), stricter § 401 certification requirements, and 

impact on private property rights, including the potential for regulatory takings). 

Response: The nomination of Davidson Canyon was prepared by the Pima Association of Governments 

Watershed Planning group (PAG), which prepared the water quality element of the Pima County’s Sonoran Desert 

Conservation Plan. As early as 2002, PAG had recommended that Pima County pursue OAW classification for 

priority streams in Pima County such as Davidson Canyon. The Department supports Pima County’s efforts to 

conserve and protect Arizona’s disappearing desert streams and riparian habitats at the watershed scale. 

The nomination of Davidson Canyon comes at the request of Pima County, the local jurisdiction 

responsible for land use decisions and water quality management planning. The Department notes that the 

Davidson Canyon nomination is supported by the unanimous vote of the Regional Council of the Pima 

Association of Governments, including the City of Tucson. The vast majority of public comments that the 
180 

Department received are in support of the proposed Davidson Canyon nomination came from local residents, nonprofit organizations, and academia. In fact, the Davidson Canyon nomination received an unprecedented level of 

support from local government and others. 

The Department agrees that an OAW classification may affect land uses in the Davidson Canyon 

watershed, particularly any land uses that may degrade existing water quality in Davidson Canyon. As the 

commenter correctly points out, Tier 3 antidegradation protection prohibits the long-term degradation of existing 

water quality in an Outstanding Arizona Water. The proposed antidegradation criteria rule would prohibit new or 

expanded point source discharges directly to the nominated reaches of Davidson Canyon. Discharges to tributaries 

or upstream of the reaches of Davidson Canyon that are classified as an OAW would be reviewed to ensure that 

existing water quality in Davidson Canyon is not degraded. Refer to the EIS for the cost/benefit analysis of this 

rule change. 

Comment #98

Sandy Bahr, Sierra Club  Grand Canyon Chapter

Under subsection G, Davidson Canyon should be number 21 not number 22 as listed in the draft rule. 

Claire L. Zucker, Pima Association of Governments (PAG)

Within the Santa Cruz watershed, the rules list four reaches of Davidson Canyon. For clarity, please add the 

qualifier (OAW) to the three reaches of Davidson Canyon that will be designated as Outstanding Arizona Waters 

as a result of this rule. 

The description of the OAW section of Davidson Canyon sited in 22 does not match the nominated reach, 

which extends from the unnamed spring at 31°59’00”/110°38’46” to the confluence of Davidson Canyon and 

Cienega Creek. Removal of the word “headwaters” from the cited reach would fix this discrepancy. 

Response: The Department thanks the commenters for their careful review. The qualifier (OAW) has been 

added to the appropriate segments in Appendix B and R18-11-112(G)(21) has been revised as follows: 

21. Davidson Canyon, from the unnamed spring at 31°59'00"/110°38'46" to its confluence 

with Cienega Creek;

R18-11-112(G)(21 and (22)) 

Davidson Canyon and Fossil Creek 

NOTE: The Department received many comments in support of the Davidson Canyon and Fossil Creek 

designations, and wishes to thank them for their involvement in the rulemaking process. Here are a few of the 

comments: 

Sandy Bahr, Sierra Club  Grand Canyon Chapter

The Sierra Club strongly supports designation of both Davidson Canyon and Fossil Creek as 

Outstanding Arizona Waters. 

Davidson Canyon, in Pima County southeast of Tucson, is a main tributary of Cienega Creek, which 

currently is designated as a Unique or Outstanding Arizona Water. Davidson Canyon should also be designated 
181 

as an Arizona Outstanding Water in order to protect its unique values and surface water quality. The canyon 

contains spring-fed perennial water and cottonwood-willow riparian habitat that provides homes and sustenance 

to numerous species of wildlife, endangered species, and many migratory birds. 

The fact that it connects to Cienega Creek, another rare perennial stream, makes it even more important 

that Davidson Canyon be protected with an Outstanding Arizona Waters designation. Davidson Canyon has 

excellent water quality, and existing data show that it would meet or exceed surface water quality standards 

required to be classified as an “Outstanding Arizona Water.” 

Under subsection G, 22, Fossil Creek is proposed for designation as an Outstanding Arizona Water. We 

strongly support this designation. Fossil Creek clearly meets both of the conditions for Outstanding Arizona 

Water designation, especially from an ecological perspective. It provides habitat for a diversity of plants and 

wildlife and, with full flows restored, presents a wonderful opportunity for restoration of native fishes. Details 

on how it is of exceptional ecological significance are outlined below. In addition to meeting this important 

criterion, the creek is perennial, is in a free-flowing condition, and has excellent water quality. 

It flows through two congressionally designated wilderness areas — Fossil Springs Wilderness and the 

Mazatzal Wilderness — and it flows almost entirely within federal public lands with the exception of several 

small parcels of private land that are just south of the current location of the Irving Power Plant. 

Fossil Creek is one of very few warm-water perennial streams that are home to an assemblage of our 

native fishes. The water quality in Fossil Creek provides habitat and is critical to the maintenance and 

propagation of these species. Additionally, according to Northern Arizona University, the Fossil Creek 

watershed is home to more than 175 species of mammals, birds, reptiles, amphibians, and invertebrates. The 

creek itself supports 147 macroinvertebrate species. 

Based on the unique characteristics of this warm-water perennial creek, the opportunities for native fish 

recovery it offers, the diverse macroinvertebrate community that inhabits it, and the travertine-forming 

character of the spring water in the creek, we strongly urge designation of Fossil Creek as a unique water and, 

under the proposed rule, an Outstanding Arizona Water. 

David Kennedy

I am writing to ask that ADEQ support “Outstanding Arizona Water” designation for both Fossil Creek and 

Davidson Canyon and also to oppose the Site Specific Standard for Dissolved Copper in Pinto Creek. 

Based on the unique characteristics of this warm water perennial creek, the opportunities for native fish 

recovery it offers, the diverse macroinvertebrate community that inhabit it, and the travertine-forming character of 

the spring water in the creek, Fossil Creek should be designated as an Outstanding Arizona Water. The Creek 

clearly meets the criteria required by the rule. 

Fossil Creek is one of very few warmwater perennial streams that are home to an assemblage of our native 

fishes. These fish include the Sonora sucker, desert sucker, headwater chub, roundtail chub, speckled dace, and 

the longfin dace. Loach minnow and spikedace, both threatened species in Arizona, were recently reintroduced to 

Fossil Creek. 

In regards to Davidson Canyon, it contains spring-fed perennial water and cottonwood-willow riparian 

habitat that provides homes and sustenance to numerous species of wildlife, including Gila topminnow, Gila 
182 

chub, Mexican gartersnake, lowland leopard frog, lesser long-nosed bat as well as many migratory birds. It 

connects to Cienega Creek, another rare perennial stream, makes it even more important that Davidson Canyon 

be protected with an Outstanding Arizona Waters designation. Davidson Canyon has excellent water quality 

and existing data show that it would meet or exceed surface water quality standards required to be classified as 

an “Outstanding Arizona Water.” 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

Davidson Canyon Designation as an Outstanding Arizona Water R18-11-112(22) 

Pima County in partnership with the Pima Association of Governments nominated segments of Davidson 

Canyon as an Outstanding Arizona Water (Attachment #13). Davidson Canyon is a rare perennial low elevation 

desert stream with native fish and frogs, unique riparian habitat, and spectacular geology. It contributes a 

significant portion of the flow in Cienega Creek already a Unique Water of the State. We continue to strongly 

support ADEQ’s proposal to designate Davidson Canyon as an Outstanding Arizona Water in this rulemaking.

Timothy J. Flood, Friends of Arizona Rivers

The Friends support the inclusion of the waters of Davidson Canyon as an Outstanding Arizona Water 

(OAW; termed a Unique Water under the rules being amended.) We acknowledge the importance of the Canyon’s 

sensitive animal species and their dependence upon high quality riparian habitat that, in turn, depends upon high 

water quality. Designation as OAW will serve to promote the protection of these species. 

Barbara Raley

Davidson Canyon is a rare perennial, low-elevation desert stream with native fish, frogs, unique riparian 

habitat and spectacular geology. We have personally kept a log of the wildlife, birds and endangered species seen 

on our own 5 acres, including bobcat, mountain lions, coyote, javalina, skunks, several species of deer, as well as 

dozens of identified birds, hundreds of bats, Red Tailed Hawks, Road runners, and reptiles such as fat healthy Gila 

Monsters who regularly burrow into outcroppings on our property, King, Gopher and Ring-tailed Diamondback 

rattlers, with an occasional Blue Racer or Coral snake. 

Carol Mangold

I strongly support the Outstanding Water designation for Davidson Canyon. Both the Sky Island Alliance 

and the AZ Dept. of Transportation have documented that Davidson Canyon is an important wildlife corridor, one 

of the few places where wildlife can safely cross the interstate. Floods coming down this canyon provide 

sediment, nutrients and seed sources for riparian areas downstream. This canyon has outstanding scenic value. 

John L. Leonard

Davidson Canyon is a valuable resource for both human and non-human creatures. It contributes a 

significant amount of water to Cienega Wash. It provides both water and a passage under I-!0 to the benefit of 

wildlife. There are significant archaeological remnants near the confluence of Davidson and Cienega Creek. And 

it's a nice place for humans to go hiking, after they've come up Cienega Creek. Water in an arid land is a precious 

resource, and I urge you to protect Davidson Canyon and its water in every way possible.

Roger Tanner

This area is also an important tourist area for birders, hiking, camping, and other desert recreational uses. I 

think it is important to maintain this area in a good state for future generations to enjoy. I moved out here for the 
183 

dark skies for my astronomy hobby and the clean air and water. Giving Davidson Canyon an Outstanding Water 

designation will help protect all this. 

Response: The Department appreciates the comments. Other similar comments on Davidson Canyon and 

Fossil Creek, which have not been printed in this final rulemaking document, may be viewed at the Arizona 

Department of Environmental Quality, 1110 West Washington, 5415A-1, Phoenix, Arizona 85007. 

R18-11-112(H) 

Comment #99

Sandy Bahr, Sierra Club  Grand Canyon Chapter

Regarding the delayed effective date for the Fossil Creek designation, it is our understanding that this is 

being included to address concerns raised by APS regarding the designation’s implication affecting the 

company’s decommissioning activities, including the removal of the dam. While we think the designation 

allows for these activities because they will not result in any permanent or long-term degradation in water 

quality, we do not object to the delayed enactment. 

Response: The commenter correctly points out that the OAW classification for Fossil Creek has a delayed 

effective date of June 10, 2010 to allow time for APS to complete decommissioning and restoration activities in 

the Fossil Creek watershed that may have been hindered or delayed by the implementation of Tier 3 

antidegradation protections upon the effective date of the rule. 

R18-11-113. EFFLUENT-DEPENDENT WATERS

R-18-11-113 

Comment #100

Claire L. Zucker, Pima Association of Governments (PAG)

R18-11-113(A) states that the Director shall classify a surface water as an effluent-dependent water by rule. 

If chronic discharge of wastewater is occurring along an ephemeral stream reach, requiring protection of our 

state’s water quality, the Director could choose to designate the reach as EDW through the rule process instead of 

relying on the permit writer to determine when to apply A&W edw standards. 

Response: The commenter is correct, however, the current rule allows both Director’s designation and 

interim use of EDW standards in permits until a reach can be officially designated. If the only option were through 

Director’s designation, the agency could not issue a permit until the surface water was appropriately classified by 

rule. This could delay permit issuance for years. This was the original reason for directing that EDW standards be 

used by the permit writer in the existing provision of R18-11-113(E) to allow permitting to proceed using 

appropriately protective standards until formal designation is made through the rulemaking process. 

Riparian Restoration Projects 

Comment #101

Claire L. Zucker, Pima Association of Governments (PAG)
184 

We recommend that ADEQ remain flexible about applying A&Wedw standards to ephemeral stream 

reaches so that riparian enhancement projects can be encouraged. In addition, some human created ecosystem 

projects are constructed for riparian habitat restoration and do not include an aquatic element even though they do 

utilize discharges of treated wastewater. According to the rule, any discharge of effluent would trigger A&W edw 

water quality standards to be applied even if no surface waters were created, such as for some restoration projects. 

PAG supports the creation of riparian restoration projects in our region, and is concerned that automatic 

application of A&Wedw standards to these projects will discourage these projects from being constructed, even 

though they offer a net ecological benefit to our region. 

Jim F. DuBois, City of Tucson – Department of Transportation

The City of Tucson would like to use reclaimed water for riparian enhancement projects designed to 

minimize discharge and maximize use of effluent to encourage riparian vegetation. Our past experience seeking 

approval for this activity has shown that ADEQ is reluctant to allow ephemeral standards to prevail in these 

circumstances. We remain skeptical that the provisions added in R18-11-113(D) and (E) will significantly relax 

restrictions on reclaimed water use in ephemeral channels. We would prefer more explicit provisions to create a 

“safe harbor” in standards and permitting requirements for this type of project. 

For all of these reasons, ADEQ should repeal or modify R18-11-113(E) to add flexibility for the above 

issues. 

Response: While the Department supports riparian restoration projects in concept, it is the attainment of 

standards and protection of aquatic life, wildlife, recreation, and other uses that are the cornerstones and 

requirements of the Clean Water Act. The current rule is clear about the applicability of the A&Wedw standards 

to regulate point source discharges from wastewater treatment plants to ephemeral waters under R18-11-113(E). 

The current R18-11-113(E) appropriately mandates the use of A&Wedw standards to regulate these discharges 

(i.e., “...the NPDES permit issuing authority shall use the water quality standards that apply to an effluentdependent water to derive discharge limitations for a point source discharge from a wastewater treatment plant to 

an ephemeral water that changes that ephemeral water into an effluent-dependent water.”). The Department agrees 

there is regulatory flexibility to apply “acute-only” A&Wedw standards under certain conditions (such as for 

sporadic or infrequent point source discharges of treated wastewater to an ephemeral water) and has included the 

new provisions in subsections (E) and (F). 

Comment #102

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1 

In general, proposed rule R18-11-113 does not provide a sufficient definition of what features of an 

“effluent-dependent water” justify stricter water quality standards than would otherwise apply to an ephemeral 

water. Rule R18-11-113(C), (D), and (E) should clarify that “effluent-dependent waters” are only those tributary 

waters that, due to the addition of a sufficient volume and frequency of effluent, are no longer ephemeral waters at 

a location where there is a significant nexus to waters of the United States pursuant to the Rapanos decision. 

Response: The Department disagrees that it must determine that there is a significant nexus to another 

water of the United States in order to regulate point source discharges of effluent to ephemeral waters under R18-
185 

11-113. The Department considers tributary ephemeral waters to be a category of surface water as that term is 

defined in A.A.C. R18-11-101(41) and a water of the United States. See Response #4 regarding Rapanos.

The proposed rule clearly states at R18-11-113(D) that the Department shall use the water quality standards 

that apply to effluent-dependent waters to derive AZPDES permit limits for a point source discharge of 

wastewater to an ephemeral water. This language has remained virtually unchanged since the inception of the rule. 

The application of the water quality standards that apply to effluent-dependent waters is not dependent upon a 

minimum volume or frequency of effluent discharge. The ephemeral water quality standards are not developed to 

protect aquatic life that live and propagate in effluent-dependent water systems and are inappropriate to protect 

effluent-dependent water systems. See Responses #19, #20, and #106. 

Comment #103

Sydney Hay, Arizona Mining Association

ADEQ has stated on numerous occasions in stakeholder meetings that the provisions of proposed A.A.C. 

R18-11-113(D)-(E) are not intended to apply to storm water discharges (i.e., that storm water is not wastewater), 

but that intent is not clearly expressed in the proposed rule language. Any final EDW rule should make clear in the 

text of the rule itself (not merely the preamble) that its provisions do not apply to discharges of storm water or 

discharges of non-storm water that are authorized by an applicable storm water permit, such as the construction or 

multi-sector general industrial permits. The AMA also supports the Coalition comment that these provisions 

should not apply to discharges authorized under ADEQ’s de minimus general permit.

Response: The Department agrees. See Response #16. 

Comment #104

Robert S. Lynch, Irrigation & Electrical Districts Association of Arizona

In R18-11-113, the reference to a point source discharge has been changed from “a wastewater treatment 

plant” to “a point source discharge of wastewater.” This change broadens the applicability of the rule and will 

include any point discharges from industrial facilities, i.e. power plants. These point source discharges will now 

be evaluated under the surface water quality standards. When asked whether the economic impact of this change 

had been considered, ADEQ staff stated the Economic Impact Statement was in the preliminary stages.

Response: Discharges from industrial facilities have always been evaluated under the surface water quality 

standards program but due to the restriction in the current R18-11-113(E) language, there was an inequity in how 

they were treated versus municipal dischargers. The final EIS includes consideration of this rule change. See 

Response #17. 

R18-11-113(D) 

Comment #105

Sandy Bahr, Sierra Club  Grand Canyon Chapter

This section clarifies that an Effluent-Dependent Water must have a point source discharge of 

wastewater; otherwise it is an ephemeral water. This change allows for inclusion of the industrial process 
186 

waters including cooling water discharge from power plants. 

Classification of an Effluent-Dependent Water should include an opportunity for public comment and 

review. The conversion of ephemeral waters to effluent-dependent waters could have significant impact on certain 

species of wildlife, including desert frogs that only surface and breed in the presence of water each year. 

Furthermore, these waters feed into larger water bodies and ultimately affect perennial streams. We are concerned 

about the “flexibility” proposed in the rule for applying only acute standards for discharge for Aquatic and 

Wildlife (edw) and for not applying the chronic standards. How will the need to apply this be determined? What 

constitutes “sporadic, infrequent, or emergency?”

Response: The administrative rulemaking process provides an opportunity for public participation, 

including an opportunity to review and comment on each surface water that the Department proposes to classify as 

an effluent-dependent water. The Department proposed to classify 29 surface waters as EDWs in this rulemaking. 

In addition, the AZPDES permit process provides the public opportunity to review and comment on the 

Department’s permitting decision including when the permit includes effluent-dependent water designation. 

The Department believes it is reasonable to provide regulatory flexibility to use acute A&W(edw) standards 

only to derive water quality-based effluent limits in AZPDES permits for point source discharges that are 

“sporadic, infrequent, or emergency” discharges. In general, the Department would use this regulatory flexibility 

in AZPDES permits where there is not a reasonable likelihood that organisms in the receiving ephemeral water or 

EDW would have chronic or long-term exposures to pollutants in the discharge. The Department will evaluate 

AZPDES-permitted point source discharges to ephemeral waters on a case-by-case basis to make this 

determination. The Department will consider the amount, frequency, and duration of the point source discharge; 

the length of time that water remains in the receiving ephemeral water or EDW; and the distance to the nearest 

downstream surface water with chronic A&W standards. This determination will be reflected in draft AZPDES 

permits and subject to public notice and comment. 

The terms sporadic and infrequent describe the types of point source discharges that might be regulated 

under acute-only A&Wedw standards and have the conventional meanings. Sporadic means occurring at irregular 

intervals or isolated instances and infrequent means not occurring often or not occurring at close intervals. The 

Department has not adopted criteria that specifically define the conditions under which discharge limits, based on 

acute-only A&Wedw standards, adequately protect the animals, plants, and other organisms that inhabit an 

ephemeral water that receives an infrequent or sporadic discharge where the water may remain for a short period 

of time before it dries up and returns to its status as a normally dry channel. This will need to be a site-specific 

evaluation as it is dependent on many factors. 

R18-11-113(D) 

Comment #106

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ has failed to properly assess the scientific basis for identifying and properly regulating effluentdependent waters. 
187 

Pima County concurs with other stakeholders that resolution of this issue can be achieved with a new 

definition of effluent-dependent waters. Pima County proposes the following definition: “Effluent-dependent 

water” means a surface water that consists of discharges of treated wastewater that the Director determines create 

a significant aquatic ecosystem in terms of size and location that would otherwise not exist due to flows from 

precipitation events alone. An effluent-dependent water is a surface water that, without the discharge of treated 

wastewater creating a significant aquatic ecosystem that would otherwise not exist due to flows from precipitation 

events alone, would be an ephemeral water.” 

Pima County objects to the proposed changes to A.A.C R18-11-101(21) and A.A.C. R18-11-113(E). Due to 

lack of scientific clarity as to the effluent discharge circumstances necessary to change an ephemeral water into an 

aquatic habitat called effluent-dependent water and under what circumstances acute or chronic standards should be 

applied, we believe that ADEQ must, until appropriate rule language has been adopted, perform site specific 

ecological and hydrological investigations on a site specific basis for each permitted discharge, to make a correct 

determination if a water should be listed in rule as an EDW or not, and what standards should apply. 

Response: The Department disagrees with any proposed definition of effluent-dependent water that 

requires the creation of a significant aquatic ecosystem for the reasons outlined in Responses #19 and 20. 

The Department disagrees that the Department should develop criteria for effluent-dependent waters that 

identify “when a substantial aquatic ecosystem has been established” that requires the protection of A&Wedw 

standards. The Department opposes this approach because it requires a subjective determination of how 

“substantial” an aquatic ecosystem that is created by the discharge of treated wastewater is before the Department 

could designate a surface water as an EDW. The term “substantial” is undefined and there are no recommended 

criteria for how the Department should determine whether an aquatic ecosystem is substantial or insubstantial. In 

the absence of clearly defined and objective tests, that determination becomes little more than a subjective value 

judgment. Development of the guidelines proposed in this rulemaking for situations where water quality may be 

protected by aquatic and wildlife acute standards only, was based on principles mutually agreed to in the 

stakeholder meetings. See R18-11-113(E). 

Comment #107

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Also, in its proposed R18-11-113(D), ADEQ provides that it “shall use the water quality standards that 

apply to an effluent-dependent water to derive water quality based effluent limits for a point source discharge of 

wastewater to an ephemeral water.” ADEQ provides no justification for requiring the application of EDW criteria 

to point source discharges of all wastewater. Such an approach allows ADEQ to apply EDW criteria in the 

permitting context to stream segments that have not yet been designated as EDW through the required rulemaking 

process. ADEQ should delete the language in R18-11-113(D). At the very least, ADEQ should replace the term 

“shall” in R18-11-113(D) to “may” to allow for some discretion in determining the appropriate criteria to apply to 

permitted wastewater discharges to waters that may or may not be classified as EDW. Additionally, ADEQ should 

insert the phrase, “Notwithstanding the language in R18-11-113(D)” to preface R18-11-113(E). 
188 

Additionally, the Coalition appreciates ADEQ’s understanding that chronic criteria should not apply to 

sporadic, infrequent, or emergency discharges, as established in R18-11-113(E). However, in order to ensure 

proper interpretation of that section, the Coalition recommends that ADEQ insert the following language before 

the first sentence in the proposed Section (E): “The Director shall not use aquatic and wildlife (edw) chronic 

standards to derive water quality based effluent limits for a sporadic, infrequence, or emergency point source 

discharge to an ephemeral water or to an effluent-dependent water.” Additionally, ADEQ should remove the 

language in R18-11-113(E)(3), which provides that ADEQ will consider distance to a downstream water with 

aquatic and wildlife chronic standards in assessing whether to apply aquatic and wildlife acute standards to an 

EDW. 

Response: Regarding the suggestion to modify R18-11-113(D) to say EDW standards may be used to 

develop permit limit, the Department disagrees. Very little change has been proposed to this Section. The 

changes made have been for clarification purposes only. What is new to this Section is subsection (E), which 

was developed after numerous stakeholder meetings to provide some clarification on when acute only standards 

might be appropriate for a discharge that is sporadic, infrequent, or of rare occurrence. The Department does 

not consider the proposed language for R18-11-113(E), regarding the prohibition of using chronic standards, to 

be protective of water quality. The Director needs to determine what is protective of water quality based on the 

four factors listed in subsection (E) only if the discharge is sporadic, infrequent, or a rare occurrence will acuteonly standards be justified; otherwise chronic is required. 

The Department believes that the consideration of the impact of a discharge on downstream surface 

waters with chronic water quality standards is both reasonable and necessary if and when a discharge might 

reach a downstream water that carries a higher level of protection. Permittees have the ability to create 

flexibility within their water quality management programs by developing multiple outlets for disposal 

including reuse, recharge or more than one surface water discharge location. 

Comment #108

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ is proposing in this rulemaking under Appendix B to change the designated use of the Black Wash 

downstream of the Pima County Avra Valley WRF from an ephemeral to EDW use. The preamble to these rules 

only provides a very brief statement that ADEQ used permit application, fact sheet, and discharge monitoring 

reports to help make their decision. There is no mention of any site specific field investigations performed by 

ADEQ or any other investigations that would have allowed ADEQ to determine that the Black Wash has been 

“changed” into an EDW. Pima County records show that the Avra Valley facility has not discharged to the Black 

Wash since November 2006. The Avra Valley facility has sufficient percolation basin capacity operated under a 

valid aquifer protection permit, to recharge all discharged effluent. Pima County has obtained a AZPDES permit 

for this facility for use on an emergency discharge basis only.

Response: The Avra Valley WWTP is authorized to discharge by an individual AZPDES permit that 

currently authorizes the discharge of 1.2 million gallons per day of treated effluent, with no limitation, to spray 

fields established in Black Wash. While Pima County Regional Wastewater Reclamation Department may direct 
189 

discharges to other methods of disposal, there is nothing in the AZPDES permit restricting the discharge of the full 

1.2 mgd every day of the year to Black Wash thereby creating and maintaining an effluent-dependent ecosystem. 

However, the Avra Valley WWTP as described by the commenter, may be the type of facility that could benefit 

from the flexibility proposed under R18-11-113(E). 

Comment #109

Claire L. Zucker, Pima Association of Governments (PAG)

Section E. of R18-11-113 indicates that A&W edw standards will be applied to ephemeral streams that 

receive any point source discharge of wastewater. The rule does not specify how much effluent, or for how long 

effluent need be discharged before an EDW is created. Therefore, intermittent or sporadic point source discharges 

to ephemeral streams from a wastewater plant will trigger A&W edw water standards. Many of Arizona’s 

wastewater plants are currently constructed to fully re-use or recharge their treated effluent, with discharge to 

streams being held as a remote back up plan. However, this rule indicates that the rare discharge of effluent to the 

ephemeral streams would change the water from ephemeral to edw, even though for the vast majority of the time 

the waters remain ephemeral and no effluent-dependent ecosystem has developed. Jurisdictions would then have 

to meet edw standards on that stream reach, but it is unclear from the rule for how long these standards must be 

met or for what extent along the stream the standards apply. Meeting these standards would place a significant 

financial burden on our jurisdictions. 

Robert A. Hollander, City of Phoenix

With the elimination of the phrase “...that changes that ephemeral water into an effluent-dependent water” 

the standard codifies only one interpretation of an effluent-dependent water based on hydrology alone. Another 

interpretation is based on a discharge to an ephemeral water creating an aquatic community that is “dependent” on 

the discharge. This issue is discussed in more detail in an E mail from Byron McMillan to Steven Pawlowski 

dated October 4, 2007, which is incorporated in these comments by reference. We request that ADEQ retain the 

current phrase. I have attached the referenced E mail for your convenience. 

Response: The commenters are correct that under the current permitting process any discharge from a 

WWTP is permitted to meet EDW standards under the existing provisions of R18-11-113(E). Standards that apply 

in this instance must be met at the point of discharge to the wash. Discharge of effluent under ephemeral standards 

is not protective of aquatic life, so if a facility maintains an AZPDES permit as a contingency, it must meet the 

EDW standards when discharge is necessary. The changes made in R18-11-113(E) provides flexibility for 

discharges that are short term, intermittent, or sporadic. 

The commenter is correct that the definition of effluent-dependent water is based on hydrology alone. All 

the stream definitions — that is, ephemeral, intermittent, perennial, and effluent-dependent are based on stream 

hydrology. The Department believes it is common knowledge and confirmed by research and experience that a 

wastewater discharge of virtually any quantity and consistency will be used by aquatic organisms, unless such 

discharge is toxic. See: “An Exploration of Nutrient and Community Variables in Effluent Dependent Streams in 

Arizona,” Arizona Department of Environmental Quality, OFR 05-09. The Department considers a hydrological 
190 

definition to be the most appropriate approach at this time. (Note: The October 4, 2007 email is reproduced in 

comment #110). 

Comment #110

Byron McMillan, Pima County Wastewater Management

On behalf of the jurisdictions listed in the comments below, please find attached suggested changes to 

ADEQ proposed rule language at R18-11-113(D). The cities of Mesa, Peoria, Phoenix, Scottsdale, Surprise and 

Tempe, Pima County, Arizona American Water, and the Superstition Mountain Community Facilities District 

appreciate the time you and your staff took on September 21, 2007, to meet with us regarding A.A.C. R18-11-

113.E and the impact ADEQ’s implementation of this rule has had on AZPDES permittees. 

During our meeting, ADEQ agreed to review a written proposal modifying part of R18-11-113 to 

accommodate the various discharge scenarios we discussed. The attached file contains the suggested 

modifications to the rule. Included is a matrix showing when to apply EDW standards on the basis of discharge 

duration. We believe this proposed rule language provides needed flexibility for applying conservative and yet 

reasonable surface water quality standards on these Arizona waters. The proposed rule language also provides 

bright line standards which will aid both ADEQ permitting staff in implementing the rule and assist the regulated 

community to comply with these rules. 

We continue to believe that applying EDW standards before an effluent-dependent ecosystem has been 

established is inappropriate and scientifically indefensible. While there is some challenge in determining what 

constitutes a self sustaining ecosystem, it is not beyond the ability of ADEQ and the regulated community to 

define that boundary as we go forward. We believe that our suggested rule language including the discharge 

durations and drying periods are reasonable based on seasonality and the minimum length of time one might 

reasonably expect an effluent dependent ecosystem to begin developing within a normally dry wash. ADEQ 

expressed concern that a discharge duration of 30 days would be unacceptably long to EPA for applying acute 

only standards. If EPA has information to show that an aquatic ecosystem can develop in a time period shorter 

than 30 days after the addition of effluent to an ephemeral stream, we believe they should share that information 

with ADEQ and us. At this point, we are unaware that EPA has any such information. Prior to ADEQ primacy, 

permits issued by EPA for discharges to ephemeral streams were written using ephemeral water quality standards. 

EPA cautioned permittees that in the future, EDW standards may apply if the stream becomes effluent-dependent. 

This is a clear indication that EPA at that time, had no information on when to expect an EDW to develop. We 

believe the scientific body of information in this regard has not changed substantially in recent years. Since EPA 

did not intend for EDW standards to apply to discharges to ephemeral waters until an effluent-dependent 

ecosystem had developed, we believe ADEQ would find support from EPA on this issue. 

We believe that ADEQ understands that adding water to a dry streambed does not instantly result in the 

emergence of aquatic life, and most certainly does not create an ecosystem dependent on effluent. ADEQ is 

reluctant to discuss an ecosystem approach as it appears to be too complicated. One simple ecosystem-based 

solution to the problem is to apply EDW standards when an indicator organism appears in the stream. The 

indicator organism could be a fish species or another species whose entire life-cycle is aquatic and has a life-span 
191 

of at least one-year. The use of indicator organisms has precedence in permitting as they are used in wholeeffluent toxicity testing and pathogen testing. 

This may be an approach that ADEQ and the regulated community can consider and pursue in the future. 

Because ADEQ is reaching the end of the Triennial Review rulemaking process and needs to move forward we 

suggest that our proposed rule language is an acceptable interim step that will provide needed flexibility for 

addressing issues such as WETT, riparian habitat restoration project permitting, and discharge seasonality issues 

where the current rules do not provide flexibility. The proposed matrix serves as an attempt to use best 

professional judgment to provide the bright lines needed for making permitting decisions. We believe it to be an 

acceptable approach in lieu of a more scientific approach that apparently is beyond the scope of this current 

triennial review. As additional data is collected and more research is conducted, the matrix can be modified to 

make it more representative of the best available science. At some point in the future, the matrix may actually 

become obsolete but for the moment, it is in our judgment a reasonable starting point. 

We just became aware of new information that we believe ADEQ ought to consider. ADEQ has expressed 

concern about how EPA will respond to Arizona’s SWQS. EPA approved the ephemeral stream standards in 

Mississippi’s Water Quality Criteria for Intrastate, Interstate and Coastal Waters. We are keenly aware that 

Arizona’s ephemeral waters definition is the primary reason for applying EDW standards to discharges to 

ephemeral waters. We strongly encourage ADEQ to consider Mississippi’s description/definition of ephemeral 

streams as it is an accurate description of waters in Arizona and it has been approved by EPA. We also note that 

the standards require domestic wastewater discharges to meet chronic toxicity limits only in downstream perennial 

waters. Acute standards are applicable.

EPHEMERAL STREAM

Waters in this classification do not support a fisheries resource and are not usable for human consumption 

or aquatic life. Ephemeral streams normally are natural watercourses, including natural watercourses that 

have been modified by channelization or manmade drainage ditches, that without the influent of point source 

discharges flow only in direct response to precipitation or irrigation return-water discharge in the immediate 

vicinity and whose channels are normally above the groundwater table. These streams may contain a transient 

population of aquatic life during the portion of the year when there is suitable habitat for fish survival. Normally, 

aquatic habitat in these streams is not adequate to support a reproductive cycle for fish and other aquatic life. 

Wetlands are excluded from this classification. 

Waters in this classification shall be protective of wildlife and humans that may come in contact with the 

waters. Waters contained in ephemeral streams shall also allow maintenance of the standards applicable to all 

downstream waters. 

A. Provisions 1,2,3 and 5 of Section II (Minimum Conditions Applicable to All Waters) are applicable 

except as they relate to fish and other aquatic life. All aspects of provisions 4 and 10 of Section II concerning 

toxicity will apply to ephemeral streams, except for domestic or compatible domestic wastewater discharges 

which will be required to meet toxicity requirements in downstream waters not classified as ephemeral. 

Alternative methods may be utilized to determine the potential toxic effect of ammonia. Acutely toxic conditions 

are prohibited under any circumstances in waters in this classification. 
192 

B. Dissolved Oxygen : The dissolved oxygen shall be maintained at an appropriate level to avoid 

nuisance conditions. 

C. Bacteria : The Permit Board may assign bacterial criteria where the probability of a public health 

hazard or other circumstances so warrant. 

D. Definitions: 

1. Fisheries resources is defined as any waterbody which has a viable gamefish population as 

documented by the Mississippi Department of Wildlife Conservation or has sufficient flow or physical 

characteristics to support the fishing use during times other than periods of flow after precipitation events or 

irrigation return water discharge. 

2. "Not usable for human consumption or aquatic life" means that sufficient flow or physical 

characteristics are not available to support these uses. 

3. "Flow only in response to precipitation or irrigation return water" means that without the influence 

of point source discharges the stream will be dry unless there has been recent rainfall or a discharge of irrigation 

return water. 

4. "Protective of wildlife and humans that may come in contact with the waters" means that toxic 

pollutants shall not be discharged in concentrations that will endanger wildlife or humans. 

5. "Nuisance conditions" means objectionable odors or aesthetic conditions that may generate 

complaints from the public. 

Recommendations for assignment of the Ephemeral Stream classification shall be made to the Commission 

on Environmental Quality by the Permit Board after appropriate demonstration of physical and hydrological 

data. The Ephemeral Stream classification shall not be assigned where environmental circumstances are such 

that a nuisance or hazardous condition would result or public health is likely to be threatened. Alternate 

discharge points shall be investigated before the Ephemeral Stream classification is considered. 

Attachment to October 4, 2007 email from Byron McMillan, Pima County Wastewater Management

Proposed Changes to ADEQ Draft R18-11-113(D) 

The Director or the NPDES permitting authority, upon determining that water quality based effluent 

limitations are necessary in a permit, may use any of the water quality standards that apply to an effluentdependent water to derive appropriate water quality based effluent limits for a point source discharge of 

wastewater to an ephemeral water. The Director or the NPDES permitting authority may use any acute and 

chronic aquatic and wildlife (effluent-dependent water) standards to derive appropriate water quality based 

effluent limits in an AZPDES or NPDES permit authorizing any of the following: 

1. A continuous discharge of wastewater to an ephemeral water. 

2. An intermittent discharge of wastewater to an ephemeral water on 30 or more consecutive days 

from April through September, or 90 or more consecutive days from October through March. 

3. A discharge to an impoundment located within a surface water, other than an impoundment listed in 

R18-11-102(B), or an impoundment allowed for storage of reclaimed water by rule adopted under A.R.S. 49-

203(A)(6). 

4a. An intermittent discharge of wastewater to an ephemeral water for less than 30 consecutive days 
193 

from April through September, with a period of time between discharge events less than those specified in the 

table below: 

i. #Days Consecutive 

Discharge 

ii. #Days Between 

Discharge 

iii. 1-5 days iv. 1 day 

v. 6-10 days vi. 2 days 

vii. 11-15 days viii. 3 days 

ix. 16-20 days x. 4 days 

xi. 21-25 days xii. 5 days 

xiii. 26-30 days xiv. 7 days 

4b. An intermittent discharge of wastewater to an ephemeral water for less than 90 consecutive days 

from October through March, with a period of time between discharge events less than those specified in the table 

below: 

xv. #Days Consecutive 

Discharge 

xvi. #Days Between 

Discharge 

xvii. 1-5 days xviii. 1 day 

xix. 6-10 days xx. 2 days 

xxi. 11-20 days xxii. 5 days 

xxiii. 21-30 days xxiv. 8 days 

xxv. 31-40 days xxvi. 9 days 

xxvii. 41-90 days xxviii. 10 days 

5. A discharge, during dry weather periods, that may reach a downstream surface water that is 

designated as A&Wc or A&Ww in Appendix B or the downstream surface water meets any of the conditions 

specified in (D)(1) through (4). 

Robert A. Hollander, City of Phoenix

The Water Services Department appreciates ADEQ working with the regulated community on addressing 

their concerns with how the Surface Water Quality Standards (SWQS) will be applied to facilities that have 

sporadic, infrequent or emergency discharges to ephemeral or effluent-dependent waters (EDWs). The proposed 

language articulates an understanding and acknowledgement that such situations are unique and require a different 

approach than do continuous discharges. However, the proposal does not discuss specifically how R18-11-113.E.1 

through 4 will be implemented. ADEQ has articulated that their approach to addressing the intermittent discharges 

to ephemeral waters and EDWs was to provide permit flexibility. While the proposed language would provide 

flexibility, it creates a great deal of uncertainty for permittees who must plan ahead and secure funding for 

potential capital improvements to meet future permit limits. Increased funding for capital improvements and 

operational changes would increase rates paid by customers and require City Council approval. 
194 

Response: The Department appreciates the commenters’ support. The issues of creating an aquatic 

ecosystem (see Responses #19, #20 and #106) and regulatory flexibility (see Responses #105 and #111) have been 

addressed in other responses. The Department agrees with stakeholders that there should be regulatory flexibility 

in R18-11-113(E) to authorize the Department to use acute A&Wedw standards as a basis for deriving water 

quality-based effluent limits in AZPDES permits for sporadic and infrequent point source discharges. 

This rule includes some general factors that the Director will consider in making a decision as to whether 

acute-only A&Wedw standards would be used to derive discharge limits in AZPDES permits or whether acute and 

chronic A&Wedw standards are necessary. These general factors include the amount, frequency, and duration of 

discharges; the length of time water is present in the receiving ephemeral water; the distance to nearest 

downstream surface water with chronic A&W standards, and the likelihood that organisms in the receiving 

ephemeral water will have long-term or chronic exposures to pollutants in the discharge. The proposal in the 

October 4, 2007 attachment is a revision of an early work session product. The Department appreciates the 

stakeholder’s efforts but does not consider the bright-line durations offered as scientifically defensible. There are 

various case-specific and location-specific factors that will need to be considered in determining the appropriate 

standards to be used. The Department acknowledges that these guidelines in R18-11-113(E) do not provide 

absolute regulatory certainty but they do provide a general framework for evaluating sporadic and infrequent 

discharges to ephemeral waters on a case-by-case basis in the context of an AZPDES permit application. The 

Department’s surface water permits unit will work with individual permit applicants on appropriate limits for 

specific discharges. 

As to the consideration of Mississippi’s water quality standards language for ephemeral systems, each state 

has a different way of defining and implementing its water quality standards programs. The Department will 

review the Mississippi proposal but note that the Mississippi approach to water resources may not be applicable in 

the second most arid state in the United States. Without a total contextual understanding of its program, rules and 

implementation, it is difficult to make an assessment of their utility and transferability to Arizona’s surface water 

management program. 

The Department notes that the last sentence in the Mississippi standard: “Alternate discharge points shall be 

investigated before the Ephemeral Stream classification is considered.” In Arizona, 102 of AZPDES dischargers 

are permitted to discharge to ephemeral streams for a total flow in excess of 650 mgd. These numbers and 

volumes of wastewater demand care and caution to ensure that Arizona’s limited water resources are protected for 

aquatic life and beneficial uses. At this time, the Department considers the changes to R18-11-113 to be important 

steps forward in dealing with effluent management and environmental protection. The Department will continue to 

work with the commenters and others to refine the EDW standard in future rulemakings, as appropriate. 

R18-11-113(E) 

Comment #111

J. Adrianne Settimo

A&W(edw) standards should never be considered unnecessary. Such stringent standards are in place to 

protect public health. The proposed language providing “regulatory flexibility,” in granting AZPDES permits with 
195 

less stringent regulations, on a “case-by-case basis” negates the purpose of having rules. AZPDES permits are 

stringent because they need to be, keeping standards the same for all creates a level playing field, and sets a 

minimum standard. This standard should not be compromised with the case-by-case approach in the proposed 

rule. 

Response: The Department created the A&Wedw subcategory in an attempt to meet a need for more 

tailored and appropriate water quality standards to protect aquatic life in the ecosystems that are created by the 

discharge of effluent to ephemeral waters. The A&Wedw standards are not designed to protect public health, as 

the commenter suggests. Body contact standards protect human health. A&Wedw standards are established to 

maintain and protect water quality for aquatic life and wildlife that live or have contact with effluent waters. The 

A&Wedw standards are expressed in two ways. There are acute A&Wedw standards to protect organisms from 

short-term exposures to pollutants in the effluent and chronic A&Wedw standards that are intended to protect 

organisms in EDWs from long-term exposures to pollutants. 

The Department adopted R18-11-113(E) to provide regulatory flexibility to apply acute A&Wedw 

standards only under certain conditions. The Department recognizes that there may be situations where a facility 

discharges effluent to a dry watercourse so infrequently or so sporadically that there is little likelihood that 

organisms in the receiving water would have long-term exposures to pollutants in the discharge. These situations 

are fact-sensitive and must be evaluated on a case-by-case basis, but they would typically involve small amounts 

of discharge of short duration that have relatively infrequent recurrence intervals. See Responses #105 & #110. 

R18-11-114. MIXING ZONES

Comment #112

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We support tightening up the provisions here including the addition of subsection (H), which prohibits 

mixing zones that are so large that they can kill drifting organisms. As indicated in previous comments, we have 

significant concerns about mixing zones overall as they rely on pollution dilution rather than pollution prevention.

Response: The Clean Water Act allows for the use of mixing zones as long as acute toxicity to drifting 

organisms is prevented and the integrity of the surface water as a whole is not impaired. According to 40 CFR 

§131.13, states may, at their discretion, adopt certain policies in their water quality standards rules that affect the 

application and implementation of the standards, such as a mixing zone. Mixing zones have been applied in the 

water quality standards program since its inception and EPA has approved state-adopted mixing zone policies 

provided the mixing zone policy ensures that: 1) mixing zones do not impair the integrity of the water body as a 

whole, 2) there is no lethality to organisms passing through the mixing zone, and 3) there are no significant health 

risks considering likely pathways of exposure. The Department adopted a limited mixing zone rule whose 

provisions are consistent with available EPA guidance on mixing zones provided in the Water Quality Standards 

Handbook, Second Edition and EPA’s Technical Support Document for Water Quality-Based Toxics Control. 

The commenter is correct that mixing zones rely on dilution. A mixing zone is defined as a limited area or 

volume of water where initial dilution of a discharge takes place and where numeric water quality standards can 
196 

be exceeded. The Department does not allow mixing zones where there is no water for dilution and appropriately 

conditions mixing zones where they are allowed. 

R18-11-115. SITE-SPECIFIC STANDARDS

Flexibility 

Comment #113

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ has proposed procedures to conduct studies for developing site-specific standards. Pima County 

fully supports the recommended procedures as relevant and appropriate for use in Arizona. However, Pima 

County believes that ADEQ has unnecessarily limited the amount and types of procedures that could be 

legitimately used for conducting studies. For example, EPA has recently approved in a federal register notice 

the use of the Biotic Ligand Model for calculating Aquatic Life Ambient Freshwater Quality Criteria for 

Copper. This method was also specifically evaluated for its valid use in Arizona as part of the Arid West Water 

Quality Research Project. This study found that because of Arid West water hardness issues, the BLM was 

actually more accurate than the generally used Water Effects Ratio procedure.

Robert A. Hollander, City of Phoenix

The Water Services Department requests that this rule should include language that allows the use of other 

scientifically valid procedures for performing site-specific studies including metals translator studies and 

procedures developed under the Arid West Water Quality Research Project. 

The Arid West Water Quality Research Project conducted a number of studies to address water quality 

criteria and standards development in effluent-dependent and ephemeral waters characteristic of the arid west. 

This included an evaluation of the reliability of the Biotic Ligand Model predictions for copper toxicity in 

waters characteristic of the arid west. EPA and ADEQ staff participated on the Regulatory Working Group of 

the Research Project.

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The Coalition appreciates ADEQ’s proposal to adopt regulations allowing for the adoption of site-specific 

SWQS under proposed R18-11-115. Such flexibility in establishing a nuanced approach to surface water quality is 

essential in Arizona, where the natural background of many surface waters is impacted by the state’s highly 

mineralized geology or affected by other natural conditions, such as conditions inherent to Arizona’s semi-arid 

climate. However, the Coalition does not believe that ADEQ has provided adequate flexibility in its proposed sitespecific standard regulations. ADEQ unnecessarily limits the procedures regulated parties may use in conducting a 

study to support the development of site-specific standards. ADEQ should revise its proposed R18-11-115 to 

allow more flexibility in using additional methods and approaches to setting site-specific standards. The Coalition 

also recommends that ADEQ include the use of EPA’s approved Biotic Ligand Model as a way to determine 

certain site specific standards. 

To increase flexibility in implementing site-specific standards for the reasons discussed above, the 

Coalition requests that ADEQ add the following language: 
197 

1. As R18-11-115(B)(5) – “The results of a use attainability analysis demonstrate that all designated 

uses of the water body are being attained, but the numerical or narrative water quality standard for one or more 

water quality parameters are not being attained; and 

2. As R18-11-115(C)(5) – “And other scientifically sound methods. A person seeking to develop a sitespecific standard based on other scientifically sound methods shall provide a study outline to the Director and 

obtain approval for the study before conducting the study. 

Response: The Department appreciates the Surface Water Quality Standards Coalition’s support for the 

adoption of R18-11-115, Site-Specific Standards. The Department has, for the first time in rule, prescribed 

approved procedures for establishing site-specific water quality standards to protect aquatic life in Arizona surface 

waters. As with all surface water quality standards, site-specific standards are subject to EPA review and approval. 

Federal and state laws and regulations do not prescribe methods for developing site-specific standards. 

However, EPA has published detailed guidance describing several methods that EPA considers acceptable for the 

development of site-specific water quality criteria. EPA states in guidance that it will approve site-specific criteria 

that have been developed using appropriate procedures. For the first state rule addressing site-specific standards 

development, the Department decided to list only those procedures for developing site-specific standards that EPA 

has previously indicated are scientifically defensible. The Department included the Recalculation Procedure and 

the Water-Effects Ratio procedures in R18-11-115 because detailed EPA guidance on how to use the two 

procedures to derive site-specific criteria is available. The Department did not specifically include the Resident 

Species Procedure in the adopted rule because it is a combination of the two other procedures and EPA has not 

published separate guidance that specifically describes how to use the method. The Department included the 

“Streamlined Water Effects Ratio Procedure for Discharges of Copper” on the strength of the availability of 

detailed EPA guidance describing the method and because it is a variant of the WER Procedure which EPA has 

previously indicated is scientifically defensible. The Department included a method for developing site-specific 

standards based on natural background conditions in R18-11-115. EPA has indicated that this is an acceptable 

method for developing site-specific criteria (See EPA policy memorandum by Tudor T. Davies entitled 

“Establishing Site-Specific Aquatic Life Criteria Equal to Natural Background (November 5, 1997) and EPA 

Region 10, Office of Water and Watersheds, EPA Region 10 Natural Conditions Workgroup Report on Principles 

to Consider When Reviewing and Using Natural Conditions Provisions (January, 2005)). 

The Department reviewed the recommended site-specific standards language provided by the Coalition in 

Attachment B of their comment letter. Most of the conditions that the Coalition recommends the Department use 

as grounds for site-specific standards development are already in R18-11-115. These four grounds, proposed by 

the Department, correspond to the Coalition’s recommended grounds for site-specific standards development at 

R18-11-115 (C)(2), (C)(3), (C)(4) and (C)(7) in Attachment B. 

However, the Department does not support the adoption of the additional recommended rule language in 

Attachment B for several reasons: 

1. The Coalition proposed a new subsection at R18-11-115(B)(5) that would allow for site-specific 

standards to be developed where a UAA finds all uses are being met but the surface water cannot meet numeric or 

narrative standards. This is counter to the foundation of the water quality standards program, which is that surface 
198 

waters are protected for all designated uses by means of standards that are protective. The Department considers 

the other site-specific standards methods, including natural background, to be appropriate and defensible in 

dealing with the situation outlined. Often a total maximum daily load study will uncover unknown sources of 

pollutants that are adding to a waterbody impairment. These types of water quality management programs must be 

used to determine the necessity of a site-specific standard. 

2. The Coalition recommends two grounds for the development of site-specific standards for human health 

standards at R18-11-115(C)(5) and (C)(6). 

● The Department does not support the concept of site-specific standards when protection of human 

health is the goal. 

● The Department does not find there is a currently scientifically sound rationale for distinguishing 

human populations and human health protections on a site-specific basis. 

3. The Coalition recommends that ADEQ allow the development of site-specific standard based on the 

concept of net ecological benefit at R18-11-115(C)(8). 

● ADEQ disagrees that this ground should be included in R18-11-115. The Department has adopted a 

separate rule authorizing modifications to water quality standards based on the net ecological benefit 

(NEB) concept. It is more appropriate to address revisions to standards based on the NEB concept in 

R18-11-106. 

4. The Coalition recommended that the Department be able to establish a site-specific standard if “[t]he 

Director determines that the default standards are not appropriate due to unique, physical, hydrological, or 

chemical conditions,” and on “[o]ther factors or combinations of factors that upon review of the Director may 

warrant modifications to the default standards.” 

● These two recommended grounds for site-specific standards development are non-specific, vague, 

and scientifically indefensible. They do not provide sufficient specificity or objective criteria that 

the Director can use to determine that a site-specific standard should be established. 

5. The Coalition recommended that the site-specific standards rule list two additional procedures for 

developing site-specific standards, which are the Resident Species Procedure and an open-ended provision in R18-

11-115 that would state that acceptable procedures for site-specific standards development include: “Other 

scientifically defensible methods such as establishing site-specific standards equal to natural background as 

described in EPA guidance documents, relevant aquatic field studies, laboratory tests, biological translators, 

toxicity testing, bioassay, bioassessment, quantitative fate and transport analyses, human health and ecological 

risk analyses, or available scientific literature.” 

● The Department did not include the Resident Species Procedure because it is included as a 

combination of the Recalculation and Water Effects Ratio procedures. The Department does not 

support the inclusion of an open-ended provision that would authorize the use of “other 

scientifically defensible methods” for site-specific standards development. The Department has a 

relatively small water quality standards program staff and is concerned about its capacity to peer 

review and complete technical evaluations of alternative methods for site-specific standards 

development that have not been considered by EPA scientists. There are no recommended 
199 

evaluation criteria for determining whether an alternative method is “scientifically or technically 

defensible.” 

● The Department will consider the inclusion of the Biotic Ligand Model as an acceptable procedure 

for the development of site-specific standards as EPA has recently published detailed guidance on 

its use. However, the Department will defer consideration of this procedure to the next rulemaking 

of the surface water quality standards. 

Comment #114

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

It is unclear in the proposed rule how the language in R18-11-115 relates to the language in proposed R18-

11-113(B), which allows ADEQ to adopt by rule site-specific SWQS for EDWs. ADEQ should delete the 

language in R18-11-113(B) to clarify that Section 115 applies equally to EDWs. Alternatively, ADEQ should 

revise R18-11-113(B) to state that ADEQ will adopt site-specific EDW standards only in accordance with the 

provisions of R18-11-115. ADEQ should clarify that the provisions in R18-11-115 apply to all categories of 

surface waters. 

Response: Similar to the changes made in R18-11-112, the Department will clarify R18-11-113(B) by 

including a reference to the new site-specific standard section of the rule. The rule has been revised as follows: 

B. The Director may adopt, by rule, under R18-11-115, a site-specific water quality 

standards standard for an effluent dependent water. 

Natural Background 

Comment #115

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

Under proposed R18-11-115(C)(4)(c), ADEQ provides that “natural background” for purposes of 

establishing site-specific standards, means the concentration of a pollutant in a surface water due “only to nonanthropogenic sources.” This definition is unnecessarily narrow. Anthropogenic sources may contribute only 

nominally or indirectly to pollutant loading in water that would otherwise have a high natural background for a 

constituent. As such, the Coalition recommends that ADEQ revise this section so that “natural background,” for 

purposes of establishing site-specific SWQS, means the concentration of a pollutant in a surface water due 

principally to non-anthropogenic sources.” 

Furthermore, with respect to the definition of “natural background,” the narrative nutrient standard draft 

guidance document states that site-specific standards are likely to be necessary for EDW lakes. However, it is 

unlikely that non-anthropogenic background could be defined for an EDW lake in an ephemeral watercourse. The 

Coalition therefore requests that ADEQ clarify how it intends to establish site-specific standards for EDW lakes 

and urban lakes where a long history of anthropogenic source impacts, unrelated to the lake but related to its urban 

setting, may predominate. 

Jim F. DuBois, City of Tucson – Department of Transportation

Fred H. Gray, City of Tucson – Parks and Recreation Department
200 

ADEQ provides that “natural background” for purposes of establishing site-specific standards, means the 

concentration of a pollutant in a surface water due “only to non-anthropogenic sources.” This definition is 

unnecessarily narrow. The narrative nutrient implementation guidance states that site-specific standards are likely 

to be necessary for EDW lakes. EDW lakes are usually urban lakes, and it is unlikely that non-anthropogenic 

background could be defined for such a water body. ADEQ should clarify how to set site-specific standards for 

EDW lakes and urban lakes where a long history of anthropogenic source impacts, unrelated to the lake but 

related to its urban setting, may predominate. 

Response: The proposed natural background provision at R18-11-115(C)(4) is based upon EPA’s policy 

“Establishing Site-Specific Aquatic Life Criteria Equal to Natural Background,” November 5, 1997. The policy 

authorizes the establishment of site-specific numeric aquatic life water quality criteria by setting the criteria value 

equal to natural background. The policy specifically defines “natural background” as the background 

concentration due only to non-anthropogenic sources; i.e., non-manmade sources. In establishing natural 

background as a ground for the development of site-specific standards, the EPA policy states that the Department 

should, at a minimum, include in its water quality standards rules: 1) a definition of natural background consistent 

with the one in the EPA policy stated above, 2) a provision that site-specific criteria may be set equal to natural 

background, and 3) a procedure for determining natural background. The Department included these three 

elements in its natural background provision in R18-11-115. 

While the Department agrees that the natural background provisions of R18-11-115 could not be used to 

establish site-specific criteria for a man-made EDW lake, the other site-specific standards development methods, 

such as the recalculation procedure or the water effects ratio procedure can be used to develop site-specific 

standards for an EDW lake. The Department will continue to study available methodologies for site-specific 

standards for EDW lakes. 

R18-11-117. CANALS AND MUNICIPAL PARK LAKES

Comment #116

David E McNeil, City of Tempe

Tempe requests that the existing term “municipal park lake” in this section and in Appendix B be changed 

to the term “urban lake.” The use of both of these terms within the water quality standards is duplicative and 

creates confusion regarding the applicability of A.A.C. R18-11-117 to urban lakes, which is clearly necessary. In 

addition, Tempe objects to the proposed elimination of the last sentence in this section. Removal of clarifying 

language regarding the effect of this section is not a “minor editorial change” as described in the preamble, and 

could change the applicability of the rule.

Robert S. Lynch, Irrigation & Electrical Districts Association of Arizona

R18-11-117, which addresses the maintenance of canals and municipal lakes, removes language that allows 

an increase in turbidity during physical or mechanical maintenance of the canal or municipal lake. Maintenance of 

these waters is necessary to maintain public health, safety and welfare. An owner should not be penalized under 

the degradation rules for regular maintenance and startup, i.e. re-filling or cleaning a canal or municipal lake.
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Response: The Department agrees “urban” is a more inclusive term and has modified the definition and 

title of this Section accordingly. The Department agrees to retain the last sentence as it is in the existing rule and 

in R18-11-118. The Department had originally proposed removing it because there is no longer a turbidity 

standard but agrees, based on the comments received, that it does provide clarification that suspended sediment 

that is directly attributable to maintenance activities would not be a violation of standards. 

R18-11-117. Canals and Municipal Park Urban Lakes 

A. Nothing in the Article shall be construed to prevent prevents the routine physical or 

mechanical maintenance of canals, drains and the municipal park urban lakes identified in 

Appendix B. Physical or mechanical maintenance includes dewatering, lining, dredging, 

and the physical, biological, or chemical control of weeds and algae. Increase in turbidity 

that result from physical or mechanical maintenance activities are permitted in canals, 

drains and the municipal park urban lakes identified in Appendix B.

R18-11-118. DAMS AND FLOOD CONTROL STRUCTURES

Based on the Comment #116 above, the Department has retained the following information in subsection 

(A) because it provides clarification that suspended sediment that is directly attributable to maintenance activities 

would not be a violation of standards. 

A. Increases in turbidity that result from the routine physical or mechanical maintenance of a dam or 

flood control structure are not violations of this Article. 

R18-11-121. SCHEDULES OF COMPLIANCE

Comment #117

Robert A. Hollander, City of Phoenix

The Water Services Department recommends that ADEQ revise the three year minimum for compliance 

schedules, and allow for schedules of ten years, with provisions for longer periods when necessary. This approach 

is consistent with the May 2007 EPA memo prepared for Region 9 in considering California’s proposed 

compliance schedule policy. On April 15, 2008, the California State Water Resources Control Board adopted a 

new compliance schedule policy. In keeping with this approach, the standards should include the provisions: 

● Any compliance schedule must require compliance as soon as possible, taking into account the 

amount of time reasonably required for the discharger to implement actions, such as designing and 

constructing facilities or implementing new or significantly expanded programs and securing 

financing, if necessary, to comply with a more stringent, permit limitation specified to implement a 

new, revised, or newly interpreted water quality objective or criterion in a water quality standard. 

● The duration of the compliance schedule may not exceed ten years from the date of adoption, 

revision, or new interpretation of the applicable water quality objective or criterion in a water 

quality standard. 
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A compliance schedule that exceeds ten years in a permit can be adopted if it implements or is consistent 

with the waste load allocations specified in a TMDL. 

Response: The Department appreciates the comment. The Department cannot make a substantive rule 

change at this point in the process but it appears that there is merit to exploring this issue further and addressing it 

in a subsequent rulemaking. 

R18-11-121(D) 

Comment #118

David E McNeil, City of Tempe

Schedules of compliance for AZPDES stormwater permits should be limited to the implementation of best 

management practices to the maximum extent practicable MEP.

Response: R18-11-121(D) does determine whether or not standards apply. This rule is not a new provision 

and simply allows the Director the discretion to include a compliance schedule in a stormwater permit. 

R18-11-123. DISCHARGE PROHIBITIONS

The Department has withdrawn two of the four proposed discharge prohibitions to the Ak-Chin Indian 

Reservation for the following reasons: (1) The Department received significant comments on the lack of 

sufficient cost analysis on the impact of the prohibitions to upstream discharges; and (2) The Department did 

not have the information about how the prohibitions would impact certain discharges and had no figures to 

support the impacts. The Department will not issue permits for discharges onto Ak-Chin lands and will 

require permittees to work with the Ak-Chin Community on their discharges until such time as the 

Department can move forward with the prohibitions in a subsequent rulemaking. 

A. The discharge of treated wastewater to Sabino Creek is the following surface waters is prohibited.:

1. Sabino Canyon Creek;

2. Vekol Wash, upstream of the Ak-Chin Indian Reservation; and

3. Smith Wash, upstream of the Ak-Chin Indian Reservation.

4. Santa Rosa Wash, from its confluence with Greene Wash to the Ak-Chin Indian Reservation; and

5. Santa Cruz Wash, from its confluence with the North Branch of the Santa Cruz Wash to the Ak Chin 

Indian Reservation.

R18-11-123(A)(2)-(5)

Comment #119

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ has improperly proposed a strict discharge prohibition to the Santa Cruz Wash, Santa Rosa Wash, 

Vekol Wash, and the Smith Wash. 

ADEQ is proposing to add a strict discharge prohibition to the above washes, but ADEQ has failed to 

provide any prior notice of this action to affected stakeholders during the almost 4 year period since the proposed 

rules were first noticed. ADEQ also provides no informative discussion in the rule or preamble as to why this 
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prohibition is necessary or beneficial to Arizona citizens. 

Pima County has obtained all necessary discharge permits for discharging treated effluent into the Santa 

Cruz River which is tributary to some or all of the designated washes and this discharge has continuously occurred 

for over 40 years. Discharged effluent consistently meets permit requirements for the designated use of the river. 

The ADEQ proposed discharge limitation is intended to prevent a discharge of wastewater to the Ak-Chin 

Indian Reservation even though discharged wastewater meets all required permit limitations. Pima County is 

unaware of any legal right by the Ak-Chin to require that ADEQ incorporate this prohibition into these rules. Pima 

County asks that ADEQ remove the requirements of A.A.C. R18-11-123(A) from this proposed rule. 

ADEQ must also revise its EIS to incorporate a discussion of the potential impacts on Pima County citizens 

and a discussion of what steps ADEQ could take to minimize any impact on Pima County small businesses. 

Response: Modifications to this Section have been out for public review since early 2007. The intent of the 

discharge prohibitions was to protect surface waters on the Ak Chin Reservation that carry additional, more 

protective designated uses. The Ak Chin Indian Community has adopted tribal water quality standards that have 

additional narrative and numeric criteria for its waterbodies. In addition, one of the surface waters, Vekol Wash, is 

recognized as a unique water under the Ak Chin water quality standards. The Ak Chin Indian Community opposes 

the flow of effluent onto its sovereign reservation land. 

This rule is adopted to prevent discharge from reaching the washes on the reservation, except those flows 

carried incidentally during precipitation events. In the case of these specific provisions, the best and ‘existing’ 

uses of these washes is considered by the Ak Chin Community to be ephemeral, and as such would be adversely 

affected by discharges. Under the Clean Water Act, Arizona has the authority to designate uses. Accordingly, the 

discharge prohibitions establish the use as ephemeral. 

As a sovereign nation, the Department respects and acknowledges the Community’s efforts to protect its 

surface waters for its established uses. The Department has committed to honoring the cultural sensitivities and 

water quality standards of tribes that may be affected by discharges when possible, whether or not those standards 

are ‘officially’ recognized by EPA – just as the Department would expect another governing state would honor 

Arizona’s position on discharges impacting Arizona lands. 

While the Department does not believe these prohibitions will have any near-term impacts on Pima 

County’s discharges that are over 50 miles south of the reservation, the Department recognizes that there are a 

small number of upstream permitted dischargers that may be impacted by a prohibition to discharge to the listed 

reach of Santa Cruz Wash and the Santa Rosa Wash. Therefore, the Department is withdrawing the prohibitions 

on both the Santa Cruz and the Santa Rosa Washes at this time and will work with permittees and the Tribe to 

resolve the issues. The Department is not aware of any discharges affecting Vekol and Smith washes. All 

dischargers seeking discharges in or near these streams that may flow onto the Ak Chin Reservation should 

promptly engage the Ak Chin Community in discussions. The Department expects that existing dischargers will 

maximize disposal options to manage effluent flows to prevent them from reaching Reservation lands. 

Comment #120

Claire L. Zucker, Pima Association of Governments (PAG)
204 

This section of the rule indicates that there is a prohibition of discharge to the Santa Cruz Wash from its 

confluence with the North Branch of the Santa Cruz Wash to the Ak Chin Indian Reservation. Although Pima 

County does not discharge to this segment of the Santa Cruz Wash it is unclear whether this prohibition would 

apply to any discharge that reaches the Ak Chin Reservation by flowing through the Santa Cruz Wash. While 

Pima County’s discharge does not generally reach the Ak Chin Indian Reservation, it is possible for their effluent 

to flow that far when infiltration along the river is decreased or when stormflows flood the river. We are 

concerned that Pima County was not given prior notice or allowed input before the proposed rule was issued. If 

Pima County is required to contain the effluent, they would be forced to build expensive facilities for no added 

benefit to water quality of the state, but at great expense to the tax payers. 

The change in this section from referring to “treated wastewater” as simply “wastewater” means that 

virtually any discharge to the Santa Cruz River system could be held accountable whenever any flow reaches the 

Ak Chin reservation. Since the term “wastewater” is left undefined, the rule does not make it clear whether or not 

stormwater, which may contain industrial discharges, would be included in this prohibition.

Response: See Response #16 regarding stormwater flows not being considered wastewater. These 

discharge prohibitions were originally proposed in early 2007 to apply to any wastewater discharge that would 

enter or extend to these reaches during dry weather because such discharges would be inconsistent with the 

existing ephemeral and cultural uses of these washes. This prohibition was not intended to extend to flows 

resulting from precipitation events, whether or not that flow contains other permitted discharges. See Response 

#119. 

Comment #121

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

ADEQ inappropriately proposes certain discharge prohibitions under R18-11-123 intended to prevent 

discharges from reaching the Ak Chin Indian Reservation, as well as prohibiting certain discharges to Lake 

Powell. Discharge prohibitions do not belong in SWQS regulations, which are intended to provide the basis of 

water quality assessments and permitting depending on designated uses. The Coalition requests that ADEQ 

remove these discharge prohibitions from this rule proposal.

Response: The Department disagrees that discharge prohibitions do not belong in standards. Discharge 

prohibitions directly relate to water quality within a waterbody, antidegradation provisions of the Clean Water 

Act, and the ability to develop and issue protective permits. Arizona surface water quality standards have included 

discharge prohibitions since 1981. See Responses #119 and #120. 

Comment #122

Sydney Hay, Arizona Mining Association

The proposed rule includes a complete prohibition on discharges of wastewater to four washes upgradient 

of the Ak-Chin Indian Reservation. The preamble provides no explanation whatsoever of the basis for this 

complete ban on discharges to these ephemeral washes, although it can be inferred that it is in response to the 

wishes of the Tribe. 
205 

There are several issues with this proposal. First, as noted above, it is unclear what is meant by 

“wastewater,” so the precise scope of the proposal is difficult to discern, especially given ADEQ’s complete lack 

of explanation for the proposal. 

Second, and of greater concern, the legal basis for these proposed prohibitions is unclear, and ADEQ 

provides no explanation in the preamble. Third, ADEQ has made no attempt to quantify the economic costs of 

these discharge prohibitions. Presumably, planned wastewater treatment plants in the vicinity would be prohibited 

from any discharge whatsoever into the washes, and would have to find an alternate method of effluent handling. 

It is unclear how existing discharges, if any, would be affected. 

The proposed discharge prohibitions should be removed from the final rules.

Response: Under the Clean Water Act, the Department has authority to designate uses. Accordingly, the 

discharge prohibitions establish the use as ephemeral in these segments. As a sovereign nation, the Department 

respects and acknowledges the Community’s efforts to protect its surface waters for its established uses. See 

Response #119. 

Comment #123

Daniel Hartley, Tohono O’odham Nation

The proposed rule “R18-11-123. Discharge Prohibitions” involves the Tohono O’odham Nation (Nation) 

by virtue of the fact that the Nation is upstream of the reach of Santa Rosa Wash where discharge of wastewater is 

prohibited in this proposal. The stream channels involved are connected as follows. Almost all flow in the Santa 

Cruz River is diverted into the former Greene Canal shortly after it crosses from Pima to Pinal County. The 

Greene Canal joins Greene Wash, which flows through the northern part of the Tohono O’odham Nation and 

continues on to its confluence with Santa Rosa Wash, which enters the Ak Chin Reservation about 12 miles 

downstream of where it leaves the Tohono O’odham Nation. Wastewater discharged into the Santa Cruz River in 

Tucson under an AZPDES permit occasionally reaches the Tohono O’odham Nation when evaporation and 

channel infiltration are reduced. We have measured a flow rate of 2 cfs on the Nation. In order for that wastewater 

to reach Santa Rosa Wash and the Ak Chin Reservation before it dries up, there has to be a large increase in flow 

volume from storm runoff. This large volume of storm runoff dilutes the wastewater so that its chemistry is not 

noticeable in the combined streamflow, so there is no effect on far downstream reaches from the wastewater 

component. If the intent of the rule is to prevent wastewater flows from affecting the Ak Chin Reservation, then 

the rule should be re-written to prohibit wastewater from entering those washes without any added stormflow 

volume.

Response: The Department appreciates the information on impacts of the Pima County flows to the 

Tohono O’odham Nation. The commenter is correct that the intent of the proposed language was to prevent 

discharges from reaching the washes on the reservation, except those flows carried incidentally during 

precipitation events. See Response #119. 

Comment #124

Sandy Bahr, Sierra Club  Grand Canyon Chapter
206 

We support prohibition of discharges into Vekol Wash, Smith Wash, Santa Rosa Wash, and Santa Cruz 

Wash in order to limit wastewater flowing on to the Ak Chin Indian Reservation.

Response: The Department appreciates the comment. 

Comment #125

Louis J. Manuel Jr., Vice-Chairman, Ak-Chin Indian Community

The Ak-Chin Indian Community (Community) fully supports the proposed revision to the State of 

Arizona’s Surface Water Quality Standards. The supported revision is within R18-11-123 Discharge Prohibitions

whereby the addition of four new discharge prohibitions that prevent point source discharges of wastewater to 

ephemeral waters that may flow onto the Ak-Chin Indian Reservation. These ephemeral waters are Vekol Wash, 

Smith Wash, Santa Rosa Wash and Santa Cruz Wash, which do transect the Reservation. 

The Community had and will continue to protect and preserve its cultural, natural and environmental 

resources such as the washes: Vekol, Smith, Santa Rosa and Santa Cruz. Our Elders and membership have the 

deepest respect for these washes because they not only carry a life sustaining element (water) but other natural 

abundances that maintain our O’odham Him-Dak (“Way of Life”). 

The Community greatly appreciates the Arizona Department of Environmental Quality’s understanding of 

the significance of these washes. 

Response: The Department appreciates the comment.See Response #119 indicating that the Department is 

not moving forward at this time with the discharge prohibition on either the Santa Cruz or the Santa Rosa Washes. 

The Department expects currently permitted dischargers to work with the Community to ensure its interests and 

water quality standards are met. 

APPENDIX A. NUMERIC WATER QUALITY STANDARDS

Comment #126

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We support the adoption of more protective standards in several areas, including for arsenic, 2,3,7,8-

Tetrachlorodibenzo-p-dioxin, and uranium. These standards will better protect the public’s health and will 

continue the improvement of surface water quality in Arizona. There are a couple of areas in which there is 

significant increase in the standard, however. For example, for Chlorine (total residual) the standard increased 

from 700 μg/L to 4,000 μg/L for Domestic Water Use and for Full and Partial Body Contact. Additionally, total 

residual chlorine standards for Aquatic and Wildlife designation increased from 11 μg/L to 19 μg/L acute and 

from 5 μg/L to 11 μg/L chronic. It is our understanding these increased standards were adopted by EPA, but we 

question if they are protective and whether or not they have been adequately reviewed. 

Response: The proposed chlorine standards for the domestic water source, partial and full body contact 

uses have been increased to match the maximum residual disinfectant level (MRDL) for total residual chlorine. 

Since 1992, it has been Department policy that where an maximum contaminant level (MCL) or MRDL for 

drinking water exists and is greater than the calculated domestic water source or full and partial body contact 

standards for that pollutant, the MCL or MRDL is substituted as the standard for that use. As the domestic 
207 

water source use pertains to natural waters that will be treated to produce potable water, this protects that use 

and minimizes the cost of treatment. For the full and partial body contact uses, the assumed water consumption 

rate of 15 mL/day is far below the assumed consumption rate of 2 liters per day used in the calculation of the 

DWS use. As the assumed consumption rate is so much lower, it is implicit that a standard calculated for a 

higher consumption rate would protect human health. 

The change to the A&W standards for total residual chlorine is to correct a long-standing inconsistency 

between state and federal criteria. The current federal criteria are 11 μg/L for acute and 19 μg/L for chronic 

exposures. The Department has researched the history of the state’s lower numbers and cannot find a 

scientifically defensible reason for keeping them artificially low. While the proposal to increase the state 

standards to match the federal criteria doubles or nearly doubles the standards (from 5 to 11 for acute and from 

11 to 19 for chronic), these are negligible increases in terms of aquatic toxicity and laboratory analysis. 

Comment #127

Sandy Bahr, Sierra Club  Grand Canyon Chapter

We support the changes in the fish consumption criteria which afford greater protection for public health, 

including the change in consumption rate and the assumption that those who are consuming fish are also being 

exposed to these pollutants via other sources. We also support implementation of a Methylmercury Fish Tissue 

Criterion as consumption of fish is a major pathway for human exposure to methylmercury. With it come serious 

public health issues including developmental impairments for children. Methylmercury is a developmental 

neurotoxicant. The developing fetuses of women who consume fish during pregnancy are most at risk and impacts 

include lifelong injury to the developing brain. 

We support the addition of numeric water quality standards for chloropyrifos, guthion, hydrogen sulfide, 

iron, malathion, mirex, paraquat, parathion, permethrin, and tributyltin. It is clear from the many assessments 

done on our nation’s waters that herbicides and pesticides are increasingly showing up in both rural and urban 

waters. 

We strongly support inclusion of these new numeric water quality criteria for total ammonia in the 

state’s effluent-dependent waters. 

Because many of the criteria in this appendix are established and based on the average weight of a human 

male, they fail to address the impacts on children and, in some instances, women. For example, there is increasing 

evidence connecting numerous pesticides and other chemicals that affect estrogen production to breast cancer in 

women. We think the department should use the precautionary principle wherever possible and use the most 

protective standards available.

Response: The Department appreciates the commenter’s support on the changes. To address much of the 

uncertainty inherent in risk analysis, the Department relies on the safety factors already designed into the 

standards derivation process. In the derivation of EPA risk values, such as the reference dose (RfD) and the oral 

cancer slope factor (OCSF) used in the calculation of water quality standards, there are many safety factors built 

into the equation to account for the uncertainty of toxic effects. These safety factors can affect a manifold decrease 

in the allowable risk for a pollutant. If there is a significant source pathway for a pollutant that involves excess 
208 

consumption by children, that issue can also be addressed in the relative source contribution calculation. Also, for 

pollutants with developmental toxicity endpoints (e.g. methylmercury), these issues can be addressed through the 

studies chosen for the derivation of the underlying RfD or OCSF. These safety factors combined offer adequate 

protection for the greater population as a whole. 

Ammonia 

Comment #128

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

The new acute criteria for total ammonia and the chronic criteria for total ammonia proposed at tables 25 

and 26 respectively, are unreasonably low. The commenter believes in order for a biological plant to consistently 

meet nitrogen limits and these new ammonia limits will require significant capital improvements. 

Standards used in the aquifer protection permit program provide flexibility to address the treatment process 

limitations by setting limits only for total nitrogen (regardless of the composition), and application of a 5-month 

rolling geometric mean. There are no such protections in the proposed rule, and the likely result will be numerous 

violations by biological treatment plants. 

Further, in SMCFD’s service area, nitrates in groundwater are a significant human health concern because 

of numerous septic tank systems and it is desirable in this area especially to favor treatment of nitrates over 

ammonia. The proposed standards do not provide flexibility to address this concern. 

SMCFD is concerned with the amount of time and significant capital resources needed to make plant 

upgrades from funding through permitting to construction. Because this is the first time numeric criteria for 

ammonia are being applied to effluent-dependent waters, ADEQ should propose a reasonable schedule for the 

effective date of these limitations that recognizes that it may take up to three years for publicly-owned treatment 

plants to fund, design, and build new infrastructure. 

Response: The aquifer protection program serves to protect groundwater, where the AZPDES program is 

to protect surface water in a manner consistent with the Clean Water Act. The two programs have very different 

goals and standards to meet and a permittee with both permits must meet both. The new ammonia standard is 

being adopted because discharges of ammonia are toxic to aquatic life and not just to fish. Ammonia is the source 

of toxicity in a number of domestic wastewater discharges. In calculating the ammonia standards using the 

established EPA method, the Cypriniform (or carp-like) golden shiner, an abundant fish in Arizona’s waters and 

one that can be logically found in EDWs, is the second most sensitive fish in the entire ammonia calculation. 

Centrarchids (bass and sunfish), also prevalent in the State’s warm water streams and EDWs, are highly sensitive. 

Nitrate in groundwater is a significant concern although it is important that neither the groundwater 

standard for total nitrogen nor the surface water standard for ammonia be violated. Nutrient removal technologies 

presently exist that can address both issues. The Department recognizes that changes in standards may require 

changes in treatment or in disposal options. However, there are already tools in the water quality standards that 

allow for phase in of standards. When any new water quality standard is implemented, there is an opportunity in a 

permit for a compliance schedule under R18-11-121. There is also the possibility for a variance if a discharger can 

qualify under R18-11-122, which must be approved by EPA. The surface water permits program will work with 
209 

individual permittees on case-by-case appropriate approaches for their facilities. 

Comment #129

Robert A. Hollander, City of Phoenix

The City of Phoenix uses chloramines for disinfection. It provides stable, longer-lasting residual. The new 

standard puts Phoenix at risk of exceeding future water quality based permit limits for total ammonia. To disinfect 

using free chlorines puts Phoenix at greater risk of running at a residual, because even in good quality effluent, 

chlorine demand is high even in advanced secondary treatment, and could potentially exceed pathogen limits. The 

City requests that ADEQ consider this in the total ammonia standard and the cost impact of imposing the standard 

on operations of wastewater treatment plants.

Response: The new ammonia standard is being adopted because discharges of ammonia are toxic to 

aquatic life. The Department understands the delicate balance WWTPs have to maintain in dealing with 

disinfection, however, this does not justify not meeting appropriate ammonia standards and the standard is 

achievable. See the EIS for the cost-benefit analysis of the new ammonia standard. 

Comment #130

Steven L. Spangle, Field Supervisor, US Fish And Wildlife Service

We support the proposed acute and chronic A&Wedw standard for ammonia and provide the following 

information. Threatened and endangered species, or their former or potentially suitable habitat, exist downstream 

of wastewater treatment plants in Arizona. For example, the Gila topminnow formerly inhabited the Santa Cruz 

River downstream of the Nogales International Wastewater Treatment Plant (NIWTP). Although the Gila 

topminnow has a wide tolerance to temperature and dissolved oxygen fluctuations, it is unable to withstand 

elevated ammonia concentrations, which have exceeded EPA’s recommended chronic criteria for ammonia 

downstream of Nogales (Boyle and Fraleigh 2003). However, the lack of an A&Wedw standard for ammonia, 

such as the Santa Cruz below the NIWTP, has negatively affected the ability of the Gila topminnow to maintain its 

population and recolonize this area (King et al. 1999). The last recorded observation of Gila topminnow in the 

Santa Cruz River downstream of the NIWTP was in 2003 at Tubac, which is approximately 10 miles downstream. 

USFWS feels the proposed acute and chronic A&Wedw standard for ammonia is protective of the endangered 

Gila topminnow. 

Response: The Department appreciates the comment. 

Arsenic 

Comment #131

Jennifer Hetherington, City of Mesa

The City of Mesa respectfully submits that the existing standard of 50 ug/L should be retained in the rule. 

In the past seven years, there have been only two violations due to exceedence of the arsenic drinking water 

standard (other violations related to arsenic can be attributed to missed routine sampling events) in the SDWIS 

database. These results indicate that arsenic in treated surface water is not an issue in Arizona. Even when issues 
210 

do arise, well water in Arizona is the primary source of treated water that can exceed the drinking water standard 

of 10 ug/L for arsenic, not surface water. There is no need to reduce the arsenic standard for domestic water 

sources to protect the treated drinking water, because treatments plants in Arizona are already meeting the current 

standard of 10 ug/L. 

To the extent that arsenic is an issue, proposed R18-11-107.01 regarding antidegradation implementation 

procedures might be the more appropriate vehicle to regulate discharges to affected waters. Surface water 

treatment plants are able to treat water down to less that 10 ug/L arsenic. Since high-level arsenic is not prevalent 

in surface water, then domestic water source limits need not match the drinking water standard – treatment will 

address any arsenic issues. However, there are drinking water plants that may have to discharge partially treated 

water to a domestic water source, in the event of high turbidity. The City of Phoenix Val Vista Treatment plant coowned by the City of Mesa is one such plant. When turbidity is high, arsenic may also be present. Thus while such 

discharges may meet the 50 ug/L standard, it will be very difficult to meet the proposed standard. This will result 

in a “Catch 22” situation for the treatment plant. The reason for this type of discharge in the first place is the noncompliance with drinking water standards, yet the discharge will still be required to meet the same standard as if it 

were treated drinking water. This will cause financial hardship, as well as design difficulties that are not 

necessary, because the domestic water would still ultimately be treated before it is ever used as drinking water, 

and as stated previously, these treatment plants are highly successful in removing arsenic. 

In conclusion, the Rules should retain the current arsenic domestic water source limit of 50 ug/L. The 

violations documented in drinking water discharges from surface water treatment plants do not indicate that 

arsenic levels in domestic water sources are an issue. 

Response: The Department disagrees that the outdated MCL should be retained. EPA revised the MCL for 

arsenic to 10 μg/L and the Department adopts the new MCL to protect surface water quality for the Domestic 

Water Source (DWS) designated use. The adoption of MCLs to protect surface water quality for the DWS is 

consistent with the way that the Department has adopted standards since 1992. If the Department applied the 

default methodology it uses to derive water quality criteria for the DWS designated use for parameters where an 

MCL is unavailable, the resulting criterion for arsenic would have been less than 10 μg/L. The fact that few 

surface waters are currently listed for arsenic impairment does not equate to there being no issue with arsenic in 

Arizona surface waters. There are over 95,000 stream miles throughout the state and the Department cannot assess 

every one of them for each assessment. There are surface waters in Arizona that have naturally occurring levels of 

arsenic higher than the current and proposed standard. The canals to which the Val Vista water treatment plant 

discharges carries the DWS designated use. Downstream users of the canal water are entitled to the same water 

quality as the upstream users. The standards provide for mixing zones, which the Val Vista AZPDES permit 

currently has for several pollutants, including arsenic. A mixing zone allows a permitted discharge to exceed an 

acute water quality standard at the end of pipe provided it is not exceeded at the edge of the mixing zone. A 

mixing zone is a prescribed area or volume contiguous to a discharge where initial dilution of the discharge takes 

place within the receiving water. 

Comment #132
211 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

MCLs are set by the EPA in order to regulate drinking water systems under the Safe Drinking Water Act 

(“SDWA”), whereas SWQS are designed to preserve and protect water quality for certain designated uses. MCLs 

apply to public water systems, which provide water to the public for “human consumption” and are applied after 

treatment. In contrast, SWQS apply to natural, pretreated water. The SWQS cut across many programs not 

considered by EPA when revising the drinking water MCLs, including the AZPDES and TMDL programs. The 

assumptions used to set MCLs for drinking water systems do not always translate into reasonable standards for 

pretreated surface water, because those standards take treatment into account. Additionally, MCLs are set on a 

national basis using national data on contaminant background levels and treatment costs, which may not be 

representative of Arizona’s hydrogeological conditions. Additionally, MCLs may be based on outdated or refuted 

science. The Coalition therefore requests that ADEQ justify its adoption of the federal MCLs as untreated SWQS.

Response: It has been long-standing Department policy to adopt MCLs, where available, to protect surface 

water quality for the Domestic Water Source (DWS) designated use. The use of the MCL to protect water quality 

for the DWS designated use in surface water is consistent with the protection of drinking water under the Safe 

Drinking Water Act. The Department believes that the level of protection for surface waters that are used as 

sources of drinking water should be equivalent to that required of public water systems that provide drinking 

water. The numeric water quality criteria for the DWS designated use are intended to be quantitative 

concentrations of levels of pollutants in water that, if not exceeded, will generally ensure adequate water quality 

for the specified designated use. MCLs represent concentrations of pollutants in finished drinking water that EPA 

considers safe for human consumption and other potable uses. The Department has made the common sense 

determination that where surface water quality does not exceed the MCL, then it generally ensures adequate water 

quality for the DWS designated use. In consideration of the Department’s goal of pollution prevention, ambient 

surface waters with the DWS designated use should not be contaminated to a level where the burden of achieving 

the MCL in drinking water is shifted away from those responsible for pollutant discharges to public water systems 

who must bear the costs of providing treatment for drinking water. 

As for the scientific validity of the arsenic standard at 10 μg/L, the criteria was adopted by EPA in January, 

2001 and was to be enforceable in January, 2006. In March of 2001, EPA requested that the National Academy of 

Sciences convene a panel of experts to review EPA’s interpretation and application of arsenic research. In October 

2001, EPA announced that the findings of the NAS were that “the 10 ppb (standard) protects the public health 

based on the best available science and ensures that the cost of the standard is achievable.” 

Bromoform 

Comment #133

Janet Hashimoto, Chief; EPA Monitoring & Assessment Office

In applying ADEQ’s methodology for calculating the numeric criteria for Full Body Contact for 

carcinogens, we derived a value of 0.00059 μg/L for bromoform relative to ADEQ’s proposed criterion of 18,667 

μg/L. Please clarify the calculation used to derive the bromoform criterions.
212 

Response: An error was made in the calculation of the full body contact standard for bromoform. The noncarcinogenic endpoint was used (RfD) rather than the oral cancer slope factor. The Department is withdrawing 

this proposed standard revision and will initiate a separate rulemaking to adopt the correct standard. 

Cadmium and Barium 

Comment #134

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The Coalition requests that ADEQ update its cadmium and barium standards to reflect current toxicity 

factors recommended by EPA and that ADEQ review its proposed standards to ensure that these are based on the 

most current toxicological information. . 

Michael Garry, Exponent, on behalf of the Pinal Creek Group

In our review of previous drafts of the numerical standards, we identified the use of incorrect RfDs for 

cadmium and barium. In both cases the errors have been carried through to the 2008 draft. 

Response: The Department is withdrawing the proposed standard revisions for both cadmium and barium 

and will initiate a separate rulemaking to adopt the corrected standards. 

Chlorine 

Comment #135

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

The proposed standard of 19 micrograms per liter for acute total residual chlorine (“TRC”) and 11 

micrograms per liter (parts per billion) for chronic TRC, although they have been loosened somewhat, are still 

unreasonable. There is no test method currently available that can reliably measure TRC at the proposed levels. 

The TRC test is highly sensitive to interferences from many different types of chemicals in the water and the TRC 

PQL for every plant will vary throughout the year and from plant to plant. 

Response: The Department is aware of current analytical limitations and issues related to chlorine 

monitoring. However, water quality standards are based on studies concerning affects to life at certain 

concentrations and the proposal to raise chlorine limits is in response to new scientific information, specifically 

EPA’s revised chlorine criteria. 

While interference and quantification issues can be problematic for the A&W chlorine standard, those 

issues are more precisely addressed in the provisions of the discharger’s permit. Surface water quality standards 

are designed to protect human health and aquatic and wildlife. Chlorine is a disinfectant added to waste streams to 

kill microorganisms and it can kill aquatic life in surface waters. AZPDES permits have specific language for how 

a permittee is to report data when analytical methods cannot detect contaminants below the standard or discharge 

limitation in the permit. Assuming the permittee is following the permit language, there is no violation of the 

permit if the samples are collected appropriately, analyzed using proper laboratory methods, and reported to the 

Department on time. 

Comment #136
213 

David E McNeil, City of Tempe

Tempe is concerned with a proposed revision of the Full Body Contact (FBC) and Partial Body Contact 

(PBC) standards for chlorine to 4,000 ppb based on the Safe Drinking Water Act maximum residual disinfectant 

level (MRDL) for two reasons: 

1. The MRDL is based on ingestion resulting in irritation to the eyes and ears, not skin exposure 

resulting in “eye and skin irritation” as explained in the rule proposal. Four thousand ppb of chlorine 

should not result in skin irritation. 

2. Safe Drinking Water Act compliance with the MRDL is calculated as a running annual average of 

monthly averages of all samples. For a drinking water system the size of Tempe’s, compliance is 

calculated by averaging 120 monthly samples each month and then averaging all of the last 12 

monthly averages. 

Response:. The commenter is correct, the full body contact (FBC) and partial body contact through 

ingestion (PBC) standards were set at the maximum residual disinfectant level (MRDL) due to irritation of eyes 

and ears not skin exposure. 

The Department’s long standing policy has been to use the MCL or MRDL if the calculated DWS or 

recreational contact standard is more restrictive. The calculated standard for residual chlorine for the full body 

contact (FBC) use would be 467μg/L using the RfD for the ingestion of water which is 10 times more restrictive 

than the MRDL of 4000 μg/L. 

Full body contact and partial body contact are “terms of art” and necessarily use consumption in calculating 

the standards. Full body contact standards are used to protect the use where an activity such as swimming can 

occur and water is ingested. Partial body contact standards protect the use where activities such as wading and 

boating can occur. The latter standard may entail ingestion because a small child could either become completely 

submerged or transfer water to their mouth on their hands. It is important that ingestion endpoints be addressed for 

both of these uses. Additionally, any waterbody with a contact standard will also have an aquatic and wildlife 

(A&W) standard, which is considerably more stringent than the human health/recreational standards referenced 

above. 

Chloroform 

Comment #137

Janet Hashimoto, Chief; EPA Monitoring & Assessment Office

ADEQ has proposed less stringent chloroform criteria for Fish Consumption and Full Body Contact 

beneficial uses, considering chloroform to be non-carcinogenic. However, EPA has not determined that 

chloroform is a non-carcinogen. We are currently in the process of updating the scientific assessment for 

chloroform. We recommend that ADEQ retain its existing chloroform criteria until EPA makes a final 

determination as to whether it is non-carcinogenic. 

Response: Arizona has a standing policy of using the oral cancer slope factor (OCSF), if available, to 

calculate the standards for the full body contact use. If the OCSF is not available, the reference dose (RfD) is used. 

As of July 7, 2008, no OCSF was available in the EPA Integrated Risk Information System (IRIS) database but it 
214 

did state: “A dose of 0.01 mg/kg/day (equal to the RfD) can be considered protective against cancer risk.” The 

Department used the RFD in calculating the new criteria. 

Iron 

Comment #138

Benjamin R. Parkhurst, HAF, Inc., on behalf of the Pinal Creek Group

The proposed chronic A&W standard for iron for cold water, warm water, and effluent-dependent water 

(1000μg/L) should be changed to 1000 μg/L dissolved iron. This proposed standard is based on the iron criterion 

in US EPA’s (1976) “Red Book.” Like all inorganic metals, only the dissolved fraction of iron is considered to be 

significantly toxic to aquatic life (US EPA 1992). 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The Coalition requests that ADEQ revise its proposed numeric SWQS for iron for aquatic and wildlife uses 

and EDWs to apply only to dissolved iron. Only dissolved iron is considered to have significant toxic effects to 

aquatic life. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

Pima county supports comments made by Dr. Ben Parkhurst concerning the A&W chronic standards for 

iron, in Appendix A Numeric Water Quality Standards. 

Response: Due to a typographical error the ‘D’ designation to indicate dissolved iron was omitted in 

Appendix B and has been corrected. 

Mercury 

Comment #139

Benjamin R. Parkhurst, HAF, Inc., on behalf of the Pinal Creek Group

It is requested that the chronic Aquatic and Wildlife (A&W) standard for mercury for cold water, warm 

water, and effluent-dependent water (0.01 μg/L dissolved mercury) be withdrawn and that it be replaced by the 

US EPA’s (2004a) chronic, freshwater, National Recommended Water Quality Criterion (0.77 μg/L dissolved 

mercury). 

ADEQ’s chronic A&W standard for mercury (0.01μg/L) was taken from US EPA’s (1985) Ambient Water 

Quality Criteria for Mercury 1984. ADEQ’s A&W standard for Hg is a human health-based standard. The FC 

standard provides greater protection to aquatic life and human health than the chronic A&W standard. 

ADEQ’s FC and chronic A&W standards are redundant, because they are both based on protection of 

human health from mercury bioaccumulation in fish. The chronic A&W standard should be 0.77 μg/L dissolved 

mercury (II), which is US EPA’s (2004a) recommended chronic criterion. If ADEQ prefers to retain its current 

A&W standard, 0.01μg/L dissolved aqueous mercury, the standard should be based on measurement of dissolved 

methylmercury in water, not total or inorganic mercury. ADEQ’s proposed FC standard, 0.3 mg/kg 

methylmercury, should be protective of most piscivorous wildlife; therefore, a separate standard to protect 

piscivorous wildlife is unnecessary. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department
215 

Pima county supports comments made by Dr. Ben Parkhurst concerning the A&W chronic standards for 

mercury in Appendix A Numeric Water Quality Standards.

Robert A. Hollander, City of Phoenix

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

We recommend that ADEQ replace its proposed chronic aquatic and wildlife and EDW standard for 

mercury with EPA’s chronic, freshwater, recommended water quality criterion of 0.77 μg/L dissolved mercury. 

ADEQ’s proposed mercury standard for these designated uses is based on data of human consumption. However, 

concerns related to human consumption are already addressed through the fish consumption designated use. 

Basing the aquatic and wildlife and EDW standards on those same assumptions is unnecessarily redundant and is 

not directed specifically at the purpose of those designated uses – to protect wildlife. 

Response: The Department disagrees. In an arid climate where water is relatively scarce, it is important to 

have aquatic and wildlife (A&W) standards that are protective of the wildlife that feed in and on all of the State’s 

surface waters. While the community that inhabits the water column of an effluent-dependent water (EDW) may 

differ slightly from that found in A&Ww and A&Wc streams, the terrestrial and avian wildlife that use these 

streams are very similar. EDW ecosystems can be an integral part of the home range of bald eagles, black crown 

night herons, great blue herons, cattle egrets, osprey, and other wildlife that prey on fish and other aquatic 

organisms. Because these streams are often extremely predictable; having consistent flows and temperatures even 

during droughts and winter freezes, these ecosystems may be even more attractive for wildlife than the 

surrounding landscape. 

The current A&Wedw chronic criterion for dissolved mercury is 0.2 μg/L and was originally adopted in 

1992. Documentation on the derivation of the A&Wedw chronic criterion for mercury indicates that the chronic 

criterion was originally proposed at 1.1 μg/L, not 0.2 μg/L using EPA’s Guidelines Methodology and 

recalculation procedures. (See Rationale for the Development of Toxic Pollutant Criteria to Protect Aquatic and 

Wildlife Designated Uses, January 10, 1992.) This derivation method only considered endpoints that were directly 

toxic to aquatic life and did not adequately protect against bioaccumulation in wildlife. However, in an addendum 

to the Concise Explanatory Statement for the 1992 rulemaking, the Department addressed the propensity for 

mercury to bioaccumulate by employing an available final residue equation based on the FDA action level for 

mercury in edible fish. Using this method, a recalculated A&Wedw standard of 0.2 μg/L was derived. 

The Department has reevaluated the technical basis for the re-calculation of the A&Wedw standard. The 

Department questions the use of FDA action level as a surrogate to protect wildlife in the equation used to 

calculate the criterion. The FDA action level is designed only to protect consumers of commercially caught and 

sold fish from symptoms of mercury poisoning such as paresthesia (a sensation of tingling, pricking, or numbness 

of a person’s skin) and not the more sensitive developmental endpoint in children. The Department questions the 

bioconcentration factor of 4994 L/kg that was used in the equation to calculate the 0.2 μg/L criterion. 

Methylmercury is an extremely bioaccumulable fraction of the total mercury addressed in the surface water 

quality standard. Methylmercury bioaccumulation potentials as high as 20,000,000 L/kg have been measured in 

the field in piscivorous fish. 
216 

In April 1994, the EPA disapproved all of Arizona’s water quality criteria for dissolved mercury to protect 

aquatic life, including the A&W(edw) chronic criterion of 0.2 μg/L (See discussion in Federal Register, Volume 

61, No. 19, p. 2769). EPA’s disapproval of the mercury criteria was based on the results of the U.S. Fish & 

Wildlife Service (USFWS) consultation under § 7 of the Endangered Species Act on the adoption of the 1992 

standards. The USFWS determined that Arizona’s mercury criteria for the protection of aquatic and wildlife uses 

were developed without adequate consideration of the bioaccumulative effects of mercury on predatory wildlife. 

The USFWS identified the adoption of mercury criteria protective of threatened and endangered wildlife as a 

“reasonable and prudent alternative” to avoid jeopardizing endangered and threatened wildlife species in Arizona. 

However, there was inadequate information regarding mercury’s impact on predatory fish and birds in Arizona for 

EPA or the state to develop scientifically defensible water quality criteria to protect wildlife. 

Like the current Arizona WQS, the present EPA mercury criterion (0.77 μg/L found at 62 FR 42160) is also 

based on a human health endpoint. This endpoint, the oral reference dose for methylmercury, is employed to 

calculate EPA’s recommended 304(a) criterion, which is published with an important caveat: 

“This recommended water quality criterion was derived from data for inorganic mercury (II), but is applied 

here to total mercury. If a substantial portion of the mercury in the water column is methylmercury, this criterion 

will probably be under protective. In addition, even though inorganic mercury is converted to methylmercury and 

methylmercury bioaccumulates to a great extent, this criterion does not account for uptake via the food chain 

because sufficient data were not available when the criterion was derived.” 

Methylmercury is an extremely bioaccumulable fraction of the total mercury addressed in the surface water 

quality standard. The bioconcentration factor used to calculate the proposed A&Wedw standard is 81,700 and the 

BCF used to calculate the present federal criterion is only 5500. Bioconcentration factors are the laboratorymeasured difference between the concentration of a substance in water and the concentration on fish tissue and do 

not consider food chain effects. The Department believes that the 81,700 BCF better addresses the probability of 

food chain bioaccumulation in wildlife. No change has been made to the rule.

Comment #140

Janet Hashimoto, Chief; EPA Monitoring & Assessment Office

ADEQ proposes to eliminate the existing 0.6 μg/L FC standard in lieu of the newly proposed 0.3 mg/kg 

methylmercury fish tissue standard. While we strongly support ADEQ’s adoption of the 0.3 mg/kg standards, fish 

tissue samples may: a) not be collected in all Arizona water bodies that contain fish and which are otherwise 

monitored for total mercury in the water column, and/or b) not always be collected to an extent sufficient for 

assessment purposes under section 303(d) of the Clean Water Act. 

We cannot assume that the chronic criterion for aquatic life can fully substitute for the 0.6 μg/L FC 

standard to ensure the current level of protection is maintained in cases where future data collection is insufficient 

to apply the proposed 0.3 mg/kg fish tissue standard. 

Response: The Department disagrees with the suggestion that it retain the FC standard for mercury in 

addition to the new fish tissue standard for methylmercury. While implementation of the 0.3 mg/kg tissue standard 

for methylmercury does not entail collecting samples from all waterbodies previously covered by the fish 
217 

consumption water column standard for mercury, Arizona has a robust REMAP sampling program that will 

sample fish tissue from representative waterbodies throughout the State. Also, the State Fish Consumption 

Advisory Program samples targeted waterbodies where angling and the consumption of fish are most likely to 

occur. 

Because all waterbodies carrying the FC designated use also have A&W standards, the Department doesn’t 

believe that the removal of the water column number for the FC designated use is problematic. The A&W chronic 

standard of 0.01 μg/L is more protective than the 0.6 μg/L fish consumption water column standard that is being 

repealed in this rulemaking. Employed together, the tissue standard for methylmercury and the chronic aquatic and 

wildlife water column standard for mercury will afford increased protection for human health over the standards in 

place. 

Methylmercury 0.3 mg/kg 

Comment #141

Robert A. Hollander, City of Phoenix

The standards are not clear on how this criterion will be implemented. We believe that the lack of specific 

provisions for applying the fish tissue criterion for permits, listings, and TMDLs will prove to be problematic for 

wastewater management utilities and for ADEQ because there are number of options that can be utilized to apply 

the fish tissue criterion to permits, listings and TMDLs, and the specific approach utilized could pose significant 

compliance issues for wastewater agencies. We recommend that ADEQ use the approach adopted by the State of 

Idaho which directly uses fish tissue rather than converting the methylmercury criterion into water column 

standards. Information on the Idaho program has been previously provided to ADEQ and is consistent with EPA’s 

Draft Methylmercury Guidance. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The Coalition appreciates ADEQ’s clarification in the preamble of the proposed rule that the proposed fish 

tissue criteria for bioaccumulative pollutants in waters with fish consumption designated uses apply in lieu of, and 

not in addition to, the previous water column criteria for bioaccumulative pollutants. The Coalition agrees in 

principal with the fish tissue criteria approach. However, the Coalition requests that ADEQ clarify, either in the 

rule or in the preamble, how the new fish tissue criteria will be translated to apply to water column testing in 

AZPDES permits. Additionally, the Coalition requests that ADEQ describe the method it proposes to use to 

calculate fish tissue criteria. The Coalition recommends that ADEQ develop an implementation plan on applying 

the fish tissue criteria in coordination with appropriate stakeholders. 

Response: The Department adopts surface water quality standards in 18 A.A.C 11, Article 1 but 

discussions of how those new or revised water quality standards will be implemented through other Department 

water quality management programs are better held during rulemakings on Impaired Waters Identification or 

AZPDES permitting. The Department is developing an implementation guidance document that will be adopted as 

policy and will be made available for public comment, for implementing the new methylmercury fish tissue 

standard in the AZPDES permit program, water quality assessment and impaired waters identification, and the fish 

consumption advisory program. However, the adoption of the methylmercury fish tissue standard is the first step 
218 

in the policy development process. There is currently no intention to translate the fish tissue criterion into water 

quality-based effluent limits in permits. Once the guidance is finished, it may result in additional rulemaking to 

incorporate necessary provisions in standards and other rules.

Comment #142

Steven L. Spangle, Field Supervisor, US Fish And Wildlife Service

A&Wedw – acute and chronic mercury

Arizona Department of Water Quality has proposed to change the mercury standard for A&Wedw acute 

from 2.6 μg/L to 2.4 μg/L and the mercury standard for A&Wedw chronic from 0.2 μg/L to 0.01 μg/L. Compared 

to the EPA’s National Recommended Water Quality Criteria (2006) for acute mercury (1.4 μg/L), Arizona’s 

number is higher. Please clarify the rationale behind this difference. 

For the A&Wedw chronic mercury standard, the FWS supports ADEQ’s decision to lower the standard, but 

thinks an even lower chronic standard (for all A&W designated uses) would better protect piscivorous wildlife. 

For the proposed change to the A&Wedw chronic mercury standard, ADEQ recognized the potential for mercury 

to bioaccumulate from water to aquatic life was greater than originally thought. 

Using a BCF of 100,000 L/kg and the proposed A&Wedw standard of 0.01 μg/L, which is also the current 

standard for A&Wc and A&Ww, we calculated a fish tissue concentration of 1 mg/kg wet weight. Methylmercury 

concentrations from 0.2-0.3 mg/kg wet weight in fish appear to be protective of bald eagles in most cases (Lusk et 

al. 2005, USFWS 2003). Since 1 mg/kg is greater than 0.3 mg/kg, the proposed chronic A&W standard is not 

protective of piscivorous wildlife. 

Mercury bioconcentration factors as high as 1,958,000 L/kg have been documented in piscivorous wildlife 

(Evers et al. 2004). Given that bioconcentration factors from water to piscivorous wildlife have been documented 

as high as 1 or 2 million, we recommend that EPA and ADEQ re-evaluate the adequacy of the chronic mercury 

A&W standard in the water column. 

A&W – tissue-based methylmercury

The FWS supports ADEQ’s proposal to revise the Fish Consumption (FC) standard for methylmercury. 

The former FC standard was based on total mercury in the water column, but ADEQ proposes to adopt a tissuebased standard for methylmercury. While this standard is designed to protect human health, Lusk et al. (2005) and 

USFWS (2003) evaluated its effectiveness to protect piscivorous wildlife. They found that 0.3 mg/kg wet weight 

in fish tissue is generally protective of piscivorous wildlife. We recommend ADEQ expand the tissue-based 

standard for methylmercury from human health to include aquatic and wildlife designated uses. This is especially 

important considering the inadequacy of the chronic mercury A&W standard to protect wildlife. 

Response: In the history of its surface water sampling program, the Department has rarely found mercury 

in water column sampling. The concern is for bioaccumulation in aquatic organisms that are then consumed by the 

public or by wildlife. The 0.01 μg/L aquatic and wildlife standard is a compromise standard developed by the 

State, EPA, and the USFWS to address the acknowledged inadequacies of the federal criterion without adopting a 

standard requiring extremely expensive sample collection and analysis. A standard calculated using the Great 

Lakes Water Quality Initiative methodology (0.0008 μg/L) would only be 0.0003 μg/L above our method 
219 

reporting limit and very possibly reasonably within the margin of error for that method. 

The adopted tissue standard of 0.3 mg/Kg methylmercury is, as the commenter pointed out, considered to 

be “generally protective of piscivorous wildlife.” The combination of the expanded scope of the current chronic 

water column standard for mercury coupled with the proposed tissue standard protects piscivorous wildlife. 

Selenium 

Comment #143

Benjamin R. Parkhurst, HAF, Inc., on behalf of the Pinal Creek Group

The chronic A&W standard for selenium should be changed from 2 μg/L to 5 μg/L. In its March 2005 

proposed revisions to its water quality standards, ADEQ proposed to increase the chronic A&W standard for 

selenium from 2 μg/L to 5 μg/L so that the standard would be consistent with US EPA’s (2004a) criterion which 

is 5 μg/L. In not including this proposed revision to its water quality standards, ADEQ cited an August 18, 2005 

letter from Thomas Gatz, USFWS, to Linda Taunt, ADEQ, which opposed the revision. The key points from this 

letter are as follows: 

1. A 2 μg/L chronic selenium standard will lead to many waters being listed as impaired when, in 

reality; many will not be experiencing significant toxic effects to biota from selenium. TMDLs will 

be required for these waters. 

2. Further studies and analyses will be needed, including measurements of selenium in water, 

sediment, macroinvertebrates, fish eggs, and aquatic bird eggs, to determine if the waters are truly 

impaired. 

3. The real risk from selenium is bioaccumulation, which is best determined by measurements of the 

concentration of selenomethionine, not total selenium, in water, and/or direct measurements of 

selenium in biota. 

To preclude the listing of many unimpaired waters with total selenium concentrations between 2 μg/L and 5 

μg/L as impaired leading to unnecessary and wasteful TMDLs, it is requested that ADEQ increase the chronic 

A&W standard for selenium from 2 μg/L to 5 μg/L. In addition, it is recommended that ADEQ undertake 

monitoring of selenium concentrations in biota to determine if any waters in the state are impaired from selenium 

bioaccumulation. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

Pima county supports comments made by Dr. Ben Parkhurst concerning the A&W chronic standards for 

selenium in Appendix A Numeric Water Quality Standards. 

Sydney Hay, Arizona Mining Association

 The AMA supports the removal of acute water quality criteria for selenium for aquatic and wildlife uses 

for the reasons outlined in the proposal. 

The AMA supports the comments of HAF Inc., on behalf of the Pinal Creek Group, requesting that ADEQ 

conform the chronic selenium standard of 2 μg/L to EPA’s § 304(a) criteria recommendation of 5 μg/L, possibly 

in conjunction with monitoring of fish tissue to determine if sediment is actually bioaccumulating in biota in those 

waters where the 5 μg/L criterion is being exceeded in the water column. 
220 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The Coalition requests that ADEQ revise its aquatic and wildlife selenium standard from 2 μg/L to 5 μg/L, 

to be consistent with EPA’s selenium criterion continuous concentration established in 2004. This standard would 

thus be more consistent with EPA’s recommendations, and would account for high selenium concentrations in 

many Arizona waters due to natural background or to out-of-state irrigation-related effects from the upper 

Colorado River Basin. 

Robert A. Hollander, City of Phoenix

The Water Services Department understands that ADEQ is retaining the 2 μg/L selenium water quality 

standard because of a request in the August, 2005 FWS letter and is concerned that the recommendations found in 

the letter are inconsistent with the comments submitted by Everett Wilson, Chief of the FWS Division of 

Environmental Quality located in Washington, D.C. FWS Headquarters office to EPA on May 19, 2005 (May 

letter) in regard to EPA’s Draft Selenium Water Quality Criteria Document. While the August letter adamantly 

calls for a 2 μg/L water quality standard, the May letter recommends a “safety-net water criterion of 2 μg/L and 

recommends that “only when the water column criterion and the fish tissue criterion are both exceeded, or the fish 

tissue criterion alone, would a full site-specific analysis including development of intermedia translation factors be 

necessary.” 

Naturally occurring selenium in Arizona streams frequently is passed through drinking water treatment 

plants and on to wastewater treatment plants. Additionally, selenium is a common dietary supplement and is found 

in products such as dandruff shampoos. Wastewater treatment facilities are not designed to remove low levels of 

selenium, thus, increasing the likelihood of selenium exceedances due to pass-through. The Water Services 

Department believes that it should not be held liable for selenium that is attributable to natural sources. According 

to the FWS August letter, most of Arizona’s high selenium concentrations are produced outside of Arizona and 

outside of ADEQ’s jurisdiction. This provides additional impetus to develop a better alternative to regulating 

discharges of selenium from wastewater treatment plants. 

The Water Services Department asks ADEQ to consider either altering the Natural Background rule to 

apply in this situation, placing the selenium standard in “reserve,” or using an alternative method for determining 

compliance. The Water Services Department believes that using fish tissue and a subsequent investigation of 

sources when an exceedance is found (the method recommended in the FWS May letter) would provide an 

acceptable interim means of regulating selenium, especially since the environmental concern is for selenium 

concentrations in fish tissue. 

Response: The Department appreciates the issues of selenium in Arizona’s source waters and the impact of 

dischargers; however, the Department is not electing to revise the current criteria. Although the U.S. 

Environmental Protection Agency (EPA) has published a nationwide § 304(a) criteria recommendation of 5 μg/L 

to protect aquatic and wildlife from chronic effects of selenium, the U.S. Fish & Wildlife Service (USFWS) 

recommended using a standard of 2 μg/L. After reviewing nearly every major experimental and field study 

conducted over the past 15 years, the USFWS did not support the use of a 5 μg/L chronic standard for selenium 

because it is not scientifically valid or fully protective of fish and wildlife resources. In aggregate, the weight of 

scientific evidence supporting a chronic criterion of ≤ 2 μg/L is now overwhelming. As early as 1991, the 
221 

evidence available in the scientific literature was sufficient for Canada to issue a national water quality guideline 

stipulating that the concentration of total selenium should not exceed 1 μg/L (Environment Canada 1991). Based 

on data collected by the U.S. Department of Interior’s National Irrigation Water Quality Program (NIWQP) from 

26 study areas in 14 western states, a 5 μg/L chronic criterion for selenium is only 50-70 percent protective 

(Adams et.al 1998), as opposed to the 95 percent level of protection that EPA’s national water quality criteria are 

intended to achieve (Stephan et. al. 1984). The NIWQP data suggest that on a dissolved basis a criterion of 1 μg/L 

would be required to be 95 percent protective, which is equivalent to a 2 μg/L criterion on a total recoverable 

basis (Peterson and Nebeker 1992). 

The USFWS provided a variety of conceptual bases for deriving a generally applicable chronic water 

quality criterion for selenium that is protective of fish and wildlife with results ranging from 1-4 μg/L. The 

available body of scientific evidence (the majority of which has been produced subsequent to EPA’s 1987 

criterion derivation for selenium) consistently supports an aquatic life criterion of 2 μg/L for the protection of 

sensitive taxa of fish and wildlife. Even a criterion of 2 μg/L, however, can fail to be protective in specific cases 

where water column contamination with selenium fails to accurately reflect food chain contamination. There is a 

strong need for developing a method to link criteria directly to food chain contamination. In the absence of sitespecific and species-specific data regarding the sensitivity of particular species and or populations, a general 

criterion of 2 μg/L is required to assure adequate protection of threatened and endangered species of fish and 

wildlife. This is especially warranted considering the steep response curves for selenium and well demonstrated 

potential for selenium facilitated pathogen susceptibility that can rapidly destroy entire populations of fish and 

wildlife via epizootic events.

Sulfide 

Comment #144

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ proposes to create a new numeric water quality standard for hydrogen sulfide that was developed 

based on toxicity data for species that do not reside in the Santa Cruz River. 

Response: The Department disagrees. Hydrogen sulfide is a soluble, highly poisonous compound that is 

appropriately regulated in effluent-dependent waters. The proposed hydrogen sulfide numeric water quality 

standard to protect aquatic life in effluent-dependent waters is based on EPA national § 304(a) criteria 

recommendations for hydrogen sulfide to protect aquatic life in fresh water. The proposed criterion is based on 

“Red Book” criteria values originally recommended by EPA in 1976. EPA has not withdrawn the hydrogen 

sulfide criteria from its current National Recommended Water Quality Criteria, U.S. Environmental Protection 

Agency, Office of Water (2006). 

Standards are not developed based on specific species that reside in a particular waterbody, but rather are 

measured on representative species that would prove protective of most aquatic species. In the case of the Santa 

Cruz, the argument is particularly inappropriate as the river does not have a healthy aquatic diversity. Some of this 

may be due to substrate and physical issues, but also is likely due to the fact that the current discharges are toxic 

due to high ammonia. 
222 

Full/Partial Body Contact 

Comment # 145

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

EPA adopts a federal methodology for deriving criteria for full body contact designated use based on an 

incidental ingestion rate of 10 ml/day. ADEQ however adopts a different and more stringent assumption of 15 

ml/day and justifies this more stringent standard by arguing that people swim more in Arizona, but provides no 

evidence for that statement. The Coalition recommends that ADEQ adopt the same methodology for deriving 

criteria for full body contact designated use as used by EPA. 

Additionally, ADEQ adopts the exact same incidental ingestion rate assumptions for deriving criteria for 

partial body contact designated uses as for full body contact. Clearly, the incidental ingestion rate for partial body 

contact is lower than that of full body, seeing as how one is partial and the other full. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

EPA has adopted full body contact designated use standards based on an incidental water ingestion rate of 

10 ml/day as specified in the preamble to this rulemaking. Contrary to the EPA methodology, ADEQ has used 

more stringent criteria assuming a water ingestion of 15 ml/day. ADEQ has not provided a substantial scientific 

rationale for taking this more conservative approach. Therefore, Pima County asks that ADEQ revise its standards 

for this rulemaking to comport with the EPA methodology and standards. 

Similarly, ADEQ has used full body contact ingestion rates to derive the proposed standards for partial 

body contact in these proposed rules. ADEQ provides no meaningful scientific discussion to justify this overly 

protective action. Partial body contact standards were developed to account for activities such as wading that 

result in a significant decrease in the potential amount of water ingested during the activity as compared with full 

body contact activities such as swimming. ADEQ should adopt the same assumptions for partial body contact 

incidental ingestion rate as those relied upon by EPA. 

Michael Garry, on behalf of the Pinal Creek Group

We note that the numerical standards for full-body contact (FBC) with surface water were modified in the 

2007 draft to incorporate a water ingestion rate of 15 mL/day, consistent with our 2005 comments, and that this 

modification has been retained in the 2008 draft. However, the numerical standards for partial-body contact (PBC) 

continue to assume a level of exposure equal to FBC. The PBC water quality standards should reflect the lower 

potential for exposure relative to FBC standards. Thus, we again request that ADEQ consider reducing the 

ingestion rate under PBC to reflect lower exposure potential relative to a FBC water body. 

Response: The Department believes the adopted revisions to the water ingestion exposure assumptions 

used to calculate the numeric criteria represent more realistic and reasonable water ingestion assumptions than 

those used to calculate the existing criteria. The existing numeric criteria for the FBC and PBC designated uses 

were calculated using 50 ml/day as the exposure assumption. In this rulemaking, a more realistic exposure of 15 

ml/day is used to represent the incidental water ingestion associated with full body contact or partial body 

recreation. See “Methodologies for Deriving Criteria for the Full Body Contact Designated Use” in the Preamble 

Section by Section Discussion in Appendix A, Numeric Water Quality Criteria. While EPA has used an incidental 
223 

ingestion rate of 10 ml/day, states are at liberty to use and justify alternative rates, however, EPA does not make 

any national § 304(a) recommendations for water quality criteria based on incidental ingestion of water from 

recreation. The Department stands by its reasons stated in the Preamble for using an incidental ingestion rate of 

15 ml/day for recreational activities in Arizona. As there is not a separate methodology for calculating the PBC 

criteria, the Department used the FBC methodology for non-carcinogens recognizing that the limited exposure 

envisioned under partial body contact would not give rise to excess cancer risk. The Department disagrees that a 

lower ingestion rate is called for. While adults may have limited exposure to water in partial body contact 

scenarios, infants and small children, the most sensitive populations, have an equally high potential for exposure 

in both full and partial body contact contexts (e.g., hand to mouth). 

Comment #146

Michael Garry, Exponent, on behalf of the Pinal Creek Group

ADEQ applies a fish consumption rate of 17.5 g/day in deriving fish consumption criteria. However, as 

noted on page 4-24 of EPA’s Methodology for Deriving Ambient Water Quality Criteria for the Protection of 

Human Health (2000), a consumption rate of 17.5 g/day “...represents the 90th percentile of the 1994-96 CSFII 

data.” We recommend ADEQ modify the text on page 970 of the proposed standards to clarify that 17.5 g/day 

represents a high-end national fish consumption rate. This will underscore the protectiveness of the fish 

consumption criteria, even for individuals who are high-end fish consumers. 

We note that in the 2008 draft standards, ADEQ provided all input values (including bioconcentration 

factors, RSCs, and RfDs) used to calculate the numerical standards for those chemicals for which the criteria 

changed relative to previous standards. This is an excellent way to provide transparency in the calculations, avoid 

confusion in how specific criteria were derived, and allow for meaningful input from reviewers. We recommend 

ADEQ include an additional table providing the bioconcentration factors, RSCs, and RfDs used to derive the 

numerical criteria, along with references for the source of those assumptions. Along this same line, we recommend 

that the equations used to derive the standards explicitly include the necessary unit conversion factors. 

Response: The Department appreciates the comment on “high end” national fish assumption and will 

clarify that in the Preamble. The Department agrees that a tabular presentation of all the input values, equations 

and units would be useful for the public to follow in setting standards and will consider preparing such a 

document for use in the future.

Relative Source Contribution (RSC) 

Comment #147

Janet Hashimoto, Chief; EPA Monitoring & Assessment Office

In calculating several of the proposed numeric criteria, ADEQ assumed a less stringent Relative Source 

Contribution (RSC) than EPA’s recommended default RSC of 20%. RSC relates to the percentage of total 

exposure to a pollutant from water versus other sources, such as diet (e.g., a 20% RSC conservatively assumes 

that 80% of total exposure comes from other sources). In the proposed rule, ADEQ assumes a RSC of 40% or 

50% for barium, boron, 1,1 dichloroethylene, nitrate, nitrite, and toluene with respect to one or more of the 
224 

following beneficial uses: Full Body Contact, Partial Body Contact, Fish Consumption, and/or Domestic Water 

Source. 

RSC strongly influences the resulting proposed standard. A less conservative RSC assumption is acceptable 

if it can be demonstrated that other sources and routes of exposure are not anticipated for the pollutant in question, 

based on information about its known/anticipated uses and chemical/physical properties. However, ADEQ’s 

proposed rule does not contain justification for assuming a 40% to 50% RSC for the six numeric criteria noted. 

We recommend that ADEQ either provide justification for these values or use the default RSC of 20%. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

The Coalition requested that ADEQ adopt language allowing for chemical-specific evaluations of relative 

source contribution (“RSC”) rather than rely solely on the default RSC of 20%. ADEQ has adopted alternative 

RSCs for certain contaminants (such as for barium), demonstrating that chemical-specific evaluations are clearly 

called for in certain circumstances. The Coalition recommends that ADEQ provide for greater flexibility in relying 

on chemical-specific evaluations of RSC, and in particular allow for reliance on the subtraction approach 

described in EPA’s Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human 

Health (2000). 

Michael Garry, Exponent, on behalf of the Pinal Creek Group

Our 2005 comments commented on the use of a default relative source contribution (RSC) term of 0.2 

rather than the use of chemical-specific information when available. We note that ADEQ has incorporated 

alternative RSC terms for a few chemicals in their 2008 draft standards (e.g., RSC of 0.5 for barium). The 

regulations should have flexibility to allow for a chemical-specific evaluation of the science if the standard is 

exceeded or if new information becomes available. For example, as we noted in our comments, EPA’s draft 

reference dose (RfD) for cadmium is intended to be protective of exposures in excess of diet, a major source of 

cadmium exposure. Therefore, in the future, a RSC term for cadmium is unnecessary when calculating health risks 

associated with water exposures. We recommend that specific language be incorporated into the standards 

allowing for a chemical-specific evaluation of RSCs and the mechanism for doing so, including the ability to use 

the subtraction approach described in EPA’s Methodology for Deriving Ambient Water Quality Criteria for the 

Protection of Human Health (2000) and discussed in our December 15, 2005, technical memorandum. 

Response: The Department currently provides for chemical-specific evaluations of relative source 

contribution within the water quality standard derivation process. However, it is important that any such 

recalculation of the relative source contribution be done on the strength of adequate reviewed and published 

scientific data. At present there are nine proposed standards where an RSC other than the default 20 percent is 

used. In each case these were adjusted on the strength of EPA’s published RSC values. 

The recalculation of an RSC value is a resource and data intensive project with an uncertain outcome. As 

an example, the recalculation of the RSC for cadmium illustrates the complexity of developing reliable chemicalspecific RSC values. Cadmium is a heavy-metal used in a number of industrial processes, and has been associated 

with both occupational and non-occupational exposures. Environmental levels of cadmium have been increasing 

from smelting, cement production, and combustion of fossil fuels. The major route of exposure for the nonsmoking general population is via food and tobacco is an important source of cadmium uptake in smokers. 
225 

Drinking water does not appear to be a significant source of cadmium exposure. Cadmium is classified as a B1 or 

probable human carcinogen and the lone reason an RfD (and for that matter the RSC) is used to calculate the 

human health water quality standard is that an oral cancer slope factor has yet to be published by the EPA. The 

bioconcentration factor for cadmium ranges as high as 44,000 in laboratory studies. These factors would make it 

very complex to calculate a reliable RSC for cadmium using the subtraction method. Since water is considered an 

insignificant source of cadmium, the RSC from that source would necessarily be small. 

Boron and 1,1 Dichloroethylene both are calculated using the 20 percent default RSC, as preferred by EPA. 

Use of the RSC was deemed not applicable for both nitrate and nitrite due to the assumptions used in the 

calculation of the RfD. Infants are the sensitive subpopulation being protected when analyzing risk from nitrates 

and nitrites. The main exposure pathways for infants are through drinking water. Long-term full-body contact is 

not an assumed use for this population group. A relative source contribution of 40 percent was determined for 

toluene because volatile chemicals are much less likely to be found in food and soil. Also, ambient air 

concentrations for toluene are decreasing steadily with the half-life of toluene in the atmosphere ranging from 

three hours to slightly greater than one day. 

The following is a table of relative source contribution factors greater than 20 percent used in the 

calculation of Arizona’s water quality standards. 

PARAMETER RfD OCSF RSC DWS FBC PBC FC Citations 

Antimony 4.00E-04 NA 0.4 6 747 747 640 3,4,5,6 

Barium 7.00E-02 NA 0.5 2,000 98,000 98,000 2,3,5,6 

Carbon tetrachloride 7.00E-04 1.30E-01 0.4 5 11 1307 2 6 

Fluoride 6.00E-02 D 0.5 4,000 140,000 140,000 2,3,6 

Hexachlorocyclopentadiene 6.00E-03 NA 0.4 50 11,200 1,200 74 6 

Nickel 2.00E-02 NA 0.3 210 28,000 28,000 511 1,6 

Nitrate 1.60E+00 NA 1.0 

10,00

0 

3,733,333 3,733,333 2,6 

Nitrite 1.00E-01 NA 1.0 1,000 233,333 233,333 1,2,6 

Tetrachloroethane 1,1,2,2 NA 2.00E-01 0.5 0.2 7 93,333 4 6 

Toluene 2.00E-01 D 0.4 1,000 373,333 373,333 

29,90

7 

6,7 

Citations

1 Drinking Water Criteria Document on Nitrate/Nitrite, U.S.EPA (1990) 

2 Guidelines for Canadian Drinking Water Quality, Health Canada (2003). 

3 Guidelines for Drinking Water Quality, WHO (2003) 

4 Human Health Criteria Calculation Matrix, EPA-822-R-02-012 

5 Minnesota Health Risk Limits for Groundwater Rule (1994) 
226 

6 Risk Assessment for Chemicals in Drinking Water: Estimation of Relative Source 

Contribution, R.A. Howd, J.P. Brown, OEHHA, California Environmental Protection 

Agency 

7 Public Health Goal for Toluene In Drinking Water, OEHHA, 1999 

APPENDIX B. SURFACE WATER AND DESIGNATED USES

Full/Partial Body Contact 

Comment #148

Claire L. Zucker, Pima Association of Governments (PAG)

ADEQ plans to apply Partial Body Contact (PBC) standards to urban lakes to protect recreational uses of 

boating and wading. For several compounds, the proposed PBC standards are more stringent than A&W w 

standards and A&W eph standards. PBC standards need to be set using technically sound rationale because they 

will become significant benchmarks for urban lakes and for urban stormwater. According to our PAG 

jurisdictional members, ADEQ has established the standards for PBC recreational use by assuming the same 

exposure pathway as for Full Body Contact, which are used for swimming use and are based on an assumed 

amount of ingestion. However, ingestion criteria are inappropriate for Partial Body Contact exposure, which 

involves dermal exposure only. This approach is inconsistent and should not be implemented in rule until the 

standards for dermal exposure are established, technically sound and defensible. 

It is unclear from the rule whether ADEQ feels it is appropriate to apply PBC standards to stormwater, and 

if so, how and where the standards should be assessed. ADEQ has stated in MS4 stakeholder groups that they 

must apply the standards, in whatever manner they are stated in the Surface Water Quality Standards rule. In the 

rule, PBC defined as appropriate for surface waters being used for recreational purposes, but recreational use of 

stormwater is discouraged by MS4s and is not common at, or near, MS4 outfalls. ADEQ should clarify whether 

PBC standards are appropriate for wet weather flows in Arizona. 

Fred H. Gray, City of Tucson, Parks and Recreation Department

ADEQ expects PBC levels to be used at urban lakes to protect recreational uses of boating and wading. 

PBC standards are more stringent than A&W standards for about 46 compounds, some of which have no standard 

for A&W protection. Because the PBC standards become significant benchmarks for urban lakes, we need to 

assure that PBC standards have been set using technically sound rationale. ADEQ has established the standards 

for PBC recreational use by assuming the same exposure pathway as for Full Body Contact. Full Body Contact 

standards are for swimming use and are based on an assumed amount of ingestion. 

This approach is inconsistent with the rule definition of the term “Partial Body Contact,” which states that 

in this type of exposure “ingestion of the water is not likely.” 

Jim F. DuBois, City of Tucson – Department of Transportation

ADEQ expects PBC levels to be used in the context of municipal stormwater permits. The City of Tucson 

and our Phase I stakeholder group questioned the appropriateness of PBC standards for stormwater during our 
227 

permit discussions this past year with ADEQ. We believe that stormwater should not be held to PBC because the 

PBC criterion assumes recreational uses as the exposure pathway, and stormwater flows are not typically subject 

to recreational use. MS4s discourage boating and wading in stormwater flows. 

Municipalities are concerned about the PBC standards because they become significant benchmarks for 

MS4s permits and because ADEQ expects PBC levels to apply at urban lakes to protect recreational uses of 

boating and wading. ADEQ should ensure that PBC standards have been set using technically sound rationale. 

ADEQ has established the standards for PBC recreational use by assuming the same exposure pathway as for Full 

Body Contact. FBC standards are for swimming use and are based on an assumed amount of ingestion. 

ADEQ should delete PBC standards from the rule until appropriate data can be developed for dermal 

exposure. Alternatively, ADEQ should identify a lower ingestion level and lesser frequency of exposure for 

boating and wading activities. 

Response: While ingestion is not likely for the partial body contact (PBC) use, it is an important pathway 

when considering that young children, having a much lower body weight, higher metabolism, and who may be 

undergoing sensitive developmental stages, may come in contact with these waters. Smaller children could 

become completely submerged or transfer water to their mouths on their hands. Infants and toddlers often may not 

have yet developed the defensive reactions that would prevent the ingestion of large amounts of water in the event 

of an accident. The Department addresses the episodic and hopefully rare nature of these events by not applying 

the cancer endpoint to the PDB use where long-term frequent exposure is minimized. Currently, all waters of the 

United States in Arizona, except listed canals, have a body contact standard. This is keeping with the 

fishable/swimmable goals of the Clean Water Act and the Department’s mission to protect human health. 

The standards that apply to stormwater are those applicable to the water receiving the stormwater 

discharge. PBC standards apply to stormwater discharging to a waterbody where PBC standards apply; the FBC 

standards apply to stormwater discharging to a waterbody where FBC standards apply. It is understood that MS4s 

and others do not intend for, or encourage, recreation within stormwater. However, it is equally clear that children 

and others playing in stormwater is a common occurrence and documented routinely by news pictures and videos. 

The Department is aware of the challenges in meeting this standard during storm events particularly as it applies 

to E. coli from MS4 discharges. MS4 permits do not have discharge limitations based on the standards because of 

the applicable “maximum extent practicable” standard in the Clean Water Act, but achieving the standards 

continues to be the ultimate goal. 

Fish Consumption 

Comment #149

Claire L. Zucker, Pima Association of Governments (PAG

Fred H. Gray, City of Tucson, Parks and Recreation Department

Fish consumption standards are applied to urban lakes such as Kennedy and Lakeside in the Tucson region. 

However, these lakes are not managed for propagation of fish as envisioned by the Clean Water Act Section 

303(c). Fish taken by fishers from Lakeside Lake were stocked by Arizona Fish and Game Department and were 

raised to catchable size elsewhere. The Bioconcentration Factor used by ADEQ to develop the Fish Consumption 
228 

Standards is inappropriate for this type of managed fishery because bioconcentration from Lakeside Lake’s waters 

is insignificant. The impact on human health from concentration of pollutants in fish tissue in the lakes would be 

due primarily to the waters in which the fish have been raised to catchable size. 

Response: While the lakes cited are “put and take” fisheries where larger fish are stocked, it is nevertheless 

important that water quality be maintained according to Arizona water quality standards and Clean Water Act 

goals. Because channel catfish that are the main fish stocked in the cited lakes and could survive and reproduce, 

there is a chance that some fish, if not caught, could live long enough to bioaccumulate pollutants. The best way to 

prevent the bioaccumulation of toxic pollutants and to protect this recreational fishery is the preservation of the 

fish consumptions standards presently in place. 

Since anglers catch fish for consumption at Kennedy Lake and Lakeside Lake, fish consumption is an 

existing use. As such, it must be listed as a designated use in Appendix B of the surface water quality standards. 

The Department does not have a subcategory of the fish consumption designated use nor is there scientifically 

defensible data to defend a subcategory for lakes that are stocked. 

Boulder Creek 

Comment #150

Teague J. Raica, Freeport-McMoRan Bagdad

The two Boulder Creek segments listed in Appendix B for the Bill Williams watershed both include 

agricultural irrigation (“Agl”) as an applicable designated use. FCX is not aware of any crop irrigation on Boulder 

Creek especially given the location and topography associated with Boulder Creek. FCX respectfully requests that 

Agl be removed as a designated use from both segments of Boulder Creek. 

Response: While the commenter may be correct that there is no crop irrigation in the watershed, in 

accordance with the CWA, the Department cannot remove a designated use without completing a use attainability 

analysis (UAA). The Department is willing to work with FCX-Bagdad prior to the next rulemaking to develop the 

evidence required in a UAA. 

EDW Listing of Unnamed Wash Tributary to Cave Creek 

Comment #151

Robert A. Hollander, City of Phoenix

The Water Services Department previously commented on this proposed listing in our letter to Steve 

Pawlowski dated December 5, 2007, which is attached and incorporated by reference. Appendix B lists the 

Unnamed Wash in the Middle Gila River below the City of Phoenix Cave Creek Water Reclamation Facility as an 

EDW. The Water Services Department does not agree that this water should be listed simply because there is a 

permitted discharge (i.e., City of Phoenix Cave Creek Water Reclamation Plant (CCWRP)). The last discharge 

from the facility occurred on March 30, 2005. As evidence that the receiving water is not an EDW, the Water 

Services Department attached photographs, to the referenced letter, showing the unnamed tributary both upstream 

and downstream from the outfall. These photographs clearly show that there is no established aquatic life despite 

the fact that the CCWRP has been a permitted facility since January 24, 2000. In addition, there are no riparian 
229 

plant species in this segment. The bank vegetation includes cactus, creosote, saltbush and other non-riparian 

species. The stream bottom is dry and consists almost entirely of sand. Clearly, this wash is not dependent upon 

the effluent to support an aquatic ecosystem or a riparian habitat. 

The Water Services Department requests ADEQ provide the data and information used to determine that 

this water body “consists of treated wastewater” as required by the EDW definition. 

Response: The City of Phoenix states in its comment that the water body that receives sporadic discharges 

from the Cave Creek Water Reclamation Plant (CCWRP) is an ephemeral tributary to Cave Creek Wash. As 

previously outlined in Responses #108 and 109, by definition discharging of effluent to an ephemeral systems, 

creates an EDW which must be listed in rule by the Director. We note that the CCWRP may be the type of facility 

that the flexibility in permitting in R18-11-113E was developed for. 

EDW Listing of Mule Gulch 

Comment #152

Michael Jaworski, Freeport-McMoRan - Copper Queen Branch

The segment of Mule Gulch no longer qualifies as effluent-depedent as the Bisbee WWTP was 

decommissioned in early 2006 and has not discharged into Mule Gulch since the first quarter of 2006. The 

designated uses for this segment of Mule Gulch should be changed from aquatic and wildlife (effluent-depedent 

water) (“A&Wedw”) and partial body contact (“PBC”) to aquatic and wildlife (ephemeral) (“A&We”) and PBC. 

Response: While the commenter may be correct that there is no longer discharges to Mule Gulch from the 

WWTP, in accordance with the CWA, the Department cannot remove a designated use without completing a use 

attainability analysis (UAA). The Department is willing to work with Freeport-McMoRan-Copper Queen Branch 

prior to the next rulemaking to develop the evidence required in a UAA. 

EDW Listing of Siphon Draw 

Comment #153

Michele Van Quathem, Superstition Mountains Community Facilities District No. 1

ADEQ proposes to include a stretch of Siphon Draw in Appendix B to the surface water quality rules. 

SMCFD opposes inclusion of Siphon Draw in Appendix B as an EDW on several grounds: 

1. SMCFD’s Effluent is Not “Wastewater.” Use of the term “wastewater” in the proposed definition of 

“effluent-dependent water” indicates untreated sewage is being discharged to the effluent-dependent 

water. SMCFD does not discharge untreated “wastewater.” 

2. In listing Siphon Draw as an “effluent-dependent water,” ADEQ fails to consider the nature of flow 

in Siphon Draw and its nexus with any water of the United States. 

3. SMCFD’s discharge location is not in Siphon Draw. SMCFD’s “outfall” is not in Siphon Draw, and 

the coordinates provided for the point where flows reach Siphon Draw are incorrect. 

For all the reasons stated above, the Department should remove Siphon Draw from Appendix B. Siphon 

Draw is not a jurisdictional water, nor is there sufficient evidence to establish a significant nexus between the 

SMCFD discharge and any water of the United States. 
230 

Response: The Department disagrees that: 1) wastewater means ‘untreated sewage’ and that SMCFD’s 

discharge is not wastewater, see Response #14; and 2) that Siphon Draw has been determined as a nonjurisdictional water, see Response #4. See Responses #19, #20 and #106 regarding the need for a sufficient 

volume of discharge. 

As for the discharge location, the following information is quoted from the Fact Sheet for the SMFCD’s 

AZPDES permit: 

“It should be noted that permit #AZ0023931, which was issued on April 9, 1996 and expired on May 11, 

2001, was drafted to authorize discharge to Weekes Wash, eventual tributary to Queen Creek in the Middle Gila 

River Basin. While the discharge location has not changed, the name of the receiving water in this draft permit 

was changed to Siphon Draw. Weekes Wash and Siphon Draw meet just upstream of Superstition Mountain CFD 

No. 1’s outfall where they are both impounded by the Powerline Flood Retarding Structure. The ephemeral wash 

that continues on past this point, and that the Superstition Mountain WWTP discharges to, is not named on the 

U.S.G.S. 1981 topographic map of the area (Desert Well). However, the wash is better known locally as Siphon 

Draw and a search for these two names on the USGS National Mapping Information website showed that Weekes 

Wash ends where the two waterways meet while Siphon Draw continues on past their juncture. For this reason, 

the name of the receiving water was changed from Weekes Wash to Siphon Draw. Siphon Draw is an eventual 

tributary to Queen Creek. According to the Tributary Rule in A.A.C. outlined above, A&We and PBC standards 

apply to all tributaries to listed waters. Siphon Draw connects with Roosevelt Canal which joins Queen Creek 

about 15 miles downstream of Superstition Mountain’s discharge point.” 

In high flow events, it is possible and even likely that flows from the SMCFD facility will reach Queen 

Creek; therefore the Department considers the designation of Siphon Draw to be accurate. 

EDW listing of Mineral Creek 

Comment #154

Scott Thomas, (Fennemore Craig, PC),

ASARCO formally submitted information in support of the removal or modification of certain designated 

uses currently applicable to the tunnel and lined channel at the Asarco Ray Mine. These manmade features were 

constructed to convey flow in Mineral Creek around mining operations. Work on the lined channel and an 

extension to the pre-existing tunnel segment was completed subsequent to the last triennial review which was 

finalized in March 2002. 

Response: The information submitted appears to meet the requirements for a use attainability analysis 

(UAA). The Department will begin a comprehensive review of the information and, if warranted, propose the 

changes in a separate rulemaking. 

Wagner Wash 

Comment #155

Robert D Anderson (Fennemore Craig), El Dorado Holdings (EDH)

EDH noted that the Department has proposed designating Wagner Wash from the outfall of the Festival 
231 

Ranch WRF (33°39'14"/112°40'18") to its confluence with the Hassayampa River as EDW, a distance of 

approximately 6 miles.

Festival Ranch WRF will discharge to Wagner Wash only when recharge and reuse options are not 

available. With this sort of sporadic discharge, and with the evapo-transpiration and percolation losses along the 

way, it is exceedingly unlikely that any effluent from the Festival Ranch WRF would ever reach the lower 

stretches of Wagner Wash. 

For the foregoing reasons, EDH requests that if Wagner Wash is to be classified as an EDW, only that 

portion in reasonable proximity to the Festival Ranch WRF (i.e., that portion in which treated wastewater may 

actually flow) be so classified. The balance of Wagner Wash should remain unlisted (as it is now) or be listed as 

an ephemeral water. 

Response: The Department has reviewed the listing and the capacity of the WWTP and agrees that the 

description of the EDW segment of Wagner Wash should initially be limited to 2 kilometers below the Festival 

Ranch WRF outfall. The entry in Appendix B has been revised to reflect this change. 

Verde River 

Comment #156

Wang Yu, Salt River Pima-Maricopa Indian Community

EPNR has concerns pertaining to the proposed total phosphorus and total nitrogen standards established for 

the Verde River and its tributaries indicated on page 1346 of the Notice of Proposed Rulemaking (Volume 14, 

Issue 17). 

In addition to other designated uses, the approximate 2-mile portion of the Verde River located within 

SRPMIC has always been regarded by its members for its sacred, cultural, and ceremonial significance. It is 

understood that these proposed standards apply only on the non-tribal portion of the Verde River and its tributaries 

upstream of SRPMIC, nevertheless the proposed standards established by ADEQ for total phosphorus (0.10 mg/L) 

for annual mean and 1.00 mg/L for single maximum) and total nitrogen (1.00 for annual mean and 3.00 for single 

maximum) still appear to be a bit too high with respect to the sacred, cultural, and ceremonial significance by 

SRPMIC on the portion of its Verde River downstream. 

Response: The Department has not made any changes to this Section. However, the Department 

acknowledges that it does not have jurisdiction to adopt surface water quality standards for the Verde River and its 

tributaries located within the tribal lands of the Salt River Pima-Maricopa Indian Community. The Department is 

committed to working proactively with tribal governments to ensure off-site discharges, when and where 

proposed, are compatible with on-reservation designated uses. 

APPENDIX C. SITE-SPECIFIC STANDARDS

Site-Specific Standard for Pinto Creek 

The Department received a number of comments concerning its development of the site-specific 
232 

standard for copper on Pinto Creek. These comments are on file with the Department. The commenters were 

generally opposed to the proposed standard of 42 μg/L for a variety of reasons including: consideration of past 

mining activities in the area, aerial deposition of copper from current and historic mines, impacts of wildfire, 

and the proximity of mining roads as well as other disturbances to areas thought to the “natural” background 

sites. The Department has reviewed these comments in detail, including photos of disturbed areas upstream of 

one or more of the Department’s sampling locations, which is new information to the Department. The 

Department had the modeling calculations revised based on the new information, and the resulting change in 

the proposed standard was significant. Based on the Department’s review of the new information and the 

modeling results, the Department is withdrawing the site-specific standard for Pinto Creek and will re-propose 

the standard under a separate rulemaking. The Department will notify each person who provided a comment on 

the Pinto Creek site-specific standard and other affected parties of the future rulemaking. 

Yuma East Wetlands 

Comment #157

Sandy Bahr, Sierra Club  Grand Canyon Chapter

The Sierra Club understands that the U.S. Fish and Wildlife Service support the site-specific standards 

for the Yuma East Wetlands but have several questions. 

Will these site-specific standards adequately protect wildlife since selenium is highly toxic to wildlife 

and invertebrate species. The proposed rule states that the site-specific standard of 2.2 μg/L of selenium is 

based on the natural background levels in that section of the Colorado River. ADEQ should focus on affording 

the highest protection for sensitive wildlife species. Excess levels of chlorine can also be toxic and can 

contribute to a decrease in reproductive performance and increases in embryonic mortality. We would 

appreciate some further explanation of how this standard was developed. 

The proposed rule states that the Director has determined that a net ecological benefit will be achieved 

through these site-specific standards. However, due to the toxicity of both selenium and chlorine, it is possible that 

the Yuma Wetlands may become a wildlife sink rather than suitable habitat and could adversely impact resident 

species as well as migratory birds. 

Response: The site-specific standards for chlorine and selenium that apply to the Yuma East Wetlands 

project will protect aquatic life and wildlife, including threatened and endangered species. The 2.2 μg/L Se site 

specific standard is based on the greatest concentration of selenium that the City of Yuma has measured in the 

Yuma East Wetlands receiving water. It represents the background concentration of Se in the lower Colorado 

River. The less stringent TRC criteria were derived using EPA recalculation procedures. The City of Yuma used 

the recalculation procedures following ADEQ recommendations for the recalculation. The rulemaking modifies 

the water quality standard applicable to this discharge for total residual chlorine to protect aquatic life from acute 

and chronic toxicity. The acute criterion is 33 μg/L and the chronic criterion is 20 μg/L. These criteria are based 

on EPA recalculation procedures and the species list for chlorine toxicity, which is located on the EPA website at 

www.epa.gov/region7/water/chlorine. The only adjustment made in the recalculation procedure was to remove 

the organism Daphnia magna from the toxicity dataset. The resulting chlorine criteria, calculated from the 
233 

modified dataset, are the criteria of 33 μg/L and 20 μg/L. See Appendix C, Site Specific Standards explanation in 

section #5 of the Preamble. 

As the commenter notes, the U.S. Fish & Wildlife Service provided a letter of support for the proposed sitespecific standards for chlorine and for selenium. The USFWS specifically supported the adoption of the acute and 

chronic total residual chlorine standards of 33 μg/L and 20 μg/L, respectively, and the proposed standard for 

selenium of 2.2 μg/L for the Yuma East Wetlands. The USFWS stated that the proposed modification of the 

selenium from 2.0 μg/L to 2.2 μg/L represented a minimal hazard to the aquatic and wildlife resources using the 

wetlands. It should be noted that the proposed site-specific standard for selenium is still more stringent than EPA’s 

nationally recommended criterion of 5 μg/L to protect freshwater aquatic life. 

ECONOMIC IMPACT STATEMENT

Comment #158

Fred H. Gray, City of Tucson – Parks and Recreation Department

In its economic impact statement in the preamble to its proposed rule, ADEQ specifically identifies only 

private wastewater utilities, mining operations and electric utilities as persons directly affected by this rulemaking, 

with vague references to the real estate and agricultural industries. 

ADEQ does not identify municipalities and the tax-paying public. This rulemaking proposes changes that 

will inevitably increase costs to many Arizona citizens and municipalities. ADEQ makes no efforts to discuss any 

less intrusive or less costly alternative methods of achieving the purpose of the proposed rule. ADEQ’s analysis 

should address the increased monitoring and maintenance costs imposed by enactment of this rule on management 

of urban lakes by municipalities. For example, the City of Tucson spent $ 250,000.00 to build and operate an 

aeration system to treat water at Lakeside Lake to manage for nutrient impacts. In the past year and a half, the City 

of Tucson has been forced to spend and additional $ 277,000.00 pertaining to required permits, and monitoring 

imposed by ADEQ. The City has also been required to abandon past efforts to use reclaimed water at the lake. 

Response: The example of Lakeside Lake underscores the inherent incompatibility of using reclaimed 

water as the sole source of water for lakes and still meet surface water standards. The City of Tucson was not 

required to stop using reclaimed water at Lakeside, the choice was made based on the degree of phosphorus 

reduction needed (and cost of doing so) that was laid out in the TMDL report. Even before a proposed 

chlorophyll-a criterion, Lakeside Lake was listed as impaired due to low DO, high pH, and a history of fish kills. 

General EIS Comments

The following comments refer primarily to costs associated with the rulemaking. The comments are 

produced here but the reader is directed to the Economic Impact Statement (EIS) for the comprehensive review 

of costs associated with the rulemaking. Topic-specific responses to comments not directly related to costs are 

provided in this portion of the Department’s response to comments. 

The Department appreciates that the following comments acknowledge the difficulty of quantifying 

costs and benefits of environmental rulemaking, which is particularly difficult at the proposed rulemaking 
234 

stage. A proposed rule is required to have only a preliminary summary, as stated in A.R.S. § 41-1001(14)(a)(v): 

“The economic, small business and consumer impact summary, or in the case of a proposed rule, a preliminary 

summary and a solicitation of input on the accuracy of the summary.” The Department has considered all 

comments received for the economic, small business, and consumer impact statement that is submitted to the 

Governor’s Regulatory Review Council as required under A.R.S. § 41-1024(C). 

Sydney Hay, Arizona Mining Association

It is admittedly difficult to quantify costs and benefits of environmental rulemakings. However, ADEQ 

must make at least a good faith effort to demonstrate that the proposed benefits of the rule exceed its costs. 

The AMA can readily identify at least four manners in which private businesses could face increased costs 

based on these proposed rules: (1) the proposal to apply EDW criteria to discharges to ephemeral washes will 

require many discharge to meet stringent chronic aquatic life criteria for the first time; (2) as noted above, the 

proposed OAW designation of Davidson Canyon has already imposed costs on at least one entity, and the 

designation could impose potentially far greater costs in the future based on Tier 3 antidegradation requirements; 

(3) also as noted above, the ban on wastewater discharges to four ephemeral washes upgradient of the Ak-Chin 

Indian Reservation (this presumably was adopted in light of specific concerns with one or more existing or 

proposed discharges, so some cost information on the effects of the ban should be obtainable by ADEQ); and (4) 

the general tightening of numeric water quality criteria contained in the rule and the adoption of new 

implementation procedures for narrative criteria, including the new biological criterion. 

The foregoing is not intended to be an exclusive summary of the potential increased costs, just an 

identification of some of the more obvious cases of increased costs that could be imposed by the proposed rule. 

David E McNeil, City of Tempe

The summary of economic, small business and consumer impact does not accurately account for costs and 

benefits of the proposed rule. 

1. The summary does not address the monetary costs associated with nutrient removal to meet the 

criteria established under the narrative nutrient standard. With drought and climate change making 

the increased use of reclaimed water for lakes a necessity in Arizona, the rule fails to address the 

costs associated with the extreme nutrient removal that ADEQ is proposing. 

2. The summary confuses the economic benefits associated with the general concept of “clean water” 

with the economic benefits that will result directly or indirectly from the changes that are being 

made to water quality standards through the proposed rulemaking. Economic benefits resulting from 

the rule should be limited to benefits that will incur from the changes in standards and that would 

not otherwise be realized in the absence of the rule changes, not the benefits that incur from “clean 

water” in general. 

Robert Hollander, City of Phoenix

The Water Services Department believes that the preamble inadequately addresses the costs of the rules to 

political subdivisions, specifically, regarding wastewater treatment and other facilities operated by municipalities 

and counties. The Preamble devotes a substantial amount of time discussing the costs of complying with the 
235 

numeric water quality criteria for ammonia. But other issues were not adequately addressed including: the 

potential cost of compliance with the proposed methylmercury standard of 0.3 mg/kg and the impact of the 

Narrative Nutrient Standard Implementation Procedures. 

ADEQ has not clarified how they will implement the (methylmuercury) standard and if it will be 

implemented in permits. Considering the very low Aquatic and Wildlife chronic standard of 0.01 μg/L proposed 

for dissolved mercury, the Water Services Department remains concerned that ADEQ will derive a water columnbased permit limit for methylmercury based on the fish tissue criterion. This could result in extremely low permit 

limits with a huge cost issue for dischargers. ADEQ needs to clarify how they intend to implement the proposed 

methylmercury standard and/or provide an analysis of the potential costs of removing this contaminant to comply 

with the standard and anticipated permit limits. 

D. Lee Decker (Gallagher & Kennedy), Surface Water Quality Standards Coalition

In its economic impact statement in the preamble to its proposed rule, ADEQ specifically identifies only 

private wastewater utilities, mining operations and electric utilities as persons directly affected by this rulemaking, 

with vague references to the real estate and agricultural industries. ADEQ does not identify other persons and 

industries impacted by this proposed rule, including those in the construction industry, municipalities, and tourist 

industries. ADEQ provides no cost-benefit analysis of the proposed rule and only briefly mentions that “some 

business, industry, and consumers may have to pay higher utility bills for sewer services” but provides no analysis 

comparing these costs to the benefits of the proposed rule. 

The Coalition requests that ADEQ reformulate its preamble to the proposed rule to (1) address the broad 

spectrum of citizens, industries, municipalities and small businesses impacted by this rule; (2) provide a true costbenefit analysis and not simply a catalog of the general benefits of clean water and a brief mention of potentially 

higher utility bills; (3) recognize all costs imposed on citizens, small businesses, employers and municipalities 

beyond simply higher utility bills; and (4) consider potential alternative methods to minimize the costs and 

administrative burdens of this proposed rule. 

Michael Gritzuk, Pima County Regional Wastewater Reclamation Department

ADEQ, in its EIS fails to address all the required analysis required by statute. ADEQ specifically mentions 

only wastewater utilities, mining operations, and electric utilities as potentially impacted by this rulemaking. 

Others that will certainly be impacted that ADEQ fails to mention are the construction and tourism industries as 

well as municipalities throughout Arizona. ADEQ also fails to provide a substantial discussion of the potential 

impacts of this rule upon small businesses including identification of those businesses that might be negatively 

impacted, a discussion of anticipated administrative costs to small businesses, and analysis of any methods ADEQ 

might undertake to reduce the regulatory burden on small business. ADEQ also provides no meaningful analysis 

of the potential costs of this rulemaking to the anticipated benefits. 

Pima County has commissioned an analysis of the anticipated costs to county ratepayers that will result as a 

consequence of this rulemaking. The cost for Pima County government to comply with just three of the numerous 

proposed new rule provisions is conservatively estimated at between 90 million to 100 billion dollars. ADEQ has 

failed to properly address the impact of these costs upon the businesses and ratepayers within Pima County and 

has failed to discuss what steps ADEQ could take to minimize these impacts. 
236 

Pima County requests that ADEQ carefully consider all the impacts of these rules upon Arizona citizens 

and to fully comply with state statutory requirements by revising and republishing its EIS for stakeholder review 

and comment. 

12. Any other matters prescribed by statute that are applicable to the specific agency or to any specific rule or 

class of rules:

None 

13. Incorporations by reference and their location in the rules:

R18-11-110(B) “2005 Review, Water Quality Standards for Salinity, Colorado River System,” 

Colorado River Basin Salinity Control Forum (October, 2005) 

R18-11-112(D)(4)(b) “Endangered and Threatened Wildlife,” 50 CFR 17.11 (Revised 2005) 

“Endangered and Threatened Plants,” 50 CFR 17.12 (Revised 2005) 

R18-11-115(C)(1) “The Recalculation Procedure,” Appendix L, pages 90 - 98, Water Quality Standards 

Handbook, Second Edition, EPA 823-B-94-005b (August 1994) 

R18-11-115(C)(2) “Water-Effects Ratio for Metals,” Appendix L, pages 1 - 89, Water Quality Standards 

Handbook, Second Edition, EPA 823-B-94-005b (August 1994) 

R18-11-115(C)(3) “Streamlined Water Effects Ratio Procedure for Discharges of Copper,” EPA-822-R01-005 (March 2001) 

14. Was this rule previously made as an emergency rule?

No 

15. The full text of the rules follows:
 

237

TITLE 18. ENVIRONMENTAL QUALITY 

CHAPTER 11. DEPARTMENT OF ENVIRONMENTAL QUALITY 

WATER QUALITY STANDARDS 

ARTICLE 1. WATER QUALITY STANDARDS FOR SURFACE WATERS 

R18-11-101. Definitions 

R18-11-102. Applicability 

R18-11-107. Antidegradation 

R18-11-107.01. Antidegradation Criteria

R18-11-108. Narrative Water Quality Standards 

R18-11-108.01. Narrative Biological Criteria for Wadeable, Perennial Streams

R18-11-108.02. Narrative Bottom Deposit Criteria for Wadeable, Perennial Streams

R18-11-108.03. Narrative Nutrient Criteria for Lakes and Reservoirs

R18-11-109. Numeric Water Quality Standards 

R18-11-110. Salinity Standards for the Colorado River 

R18-11-111. Analytical Methods 

R18-11-112. Unique Outstanding Arizona Waters 

R18-11-113. Effluent-dependent Effluent-Dependent Waters 

R18-11-114. Mixing Zones 

R18-11-115. Repealed Site-Specific Standards

R18-11-116. Resource management agencies Management Agencies

R18-11-117. Canals and Municipal Urban Park Lakes 

R18-11-118. Dams and Flood Control Structures 

R18-11-121. Schedules of Compliance 

R18-11-122. Variances 

R18-11-123. Prohibition Against Discharge Prohibitions

Appendix A. APPENDIX A. Numeric Water Quality Criteria NUMERIC WATER QUALITY STANDARDS

Table 1. Human Health and Agricultural Designated Uses Water Quality Criteria By Designated Use

Table 2. Aquatic & Wildlife Designated Uses Acute Water Quality Standards for Dissolved Cadmium

Aquatic and Wildlife coldwater

Table 3. Acute Water Quality Standards for dissolved Cadmium Aquatic and Wildlife ephemeral

Chronic Water Quality Standards for Dissolved Cadmium Aquatic and Wildlife coldwater

Table 4. Acute Water Quality Standards for dissolved Dissolved Cadmium Aquatic and Wildlife 

coldwater, warmwater, and edw

Table 5. Chronic Water Quality Standards for dissolved Dissolved Cadmium Aquatic and Wildlife 

coldwater, warmwater, and edw 
 

238

Table 6. Acute Water Quality Standards for Dissolved Cadmium Aquatic and Wildlife ephemeral

Table 7. Acute Water Quality Standards for dissolved Dissolved Chromium III Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 8. Chronic Water Quality Standards for dissolved Dissolved Chromium III Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 6. 9. Acute Water Quality Standards for dissolved Dissolved Chromium III Aquatic and 

Wildlife ephemeral 

Table 11. 10. Acute Water Quality Standards for dissolved Dissolved Copper Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 9. 11. Chronic Water Quality Standards for dissolved Dissolved Copper Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 10. 12. Acute Water Quality Standards for dissolved Dissolved Copper Aquatic and Wildlife 

ephemeral 

Table 14. 13. Acute Water Quality Standards for dissolved Dissolved Lead Aquatic and Wildlife coldwater, 

warmwater, and edw 

Table 15. 14. Chronic Water Quality Standards for dissolved Dissolved Lead Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 13. 15. Acute Water Quality Standards for dissolved Dissolved Lead Aquatic and Wildlife ephemeral 

Table 16. Acute Water Quality Standards for dissolved Dissolved Nickel Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 17. Chronic Water Quality Standards for dissolved Dissolved Nickel Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 18. Water Quality Standards for dissolved Silver Aquatic and Wildlife coldwater, warmwater, 

edw, and ephemeral

Table 12. 18. Acute Water Quality Standards for dissolved Dissolved Nickel Aquatic and Wildlife 

ephemeral 

Table 19. Water Quality Standards for Dissolved Silver Aquatic and Wildlife coldwater, warmwater, 

edw, and ephemeral 

Table 20. Acute and Chronic Water Quality Standards for dissolved Dissolved Zinc Aquatic and 

Wildlife coldwater, warmwater, and edw 

Table 19. 21. Acute Water Quality Standards for dissolved Dissolved Zinc Aquatic and Wildlife ephemeral 

Table 21. 22. Acute Water Quality Standards for Pentachlorophenol Acute Aquatic and Wildlife coldwater, 

warmwater, and edw 

Table 22. 23. Chronic Water Quality Standards for Pentachlorophenol Chronic Aquatic and Wildlife 

coldwater, warmwater, and edw 

Table 23. 24. Acute Water Quality Standards for Pentachlorophenol Acute Aquatic and Wildlife ephemeral 
 

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Table 24. 25. Acute Criteria for Total Ammonia (in mg/L as N) Aquatic and Wildlife coldwater, 

warmwater, and edw

Table 25. 26. Chronic Criteria for Total Ammonia (in mg/L as N) A&Wc, A&Ww Aquatic and Wildlife 

coldwater, warmwater, and edw 

Appendix B. APPENDIX B. List of Surface Waters and Designated Uses SURFACE WATERS AND 

DESIGNATED USES

Appendix C. APPENDIX C. Repealed SITE-SPECIFIC STANDARDS
 

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 TITLE 18. ENVIRONMENTAL QUALITY 

CHAPTER 11. DEPARTMENT OF ENVIRONMENTAL QUALITY 

WATER QUALITY STANDARDS 

ARTICLE 1. WATER QUALITY STANDARDS FOR SURFACE WATERS 

R18-11-101. Definitions 

The following terms of apply to this Article have the following meanings: 

1. “Acute toxicity” means toxicity involving a stimulus severe enough to induce a rapid response 

rapidly. In aquatic toxicity tests, an effect observed in 96 hours or less is considered acute. 

2. “AgI” means agricultural irrigation.

3. “AgL” means agricultural livestock watering.

4.2. “Agricultural irrigation (AgI)” means the use of a surface water for the irrigation of crops crop 

irrigation.

5.3. “Agricultural livestock watering (AgL)” means the use of a surface water as a supply of water supply

for consumption by livestock.

6.4. “Annual mean” means is the arithmetic mean of monthly values determined over a consecutive 12-

month period, provided that monthly values are determined for at least three months. The A monthly 

value is the arithmetic mean of all values determined in a calendar month.

7.5. “Aquatic and wildlife (cold water) (A&Wc)” means the use of a surface water by animals, plants, or 

other cold-water organisms, generally occurring at elevations an elevation greater than 5000 feet, for 

habitation, growth, or propagation. 

8.6. “Aquatic and wildlife (effluent-dependent water) (A&Wedw)” means the use of an effluentdependent water by animals, plants, or other organisms for habitation, growth, or propagation. 

9.7. “Aquatic and wildlife (ephemeral) (A&We)” means the use of an ephemeral water by animals, plants, 

or other organisms, excluding fish, for habitation, growth, or propagation. 

10.8. “Aquatic and wildlife (warm water) (A&Ww)” means the use of a surface water by animals, plants, 

or other warm-water organisms, generally occurring at elevations an elevation less than 5000 feet, for 

habitation, growth, or propagation. 

11. “A&Wc” means aquatic and wildlife (cold water).

12. “A&We” means aquatic and wildlife (ephemeral).

13. “A&Wedw” means aquatic and wildlife (effluent-dependent water).

14. “A&Ww” means aquatic and wildlife (warm water).

9. “Arizona Pollutant Discharge Elimination System (AZPDES)” means the point source discharge 

permitting program established under 18 A.A.C. 9, Article 9.

10. “Assimilative capacity” means the difference between the baseline water quality concentration for a 

pollutant and the most stringent applicable water quality criterion for that pollutant.
 

241

15.11. “Clean Water Act” means the Federal Water Pollution Control Act [33 U.S.C. 1251 to 1387].

16.12. “Criteria” means elements of water quality standards that are expressed as pollutant concentrations, 

levels, or narrative statements representing a water quality that supports a designated use. 

13. “Critical flow condition” means the lowest flow over seven consecutive days that has a probability of 

occurring once in 10 years (7 Q 10).

14. “Deep lake” means a lake or reservoir with an average depth of more than 6 meters.

17.15. “Designated use” means a use specified in Appendix B of this Article for a surface water. 

18.16. “Domestic water source (DWS)” means the use of a surface water as a source of potable water 

supply. Coagulation, sedimentation, filtration, disinfection, or other treatments Treatment of a surface 

water may be necessary to yield a finished water suitable for human consumption. 

19. “DWS” means domestic water source.

20. “EDW” means effluent-dependent water.

21.17. “Effluent-dependent water (EDW)” means a surface water, classified under R18-11-113, that consists 

of a point source discharges discharge of treated wastewater that is classified as an effluentdependent water by the Director under R18-11-113. An effluent-dependent water is a surface water 

that, without the point source discharge of treated wastewater, would be an ephemeral water. 

22.18. “Ephemeral water” means a surface water that has a channel that is at all times above the water table,

and that flows only in direct response to precipitation. 

23.19. “Existing use” means those uses actually a use attained in the waterbody on or after November 28, 

1975, whether or not they are it is included in the water quality standards. 

24. “FBC” means full-body contact.”

25. “FC” means fish consumption.

26.20. “Fish consumption (FC)” means the use of a surface water by humans for harvesting aquatic 

organisms for consumption. Harvestable aquatic organisms include, but are not limited to, fish, 

clams, turtles, crayfish, and frogs. 

27.21. “Full-body contact (FBC)” means the use of a surface water for swimming or other recreational 

activity that causes the human body to come into direct contact with the water to the point of 

complete submergence. The use is such that ingestion of the water is likely and sensitive body 

organs, such as the eyes, ears, or nose, may be exposed to direct contact with the water.

28.22. “Geometric mean” means the nth root of the product of n items or values. The geometric mean is 

calculated using the following formula: 

n y YYYYGM n ))...()()(( = 321

29.23. “Hardness” means the sum of the calcium and magnesium concentrations, expressed as calcium 

carbonate (CaCO3) in milligrams per liter. 

24. “Igneous lake” means a lake located in volcanic, basaltic, or granite geology and soils.
 

242

30.25. “Intermittent surface water” means a stream or reach of a stream that flows continuously only at 

certain times of the year, as when it receives water from a spring or from another surface source, such 

as melting snow. 

31.26. “Mixing zone” means a prescribed an area or volume of a surface water that is contiguous to a point 

source discharge where initial dilution of the discharge takes place. 

32. “National Pollutant Discharge Elimination System means the point source discharge permit program 

established by § 402 of the Clean Water Act [33 U.S.C. 1342].

33. “Ninetieth percentile” means the value that may not be exceeded by more than 10% of the 

observations in a consecutive 12 month period. A minimum of 10 samples, each taken at least 10 

days apart, are required to determine a ninetieth percentile.

34. “NNS” means no numeric standard.

35.27. “Oil” means petroleum in any form, including but not limited to crude oil, gasoline, fuel oil, diesel 

oil, lubricating oil, or sludge. 

28. “Outstanding Arizona water (OAW)” means a surface water that is classified as an outstanding state 

resource water by the Director under R18-11-112.

36.29. “Partial-body contact (PBC)” means the recreational use of a surface water that may cause the human 

body to come into direct contact with the water, but normally not to the point of complete 

submergence (for example, wading or boating). The use is such that ingestion of the water is not 

likely and sensitive body organs, such as the eyes, ears, or nose, will not normally be exposed to 

direct contact with the water. 

37. “PBC” means partial-body contact.”

38.30. “Perennial surface water” means a surface water that flows continuously throughout the year.

39.31. “Pollutant” means fluids, contaminants, toxic wastes, toxic pollutants, dredged spoil, solid waste, 

substances and chemicals, pesticides, herbicides, fertilizers and other agricultural chemicals, 

incinerator residue, sewage, garbage, sewage sludge, munitions, petroleum products, chemical 

wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, 

cellar dirt, and mining, industrial, municipal, and agricultural wastes or any other liquid, solid, 

gaseous, or hazardous substance.

“Pollutant” means fluids, contaminants, toxic wastes, toxic pollutants, dredged spoil, solid waste, 

substances and chemicals, pesticides, herbicides, fertilizers and other agricultural chemicals, 

incinerator residue, sewage, garbage, sewage sludge, munitions, petroleum products, chemical 

wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, 

sand, cellar dirt, and mining, industrial, municipal, and agricultural wastes or any other liquid, 

solid, gaseous, or hazardous substance. A.R.S § 49-201(29)

40.32. “Practical quantitation limit” means the lowest level of quantitative measurement that can be reliably 

achieved during a routine laboratory operations operation. 

41. “Recreational uses” means the full-body contact and partial-body contact designated uses.
 

243

33. “Reference condition” means a set of ecological measurements from a population of relatively 

undisturbed waterbodies within a region that establish a basis for making comparisons of biological 

condition among samples.

42.34. “Regional Administrator” means the Regional Administrator of Region IX of the U.S. Environmental 

Protection Agency. 

35. “Regulated discharge” means a point-source discharge regulated under an AZPDES permit, a 

discharge regulated by a § 404 permit, and any discharge authorized by a federal permit or license 

that is subject to state water quality certification under § 401 of the Clean Water Act.

36. “Riffle habitat” means a stream segment where moderate water velocity and substrate roughness 

produce moderately turbulent conditions that break the surface tension of the water and may produce 

breaking wavelets that turn the surface water into white water.

37. “Run habitat” means a stream segment where there is moderate water velocity that does not break the 

surface tension of the water and does not produce breaking wavelets that turn the surface water into 

white water.

38. “Sedimentary lake” means a lake or reservoir in sedimentary or karst geology and soils.

39. “Shallow lake” means a lake or reservoir, excluding an urban lake, with a smaller, flatter morphology 

and an average depth of less than 3 meters and a maximum depth of less than 4 meters.

40. “Significant degradation” means:

a. The consumption of 20 percent or more of the available assimilative capacity for a pollutant

of concern at critical flow conditions, or

b. Any consumption of assimilative capacity beyond the cumulative cap of 50 percent of 

assimilative capacity.

43.41. “Surface water” means a water of the United States and includes the following: 

a. A water that is currently used, was used in the past, or may be susceptible to use in interstate 

or foreign commerce; 

b. An interstate water, including an interstate wetland; 

c. All other waters, such as an intrastate lake, reservoir, natural pond, river, stream (including an 

intermittent or ephemeral stream), creek, wash, draw, mudflat, sandflat, wetland, slough, 

backwater, prairie pothole, wet meadow, or playa lake, the use, degradation, or destruction of 

which would affect or could affect interstate or foreign commerce, including any such water: 

i. That is or could be used by interstate or foreign travelers for recreational or other 

purposes; 

ii. From which fish or shellfish are or could be taken and sold in interstate or foreign 

commerce; or 

iii. That is used or could be used for industrial purposes by industries in interstate or 

foreign commerce; 

d. An impoundment of a surface water as defined by this definition; 
 

244

e. A tributary of a surface water identified in subsections (41)(a) through (d) of this definition; 

and 

f. A wetland adjacent to a surface water identified in subsections (41)(a) through (e) of this 

definition. 

44.42. “Total nitrogen” means the sum of the concentrations of ammonia (NH3), ammonium ion (NH4+), 

nitrite (NO2), and nitrate (NO3), and dissolved and particulate organic nitrogen expressed as 

elemental nitrogen. 

45.43. “Total phosphorus” means all of the phosphorus present in a sample, regardless of form, as measured 

by a persulfate digestion procedure. 

46.44. “Toxic” means a pollutant or combination of pollutants, that after discharge and upon exposure, 

ingestion, inhalation, or assimilation into an organism, either directly from the environment or 

indirectly by ingestion through food chains, may cause death, disease, behavioral abnormalities, 

cancer, genetic mutations, physiological malfunctions (including malfunctions in reproduction), or 

physical deformations in the organism or its offspring. 

47. “Unique water” means a surface water that is classified as an outstanding state resource water by the 

Director under R18-11-112.

45. “Urban lake” means a manmade lake within an urban landscape.

48.46. “Use attainability analysis” means a structured scientific assessment of the factors affecting the 

attainment of a designated use including physical, chemical, biological, and economic factors. 

47. “Wadeable” means a surface water can be safely crossed on foot and sampled without a boat.

48. “Wastewater” does not mean:

1. Stormwater;

2. Discharges authorized under the De Minimus General Permit;

3. Other allowable non-stormwater discharges permitted under the Construction General Permit

or the Multi-sector General Permit; or

4. Stormwater discharges from a municipal storm sewer system (MS4) containing incidental 

amounts of non-stormwater that the MS4 is not required to prohibit.

49. “Wetland” means an area that is inundated or saturated by surface or groundwater at a frequency and 

duration sufficient to support, and that under normal circumstances does support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. A wetland includes a swamp, marsh, 

bog, cienega, tinaja, and similar areas. 

50. “Zone of passage” means a continuous water route of volume, cross-sectional area, and quality 

necessary to allow passage of free-swimming or drifting organisms with no acutely toxic effect 

produced on the organisms. 

R18-11-102. Applicability

A. The water quality standards prescribed in this Article apply to surface waters. 
 

245

B. The water quality standards prescribed in this Article do not apply to the following: 

1. A waste treatment system, including an impoundment, pond, lagoon, or constructed wetland that is a 

part of the waste treatment system.;

2. A man-made surface impoundment and any associated ditches ditch and conveyances conveyance

used in the extraction, beneficiation, or processing of metallic ores that is not a surface water or is 

located in an area that once was a surface water but is no longer a surface water because it has been 

and remains legally converted, including:

a. a A pit, 

b. pregnant Pregnant leach solution pond, 

c. raffinate Raffinate pond, 

d. tailing Tailing impoundment, 

e. decant Decant pond, 

f. pond Pond or a sump in a mine pit associated with dewatering activity, 

g. pond Pond holding water that has come into contact with a process or product and that is 

being held for recycling, 

h. spill Spill or upset catchment pond, or 

i. A pond used for onsite remediation, that is not a surface water or is located in an area that 

once was a surface water but no longer remains a surface water because it has been and 

remains legally converted.;

3. A man-made cooling pond that is neither created in a surface water nor results from the impoundment 

of a surface water; or

4. A surface water located on tribal lands.

R18-11-107. Antidegradation

A. The Director shall, using R18-11-107.01 and this Section, determine whether there is degradation of water 

quality in a surface water on a pollutant-by-pollutant basis.

B. Tier 1: The level of water quality necessary to protect support an existing uses use shall be maintained and 

protected. No degradation of existing water quality is permitted in a surface water where the existing water 

quality does not meet the applicable water quality standards. 

C. Tier 2: Where existing water quality in a surface water is better than the applicable water quality standard, 

the existing water quality shall be maintained and protected. The Director may allow limited degradation of 

existing water quality in the surface water, provided that the Department holds a public hearing on whether 

degradation should be allowed under the general public hearing procedures prescribed at R18-1-401 and 

R18-1-402 and if the Director makes all of the following findings: 

1. The level of water quality necessary to protect for existing uses is fully protected. Water and water

quality shall is not be lowered to a level that does not comply with applicable water quality 

standards.,
 

246

2. The highest statutory and regulatory requirements for new and existing point sources are achieved.,

3. All cost-effective and reasonable best management practices for nonpoint source pollution control are 

implemented., and

4. Allowing lower water quality is necessary to accommodate important economic or social 

development in the area where the surface water is located. 

D. Tier 3: Existing water quality shall be maintained and protected in a surface water that is classified as a 

unique water an OAW under R18-11-112. The Director shall not allow limited degradation Degradation of a 

unique water an OAW under subsection (C) is prohibited. 

E. The Department Director shall implement this Section in a manner consistent with § 316 of the Clean Water 

Act [33 U.S.C. § 1326] if a potential water quality impairment associated with a thermal discharge is 

involved. 

R18-11-107.01. Antidegradation Criteria

A. Tier 1 antidegradation protection.

1. Tier 1 antidegradation protection applies to the following surface waters:

a. A surface water listed on the 303(d) list for the pollutant that resulted in the listing,

b, An effluent dependent water,

c. An ephemeral water,

d. An intermittent water, and

e. A canal listed in Appendix B.

2. A regulated discharge shall not cause a violation of a surface water quality standard or a wasteload 

allocation in a total maximum daily load approved by EPA.

3. Except as provided in subsections (E) and (F), Tier 1 antidegradation review requirements are 

satisfied for a point-source discharge regulated under an individual AZPDES permit to an ephemeral 

water, effluent dependent water, intermittent water, or a canal listed in Appendix B, if water qualitybased effluent limitations designed to achieve compliance with applicable surface water quality 

standards are established in the permit and technology-based requirements of the Clean Water Act for 

the point source discharge are met.

B. Tier 2 antidegradation protection.

1. Tier 2 antidegradation protection applies to a perennial water with existing water quality that is better 

than applicable water quality standards. A perennial water that is not listed in subsection (A)(1) nor 

classified as an OAW under R18-9-112(G) has Tier 2 antidegradation protection for all pollutants of 

concern.

2. A regulated discharge that meets the following criteria, at critical flow conditions, does not cause 

significant degradation:

a. The regulated discharge consumes less than 20 percent of the available assimilative capacity 

for each pollutant of concern, and
 

247

b. At least 50 percent of the assimilative capacity for each pollutant of concern remains available 

in the surface water for each pollutant of concern.

3. Antidegradation review. Any person proposing a new or expanded regulated discharge under an 

individual AZPDES permit that may cause significant degradation shall provide the Department with 

the following information:

a. Alternative analysis.

i. The person seeking authorization for the discharge shall prepare and submit a written 

analysis of alternatives to the discharge. The analysis shall provide information on all 

reasonable, cost-effective, less-degrading or non-degrading discharge alternatives. 

Alternatives may include wastewater treatment process changes or upgrades, pollution 

prevention measures, source reduction, water reclamation, alternative discharge 

locations, groundwater recharge, land application or treatment, local pretreatment 

programs, improved operation and maintenance of existing systems, seasonal or 

controlled discharge to avoid critical flow conditions, and zero discharge;

ii. The alternatives analysis shall include cost information on base pollution control 

measures associated with the regulated discharge and cost information for each 

alternative;

iii. The person shall implement the alternative that is cost-effective and reasonable, results 

in the least degradation, and is approved by the Director. An alternative is costeffective and reasonable if treatment costs associated with the alternative are less than 

a 10 percent increase above the cost of base pollution control measures;

iv. For purposes of this subsection, “base pollution control measures” are water pollution 

control measures required to meet technology-based requirements of the Clean Water 

Act and water quality-based effluent limits designed to achieve compliance with 

applicable water quality standards;

b. Social and economic justification. The person shall demonstrate to the Director that 

significant degradation is necessary to accommodate important economic or social 

development in the local area. The person seeking authorization for the discharge shall 

prepare a written social and economic justification that includes a description of the 

following:

i. The geographic area where significant degradation of existing water quality will 

occur;

ii. The current baseline social and economic conditions in the local area;

iii. The net positive social and economic effects of development associated with the 

regulated discharge and allowing significant degradation;

iv. The negative social, environmental, and economic effects of allowing significant 

degradation of existing water quality; and
 

248

v. Alternatives to the regulated discharge that do not significantly degrade water quality 

yet may yield comparable social and economic benefits;

c. Baseline characterization. A person seeking authorization to discharge under an individual 

AZPDES permit to a perennial water shall provide baseline water quality data on pollutants of 

concern where no data exist or there are insufficient data to characterize baseline water 

quality and to determine available assimilative capacity. A discharger shall characterize 

baseline water quality at a location upstream of the proposed discharge location; and

4. For purposes of this Section, the term “pollutant of concern” means a pollutant with either a numeric 

or narrative water quality standard.

5. Public participation. The Director shall provide public notice and an opportunity to comment on an 

antidegradation review under subsection (B)(3) and shall provide an opportunity for a public hearing 

under A.A.C. R18-9-A908(B).

C. Tier 3 antidegradation protection.

1. Tier 3 antidegradation protection applies only to an OAW listed in R18-11-112(G).

2. A new or expanded point-source discharge directly to an OAW is prohibited.

3. A person seeking authorization for a regulated discharge to a tributary to, or upstream of, an OAW 

shall demonstrate in a permit application or in other documentation submitted to the Department that 

the regulated discharge will not degrade existing water quality in the downstream OAW.

4. A discharge regulated under a § 404 permit that may affect existing water quality of an OAW 

requires an individual § 401 water quality certification to ensure that existing water quality is 

maintained and protected and any water quality impacts are temporary. Temporary water quality 

impacts are those impacts that occur for a period of six months or less.

D. Antidegradation review of a § 404 permit. The Director shall conduct the antidegradation review of any 

discharge authorized under a nationwide or regional § 404 permit as part of the § 401 water quality 

certification prior to issuance of the nationwide or regional permit. The Director shall conduct the 

antidegradation review of an individual § 404 permit if the discharge may degrade existing water quality in 

an OAW or a water listed on the 303(d) List of impaired waters. For regulated discharges that may degrade 

water quality in an OAW or a water that is on the 303(d) List of impaired waters, the Director shall conduct 

the antidegradation review as part of the § 401 water quality certification process.

E. Antidegradation review of an AZPDES stormwater permit. An individual stormwater permit for a municipal 

separate storm sewer system (MS4) meets antidegradation requirements if the permittee complies with the 

permit, including developing a stormwater management plan containing controls that reduce the level of 

pollutants in stormwater discharges to the maximum extent practicable.

F. Antidegradation review of a general permit. The Director shall conduct the antidegradation review of a 

regulated discharge authorized by a general permit at the time the general permit is issued or renewed. A 

person seeking authorization to discharge under a general permit is not required to undergo an individual 

antidegradation review at the time the Notice of Intent is submitted unless the discharge may degrade 
 

249

existing water quality in an OAW or a water listed on the 303(d) List of impaired waters.

R18-11-108. Narrative Water Quality Standards

A. A surface water shall be free from not contain pollutants in amounts or combinations that: 

1. Settle to form bottom deposits that inhibit or prohibit the habitation, growth, or propagation of 

aquatic life; 

2. Cause objectionable odor in the area in which the surface water is located; 

3. Cause off-taste or odor in drinking water; 

4. Cause off-flavor in aquatic organisms; 

5. Are toxic to humans, animals, plants, or other organisms; 

6. Cause the growth of algae or aquatic plants that inhibit or prohibit the habitation, growth, or 

propagation of other aquatic life or that impair recreational uses; 

7. Cause or contribute to a violation of an aquifer water quality standard prescribed in R18-11-405 or 

R18-11-406; or 

8. Change the color of the surface water from natural background levels of color. 

B. A surface water shall be free from not contain oil, grease, and or any other pollutants pollutant that float

floats as debris, foam, or scum; or that cause causes a film or iridescent appearance on the surface of the 

water; or that cause causes a deposit on a shoreline, bank, or aquatic vegetation. The discharge of lubricating 

oil or gasoline associated with the normal operation of a recreational watercraft is not a violation of this 

narrative standard. 

C. A discharge of suspended solids to a surface water shall not be A surface water shall not contain a discharge 

of suspended solids in quantities or concentrations that either interfere with the treatment processes at the 

nearest downstream potable water treatment plant or substantially increase the cost of handling solids 

produced at the nearest downstream potable water treatment plant. 

D. A surface water shall not contain solid waste such as refuse, rubbish, demolition or construction debris, trash, 

garbage, motor vehicles, appliances, or tires.

E. A wadeable, perennial stream shall support and maintain a community of organisms having a taxa richness, 

species composition, tolerance, and functional organization comparable to that of a stream with reference 

conditions in Arizona.

R18-11-108.01. Narrative Biological Criteria for Wadeable, Perennial Streams

A. The narrative biological criteria in this Section apply to a wadeable, perennial stream with either an aquatic 

and wildlife (cold water) or an aquatic and wildlife (warm water) designated use.

B. The biological standard in R18-11-108(E) is met when a bioassessment result, as measured by the Arizona 

Index of Biological Integrity (IBI), for cold or warm water is:

1. Greater than or equal to the 25th percentile of reference condition, or
 

250

2. Greater than the 10th percentile of reference condition and less than the 25th percentile of reference 

condition and a verification bioassessment result is greater than or equal to the 25th percentile of 

reference condition.

C. Arizona Index of Biological Integrity (IBI) scores.

Index of Biological Integrity Scores Bioassessment Result

A&Wc A&Ww

Greater than or equal to the 25th 

percentile of reference condition

≥ 52 ≥ 50

Greater than the 10th and less than the 

25th percentile of reference condition

46 - 51 40 - 49

R18-11-108.02. Narrative Bottom Deposit Criteria for Wadeable, Perennial Streams

A. The narrative bottom deposit criteria in this Section apply to wadeable, perennial streams with an aquatic and 

wildlife (cold water) or an aquatic and wildlife (warm water) designated use.

B. The narrative water quality standard for bottom deposits at R18-11-108(A)(1) is met when:

1. The percentage of fine sediments in the riffle habitats of a wadeable, perennial stream with an A&Wc

designated use, as determined by a riffle pebble count, is less than or equal to 30 percent.

2. The percentage of fine sediments in all stream habitats of a wadeable, perennial stream with an 

A&Ww designated use, as determined by a reach level pebble count, is equal to or less than 50 

percent.

R18-11-108.03. Narrative Nutrient Criteria for Lakes and Reservoirs

A. The narrative nutrient criteria in this Section apply to those lakes and reservoirs categorized in Appendix B.

B. The narrative water quality standard for nutrients at R18-11-108(A)(6) is met when, based on a minimum of 

two lake sample events conducted during the peak season based on lake productivity, the results show an 

average chlorophyll-a value below the applicable threshold for designated use and lake and reservoir 

category in subsection (D).

1. The mean chlorophyll-a concentration is less than the lower value in the target range chlorophyll-a

for the lake and reservoir category; or

2. The mean chlorophyll-a concentration is within the target range for the lake and reservoir category 

and:

a. The mean blue green algae count is at or below 20,000 per milliliter, and

b. The blue green algae count is less than 50 percent of the total algae count, and

c. There is no evidence of nutrient-related impairments such as:

i. An exceedance of dissolved oxygen or pH standards;

ii. A fish kill coincident with a dissolved oxygen or pH exceedance;

iii. A fish kill or other aquatic organism mortality coincident with algal toxicity;
 

251

iv. Secchi depth is less than the lower value prescribed for the lake and reservoir category;

v. A nuisance algal bloom is present in the limnetic portion of the lake or reservoir; or

vi. The concentration of total phosphorous, total nitrogen, or total Kjehdal nitrogen (TKN) is 

greater than the upper value in the range prescribed for the lake and reservoir category; or

3. For a shallow lake. In addition to meeting the mean chlorophyll-a concentrations in subsections 

(B)(1) or (2), submerged aquatic vegetation covers 50 percent or less of the lake bottom and there is 

less than a 5 mg/L swing in diel-dissolved oxygen concentration measured within the photic zone.

C. The following threshold ranges apply during the peak season for lake productivity:

1. Warm water lakes peak season, April – October;

2. Cold water lakes peak season, May – September.

D. The following table lists the numeric targets for lakes and reservoirs.

NUMERIC TARGETS FOR LAKES AND RESERVOIRS

Designated

Use

Lake

Category

Chl-a

(μg/L)

Secchi

Depth

(m)

Total

Phosphorus

(μg/L)

Total

Nitrogen

(mg/L)

Total

Kjehldal

Nitrogen

(TKN)

(mg/L)

BlueGreen

Algae

(per ml)

BlueGreen

Algae

(% of total 

count)

Dissolved 

Oxygen

(mg/L)

pH

(SU)

Deep 10-15 1.5-2.5 70-90 1.2-1.4 1.0-1.1 

Shallow 10-15 1.5-2.0 70-90 1.2-1.4 1.0-1.1 

Igneous 20-30 0.5-1.0 100-125 1.5-1.7 1.2-1.4 

Sedimentary 20-30 1.5-2.0 100-125 1.5-1.7 1.2-1.4 

FBC and

PBC

Urban 20-30 0.5-1.0 100-125 1.5-1.7 1.2-1.4

20,000

 

6.5-9.0

A&Wc All 5-15 1.5-2.0 50-90 1.0-1.4 0.7-1.1 7

(top m)

All (except 

urban lakes)

25-40 0.8-1.0 115-140 1.6-1.8 1.3-1.6 A&Ww

Urban 30-50 0.7-1.0 125-160 1.7-1.9 1.4-1.7 

6.5-9.0

A&Wedw All 30-50 0.7-1.0 125-160 1.7-1.9 1.4-1.7 

<50

6

(top m)

6.5-9.0

DWS All 10-20 0.5-1.5 70-100 1.2-1.5 1.0-1.2 20,000 5.0-9.0

R18-11-109. Numeric Water Quality Standards 

A. E. coli bacteria. The following water quality standards for Escherichia coli (E. coli), Escherichia coli (E. 

coli) are expressed in colony forming units per 100 milliliters of water (cfu / 100 ml), or as a Most Probable

Number (MPN) shall not be exceeded

E. coli FBC PBC 

Geometric mean (four-sample minimum of four samples in 30 days) 126 126 

Single sample maximum 235 576 575

B. pH. The following water quality standards for pH, are expressed in standard units, shall not be violated: 
 

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pH DWS FBC, PBC, A&W 1 AgI AgL 

Maximum 9.0 9.0 9.0 9.0 

Minimum 5.0 6.5 4.5 6.5 

Maximum change

due to discharge NNS 0.5 NNS NNS

C. The following maximum allowable increase in ambient water temperature, expressed in degrees Celsius, 

shall not be exceeded due to a thermal discharge is as follows: 

Temperature A&Ww, A&Wedw A&Wc

Maximum increase

due to a thermal discharge 2,3 3.0 1.0

 A&Ww A&Wedw A&Wc

 3.0° C 3.0° C 1.0° C

D.C. Suspended sediment concentration.

1. The following water quality standard standards for suspended sediment concentration, expressed in 

milligrams per liter (mg/L), are expressed as a geometric mean median value (four-sample minimum)

determined from a minimum of four samples collected at least seven days apart shall not be 

exceeded. The standard applies to a surface water that is at or near base flow and does not apply to a 

surface water during or soon after a precipitation event:

A&Wc, A&Ww

80 mg / L

A&Wc A&Ww

 25 80

2. The Director shall not use the results of a suspended sediment concentration sample collected during 

or within 48 hours after a local storm event to determine the median value.

E.D. Dissolved oxygen. The following are the water quality standards for dissolved oxygen, are expressed in 

milligrams per liter (mg/L). The dissolved oxygen concentration in a surface water shall not fall below the 

following minimum concentrations:

1. Dissolved oxygen A&Ww A&Wc 

Single sample minimum 4 2 6.0 7.0 

2. Dissolved oxygen in effluent-dependent waters 

(single sample minimum): A&W edw 

Three hours after sunrise to sunset 3.0 

Sunset to three hours after sunrise 1.0 

3. A surface water is in compliance with meets the water quality standard for dissolved oxygen if the 

percent saturation of dissolved oxygen is equal to or greater than 90% percent. 

F.E. Nutrient criteria. The following water quality standards for total phosphorus and total nitrogen, are expressed 

in milligrams per liter (mg/L), shall not be exceeded:. A minimum of 10 samples, each taken at least 10 days 
 

253

apart in a consecutive 12-month period, are required to determine a 90th percentile. Not more than 10 

percent of the samples may exceed the 90th percentile value listed below:

 Annual 

Mean

90th 

percentile

Single 

Sample 

Maximum

1. Verde River and its tributaries from headwaters to Bartlett 

Lake:

Total phosphorus

Total nitrogen

0.10

1.00

0.30

1.50

1.00

3.00

2. Black River, Tonto Creek, and their tributaries that are not 

located on tribal lands:

Total phosphorus

Total nitrogen

0.10

0.50

0.20

1.00

0.80

2.00

3. Salt River and its tributaries that are not located on tribal 

lands but not Pinal Creek above Theodore Roosevelt Lake:

Total phosphorus

Total nitrogen

0.12

0.60

0.30

1.20

1.00

2.00

4. Theodore Roosevelt, Apache, Canyon, and Saguaro Lakes: Total phosphorus

Total nitrogen

0.03 5

0.30 5

NNS

NNS

0.60 6

1.00 6

5. Salt River below Stewart Mountain Dam to confluence with 

the Verde River:

Total phosphorus

Total nitrogen

0.05

0.60

NNS

NNS

0.20

3.00

6. Little Colorado River and its tributaries above River 

Reservoir in Greer, South Fork of Little Colorado River 

above South Fork Campground, Water Canyon Creek above 

Apache-Sitgreaves National Forest boundary:

Total phosphorus

Total nitrogen

0.08

0.60

0.10

0.75

0.75

1.10

7. Little Colorado River at the crossing of Apache County Road 

No. 124:

Total phosphorus

Total nitrogen

NNS

NNS

NNS

NNS

0.75

1.80

8. Little Colorado River above Lyman Lake to above the Amity 

Ditch diversion near crossing of Arizona Highway 273 

(applies only when in-stream turbidity is less than 50 NTU):

Total phosphorus

Total nitrogen

0.20

0.70

0.30

1.20

0.75

1.50

9. Colorado River, at Northern International Boundary near 

Morelos Dam:

Total phosphorus

Total nitrogen

NNS

NNS

0.33

2.50

NNS

NNS

10. San Pedro River, from Curtis to Benson: Total phosphorus

Total nitrate as N

NNS

NNS

NNS

NNS

NNS

10.00

11. The discharge of wastewater to Show Low Creek and tributaries upstream of and including Fools Hollow 

Lake shall not exceed 0.16 mg/L total phosphates as P.

12. The discharge of wastewater to the San Francisco River and tributaries upstream of Luna Lake Dam shall 

not exceed 1.0 mg/L total phosphates as P.

Surface Water

Annual 

Mean

90th 

Percentile

Single Sample 

Maximum

1. Verde River and its tributaries from the Verde headwaters to Bartlett Lake
 

254

Total phosphorus

Total nitrogen

0.10

1.00

0.30

1.50

1.00

3.00

2. Black River, Tonto Creek, and their tributaries that are not located on tribal lands:

Total phosphorus

Total nitrogen

0.10

0.50

0.20

1.00

0.80

2.00

3. Salt River and its tributaries above Roosevelt Reservoir, excluding Pinal Creek,

that are not located on tribal lands:

Total phosphorus

Total nitrogen

0.12

0.60

0.30

1.20

1.00

2.00

4. Salt River below Stewart Mountain Dam to its confluence with the Verde River:

Total phosphorus

Total nitrogen

0.05

0.60

0.20

3.00

5. Little Colorado River and its tributaries above River Reservoir in Greer; South 

Fork of Little Colorado River above South Fork Campground; and Water Canyon 

Creek above Apache-Sitgreaves National Forest boundary:

Total phosphorus

Total nitrogen

0.08

0.60

0.10

0.75

0.75

1.10

6. Little Colorado River at the crossing of Apache County Road No. 124:

Total phosphorus

Total nitrogen 0.751.80

7. Little Colorado River above Lyman Lake to above the Amity Ditch diversion 

near crossing of Arizona Highway 273 (applies only when in-stream turbidity is 

less than 50 NTU):

Total phosphorus

Total nitrogen

0.20

0.70

0.30

1.20

0.75

1.50

8. Colorado River at the Northern International Boundary near Morelos Dam:

Total phosphorus

Total nitrogen

0.33

2.50

9. Oak Creek from its headwaters at 35°01'30"/111°44'12" to its confluence with 

the Verde River at 34°40'41"/111°56'30" and the West Fork of Oak Creek from 

its headwaters at 35°02'44"/111°54'48" to its confluence with Oak Creek at 

34°59'14"/111°44'46".

Total phosphorus

Total nitrogen

1.00

0.10

1.50

0.25

2.50

0.30

10. No discharge of wastewater to Show Low Creek or its tributaries upstream of and 

including Fools Hollow Lake shall exceed 0.16 mg/L total phosphates as P.

11. No discharge of wastewater to the San Francisco River or its tributaries upstream 
 

255

of Luna Lake Dam shall exceed 1.0 mg/L total phosphates as P.

G. The following water quality standards for radiochemicals shall not be exceeded in surface waters with the 

domestic water source designated use:

1. The concentration of gross alpha particle activity, including radium-226, but excluding radon and 

uranium, shall not exceed 15 picocuries per liter of water.

2. The concentration of combined radium-226 and radium-228 shall not exceed five picocuries per liter 

of water.

3. The concentration of strontium-90 shall not exceed 8 eight picocuries per liter of water.

4. The concentration of tritium shall not exceed 20,000 picocuries per liter of water.

5. The average annual concentration of beta particle activity and photon emitters from manmade 

radionuclides shall not produce an annual dose equivalent to the total body or any internal organ 

greater than four millirems per year.

Footnotes: 

1

 Includes A&Wc, A&Ww, A&Wedw, and A&We. 

2

 Does not apply to Cholla Lake.

3

 Does not apply to a wastewater treatment plant discharge to a dry watercourse that creates an effluentdependent water or to a stormwater discharge.

4 2

 The dissolved oxygen water quality standard for a lake shall apply applies below the water surface but not 

at a depth greater than one meter. 

5 Means the annual mean of representative composite samples taken from the surface and at two and five 

meter depths.

6 Means the maximum for any set of representative composite samples taken from the surface and at two 

and five meter depths.

R18-11-110. Salinity Standards for the Colorado River 

A. The flow-weighted average annual salinity in the lower main stem of the Colorado River shall be maintained 

at or below not exceed the following concentrations criteria: 

Location Total Dissolved Solids 

Below Hoover Dam 723 mg/L 

Below Parker Dam 747 mg/L 

At Imperial Dam 879 mg/L 

B. To preserve the basin-wide approach to salinity control developed by the Colorado River Basin states and to 

ensure compliance with the numeric criteria for salinity in subsection (A), the Department adopts the The

plan of implementation contained in the “1999 2005 Review, Water Quality Standards for Salinity, Colorado 

River System,” approved October 2005, Colorado River Basin Salinity Control Forum, 106 West 500 South, 

Suite 101, Bountiful, Utah 84010-6232 (June, 1999), which is incorporated by reference and on file with the 

Office of the Secretary of State and the Department is incorporated by reference to preserve the basin-wide 
 

256

approach to salinity control developed by the Colorado River Basin Salinity Control Forum and to ensure 

compliance with the numeric criteria for salinity in subsection (A). This incorporation by reference contains 

no future editions or amendments. This material does not include any later amendments or editions of the 

incorporated material. Copies of the incorporated material are available for inspection at the Arizona

Department of Environmental Quality, 1110 W. Washington Street, Phoenix, Arizona 85007 or may be 

obtained from the Colorado River Basin Salinity Control Forum, 106 West 500 South, Suite 101, Bountiful, 

Utah 84010-6232.

R18-11-111. Analytical Methods 

A. A person conducting an analysis of a sample taken to determine compliance with a water quality standard 

shall use an approved analytical method prescribed in 9 A.A.C. 14, Article 6 A.A.C. R9-14-610, 40 CFR 

136.3, or an alternative analytical method that is approved by the Director of the Arizona Department of 

Health Services under R9-16-610(B) A.A.C. R9-14-610(C). 

B. A test result from a sample taken to determine compliance with a water quality standard is valid only if the 

sample is analyzed by a laboratory that is licensed by the Arizona Department of Health Services, an out-ofstate laboratory licensed under A.R.S. § 36-495.14, or a laboratory exempted under A.R.S. § 36-495.02, for 

the analysis performed. 

R18-11-112. Unique Outstanding Arizona Waters

A. The Director shall classify a surface water as a unique water an outstanding Arizona water (OAW) by rule. 

The Director shall consider nominations to classify a surface water as a unique water during the triennial 

review of water quality standards for surface waters.

B. The Director may adopt, by rule under R18-11-115, a site-specific water quality standards standard to 

maintain and protect existing water quality in a unique water an OAW. 

C. Any person may nominate a surface water for classification as a unique water an OAW by filing a 

nomination with the Department Director. The nomination to classify a surface water as a unique water shall 

include: 

1. A map and a description of the surface water; 

2. A written statement in support of the nomination, including specific reference to the applicable 

criteria for unique water an OAW classification prescribed in subsection (D); 

3. Supporting evidence demonstrating that the applicable unique water criteria prescribed in subsection 

(D) are met; and 

4. Available water quality data relevant to establishing the baseline water quality of the proposed unique 

water OAW. 

D. The Director may classify a surface water as a unique water upon finding that the surface water is an 

outstanding state resource water an OAW based upon the following criteria: 

1. The surface water is a perennial or intermittent water; 
 

257

2. The surface water is in a free-flowing condition. For purposes of this subsection, “in a free-flowing 

condition” means that a surface water does not have an impoundment, diversion, channelization, riprapping or other bank armor, or another hydrological modification within the reach nominated for a 

unique water an OAW classification; 

3. The surface water has good water quality. For purposes of this subsection, “good water quality” 

means that the surface water has water quality that meets or exceeds is better than applicable surface 

water quality standards. A surface water that is listed as impaired under § 303(d) of the Clean Water 

Act (33 U.S.C. § 1313) A.A.C. R18-11-604(E) is ineligible for unique waters OAW classification; 

and 

4. The surface water meets one or both of the following conditions: 

a. The surface water is of exceptional recreational or ecological significance because of its 

unique attributes, including but not limited to, attributes related to such as the geology, flora,

and fauna, water quality, aesthetic values value, or the wilderness characteristics characteristic

of the surface water.;

b. Threatened or endangered species are known to be An endangered or threatened species is

associated with the surface water and the existing water quality is essential to the species’

maintenance and propagation of a threatened or endangered species or the surface water 

provides critical habitat for a the threatened or endangered species. Endangered or An 

endangered or threatened species are is identified in “Endangered and Threatened Wildlife 

and Plants,” 50 CFR § 17.11 (revised 2005), and § “Endangered and Threatened Plants,” 50 

CFR 17.12 (revised as of October 1, 2000 2005). which This material is incorporated by 

reference and on file with the Department and the Office of the Secretary of State. This 

incorporation by reference contains no future editions or amendments. and does not include 

any later amendments or editions of the incorporated material. Copies of the incorporated 

material are available for inspection at the Arizona Department of Environmental Quality, 

1110 W. Washington Street, Phoenix, Arizona 85007 or may be obtained from the National 

Archives and Records Administration at http://www.access.gpo.gov/nara/cfr/cfr-tablesearch.html#page1.

E. The Director shall hold at least one public meeting in the local area of a surface water that is nominated for 

classification as an OAW to solicit public comment on the nomination.

F. The Director shall consider the following factors when deciding whether to classify a surface water as an 

OAW:

1. Whether there is the ability to manage the surface water and its watershed to maintain and protect 

existing water quality;

2. The social and economic impact of Tier 3 antidegradation protection;

3. The public comments in support of, or in opposition to, an OAW classification;

4. The timing of the nomination relative to the triennial review of surface water quality standards;
 

258

5. The consistency of an OAW classification with applicable water quality management plans; and

6. Whether the nominated surface water is located within a national or state park, national monument, 

national recreation area, wilderness area, riparian conservation area, area of critical environmental 

concern, or it has another special use designation (for example, Wild and Scenic River).

E.G. The following surface waters are classified as unique water OAWs: 

1. The West Fork of the Little Colorado River, above from its headwaters at 33°55'02"/109°33'30" to 

Government Springs at 33°59'33"/109°27'54" (approximately 9.1 river miles); 

2. Oak Creek, including the West Fork of Oak Creek from its headwaters at 35°01'30"/111°44'12" to its 

confluence with the Verde River at 34°40'41"/111°56'30 (approximately 50.3 river miles); 

3. West Fork of Oak Creek, from its headwaters at 35°02'44"/111°54'48" to its confluence with Oak 

Creek at 34°59'14"/111°44'46" (approximately 15.8 river miles);

3.4. Peoples Peeples Canyon Creek, tributary to the Santa Maria River from its headwaters at 

34°23'57"/113°19'45" to its confluence with the Santa Maria River at 34°20'36"/113°15'12" 

(approximately 8.1 river miles); 

4.5. Burro Creek, above its confluence with Boulder Creek from its headwaters at 

34°52'46.5"/113°05'13.5" to its confluence with Boulder Creek at 34°374.5"/113°18'36" 

(approximately 29.5 miles); 

5.6. Francis Creek, in Mohave and Yavapai counties from its headwaters at 34°54'38"/113°20'30" to its 

confluence with Burro Creek at 34°44'29"/113°14'37" (approximately 22.9 river miles); 

6.7. Bonita Creek, tributary to the upper Gila River from its boundary of the San Carlos Indian 

Reservation at 33°03'08"/109°33'41" to its confluence with the Gila River at 32°53'36"/109°28'43"

(approximately 14.7 river miles); 

7.8. Cienega Creek, from its confluence with Gardner Canyon and Spring Water Canyon at R18E T17S

31°47'38.5"/110°35'21.5" to the USGS gaging station at 32°02'09"/110°40'34", in Pima County

(approximately 28.3 river miles); 

8.9. Aravaipa Creek, from its confluence with Stowe Gulch at 32°52'10"/110°22'03" to the downstream 

boundary of the Aravaipa Canyon Wilderness Area at 32°54'23"/110°33'42" (approximately 15.5 

river miles); 

9.10. Cave Creek and the South Fork of Cave Creek (Chircahua Mountains), from the its headwaters at 

31°50'30"/109°17'04.5" to the Coronado National Forest boundary at 31°54'38"/109°08'40" 

(approximately 10.4 river miles); 

11. South Fork of Cave Creek, from its headwaters at 31°50'20"/109°16'33" to its confluence with Cave 

Creek at 31°53'04"/109°10'30" (approximately 8.6 river miles);

10.12. Buehman Canyon Creek, from its headwaters (Lat. 32°24'55.5" N, Long. 110°39'43.5”W) at 

32°52'0.5"/110°39'54.5" to approximately 9.8 miles downstream (Lat. 32°24'31.5" N, Long. 

10°32'08" W) its confluence with unnamed tributary at 32°24'31.5"/110°32'08" (approximately 9.8 

river miles); 
 

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11.13. Lee Valley Creek, from its headwaters at 33°55'49"/109°31'34" to its confluence with Lee Valley 

Reservoir at 33°56'28"/109°30'15.5" (approximately 1.6 river miles); 

12.14. Bear Wallow Creek, from its headwaters at 33°35'54"/109°26'54.5" to the boundary of the San Carlos 

Indian Reservation at 33°37'52"/109°29'44" (approximately 4.25 river miles); 

13.15. North Fork of Bear Wallow Creek, from its headwaters at 33°34'47.5"/109°21'59.5" to its confluence 

with Bear Wallow Creek at 33°35'54"/109°26'54.5" (approximately 3.8 river miles); 

14.16. South Fork of Bear Wallow Creek, from its headwaters at 33°34'38.5"/109°23'58" to its confluence 

with Bear Wallow Creek at 33°35'54"/109°26'54.5" (approximately 3.8 river miles); 

15.17. Snake Creek, from its headwaters at 33°37'21.5"/109°26'11" to its confluence with the Black River at 

33°40'31.5"/109°28'58.5" (approximately 6.2 river miles); 

17.18. Hay Creek, from its headwaters at 33°51'00"/109°28'48" to its confluence with the West Fork of the 

Black River at 33°48'30"/109°25'19" (approximately 5.5 river miles); 

18.19. Stinky Creek, from the Fort White Mountain Apache Indian Reservation boundary at 

33°52'36.5"/109°29'45" to its confluence with the West Fork of the Black River at 

33°51'21.5"/109°27'09.5" (approximately 3.0 river miles); and

19.20. KP Creek, from its headwaters at 33°34'03"/109°21'19" to its confluence with the Blue River at 

33°31'44"/109°12'04.5" (approximately 12.7 river miles).;

21. Davidson Canyon, from the unnamed spring at 31°59'00"/110°38'46" to its confluence with Cienega 

Creek; and

22. Fossil Creek, from its headwaters at the confluence of Sandrock and Calf Pen Canyons above Fossil 

Springs at 34°26'48.7"/111°32'25" to its confluence with the Verde River at 34°18'21.8"/111°40'31.6" 

(approximately 17.2 river miles).

F. The Department shall hold at least one public meeting in the local area of a nominated unique water to solicit 

public comment on the nomination.

G. The Director may consider the following factors when making a decision whether to classify a nominated 

surface water as a unique water:

1. Whether there is the ability to manage the unique water and its watershed to maintain and protect 

existing water quality;

2. The social and economic impact of Tier 3 antidegradation protection;

3. The public comments in support or opposition to a unique waters classification;

4. The support or opposition of federal and state land management and natural resources agencies to a 

nomination;

5. Agency resource constraints;

6. The timing of the unique water nomination relative to the triennial review of surface water quality 

standards;

7. The consistency of a unique water classification with applicable water quality management plans (for 

example, § 208 water quality management plans); and
 

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8. Whether the nominated surface water is located within a national or state park, national monument, 

national recreation area, wilderness area, riparian conservation area, area of critical environmental 

concern, or it has another special use designation (for example, Wild and Scenic River designation).

H. The following water quality standards apply to the listed unique waters. Water quality standards prescribed 

in this subsection supplement the water quality standards prescribed by this Article.

1. The West Fork of the Little Colorado River, above Government Springs:

 Parameter Standard

 pH (standard units) No change due to discharge

 Temperature No increase due to discharge

 Dissolved oxygen No decrease due to discharge

 Total dissolved solids No increase due to discharge

 Chromium (as Cr)(D) 10 μg / L

2. Oak Creek, including the West Fork of Oak:

 Parameter Standard

 pH (standard units) No change due to discharge

 Nitrogen (T) 1.00 mg / L (annual mean)

 1.50 mg / L (90th percentile)

 2.50 mg / L (single sample max.)

 Phosphorus (T) 0.10 mg / L (annual mean)

 0.25 mg / L (90th percentile)

 0.30 mg / L (single sample max.) 

 Chromium (as Cr) (D) 5 μg / L

 Turbidity change due to discharge 3 NTUs

3. Peoples Canyon Creek, tributary to the Santa Maria:

 Parameter Standard

 Temperature No increase due to discharge

 Dissolved oxygen No decrease due to discharge

 Turbidity change due to discharge 5 NTUs

 Arsenic (T) 20 μg / L

 Manganese (T) 500 μg / L

4. Burro Creek, above its confluence with Boulder Creek:

 Parameter Standard

 Manganese (T) 500 μg / L

5. Francis Creek, in Mohave and Yavapai counties:

 Parameter Standard

 Manganese (T) 500 μg / L

6. Cienega Creek, from its confluence with Gardner Canyon and Spring Water Canyon 
 

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at R18E T17S to Del Lago Dam, in Pima County:

 Parameter Standard

 pH No change due to discharge

 Temperature No increase due to discharge

 Dissolved oxygen No decrease due to discharge

 Total dissolved solids No increase due to discharge

 Turbidity 10 NTUs

75. Bonita Creek, tributary to the Upper Gila River:

 Parameter Standard

 pH No change due to discharge

 Temperature No increase due to discharge

 Dissolved oxygen No decrease due to discharge

 Total dissolved solids No increase due to discharge

 Turbidity 15 NTUs

Abbreviations:

“(D)” means dissolved fraction

“(T)” means total recoverable

“NTUs” means nephelometric turbidity units

“mg / L” means milligrams per liter

“μg / L” means micrograms per liter

H. The designation of Fossil Creek as an OAW under subsection (G)(22) takes effect on June 30, 2010.

R18-11-113. Effluent-dependent Effluent-Dependent Waters 

A. The Director shall classify a surface water as an effluent-dependent water by rule. 

B. The Director may adopt, by rule, under R18-11-115, a site-specific water quality standards standard for an 

effluent-dependent water. 

C. Any person may submit a petition for rule adoption requesting that the Director classify a surface water as an 

effluent-dependent water. The petition for rule adoption shall include: 

1. A map and a description of the surface water,;

2. Information that demonstrates that the surface water consists of discharges of treated wastewater a 

point source discharge of wastewater; and 

3. Information that demonstrates that, without a point source discharge of a wastewater, the receiving 

water is an ephemeral water in the absence of the discharge of treated wastewater. 

D. The following surface waters are classified as effluent-dependent waters:

1. In the Colorado River Main Stem Basin:

a. Bright Angel Wash from the South Rim Grand Canyon WWTP outfall to its confluence with 

Coconino Wash,
 

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b. Cataract Creek from the Williams WWTP outfall to one kilometer downstream from the 

outfall,

c. Holy Moses Wash from the Kingman WWTP outfall to three kilometers downstream from the 

outfall, and

d. Transept Canyon from the North Rim Grand Canyon WWTP outfall to one kilometer 

downstream from the outfall.

2. In the Little Colorado River Basin:

a. Dry Lake,

b. Lake Humphreys,

c. Lower Walnut Canyon Lake,

d. Ned Lake,

e. Pintail Lake,

f. Telephone Lake,

g. Rio de Flag from the City of Flagstaff WWTP outfall to its confluence with San Francisco 

Wash, and

h. Whale Lake.

3. In the Middle Gila River Basin:

a. Unnamed wash from the Town of Prescott Valley WWTP outfall to its confluence with the 

Agua Fria River, and the Agua Fria River below its confluence with the unnamed wash 

receiving treated wastewater from the Prescott Valley WWTP to State Route 169;

b. Agua Fria river from the El Mirage WWTP outfall to two kilometers downstream from the 

outfall;

c. Gila River from the Florence WWTP outfall to Felix Road,

d. Gila River from its confluence with the Salt River to Gillespie Dam; 

e. Queen Creek from the Town of Superior WWTP outfall to its confluence with Potts Canyon;

f. Unnamed wash from the Gila Bend WWTP outfall to its confluence with the Gila River;

g. Unnamed wash from the Luke AFB WWTP outfall to its confluence with the Agua Fria 

River; and

h. Unnamed wash from the Queen Valley WWTP outfall to its confluence with Queen Creek.

4. In the Rios de Mexico Basin:

a. Mule Gulch, from the Bisbee WWTP outfall to the Highway 80 bridge, and

b. Unnamed wash from the Bisbee-Douglas International Airport WWTP outfall to Whitewater 

Draw.

5. In the Salt River Basin:

a. Unnamed wash from the Globe WWTP outfall to its confluence with Pinal Creek and Pinal 

Creek from its confluence with the unnamed wash to Radium, and

b. Salt River from the 23rd Avenue WWTP outfall to its confluence with the Gila River.
 

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6. In the San Pedro River Basin:

a. Unnamed wash from the Mt. Lemmon WWTP outfall to 0.25 kilometers downstream, and

b. Walnut Gulch from the Tombstone WWTP outfall to its confluence with Tombstone Gulch.

7. In the Santa Cruz Basin:

a. Santa Cruz River from the Nogales International WWTP outfall to Tubac Bridge,

b. Santa Cruz River from the Roger Road WWTP outfall to Baumgartner Road crossing,

c. Unnamed wash from the Oracle WWTP outfall to five kilometers downstream, and

d. Sonoita Creek from the Town of Patagonia WWTP outfall to 750 feet downstream.

8. In the Upper Gila River Basin:

a. Bennett Wash from the Arizona Department of Corrections-Safford WWTP outfall to the Gila 

River. and

b. Unnamed wash from the Arizona Department of Corrections-Globe WWTP outfall to the 

boundary of the San Carlos Indian Reservation.

9. In the Verde River Basin:

a. American Gulch from the Northern Gila County Sanitary District WWTP outfall to the East 

Verde River,

b. Bitter Creek from the Jerome WWTP outfall to 2.5 kilometers downstream from the outfall, 

and

c. Jacks Canyon Wash from the Big Park WWTP outfall to its confluence with Dry Beaver 

Creek.

10. In the Willcox Playa Basin: Lake Cochise

E.D. The NPDES permit issuing authority Director shall use the water quality standards that apply to an effluentdependent water to derive discharge limitations water quality-based effluent limits for a point source 

discharge from a wastewater treatment plant of wastewater to an ephemeral water that changes that 

ephemeral water into an effluent-dependent water. 

E. The Director may use aquatic and wildlife (edw) acute standards only to derive water quality based effluent 

limits for a sporadic, infrequent, or emergency point source discharge to an ephemeral water or to an

effluent-dependent water. The Director shall consider the following factors when deciding whether to apply 

A&Wedw (acute) standards:

1. The amount, frequency, and duration of the discharge,

2. The length of time water may be present in the receiving water,

3. The distance to a downstream water with aquatic and wildlife chronic standards, and

4. The likelihood of chronic exposure to pollutants.

F. The Director may establish alternative water quality-based effluent limits in an AZPDES permit based on 

seasonal differences in the discharge.
 

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F. The site-specific standard of 36 μg / L for dissolved copper for the aquatic and wildlife (effluent-dependent 

water) designated use applies to the Rio de Flag from the City of Flagstaff WWTP outfall to its confluence 

with the San Francisco Wash.

R18-11-114. Mixing Zones 

A. The Director may establish a mixing zone for a point source discharge to a surface water as a condition of a 

NPDES an AZPDES permit. Mixing zones are A mixing zone is prohibited in an ephemeral waters water or 

where there is no water for dilution. 

B. The owner or operator of a point source seeking the establishment of a mixing zone shall submit a mixing 

zone application to the Department on a standard form that is available from the Department request to the 

Director for a mixing zone as part of an application for an AZPDES permit. The application request shall 

include: 

1. Identification An identification of the pollutant for which the mixing zone is requested; 

2. A proposed outfall design; 

3. A definition of the boundary of the proposed mixing zone. For purposes of this subsection, the 

boundary of a mixing zone means the location where the concentration of treated wastewater across a 

transect of the surface water differs by less than 5% percent; and 

4. A complete and detailed description of the existing physical, biological, and chemical conditions of 

the receiving water and the predicted impact of the proposed mixing zone on those conditions. 

C. The Department Director shall review the application request for a mixing zone to determine whether the 

application written request is complete. If the application request is incomplete, the Department Director

shall identify in writing provide the applicant with a list of the additional information required that must be 

submitted to the Department to complete the mixing zone application. 

D. The Director shall consider the following factors when deciding whether to grant or deny a request for a 

mixing zone: 

1. The assimilative capacity of the receiving water; 

2. The likelihood of adverse human health effects; 

3. The location of drinking water plant intakes and public swimming areas; 

4. The predicted exposure of biota and the likelihood that resident biota will be adversely affected; 

5. Bioaccumulation and bioconcentration; 

6. Whether there will be acute toxicity in the mixing zone, and, if so, the size of the area of acute 

toxicity zone of initial dilution; 

7. The known or predicted safe exposure levels for the pollutant of concern for which the mixing zone is 

requested; 

8. The size of the mixing zone; 

9. The location of the mixing zone relative to biologically sensitive areas in the surface water; 

10. The concentration gradient of the pollutant within the mixing zone; 
 

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11. Sediment deposition; 

12. The potential for attracting aquatic life to the mixing zone; and 

13. The cumulative impacts of other mixing zones and other discharges to the surface water. 

E. Director determination.

1. The Director shall deny the a request to establish a mixing zone if a water quality standards standard

will be violated outside the boundaries of the proposed mixing zone will be violated. The Director 

shall notify the owner or operator of the denial of a request for a mixing zone shall be in writing and 

shall state the reason for the denial. 

2. If the Director determines that approves the request to establish a mixing zone should be established, 

the Director shall establish the mixing zone as a condition of a NPDES an AZPDES permit. The 

Director may shall include any mixing zone conditions condition in the AZPDES permit that the 

Director deems is necessary to protect human health and the designated uses of the surface water. 

F. Any person who is adversely affected by the Director’s decision to grant or deny a request for a mixing zone 

may appeal the decision to an administrative law judge under A.R.S. § 49-321 et seq. and A.R.S. § 41-1092 

et seq. 

G. The Department Director shall reevaluate a mixing zone upon issuance, reissuance, or modification of the 

National Pollutant Discharge Elimination System AZPDES permit for the point source or a modification of 

the outfall structure. 

H. The length of a mixing zone shall not exceed 500 meters in a stream. The total horizontal area allocated to all 

mixing zones on a lake shall not exceed 10% of the surface area of the lake. Adjacent mixing zones in a lake 

shall be no closer than the greatest horizontal dimension of any individual mixing zone.

I. A mixing zone shall provide for a zone of passage of not less than 50% of the cross-sectional area of a river 

or stream.

J. The discharge outfall shall be designed to maximize initial dilution of the treated wastewater in a surface 

water.

H. Mixing zone requirements.

1. The length of a mixing zone shall not exceed 500 meters in a stream.

2. The total horizontal area allocated to all mixing zones on a lake shall not exceed 10 percent of the 

surface area of the lake.

3. Adjacent mixing zones in a lake shall not overlap or be located closer together than the greatest 

horizontal dimension of the largest mixing zone.

4. A mixing zone shall provide for a zone of passage of not less than 50 percent of the cross-sectional 

area of a river or stream.

5. The design of any discharge outfall shall maximize initial dilution of the wastewater in a surface 

water.

6. The size of the zone of initial dilution in a mixing zone shall prevent lethality to organisms passing 

through the zone of initial dilution.
 

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K. A mixing zone is prohibited The Director shall not establish a mixing zone in an AZPDES permit for the 

following persistent, bioaccumulative pollutants: 

1. Chlordane, 

2. DDT and its metabolites (DDD and DDE), 

3. Dieldrin, 

4. Dioxin, 

5. Endrin, 

6. Endrin aldehyde, 

7. Heptachlor, 

8. Heptachlor epoxide, 

9. Lindane, 

10. Mercury, 

11. Polychlorinated biphenyls (PCBs), and 

12. Toxaphene. 

R18-11-115. Repealed Site-Specific Standards

A. The Director shall adopt a site-specific standard by rule.

B. The Director may adopt a site-specific standard based upon a request or upon the Director’s initiative for any 

of the following reasons:

1. Local physical, chemical, or hydrological conditions of a surface water such as pH, hardness, or 

temperature alters the biological availability or toxicity of a pollutant;

2. The sensitivity of resident aquatic organisms that occur in a surface water to a pollutant differs from 

the sensitivity of the species used to derive the numeric water quality standards to protect aquatic life 

in Appendix A;

3. Resident aquatic organisms that occur in a surface water represent a narrower mix of species than 

those in the dataset used by the Department to derive numeric water quality standards to protect 

aquatic life in Appendix A; or

4. The natural background concentration of a pollutant is greater than the numeric water quality 

standard to protect aquatic life prescribed in Appendix A.

C. Site-specific study. A person shall conduct a study to support the development of a site-specific standard

using one of the following procedures:

1. The Recalculation Procedure, Appendix L, pages 90 - 98, Water Quality Standards Handbook, 

Second Edition, EPA 823-B-94-005b, August 1994. This material is incorporated by reference and 

does not include any later amendments or editions of the incorporated material. A copy of the 

incorporated material is available for inspection at the Arizona Department of Environmental Quality, 

1110 W. Washington, Phoenix, Arizona 85007 or: may be obtained from the U.S. Environmental 

Protection Agency, Office of Water at http://www.epa.gov/waterscience/standards/handbook/
 

267

handbookappxL.pdf.

2. Water-Effects Ratio for Metals, Appendix L, pages 1 - 89, Water Quality Standards Handbook, 

Second Edition, EPA 823-B-94-005b, August 1994. This material is incorporated by reference and 

does not include any later amendments or editions of the incorporated material. A copy of the 

incorporated material is available for inspection at the Arizona Department of Environmental Quality, 

1110 W. Washington, Phoenix, Arizona 85007 or: may be obtained from the U.S. Environmental 

Protection Agency, Office of Water at http://www.epa.gov/waterscience/standards/handbook/

handbookappxL.pdf.

3. Streamlined Water Effects Ratio Procedure for Discharges of Copper, EPA-822-R-01-005, March 

2001. This material is incorporated by reference and does not include any later amendments or 

editions of the incorporated material. A copy of the incorporated material is available for inspection 

at the Arizona Department of Environmental Quality, 1110 W. Washington, Phoenix, Arizona 85007 

or: may be obtained from the U.S. Environmental Protection Agency, Office of Water at 

http://www.epa.gov/ost/criteria/copper/copper.pdf.

4. Natural background.

a. A person seeking to develop a site-specific standard based on natural background shall provide 

a study outline to the Director and obtain the Director’s approval before conducting the study.

i. The person may use statistical or modeling approaches to determine natural background 

concentration.

ii. Modeling approaches include Better Assessment Science Integrating Source and 

Nonpoint Sources (Basins), Hydrologic Simulation Program-Fortran (HSPF), and 

Hydrologic Engineering Center (HEC) programs developed by the U.S. Army Corps of 

Engineers.

b. The Director may establish a site-specific standard at a concentration equal to the natural 

background concentration.

c. For purposes of this subsection, “natural background” means the concentration of a pollutant in 

a surface water due only to non-anthropogenic sources.

R18-11-116. Resource management agencies Management Agencies

Nothing in this Article shall be construed to prohibit prohibits fisheries management activities by the Arizona Game 

and Fish Department or the U.S. Fish and Wildlife Service. This provision Article does not exempt fish hatcheries 

from National Pollutant Discharge Elimination System AZPDES permit requirements. 

R18-11-117. Canals and Municipal Urban Park Lakes 

A. Nothing in this Article shall be construed to prevent prevents the routine physical or mechanical maintenance 

of canals, drains, and the municipal park urban lakes identified in Appendix B. Physical or mechanical 

maintenance includes dewatering, lining, dredging, and the physical, biological, or chemical control of 
 

268

weeds and algae. Increases in turbidity that result from physical or mechanical maintenance activities are 

permitted in canals, drains, and the municipal park urban lakes identified in Appendix B. 

B. The discharge of lubricating oil that is associated with the start-up of well pumps which that discharge to 

canals is not a violation of R18-11-108(B). 

R18-11-118. Dams and Flood Control Structures 

A. Increases in turbidity that result from the routine physical or mechanical maintenance of a dam or flood 

control structure are not violations of this Article. 

B. Nothing in this Article shall be construed to require requires the release of water from a dam or a flood 

control structure. 

R18-11-121. Schedules of Compliance 

A. A The Director may establish a schedule in an AZPDES permit to bring an existing point source into 

compliance with a new or revised water quality standard may be established in a National Pollutant 

Discharge Elimination System permit for an existing point source. A compliance schedule in an AZPDES 

permit for an existing point source, other than a storm water stormwater discharge, shall require compliance

the permittee to comply with a discharge limitation based upon a new or revised water quality standard no 

later than three years after the effective date of the National Pollutant Discharge Elimination System

AZPDES permit. For a schedule of compliance to be granted, the owner or operator of the existing point 

source The permittee shall demonstrate that all requirements under § 301(b) and § 306 of the Clean Water 

Act [33 U.S.C. § 1311(b) and § 1316] have been are achieved and that the point source cannot comply with a 

discharge limitation based upon the new or revised water quality standard through the application of existing 

water pollution control technology, operational changes, or source reduction. 

B. A The Director may establish a schedule of compliance may be established in a National Pollutant Discharge 

Elimination System an AZPDES permit for a new point source. The first National Pollutant Discharge 

Elimination System AZPDES permit issued to a new point source may contain a schedule of compliance 

only when necessary to allow a reasonable opportunity the permittee to attain compliance with a new or 

revised water quality standard that becomes effective after commencement of construction but less than three 

years before commencement of the discharge begins. For purposes of this subsection, “commencement of 

construction” means that the owner or operator of the point source has obtained the federal, state, and local 

approvals or permits necessary to begin physical construction of the point source and either: 

1. Onsite physical construction has begun; or 

2. The owner or operator has entered into a contract for physical construction of the point source and the 

contract cannot be cancelled or modified without substantial loss. For purposes of this subsection, 

“substantial loss” means in excess of 10% percent of the total cost incurred for physical construction. 

C. A The Director may establish a schedule of compliance may be established in a National Pollutant Discharge 

Elimination System an AZPDES permit for a recommencing point source discharge. The first National 
 

269

Pollutant Discharge Elimination System AZPDES permit issued to a recommencing point source discharge

discharger may contain a schedule of compliance only when necessary to allow a reasonable opportunity to 

attain compliance with a new or revised water quality standard that becomes is effective less than three years 

before recommencement of the discharge. 

D. A The Director may establish a schedule to bring a point source discharge of storm water stormwater into 

compliance with a water quality standard may be established in a National Pollutant Discharge Elimination 

System an AZPDES permit. A compliance schedule for a storm water stormwater discharge shall require 

implementation of all reasonable and cost-effective best management practices to control the discharge of 

pollutants in storm water stormwater. 

R18-11-122. Variances 

A. The Director may grant shall consider a variance from a water quality standard for a point source discharge if 

the discharger demonstrates that treatment more advanced than that required to comply with technologybased effluent limitations is necessary to comply with the water quality standard and: 

1. It is not technically feasible to achieve compliance within the next five years, 

2. The cost of the treatment would result in substantial and widespread economic and social impact, or 

3. Human-caused conditions or sources of pollution prevent attainment of the water quality standard and 

cannot be remedied within the next five years.

B. A variance may be granted only on a pollutant-specific basis. A point source discharge is required to comply 

with all other applicable water quality standards for which a variance is not granted.

C. A variance applies only to a specific point source discharge. The granting of a variance does not modify a 

water quality standard. Other point source dischargers to the surface water shall comply with applicable 

water quality standards, including any water quality standard for which a variance has been granted for a 

specific point source discharge.

B. If the Director grants a variance for a point source discharge:

1. The Director shall issue the variance for a fixed term not to exceed five years,

2. The variance shall apply only on a pollutant-specific basis. The point source discharge shall meet all 

other applicable water quality standards for which a variance is not granted, and

3. The variance shall not modify a water quality standard. Other point source discharges to the surface 

water shall meet applicable water quality standards.

D.C. A variance is for a fixed term not to exceed five years. Upon expiration of a variance, a point source 

discharger shall either comply with the water quality standard or apply for renewal of the variance. To renew 

a variance, the applicant shall demonstrate reasonable progress towards compliance with the water quality 

standard during the term of the variance. 

E.D. The Department Director shall reevaluate a variance upon the issuance, reissuance, or modification of the 

National Pollutant Discharge Elimination System AZPDES permit for the point source discharge. 
 

270

F.E. A person who seeks a variance from a water quality standard shall submit a written request for a variance to 

the Department Director. A request for a variance shall include the following information: 

1. Identification of the specific pollutant and water quality standard for which a variance is sought; 

2. Identification of the receiving surface water; 

3. For an existing point source discharge, a detailed description of the existing discharge control 

technologies that are used to achieve compliance with applicable water quality standards. For a new 

point source discharge, a detailed description of the proposed discharge control technologies that will 

be used to achieve compliance with applicable water quality standards; 

4. Documentation that the existing or proposed discharge control technologies will comply with 

applicable technology-based effluent limitations and that more advanced treatment technology is 

necessary to achieve compliance with the water quality standard for which a variance is sought; 

5. A detailed discussion of the reasons why compliance with the water quality standard cannot be 

achieved; 

6. A detailed discussion of the discharge control technologies that are available for achieving 

compliance with the water quality standard for which a variance is sought; 

7. Documentation of one of the following: 

a. That it is not technically feasible to install and operate any of the available discharge control 

technologies to achieve compliance with the water quality standard for which a variance is 

sought, 

b. That installation and operation of each of the available discharge technologies to achieve 

compliance with the water quality standard would result in substantial and widespread 

economic and social impact, or 

c. That human-caused conditions or sources of pollution prevent the attainment of the water 

quality standard for which the variance is sought and it is not possible to remedy the 

conditions or sources of pollution within the next five years;

8. Documentation that the point source discharger has reduced, to the maximum extent practicable, the 

discharge of the pollutant for which a variance is sought through implementation of a local 

pretreatment, source reduction, or waste minimization program,; and 

9. A detailed description of proposed interim discharge limitations that represent the highest level of 

treatment achievable by the point source discharger during the term of the variance. Interim 

discharge limitations shall not be less stringent than technology-based effluent limitations.

G.F. In making a decision on whether to grant or deny the request for a variance, the The Director shall consider 

the following factors when deciding whether to grant or deny a variance request: 

1. Bioaccumulation and bioconcentration, 

2. The predicted exposure of biota and the likelihood that resident biota will be adversely affected, 

3. The known or predicted safe exposure levels for the pollutant of concern for which the variance is 

requested, and 
 

271

4. The likelihood of adverse human health effects. 

H.G. The Department Director shall issue a public notice and shall provide an opportunity for a public hearing on 

whether the request for a variance should be granted or denied under procedures prescribed in R18-1-401 

and R18-1-402 A.A.C. R18-9-A907 and A.A.C. R18-9-A908. An interested party may request a public 

hearing on a variance under A.A.C. R18-9-A908(B).

H. Any variance granted by the Director is subject to review and approval by the Regional Administrator.

I. Any person who is adversely affected by a decision of the Director to grant or deny a variance and who has 

exercised any right to comment on the decision may appeal the decision to an administrative law judge under 

A.R.S. § 49-321 et seq. and A.R.S. § 41-1092 et seq. 

J. The Department Director shall not grant a variance for a point source discharge to a unique water an OAW

listed in R18-11-112(G). 

K. A variance is subject to review and approval by the Regional Administrator of the U.S. Environmental 

Protection Agency.

R18-11-123. Prohibition Against Discharge Prohibitions

A. The discharge of treated wastewater to Sabino Creek is the following surface waters is prohibited.:

1. Sabino Canyon Creek;

2. Vekol Wash, upstream of the Ak-Chin Indian Reservation; and

3. Smith Wash, upstream of the Ak-Chin Indian Reservation.

B. The discharge to Lake Powell of human body wastes and the wastes from toilets and other receptacles 

intended to receive or retain those wastes on from a vessel to Lake Powell is prohibited. 
272 

Appendix A: Numeric Water Quality Criteria APPENDIX A. NUMERIC WATER QUALITY STANDARDS

Table 1. Human Health and Agricultural Designated Uses Water Quality Criteria By Designated Use

PARAMETER

CAS*

NUMBER

DWS

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

AgI

(μg/L)

AgL

(μg/L)

Acenaphthene 83-32-9 420 2670 84,000 84,000 NNS NNS

Acenaphthylene 208-96-8 NNS NNS NNS NNS NNS NNS

Acrolein 107-02-8 3.5 25 700 700 NNS NNS

Acrylonitrile 107-13-1 0.07 0.7 3 56,000 NNS NNS

Alachlor 15972-60-8 2 NNS 14,000 14,000 NNS NNS

Aldrin 309-00-2 0.002 0.0001 0.08 42 p p

Ammonia 7664-41-7 NNS NNS NNS NNS NNS NNS

Anthracene 120-12-7 2100 1000 420,000 420,000 NNS NNS

Antimony (as Sb) 7440-36-0 6 T 4,300 T 560 T 560 T NNS NNS

Arsenic (as As) 7440-38-2 50 T 1450 T 50 T 420 T 2000 T 200 T

Asbestos 1332-21-4 a NNS NNS NNS NNS NNS

Atrazine 1912-24-9 3 NNS 49,000 49,000 NNS NNS

Barium (as Ba) 7440-39-3 2000 T NNS 98,000 T 98,000 T NNS NNS

Benzene 71-43-2 5 140 93 93 NNS NNS

Benzidine 92-87-5 0.0002 0.001 0.01 4,200 0.01 0.01

Benz (a) anthracene 56-55-3 0.048 0.49 1.9 1.9 NNS NNS

Benzo (a) pyrene 50-32-8 0.2 0.05 0.2 0.2 NNS NNS

Benzo (ghi) perylene 191-24-2 NNS NNS NNS NNS NNS NNS

Benzo (k) fluoranthene 207-08-9 0.048 0.49 1.9 1.9 NNS NNS

3,4-Benzofluoranthene 205-99-2 0.048 0.49 1.9 1.9 NNS NNS

Beryllium (as Be) 7440-41-7 4 T 1,130 T 2,800 T 2,800 T NNS NNS

Bis (2-chloroethoxy) methane 111-91-1 NNS NNS NNS NNS NNS NNS

Bis (2-chloroethyl) ether 111-44-4 0.03 1.4 1.3 1.3 NNS NNS

Bis (2-chloroisopropyl) ether 108-60-1 280 174,400 56,000 56,000 NNS NNS

Boron (as B) 7440-42-8 630 T NNS 126,000 T 126,000 T 1000 T NNS

Bromodichloromethane 75-27-4 TTHM 46 TTHM 28,000 NNS NNS

p-Bromodiphenyl ether 101-55-3 NNS NNS NNS NNS NNS NNS

Bromoform 75-25-2 TTHM 360 180 28,000 NNS NNS

Bromomethane 74-83-9 9.8 4020 2000 2000 NNS NNS

Butyl benzyl phthalate 85-68-7 1400 5200 280,000 280,000 NNS NNS

Cadmium (as Cd) 7440-43-9 5 T 84 T 700 T 700 T 50 T 50 T

Carbofuran 1563-66-2 40 NNS 7,000 7,000 NNS NNS

Carbon tetrachloride 56-23-5 5 4 11 980 NNS NNS

Chlordane 57-74-9 2 0.002 4 700 NNS NNS

Chlorine (total residual) 7782-50-5 700 NNS 140,000 140,000 NNS NNS

Chlorobenzene 108-90-7 100 20,900 28,000 28,000 NNS NNS

p-Chloro-m-cresol 59-50-7 NNS NNS NNS NNS NNS NNS

2-Chloroethyl vinyl ether 110-75-8 NNS NNS NNS NNS NNS NNS
273 

Chloroform 67-66-3 TTHM 470 230 14,000 NNS NNS

Chloromethane 74-87-3 NNS NNS NNS NNS NNS NNS

Chloronapthalene beta 91-58-7 560 4,300 112,000 112,000 NNS NNS

2-Chlorophenol 95-57-8 35 400 7,000 7,000 NNS NNS

4-Chlorophenyl phenyl ether 7005-72-3 NNS NNS NNS NNS NNS NNS

Chromium (as Cr III) 16065-83-1 10,500 T 1,010,000 T

2,100,000 

T

2,100,000 

T

NNS NNS

Chromium (as Cr VI) 18540-29-9 21 T 2,000T 4,200 T 4,200 T NNS NNS

Chromium (Total as Cr) 7440-47-3 100 T NNS 100 T 100 T 1000 T 1000 T

Chrysene 218-01-9 0.479 4.92 19.2 19 NNS NNS

Copper (as Cu) 7440-50-8 1,300 T NNS 1,300 T 1,300 T 5000 T 500 T

Cyanide 57-12-5 200 T 215,000 T 28,000 T 28,000 T NNS 200 T

Dalapon 75-99-0 200 161,500 42,000 42,000 NNS NNS

Dibenz (ah) anthracene 53-70-3 0.048 0.20 1.9 1.9 NNS NNS

Dibromochloromethane 124-48-1 TTHM 34 TTHM 28,000 NNS NNS

1,2-Dibromo-3-chloropropane 

(DBCP)

96-12-8 0.2 NNS 2,800 2,800 NNS NNS

1,2-Dibromoethane (EDB) 106-93-4 0.05 NNS 0.05 0.05 NNS NNS

Dibutyl phthalate 84-74-2 700 12,100 140,000 140,000 NNS NNS

1,2-Dichlorobenzene 95-50-1 600 2800 126,000 126,000 NNS NNS

1,3-Dichlorobenzene 541-73-1 NNS NNS NNS NNS NNS NNS

1,4-Dichlorobenzene 106-46-7 75 77,500 560,000 560,000 NNS NNS

3,3'-Dichlorobenzidine 91-94-1 0.08 0.08 3.1 3.1 NNS NNS

p,p'-

Dichlorodiphenyldichloroethane 

(DDD)

72-54-8 0.15 0.001 5.8 5.8 0.001 0.001

p,p'-

Dichlorodiphenyldichloroethylene 

(DDE)

72-55-9 0.1 0.001 4.1 4.1 0.001 0.001

p,p'-

Dichlorodiphenyltrichloroethane 

(DDT)

50-29-3 0.1 0.0006 4.1 700 0.001 0.001

1,1-Dichloroethane 75-34-3 NNS NNS NNS NNS NNS NNS

1,2-Dichloroethane 107-06-2 5 100 15 280,000 NNS NNS

1,1-Dichloroethylene 75-35-4 7 320 230 12,600 NNS NNS

1,2-cis-Dichloroethylene 156-59-2 70 NNS 70 70 NNS NNS

1,2-trans-Dichloroethylene 156-60-5 100 136,000 28,000 28,000 NNS NNS

Dichloromethane 75-09-2 5 1600 190 84,000 NNS NNS

2,4-Dichlorophenol 120-83-2 21 800 4,200 4,200 NNS NNS

2,4-Dichlorophenoxyacetic acid 

(2,4-D)

94-75-7 70 NNS 14,000 14,000 NNS NNS

1,2-Dichloropropane 78-87-5 5 236,000 126,000 126,000 NNS NNS
274 

1,3-Dichloropropene 542-75-6 2 1,700 420 420 NNS NNS

Dieldrin 60-57-1 0.002 0.0001 0.09 70 p p

Diethyl phthalate 84-66-2 5600 118,000 1,120,000 1,120,000 NNS NNS

Di (2-ethylhexyl) adipate 103-23-1 400 NNS 1,200 840,000 NNS NNS

Di (2-ethylhexyl) phthalate 117-81-7 6 7.4 100 28,000 NNS NNS

2,4-Dimethylphenol 105-67-9 140 2300 28,000 28,000 NNS NNS

Dimethyl phthalate 131-11-3 NNS NNS NNS NNS NNS NNS

4,6-Dinitro-o-cresol 534-52-1 28 7,800 5,600 5,600 NNS NNS

2,4-Dinitrophenol 51-28-5 14 14,400 2,800 2,800 NNS NNS

2,4-Dinitrotoluene 121-14-2 14 5,700 2,800 2,800 NNS NNS

2,6-Dinitrotoluene 606-20-2 0.05 NNS 2 5,600 NNS NNS

Di-n-octyl phthalate 117-84-0 2800 NNS 560,000 560,000 NNS NNS

Dinoseb 88-85-7 7 NNS 1,400 1,400 NNS NNS

1,2-Diphenylhydrazine 122-66-7 0.04 0.5 1.8 1.8 NNS NNS

Diquat 85-00-7 20 NNS 3,080 3,080 NNS NNS

Endosulfan sulfate 1031-07-8 NNS NNS NNS NNS NNS NNS

Endosulfan (Total) 115-29-7 42 240 8,400 8,400 NNS NNS

Endothall 145-73-3 100 NNS 28,000 28,000 NNS NNS

Endrin 72-20-8 2 0.8 420 420 0.004 0.004

Endrin aldehyde 7421-93-3 NNS NNS NNS NNS NNS NNS

Ethylbenzene 100-41-4 700 28,700 140,000 140,000 NNS NNS

Ethyl chloride 75-00-3 NNS NNS NNS NNS NNS NNS

Fluoranthene 206-44-0 280 380 56,000 56,000 NNS NNS

Fluorene 86-73-7 280 14,400 56,000 56,000 NNS NNS

Fluoride 7782-41-4 4000 NNS 84,000 84,000 NNS NNS

Glyphosate 1071-83-6 700 1,077,000 140,000 140,000 NNS NNS

Heptachlor 76-44-8 0.4 0.0002 0.4 700 NNS NNS

Heptachlor epoxide 1024-57-3 0.2 0.0001 0.2 18 NNS NNS

Hexachlorobenzene 118-74-1 1 0.001 1 1,120 NNS NNS

Hexachlorobutadiene 87-68-3 0.45 50 18 280 NNS NNS

Hexachlorocyclohexane alpha 319-84-6 0.006 0.01 0.22 11,200 NNS NNS

Hexachlorocyclohexane beta 319-85-7 0.02 0.02 0.78 840 NNS NNS

Hexachlorocyclohexane delta 319-86-8 NNS NNS NNS NNS NNS NNS

Hexachlorocyclohexane gamma 

(lindane)

58-89-9 0.2 25 420 420 NNS NNS

Hexachlorocyclopentadiene 77-47-4 50 580 9,800 9,800 NNS NNS

Hexachloroethane 67-72-1 2.5 9 100 1,400 NNS NNS

Indeno (1,2,3-cd) pyrene 193-39-5 0.048 0.49 1.9 1.9 NNS NNS

Isophorone 78-59-1 37 2,600 1,500 280,000 NNS NNS

Lead (as Pb) 7439-97-1 15 T NNS 15 T 15 T

10000 

T

100 T

Manganese (as Mn) 7439-96-5 980 T NNS 196,000 T 196,000 T 10000 NNS
275 

Mercury (as Hg) 7439-97-6 2 T 0.6 T 420 T 420 T NNS 10 T

Methoxychlor 72-43-5 40 NNS 7,000 7,000 NNS NNS

Naphthalene 91-20-3 140 20,500 28,000 28,000 NNS NNS

Nickel (as Ni) 7440-02-0 140 T 4,600 T 28,000 T 28,000 T NNS NNS

Nitrate (as N) 14797-55-8 10000 NNS 2,240,000 2,240,000 NNS NNS

Nitrite (as N) 14797-65-0 1000 NNS 140,000 140,000 NNS NNS

Nitrate/Nitrite (as Total N) 10000 NNS NNS NNS NNS NNS

Nitrobenzene 98-95-3 3.5 1,900 700 700 NNS NNS

o-Nitrophenol 88-75-5 NNS NNS NNS NNS NNS NNS

p-Nitrophenol 100-02-7 NNS NNS NNS NNS NNS NNS

N-nitrosodimethylamine 62-75-9 0.001 8 0.03 0.03 NNS NNS

N-nitrosodiphenylamine 86-30-6 7.1 16 290 290 NNS NNS

N-nitrosodi-n-propylamine 621-64-7 0.005 1.4 0.2 133,000 NNS NNS

Oxamyl 23135-22-0 200 NNS 35,000 35,000 NNS NNS

Pentachlorophenol 87-86-5 1 1000 12 42,000 NNS NNS

Phenanthrene 85-01-8 NNS NNS NNS NNS NNS NNS

Phenol 108-95-2 4200 1,000 840,000 840,000 NNS NNS

Picloram 1918-02-1 500 24,300 98,000 98,000 NNS NNS

Polychlorinatedbiphenyls (PCBs) 1336-36-3 0.5 0.007 28 28 0.001 0.001

Pyrene 129-00-0 210 10,800 42,000 42,000 NNS NNS

Selenium (as Se) 7782-49-2 50 T 9000 T 7,000 T 7,000 T 20 T 50 T

Silver (as Ag) 7440-22-4 35 T 107,700 T 7,000 T 7,000 T NNS NNS

Simazine 112-34-9 4 NNS 7,000 7,000 NNS NNS

Styrene 100-42-5 100 NNS 280,000 280,000 NNS NNS

Sulfides NNS NNS NNS NNS NNS NNS

2,3,7,8-Tetrachlorodibenzo-pdioxin (2,3,7,8-TCDD)

1746-01-6 0.0000003 0.000000004 0.00009 1.4 NNS NNS

1,1,2,2-Tetrachloroethane 79-34-5 0.17 11 7 56,000 NNS NNS

Tetrachloroethylene 127-18-4 5 3,500 14,000 14,000 NNS NNS

Thallium (as Tl) 7440-28-0 2 T 7.2 T 112 T 112 T NNS NNS

Toluene 108-88-3 1000 201,000 280,000 280,000 NNS NNS

Toxaphene 8001-35-2 3 0.001 1.3 1400 0.005 0.005

1,2,4-Trichlorobenzene 120-82-1 70 950 14,000 14,000 NNS NNS

1,1,1-Trichloroethane 71-55-6 200 NNS 200 200 1000 NNS

1,1,2-Trichloroethane 79-00-5 5 42 25 5,600 NNS NNS

Trichloroethylene 79-01-6 5 203,200 280,000 280,000 NNS NNS

2,4,6-Trichlorophenol 88-06-2 3.2 6.5 130 130 NNS NNS

2-(2,4,5-Trichlorophenoxy) 

proprionic acid (2,4,5-TP)

93-72-1 50 NNS 11,200 11,200 NNS NNS

Trihalomethanes, Total 100 NNS NNS NNS NNS NNS

Uranium (as Ur) 7440-61-1 35 D NNS NNS NNS NNS NNS

Vinyl chloride 75-01-4 2 13 2 4,200 NNS NNS
276 

Xylenes (Total) 1330-20-7 10000 NNS 2,800,000 2,800,000 NNS NNS

Zinc (as Zn) 7440-66-6 2100 T 69,000 T 420,000 T 420,000 T

10000 

T

25000 

T
277 

PARAMETER

CAS 

NUMBER

DWS 

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

A&Wc

Acute 

(μg/L)

A&Wc 

Chronic 

(μg/L)

A&Ww 

Acute 

(μg/L)

A&Ww 

Chronic 

(μg/L)

A&Wedw 

Acute 

(μg/L)

A&W

Chro

(μg/

Acenaphthene 83329 420 198 56,000 56,000 850 550 850 550 850 550Acrolein 107028 3.5 1.9 467 467 34 30 34 30 34 30Acrylonitrile 107131 0.06 0.2 3 37,333 3,800 250 3,800 250 3,800 250Alachlor 15972608 2 9,333 9,333 2,500 170 2,500 170 2,500 170Aldrin 309002 0.002 0.00005 0.08 28 3 3 3 Alpha Particles (Gross) Radioactivity

15

pCi/L

Ammonia 7664417

See (e) &

Table 25

See (e) &

Table 26

See (e) &

Table 25

See (e) &

Table 26

See (e) &

Table 25

See (e

Table 

Anthracene 120127 2,100 74 280,000 280,000Antimony 7440360 6 T 640 T 747 T 747 T 88 D 30 D 88 D 30 D 1,000 D 600 Arsenic 7440382 10 T 80 T 30 T 280 T 340 D 150 D 340 D 150 D 340 D 150 Asbestos 1332214 See (a)Atrazine 1912249 3 32,667 32,667Barium 7440393 2,000 T 98,000 T 98,000 TBenz(a)anthracene 56553 0.005 0.02 0.2 0.2Benzene 71432 5 114 93 3,733 2,700 180 2,700 180 8,800 5603, 4 Benzofluoranthene 205992 0.005 0.02 1.9 1.9Benzidine 92875 0.0002 0.0002 0.01 2,800 1,300 89 1,300 89 1,300 89 Benzo(a)pyrene 50328 0.2 0.02 0.2 0.2Benzo(k)fluoranthene 207089 0.005 0.02 1.9 1.9Beryllium 7440417 4 T 84 T 1,867 T 1,867 TBeta particles and photon emitters

4 

millirems/

year

Bis(2-chloroethyl) ether 111444 0.03 0.5 1 1 120,000 6,700 120,000 6,700 120,000 6,70
278 

PARAMETER

CAS 

NUMBER

DWS 

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

A&Wc

Acute 

(μg/L)

A&Wc 

Chronic 

(μg/L)

A&Ww 

Acute 

(μg/L)

A&Ww 

Chronic 

(μg/L)

A&Wedw 

Acute 

(μg/L)

A&W

Chro

(μg/

Bis(2-chloroisopropyl) ether 108601 280 3,441 37,333 37,333Boron 7440428 1,400 T 186,667 T 186,667 T Bromodichloromethane 75274

TTHM

See (g)

17 18,667 18,667

p-Bromodiphenyl ether 101553 180 14 180 14 180 14Bromoform 75252

TTHM

See (g)

133 180 18,667 15,000 10,000 15,000 10,000 15,000 10,0

Bromomethane 74839 9.8 299 1,307 1,307 5,500 360 5,500 360 5,500 360Butyl benzyl phthalate 85687 1,400 386 186,667 186,667 1,700 130 1,700 130 1,700 130Cadmium 7440439 5 T 84 T 700 T 700 T

See (d) &

Table 2

See (d) &

Table 3

See (d) &

Table 4

See (d) &

Table 5

See (d) &

Table 4

See (d

Tabl

Carbofuran 1563662 40 4,667 4,667 650 50 650 50 650 50Carbon tetrachloride 56235 5 2 11 1,307 18,000 1,100 18,000 1,100 18,000 1,10Chlordane 57749 2 0.0008 4 467 2.4 0.004 2.4 0.2 2.4 0.2 Chlorine (total residual) 7782505 4,000 4,000 4,000 19 11 19 11 19 11Chlorobenzene 108907 100 1,553 18,667 18,667 3,800 260 3,800 260 3,800 2602-Chloroethyl vinyl ether 110758 180,000 9,800 180,000 9,800 180,000 9,80Chloroform 67663

TTHM

See (g)

2,133 9,333 9,333 14,000 900 14,000 900 14,000 900

p-Chloro-m-cresol 59507 15 4.7 15 4.7 15 4.7 Chloromethane 74873 270,000 15,000 270,000 15,000 270,000 15,02-Chloronapthalene 91587 560 317 74,667 74,6672-Chlorophenol 95578 35 30 4,667 4,667 2,200 150 2,200 150 2,200 150Chloropyrifos 2921882 21 2,800 2,800 0.08 0.04 0.08 0.04 0.08 0.0Chromium III 16065831 75,000 T

1,400,000

T

1,400,000

T

See (d) &

Table 7

See (d) &

Table 8

See (d) &

Table 7

See (d) &

Table 8

See (d) &

Table 7

See (d

Tabl

Chromium VI 18540299 21 T 150 T 2,800 T 2,800 T 16 D 11 D 16 D 11 D 16 D 11 D 
279 

PARAMETER

CAS 

NUMBER

DWS 

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

A&Wc

Acute 

(μg/L)

A&Wc 

Chronic 

(μg/L)

A&Ww 

Acute 

(μg/L)

A&Ww 

Chronic 

(μg/L)

A&Wedw 

Acute 

(μg/L)

A&W

Chro

(μg/

Chromium (Total) 7440473 100 T Chrysene 218019 0.005 0.02 19 19Copper 7440508 1,300 T 1,300 T 1,300 T

See (d) &

Table 10

See (d) &

Table 11

See (d) &

Table 10

See (d) &

Table 11

See (d) &

Table 10

See (d

Table 

Cyanide (as free cyanide) 57125 200 T 16,000 T 18,667 T 18,667 T 22 T 5.2 T 41 T 9.7 T 41 T 9.7 Dalapon 75990 200 8,000 28,000 28,000Dibenz (ah) anthracene 53703 0.005 0.02 1.9 1.9Dibromochloromethane 124481

TTHM

See (g)

13 18,667 18,667

1,2-Dibromo-3-chloropropane 96128 0.21,2-Dibromoethane 106934 0.05 8,400 8,400Dibutyl phthalate 84742 700 899 93,333 93,333 470 35 470 35 470 35 1,2-Dichlorobenzene 95501 600 205 84,000 84,000 790 300 1,200 470 1,200 470 1,3-Dichlorobenzene 541731 2,500 970 2,500 970 2,500 9701,4-Dichlorobenzene 106467 75 5,755 373,333 373,333 560 210 2,000 780 2,000 780 3,3'-Dichlorobenzidine 91941 0.08 0.03 3 3p,p'-Dichlorodiphenyltrichloroethane (DDT) and metabolites (DDD) and (DDE)

50293 0.1 0.0002 4 467 1.1 0.001 1.1 0.001 1.1 0.00

1,2-Dichloroethane 107062 5 37 15 186,667 59,000 41,000 59,000 41,000 59,000 41,01,1-Dichloroethylene 75354 7 7,143 46,667 46,667 15,000 950 15,000 950 15,000 9501,2-cis-Dichloroethylene 156592 70 70 701,2-trans-Dichloroethylene 156605 100 10,127 18,667 18,667 68,000 3,900 68,000 3,900 68,000 3,90Dichloromethane 75092 5 593 190 56,000 97,000 5,500 97,000 5,500 97,000 5,502,4-Dichlorophenol 120832 21 59 2,800 2,800 1,000 88 1,000 88 1,000 882,4-Dichlorophenoxyacetic acid 94757 70 9,333 9,333
280 

PARAMETER

CAS 

NUMBER

DWS 

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

A&Wc

Acute 

(μg/L)

A&Wc 

Chronic 

(μg/L)

A&Ww 

Acute 

(μg/L)

A&Ww 

Chronic 

(μg/L)

A&Wedw 

Acute 

(μg/L)

A&W

Chro

(μg/

(2,4-D)1,2-Dichloropropane 78875 5 17,518 84,000 84,000 26,000 9,200 26,000 9,200 26,000 9,201,3-Dichloropropene 542756 0.7 42 420 28,000 3,000 1,100 3,000 1,100 3,000 1,10Dieldrin 60571 0.002 0.00005 0.09 47 0.2 0.06 0.2 0.06 0.2 0.0Diethyl phthalate 84662 5,600 8,767 746,667 746,667 26,000 1,600 26,000 1,600 26,000 1,60Di (2-ethylhexyl) adipate 103231 400 560,000 560,000Di (2-ethylhexyl) phthalate 117817 6 3 1,200 18,667 400 360 400 360 400 360 2,4-Dimethylphenol 105679 140 171 18,667 18,667 1,000 310 1,000 310 1,000 310 Dimethyl phthalate 131113 17,000 1,000 17,000 1,000 17,000 1,004,6-Dinitro-o-cresol 534521 28 582 3,733 3,733 310 24 310 24 310 242,4-Dinitrophenol 51285 14 1,067 1,867 1,867 110 9.2 110 9.2 110 9.22,4-Dinitrotoluene 121142 14 421 1,867 1,867 14,000 860 14,000 860 14,000 8602,6-Dinitrotoluene 606202 0.05 2 3,733Di-n-octyl phthalate 117840 2,800 373,333 373,333Dinoseb 88857 7 933 9331,2-Diphenylhydrazine 122667 0.04 0.2 1.8 1.8 130 11 130 11 130 11Diquat 85007 20 2,053 2,053Endosulfan sulfate 1031078 42 18 5,600 5,600 0.2 0.06 0.2 0.06 0.2 0.0Endosulfan (Total) 115297 42 18 5,600 5,600 0.2 0.06 0.2 0.06 0.2 0.0Endothall 145733 100 18,667 18,667Endrin 72208 2 0.06 280 280 0.09 0.04 0.09 0.04 0.09 0.0Endrin aldehyde 7421933 0.09 0.04 0.09 0.04 0.09 0.0Ethylbenzene 100414 700 2,133 93,333 93,333 23,000 1,400 23,000 1,400 23,000 1,40Fluoranthene 206440 280 28 37,333 37,333 2,000 1,600 2,000 1,600 2,000 1,60Fluorene 86737 280 1,067 37,333 37,333Fluoride 7782414 4,000 140,000 140,000Glyphosate 1071836 700 266,667 93,333 93,333
281 

PARAMETER

CAS 

NUMBER

DWS 

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

A&Wc

Acute 

(μg/L)

A&Wc 

Chronic 

(μg/L)

A&Ww 

Acute 

(μg/L)

A&Ww 

Chronic 

(μg/L)

A&Wedw 

Acute 

(μg/L)

A&W

Chro

(μg/

Guthion 86500 0.01 0.01 0.0Heptachlor 76448 0.4 0.00008 0.4 467 0.5 0.004 0.5 0.004 0.6 0.0Heptachlor epoxide 1024573 0.2 0.00004 0.2 12 0.5 0.004 0.5 0.004 0.6 0.0Hexachlorobenzene 118741 1 0.0003 1 747 6 3.7 6 3.7 6 3.7Hexachlorobutadiene 87683 0.4 18 18 187 45 8.2 45 8.2 45 8.2Hexachlorocyclohexane alpha 319846 0.006 0.005 0.22 7,467 1,600 130 1,600 130 1,600 130 Hexachlorocyclohexane beta 319857 0.02 0.02 0.78 560 1,600 130 1,600 130 1,600 130 Hexachlorocyclohexane delta 319868 1,600 130 1,600 130 1,600 130 Hexachlorocyclohexane gamma (lindane)

58899 0.2 1.8 280 280 1 1 1 

Hexachlorocyclopentadiene 77474 50 74 11,200 11,200 3.5 0.3 3.5 0.3 3.5 0.3Hexachloroethane 67721 2.5 3.3 100 933 490 350 490 350 490 350 Hydrogen sulfide 7783064

2

See (c)

2

See (c)

2

See 

Indeno (1,2,3-cd) pyrene 193395 0.05 0.2 1.9 1.9Iron 7439896 1,000 D 1,000 D 1,000 Isophorone 78591 37 961 1,500 186,667 59,000 43,000 59,000 43,000 59,000 43,0Lead 7439971 15 T 15 T 15 T

See (d) &

Table 13

See (d) &

Table 14

See (d) &

Table 13

See (d) &

Table 14

See (d) &

Table 13

See (d

Table 

Malathion 121755 140 18,667 18,667 0.1 0.1 0.1Manganese 7439965 980 130,667 130,667 Mercury 7439976 2 T 280 T 280 T 2.4 D 0.01 D 2.4 D 0.01 D 2.4 D 0.01 Methoxychlor 72435 40 4,667 4,667 0.03 0.03 0.0Methylmercury 0.3 mg/kgMirex 2385855 1 187 187 0.001 0.001 0.00Naphthalene 91203 140 1,524 18,667 18,667 1,100 210 3,200 580 3,200 580Nickel 7440020 210 T 511 T 28,000 T 28,000 T See (d) & See (d) & See (d) & See (d) & See (d) & See (d
282 

PARAMETER

CAS 

NUMBER

DWS 

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

A&Wc

Acute 

(μg/L)

A&Wc 

Chronic 

(μg/L)

A&Ww 

Acute 

(μg/L)

A&Ww 

Chronic 

(μg/L)

A&Wedw 

Acute 

(μg/L)

A&W

Chro

(μg/

Table 16 Table 17 Table 16 Table 17 Table 16 Table 

Nitrate 14797558 10,000 3,733,333 3,733,333Nitrite 14797650 1,000 233,333 233,333Nitrate + Nitrite 10,000Nitrobenzene 98953 3.5 138 467 467 1,300 850 1,300 850 1,300 850p-Nitrophenol 100027 4,100 3,000 4,100 3,000 4,100 3,00N-nitrosodimethylamine 62759 0.001 3 0.03 0.03N-nitrosodi-n-phenylamine 86306 7.1 6 290 290 2,900 200 2,900 200 2,900 200N-nitrosodi-n-propylamine 621647 0.005 0.5 0.2 88,667Oxamyl 23135220 200 23,333 23,333Parathion 56382 0.07 0.01 0.07 0.01 0.07 0.0Paraquat 1910425 32 4,200 4,200 100 54 100 54 100 54Pentachlorophenol 87865 1 370 12 28,000

See (e) &

Table 22

See (e) &

Table 23

See (e) &

Table 22

See (e) &

Table 23

See (e) &

Table 22

See (e

Table 

Permethrin 52645531 350 46,667 46,667 0.3 0.2 0.3 0.2 0.3 0.2Phenanthrene 85018 30 6.3 30 6.3 30 6.3Phenol 108952 2,100 37 280,000 280,000 5,100 730 7,000 1,000 7,000 1,00Picloram 1918021 500 2,710 65,333 65,333Polychlorinatedbiphenyls (PCBs) 1336363 0.5 0.00006 19 19 2 0.01 2 0.02 2 0.0Pyrene 129000 210 800 28,000 28,000Radium 226 + Radium 228 5 pCi/LSelenium 7782492 50 T 667 T 4,667 T 4,667 T 2 T 2 T 2 T Silver 7440224 35 T 8,000 T 4,667 T 4,667 T

See (d) &

Table 19

See (d) &

Table 19

See (d) &

Table 19

Simazine 112349 4 4,667 4,667Styrene 100425 100 186,667 186,667 5,600 370 5,600 370 5,600 3702,3,7,8-Tetrachlorodibenzo-p- 1746016 0.00003 5x10-9 0.00003 0.0009 0.01 0.005 0.01 0.005 0.01 0.00
283 

PARAMETER

CAS 

NUMBER

DWS 

(μg/L)

FC

(μg/L)

FBC

(μg/L)

PBC

(μg/L)

A&Wc

Acute 

(μg/L)

A&Wc 

Chronic 

(μg/L)

A&Ww 

Acute 

(μg/L)

A&Ww 

Chronic 

(μg/L)

A&Wedw 

Acute 

(μg/L)

A&W

Chro

(μg/

dioxin (2,3,7,8-TCDD)1,1,2,2-Tetrachloroethane 79345 0.2 4 7 93,333 4,700 3,200 4,700 3,200 4,700 3,20Tetrachloroethylene 127184 5 261 9,333 9,333 2,600 280 6,500 680 6,500 680 Thallium 7440280 2 T 1 T 75 T 75 T 700 D 150 D 700 D 150 D 700 D 150 Toluene 108883 1,000 29,907 373,333 373,333 8,700 180 8,700 180 8,700 180Toxaphene 8001352 3 0.0003 1.3 933 0.7 0.0002 0.7 0.0002 0.7 0.00Tributyltin 0.5 0.07 0.5 0.07 0.5 0.01,2,4-Trichlorobenzene 120821 70 70 9,333 9,333 750 130 1,700 300 1,700 3001,1,1-Trichloroethane 71556 200 428,571 1,866,667 1,866,667 2,600 1,600 2,600 1,600 2,600 1,601,1,2-Trichloroethane 79005 5 16 25 3,733 18,000 12,000 18,000 12,000 18,000 12,0Trichloroethylene 79016 5 29 280,000 280 20,000 1,300 20,000 1,300 20,000 1,302,4,6-Trichlorophenol 88062 3.2 2 130 130 160 25 160 25 160 25 2,4,5-Trichlorophenoxy proprionic acid (2,4,5-TP)

93721 50 7,467 7,467

Trihalomethanes (T) 80Uranium 7440611 30 D 2,800 2,800Vinyl chloride 75014 2 5 2 2,800Xylenes (T) 1330207 10,000 186,667 186,667Zinc 7440666 2,100 T 5,106 T 280,000 T 280,000 T

See (d) &

Table 20

See (d) &

Table 20

See (d) &

Table 20

See (d) &

Table 20

See (d) &

Table 20

See (d

Table 
284 

Footnotes

a. The asbestos standard is 7 million fibers (longer than 10 micrometers) per liter.

b. The aldrin/dieldrin standard is exceeded when the sum of the two compounds exceeds 0.003 μg/L.

c. In lakes, the criteria for hydrogen sulfide apply only to water samples taken from the epilimnion, or the upper layer of a 

lake or reservoir.

d. Hardness, expressed as mg/L CaCO3, is determined according to the following criteria:

i. If the receiving water body has an A&Wc or A&Ww designated use, then hardness is based on the hardness of 

the receiving water body from a sample taken at the same time that the sample for the metal is taken, except that 

the hardness may not exceed 400 mg/L CaCO3.

ii. If the receiving water has an A&Wedw or A&We designated use, then the hardness is based on the hardness of 

the effluent from a sample taken at the same time that the sample for the metal is taken, except that the hardness 

may not exceed 400 mg/L CaCO3.

e. pH is determined according to the following criteria:

i. If the receiving water has an A&Wc or A&Ww designated use, then pH is based on the pH of the receiving 

water body from a sample taken at the same time that the sample for pentachlorophenol or ammonia is taken.

ii. If the receiving water body has an A&Wedw or A&We designated use, then the pH is based on the pH of the 

effluent from a sample taken at the same time that the sample for pentachlorophenol or ammonia is taken.

f. Table 1 abbreviations.

i. μg/L = micrograms per liter,

ii. mg/kg = milligrams per kilogram,

iii. pCi/L = picocuries per liter,

iv. D = dissolved,

v. T = total recoverable,

vi. TTHM indicates that the chemical is a trihalomethane.

g. The total trihalomethane (TTHM) standard is exceeded when the sum of these four compounds exceeds 80 μg/L, as a 

rolling annual average.

Appendix A: Numeric Water Quality Criteria

Table 2. Aquatic & Wildlife Designated Uses Acute Water Quality Standards for Dissolved Cadmium

Aquatic and Wildlife coldwater

PARAMETER

CAS*

NUMBER

A&Wc

Acute

(μg/L)

A&Wc

Chronic

(μg/L)

A&Ww

Acute

(μg/L)

A&Ww

Chronic

(μg/L)

A&Wedw

Acute

(μg/L)

A&Wedw

Chronic

(μg/L)

A&We

Acute

(μg/L)

Acenaphthene 83-32-9 850 550 850 550 850 550 NNS

Acenaphthylene 208-96-8 NNS NNS NNS NNS NNS NNS NNS

Acrolein 107-02-8 34 30 34 30 34 30 NNS

Acrylonitrile 107-13-1 3800 250 3800 250 3800 250 NNS

Alachlor 15972-60-8 2500 170 2500 170 2500 170 NNS

Aldrin 309-00-2 2.0 NNS 2.0 NNS 2.0 NNS 4.5

Ammonia 7664-41-7 b b b b NNS NNS NNS

Anthracene 120-12-7 NNS NNS NNS NNS NNS NNS NNS

Antimony (as Sb) 7440-36-0 88 D 30 D 88 D 30 D 1000 D 600 D NNS
285 

Arsenic (as As) 7440-38-2 360 D 190 D 360 D 190 D 360 D 190 D 440 D

Asbestos 1332-21-4 NNS NNS NNS NNS NNS NNS NNS

Atrazine 1912-24-9 NNS NNS NNS NNS NNS NNS NNS

Barium (as Ba) 7440-39-3 NNS NNS NNS NNS NNS NNS NNS

Benzene 71-43-2 2700 180 2700 180 8800 560 NNS

Benzidine 92-87-5 1300 89 1300 89 1300 89 10000

Benz (a) anthracene 56-55-3 NNS NNS NNS NNS NNS NNS NNS

Benzo (a) pyrene 50-32-8 NNS NNS NNS NNS NNS NNS NNS

Benzo (ghi) perylene 191-24-2 NNS NNS NNS NNS NNS NNS NNS

Benzo (k) fluoranthene 207-08-9 NNS NNS NNS NNS NNS NNS NNS

3,4-Benzofluoranthene 205-99-2 NNS NNS NNS NNS NNS NNS NNS

Beryllium (as Be) 7440-41-7 65 D 5.3 D 65 D 5.3 D 65 D 5.3 D NNS

Bis (2-chloroethoxy) methane 111-91-1 NNS NNS NNS NNS NNS NNS NNS

Bis (2-chlorethyl) ether 111-44-4 120000 6700 120000 6700 120000 6700 NNS

Bis (2-chloroisopropyl) ether 108-60-1 NNS NNS NNS NNS NNS NNS NNS

Boron (as B) 7440-42-8 NNS NNS NNS NNS NNS NNS NNS

Bromodichloromethane 75-27-4 NNS NNS NNS NNS NNS NNS NNS

p-Bromodiphenyl ether 101-55-3 180 14 180 14 180 14 NNS

Bromoform 75-25-2 15000 10000 15000 10000 15000 10000 NNS

Bromomethane 74-83-9 5500 360 5500 360 5500 360 NNS

Butyl benzyl phthalate 85-68-7 1700 130 1700 130 1700 130 NNS

Cadmium (as Cd) 7440-43-9 c D c D c D c D c D c D c D

Carbofuran 1563-66-2 650 50 650 50 650 50 NNS

Carbon tetrachloride 56-23-5 18000 1100 18000 1100 18000 1100 NNS

Chlordane 57-74-9 2.4 0.004 2.4 0.21 2.4 0.21 3.2

Chlorine (total residual) 7782-50-5 11 5.0 11 5.0 11 5.0 NNS

Chlorobenzene 108-90-7 3800 260 3800 260 3800 260 NNS

p-Chloro-m-cresol 59-50-7 15 4.7 15 4.7 15 4.7 48000

2-Chloroethyl vinyl ether 110-75-8 180000 9800 180000 9800 180000 9800 NNS

Chloroform 67-66-3 14000 900 14000 900 14000 900 NNS

Chloromethane 74-87-3 270000 15000 270000 15000 270000 15000 NNS

Chloronapthalene beta 91-58-7 NNS NNS NNS NNS NNS NNS NNS

2-Chlorophenol 95-57-8 2200 150 2200 150 2200 150 NNS

4-Chlorophenyl phenyl ether 7005-72-3 NNS NNS NNS NNS NNS NNS NNS

Chromium (as Cr III) 16065-83-1 d D d D d D d D d D d D d D

Chromium (as Cr VI) 18540-29-9 16 D 11 D 16 D 11 D 16 D 11 D 34 D

Chromium (Total as Cr) 7440-47-3 NNS NNS NNS NNS NNS NNS NNS

Chrysene 218-01-9 NNS NNS NNS NNS NNS NNS NNS

Copper (as Cu) 7440-50-8 e D e D e D e D e D e D e D

Cyanide 57-12-5 22 T 5.2 T 41 T 9.7 T 41 T 9.7 T 84 T

Dibenz (ah) anthracene 53-70-3 NNS NNS NNS NNS NNS NNS NNS
286 

Dibromochloromethane 124-48-1 NNS NNS NNS NNS NNS NNS NNS

1,2-Dibromo-3-chloropropane 

(DBCP)

96-12-8 NNS NNS NNS NNS NNS NNS NNS

1,2-Dibromoethane (EDB) 106-93-4 NNS NNS NNS NNS NNS NNS NNS

Dibutyl phthalate 84-74-2 470 35 470 35 470 35 1100

1,2-Dichlorobenzene 95-50-1 790 300 1200 470 1200 470 5900

1,3-Dichlorobenzene 541-73-1 2500 970 2500 970 2500 970 NNS

1,4-Dichlorobenzene 106-46-7 560 210 2000 780 2000 780 6500

3,3'-Dichlorobenzidine 91-94-1 NNS NNS NNS NNS NNS NNS NNS

p,p'-

Dichlorodiphenyldichloroethane 

(DDD)

72-54-8 1.1 0.001 1.1 0.02 1.1 0.02 1.1

p,p'-

Dichlorodiphenyldichloroethylene 

(DDE)

72-55-9 1.1 0.001 1.1 0.02 1.1 0.02 1.1

p,p'-

Dichlorodiphenyltrichloroethane 

(DDT)

50-29-3 1.1 0.001 1.1 0.001 1.1 0.001 1.1

1,1-Dichloroethane 75-34-3 NNS NNS NNS NNS NNS NNS NNS

1,2-Dichloroethane 107-06-2 59000 41000 59000 41000 59000 41000 NNS

1,1-Dichloroethylene 75-35-4 15000 950 15000 950 15000 950 NNS

1,2-cis-Dichloroethylene 156-59-2 NNS NNS NNS NNS NNS NNS NNS

1,2-trans-Dichloroethylene 156-60-5 68000 3900 68000 3900 68000 3900 NNS

Dichloromethane 75-09-2 97000 5500 97000 5500 97000 5500 NNS

2,4-Dichlorophenol 120-83-2 1000 88 1000 88 1000 88 NNS

2,4-Dichlorophenoxyacetic acid 

(2,4-D)

94-75-7 NNS NNS NNS NNS NNS NNS NNS

1,2-Dichloropropane 78-87-5 26000 9200 26000 9200 26000 9200 NNS

1,3-Dichloropropene 542-75-6 3000 1100 3000 1100 3000 1100 NNS

Dieldrin 60-57-1 2.5 0.002 2.5 0.002 2.5 0.005 4

Diethyl phthalate 84-66-2 26000 1600 26000 1600 26000 1600 NNS

Di(2-ethylhexyl) phthalate 117-81-7 400 360 400 360 400 360 3100

2,4-Dimethylphenol 105-67-9 1000 310 1000 310 1100 310 150000

Dimethyl phthalate 131-11-3 17000 1000 17000 1000 17000 1000 NNS

4,6-Dinitro-o-cresol 534-52-1 310 24 310 24 310 24 NNS

2,4-Dinitrophenol 51-28-5 110 9.2 110 9.2 110 9.2 NNS

2,4-Dinitrotoluene 121-14-2 14000 860 14000 860 14000 860 NNS

2,6-Dinitrotoluene 606-20-2 NNS NNS NNS NNS NNS NNS NNS

-Di-n-octyl phthalate 117-84-0 NNS NNS NNS NNS NNS NNS NNS

1,2-Diphenylhydrazine 122-66-7 130 11 130 11 130 11 NNS

Endosulfan sulfate 1031-07-8 0.22 0.06 0.22 0.06 0.22 0.06 3.0

Endosulfan (Total) 115-29-7 0.22 0.06 0.22 0.06 0.22 0.06 3.0
287 

Endrin 72-20-8 0.18 0.002 0.2 0.08 0.2 0.08 0.7

Endrin aldehyde 7421-93-3 0.18 0.002 0.2 0.08 0.2 0.08 0.7

Ethylbenzene 100-41-4 23000 1400 23000 1400 23000 1400 NNS

Ethyl chloride 75-00-3 NNS NNS NNS NNS NNS NNS NNS

Fluoranthene 206-44-0 2000 1600 2000 1600 2000 1600 NNS

Fluorene 86-73-7 NNS NNS NNS NNS NNS NNS NNS

Fluorine 7782-41-4 NNS NNS NNS NNS NNS NNS NNS

Heptachlor 76-44-8 0.52 0.004 0.52 0.004 0.58 0.013 0.9

Heptachlor epoxide 1024-57-3 0.52 0.004 0.52 0.004 0.58 0.013 0.9

Hexachlorobenzene 118-74-1 6.0 3.7 NNS NNS NNS NNS NNS

Hexachlorobutadiene 87-68-3 45 8.2 45 8.2 45 8.2 NNS

Hexachlorocyclohexane alpha 319-84-6 1600 130 1600 130 1600 130 1600

Hexachlorocyclohexane beta 319-85-7 1600 130 1600 130 1600 130 1600

Hexachlorocyclohexane delta 319-86-8 1600 130 1600 130 1600 130 1600

Hexachlorocyclohexane gamma 

(lindane)

58-89-9 2.0 0.08 3.4 0.28 7.6 0.61 11

Hexachlorocyclopentadiene 77-47-4 3.5 0.3 3.5 0.3 3.5 0.3 NNS

Hexachloroethane 67-72-1 490 350 490 350 490 350 850

Indeno (1,2,3-cd) pyrene 193-39-5 NNS NNS NNS NNS NNS NNS NNS

Isophorone 78-59-1 59000 43000 59000 43000 59000 43000 NNS

Lead (as Pb) 7439-97-1 f D f D f D f D f D f D f D

Manganese (as Mn) 7439-96-5 NNS NNS NNS NNS NNS NNS NNS

Mercury (as Hg) 7439-97-6 2.4 D 0.01 D 2.4 D 0.01 D 2.6 D 0.2 D 5.0 D

Methoxychlor 72-43-5 NNS NNS NNS NNS NNS NNS NNS

Naphthalene 91-20-3 1100 210 3200 580 3200 580 NNS

Nickel (as Ni) 7440-02-0 g D g D g D g D g D g D g D

Nitrate (as N) 14797-55-8 NNS NNS NNS NNS NNS NNS NNS

Nitrite (as N) 14797-65-0 NNS NNS NNS NNS NNS NNS NNS

Nitrate/Nitrite (as Total N) NNS NNS NNS NNS NNS NNS NNS

Nitrobenzene 98-95-3 1300 850 1300 850 1300 850 NNS

o-Nitrophenol 88-75-5 NNS NNS NNS NNS NNS NNS NNS

p-Nitrophenol 100-02-7 4100 3000 4100 3000 4100 3000 NNS

N-nitrosodimethylamine 62-75-9 NNS NNS NNS NNS NNS NNS NNS

N-nitrosodiphenylamine 86-30-6 2900 200 2900 200 2900 200 NNS

N-nitrosodi-n-propylamine 621-64-7 NNS NNS NNS NNS NNS NNS NNS

Pentachlorophenol 87-86-5 h h h h h h h

Phenanthrene 85-01-8 30 6.3 30 6.3 54 6.3 NNS

Phenol 108-95-2 5100 730 7000 1000 7000 1000 180000

Polychlorinatedbiphenyls (PCBs) 1336-36-3 2.0 0.01 2.0 0.02 2.0 0.02 11

Pyrene 129-00-0 NNS NNS NNS NNS NNS NNS NNS

Selenium (as Se) 7782-49-2 20 T 2.0 T 20 T 2.0 T 50 T 2.0 T 33 T
288 

Silver (as Ag) 7440-22-4 i D NNS i D NNS i D NNS i D

Styrene 100-42-5 5600 370 5600 370 5600 370 NNS

Sulfides n 100 NNS 100 NNS 100 NNS 100

2,3,7,8-Tetrachlorodibenzo-pdioxin (2,3,7,8-TCDD)

1746-01-6 0.01 0.005 0.01 0.005 0.12 0.01 0.1

1,1,2,2-Tetrachloroethane 79-34-5 4700 3200 4700 3200 4700 3200 NNS

Tetrachloroethylene 127-18-4 2600 280 6500 680 6500 680 15000

Thallium (as Tl) 7440-28-0 700 D 150 D 700 D 150 D 700 D 150 D NNS

Toluene 108-88-3 8700 180 8700 180 8700 180 NNS

Toxaphene 8001-35-2 0.73 0.0002 0.73 0.02 0.73 0.02 11

1,2,4-Trichlorobenzene 120-82-1 750 130 1700 300 NNS NNS NNS

1,1,1-Trichloroethane 71-55-6 2600 1600 2600 1600 2600 1600 NNS

1,1,2-Trichloroethane 79-00-5 18000 12000 18000 12000 18000 12000 NNS

Trichloroethylene 79-01-6 20000 1300 20000 1300 20000 1300 NNS

2,4,6-Trichlorophenol 88-06-2 160 25 160 25 160 25 3000

2-(2,4,5-Trichlorophenoxy) 

proprionic acid (2,4,5-TP)

93-72-1 NNS NNS NNS NNS NNS NNS NNS

Trihalomethanes, Total NNS NNS NNS NNS NNS NNS NNS

Uranium (as Ur) 7440-61-1 NNS NNS NNS NNS NNS NNS NNS

Vinyl chloride 75-01-4 NNS NNS NNS NNS NNS NNS NNS

Xylenes (Total) 1330-20-7 NNS NNS NNS NNS NNS NNS NNS

Zinc (as Zn) 7440-66-6 j D j D j D j D j D j D j D

Footnotes

a. The standard to protect this use is 7 million fibers (longer than 10 micrometers) per liter.

b. Values for ammonia are contained in separate tables located at the end of Appendix A 

c. Cadmium

A&Wc acute standard: (e(1.128 [ln(Hardness)] - 3.6867)) * (1.136672-ln(hardness) * (0.041838))

A&Wc chronic standard: (e(0.7852 [ln(Hardness)] - 2.715)) * (1.101672-ln(hardness) * (0.041838))

A&Ww acute standard: (e(1.128 [ln(Hardness)] - 3.6867)) * (1.136672-ln(hardness) * (0.041838))

A&Ww chronic standard: (e(0.7852 [ln(Hardness)] - 2.715)) * (1.101672-ln(hardness) * (0.041838))

A&Wedw acute standard: (e(1.128 [ln(Hardness)] - 3.6867)) * (1.136672-ln(hardness) * (0.041838))

A&Wedw chronic standard: (e(0.7852 [ln(Hardness)] – 2.715)) * (1.101672-ln(hardness)] * (0.041838))

A&We acute standard: (e(1.128 [ln(Hardness)] - 0.9691)) * (1.136672-ln(hardness)] * (0.041838))

 (See Footnote k)

d. Chromium III

A&Wc acute standard: (e (0.8190 [ln(Hardness)] [(ln hardness)] + 3.7256)) * (0.316)

A&Wc chronic standard: (e (0.8190 [ln(Hardness)] [(ln hardness)] + 0.6848)) * (0.86)

A&Ww acute standard: (e (0.8190 [ln(Hardness)] [(ln hardness)] + 3.7256)) * (0.316)

A&Ww chronic standard: (e (0.8190 [ln(Hardness)] [(ln hardness)] + 0.6848)) * (0.86)
289 

A&Wedw acute standard: (e (0.8190 [ln(Hardness)] [(ln hardness)] + 3.7256)) * (0.316)

A&Wedw chronic standard: (e (0.8190 [ln(Hardness)] [(ln hardness)] + 0.6848)) * (0.86)

A&We acute standard: (e (0.8190 [ln(Hardness)] [(ln hardness)] + 4.9361)) * (0.316)

(See Footnote k)

e. Copper

A&Wc acute standard: (e (0.9422 [ln(Hardness)] [(ln hardness)] - 1.7)) * (0.96)

A&Wc chronic standard: (e (0.8545 [ln(Hardness)] [(ln hardness)] - 1.702)) * (0.96)

A&Ww acute standard: (e (0.9422 [ln(Hardness)] [(ln hardness)] - 1.7)) * (0.96)

A&Ww chronic standard: (e (0.8545 [ln(Hardness)] [(ln hardness)] - 1.702)) * (0.96)

A&Wedw acute standard: (e (0.9422 [ln(Hardness)] [(ln hardness)] - 1.7)) * (0.96)

A&Wedw chronic standard: (e (0.8545 [ln(Hardness)] [(ln hardness)] - 1.702)) * (0.96)

A&We acute standard: (e (0.9422 [ln(Hardness)] [(ln hardness)] - 1.1514)) * (0.96)

(See Footnote k)

f. Lead

A&Wc acute standard: (e (1.2730 [ln(Hardness)] [ln(hardness)] - 1.460)) * (1.46203-ln(hardness) * (0.145712))

A&Wc chronic standard: (e (1.2730 [ln(Hardness)] [ln(hardness)] - 4.705)) * (1.46203-ln(hardness) * (0.145712))

A&Ww acute standard: (e (1.2730 [ln(Hardness)] [ln(hardness)] - 1.460)) * (1.46203-ln(hardness) * (0.145712))

A&Ww chronic standard: (e (1.2730 [ln(Hardness)] [ln(hardness)] - 4.705)) * (1.46203-ln(hardness) * (0.145712))

A&Wedw acute standard: (e (1.2730 [ln(Hardness)] [ln(hardness)] - 1.460)) * (1.46203-ln(hardness) * (0.145712))

A&Wedw chronic standard: (e (1.2730 [ln(Hardness)] [ln(hardness)] - 4.705)) * (1.46203-ln(hardness) * (0.145712))

A&We acute standard: (e (1.2730 [ln(Hardness)] [ln(hardness)] - 0.7131)) * (1.46203-ln(hardness) * (0.145712))

(See Footnote k)

g. Nickel

A&Wc acute standard: (e (0.8460 [ln(Hardness)] [ln(hardness)] + 2.255)) * (0.998)

A&Wc chronic standard: (e (0.8460 [ln(Hardness)] [ln(hardness)] + 0.0584)) * (0.997)

A&Ww acute standard: (e (0.8460 [ln(Hardness)] [ln(hardness)] + 2.255)) * (0.998)

A&Ww chronic standard: (e (0.8460 [ln(Hardness)] [ln(hardness)] + 0.0584)) * (0.997)

A&Wedw acute standard: (e (0.8460 [ln(Hardness)] [ln(hardness)] + 2.255)) * (0.998)

A&Wedw chronic standard: (e (0.8460 [ln(Hardness)] [ln(hardness)] + 0.0584)) * (0.997)

A&We acute standard: (e (0.8460 [ln(Hardness)] [ln(hardness)] + 4.4389)) * (0.998)

(See Footnote k)

h. Pentachlorophenol

A&Wc acute standard: e (1.005 (pH) - 4.830)

A&Wc chronic standard: e (1.005 (pH) - 5.290)

A&Ww acute standard: e (1.005 (pH) - 4.830) 

A&Ww chronic standard: e (1.005 (pH) - 5.290)

A&Wedw acute standard: e (1.005 (pH) - 4.830)

A&Wedw chronic standard: e (1.005 (pH) - 5.290)

A&We acute standard: e (1.005 (pH) - 3.4306)

(See Footnote )

i. Silver

A&Wc acute standard: (e (1.72 [ln(Hardness)] [ln(hardness)] - 6.52 6.59)

) * (0.85)

A&Ww acute standard: (e (1.72 [ln(Hardness)] [ln(hardness)] - .52 6.59)

) * (0.85)
290 

A&Wedw acute standard: (e (1.72 [ln(Hardness)] [ln(hardness)]- 6.52 6.59)) * (0.85)

A&We acute standard: (e (1.72 [ln(Hardness)] [ln(hardness)] - 6.52 6.59)

) * (0.85)

(See Footnote k)

j. Zinc

A&Wc acute standard: (e (0.8473 [ln(Hardness)] [ln(hardness)] + 0.884)) * (0.978)

A&Wc chronic standard: (e (0.8473 [ln(Hardness)] [ln(hardness)] + 0.884)) * (0.978)

A&Ww acute standard: (e (0.8473 [ln(Hardness)] [ln(hardness)] + 0.884)) * 0.978)

A&Ww chronic standard: (e (0.8473 [ln(Hardness)] [ln(hardness)] + 0.884)) * (0.978)

A&Wedw acute standard: (e (0.8473 [ln(Hardness)] [ln(hardness)] + 0.884)) * (0.978)

A&Wedw chronic standard: (e (0.8473 [ln(Hardness)] [ln(hardness)] + 0.884)) * (0.978)

A&We acute standard: (e (0.8473 [ln(Hardness)] [ln(hardness)] + 3.1342)) * (0.978)

(See Footnote k)

k. Hardness, expressed as mg/L CaCO3, is inserted into the equation where it says “Hardness.” Hardness is determined 

according to the following criteria:

1. If the receiving water body has an A&Wc or A&Ww designated use, then hardness is based on the hardness of 

the receiving water body from a sample taken at the same time that the sample for the metal is taken, except that 

the hardness may not exceed 400 mg/L CaCO3.

2. If the receiving water has an A&Wedw or A&We designated use, then the hardness is based on the hardness of 

the effluent from a sample taken at the same time that the sample for the metal is taken, except that the hardness 

may not exceed 400 mg/L CaCO3.

l. The pH is inserted into the equation where it says “pH”. pH is determined according to the following criteria:

1. If the receiving water has an A&Wc or A&Ww designated use, then pH is based on the pH of the receiving 

water body from a sample taken at the same time that the sample for pentachlorophenol is taken.

2. If the receiving water body has an A&Wedw or A&We designated use, then the pH is based on the pH of the 

effluent from a sample taken at the same time that the sample for pentachlorophenol is taken.

m. The mathematical equations for the pH dependent and hardness dependent parameters represent the water quality 

standards. Criteria for the hardness dependent and pH dependent parameters have been calculated and are presented in 

separate tables at the end of Appendix A for the convenience of the user.

n. In lakes, the acute criteria for sulfide apply only to water samples taken from the epilimnion, or the upper layer of a lake 

or reservoir.

o. Bromoform, chloroform, chlorodibromomethane, and dichlorobromomethane are trihalomethanes regulated by the total 

trihalomethane numeric standard. The total trihalomethane standard is exceeded when the sum of these four compounds 

exceeds 100 μg/L.

p. The standard to protect this use is 0.003 μg/L aldrin/dieldrin.

μg/L micrograms per liter

NNS No numeric standard

D Dissolved 

T Total recoverable

TTHM indicates that the chemical is a trihalomethane. See Trihalomethanes, Total for DWS standard
291

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 0.02 41 0.85 81 1.64 121 2.42 161 3.20 201 3.97 241 4.73 281 5.49 321 2 0.04 42 0.87 82 1.66 122 2.44 162 3.22 202 3.99 242 4.75 282 5.51 322 3 0.07 43 0.89 83 1.68 123 2.46 163 3.24 203 4.01 243 4.77 283 5.53 323 4 0.09 44 0.91 84 1.70 124 2.48 164 3.26 204 4.03 244 4.79 284 5.55 324 5 0.11 45 0.93 85 1.72 125 2.50 165 3.28 205 4.04 245 4.81 285 5.57 325 6 0.13 46 0.95 86 1.74 126 2.52 166 3.30 206 4.06 246 4.83 286 5.59 326 7 0.15 47 0.97 87 1.76 127 2.54 167 3.31 207 4.08 247 4.85 287 5.61 327 8 0.17 48 0.99 88 1.78 128 2.56 168 3.33 208 4.10 248 4.87 288 5.63 328 9 0.19 49 1.01 89 1.80 129 2.58 169 3.35 209 4.12 249 4.88 289 5.64 329 

10 0.21 50 1.03 90 1.82 130 2.60 170 3.37 210 4.14 250 4.90 290 5.66 330 11 0.23 51 1.05 91 1.84 131 2.62 171 3.39 211 4.16 251 4.92 291 5.68 331 12 0.26 52 1.07 92 1.86 132 2.64 172 3.41 212 4.18 252 4.94 292 5.70 332 13 0.28 53 1.09 93 1.88 133 2.66 173 3.43 213 4.20 253 4.96 293 5.72 333 14 0.30 54 1.11 94 1.90 134 2.68 174 3.45 214 4.22 254 4.98 294 5.74 334 15 0.32 55 1.13 95 1.92 135 2.70 175 3.47 215 4.24 255 5.00 295 5.76 335 16 0.34 56 1.15 96 1.94 136 2.72 176 3.49 216 4.26 256 5.02 296 5.78 336 17 0.36 57 1.17 97 1.95 137 2.73 177 3.51 217 4.27 257 5.04 297 5.80 337 18 0.38 58 1.19 98 1.97 138 2.75 178 3.53 218 4.29 258 5.06 298 5.81 338 19 0.40 59 1.21 99 1.99 139 2.77 179 3.55 219 4.31 259 5.08 299 5.83 339 20 0.42 60 1.23 100 2.01 140 2.79 180 3.56 220 4.33 260 5.09 300 5.85 340 21 0.44 61 1.25 101 2.03 141 2.81 181 3.58 221 4.35 261 5.11 301 5.87 341 22 0.46 62 1.26 102 2.05 142 2.83 182 3.60 222 4.37 262 5.13 302 5.89 342 23 0.48 63 1.28 103 2.07 143 2.85 183 3.62 223 4.39 263 5.15 303 5.91 343 24 0.50 64 1.30 104 2.09 144 2.87 184 3.64 224 4.41 264 5.17 304 5.93 344 25 0.52 65 1.32 105 2.11 145 2.89 185 3.66 225 4.43 265 5.19 305 5.95 345 
292

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

26 0.54 66 1.34 106 2.13 146 2.91 186 3.68 226 4.45 266 5.21 306 5.97 346 27 0.56 67 1.36 107 2.15 147 2.93 187 3.70 227 4.47 267 5.23 307 5.99 347 28 0.58 68 1.38 108 2.17 148 2.95 188 3.72 228 4.48 268 5.25 308 6.00 348 29 0.60 69 1.40 109 2.19 149 2.97 189 3.74 229 4.50 269 5.27 309 6.02 349 30 0.62 70 1.42 110 2.21 150 2.99 190 3.76 230 4.52 270 5.28 310 6.04 350 31 0.64 71 1.44 111 2.23 151 3.01 191 3.78 231 4.54 271 5.30 311 6.06 351 32 0.66 72 1.46 112 2.25 152 3.03 192 3.80 232 4.56 272 5.32 312 6.08 352 33 0.68 73 1.48 113 2.27 153 3.04 193 3.81 233 4.58 273 5.34 313 6.10 353 34 0.70 74 1.50 114 2.29 154 3.06 194 3.83 234 4.60 274 5.36 314 6.12 354 35 0.72 75 1.52 115 2.31 155 3.08 195 3.85 235 4.62 275 5.38 315 6.14 355 36 0.75 76 1.54 116 2.33 156 3.10 196 3.87 236 4.64 276 5.40 316 6.16 356 37 0.77 77 1.56 117 2.35 157 3.12 197 3.89 237 4.66 277 5.42 317 6.17 357 38 0.79 78 1.58 118 2.37 158 3.14 198 3.91 238 4.68 278 5.44 318 6.19 358 39 0.81 79 1.60 119 2.38 159 3.16 199 3.93 239 4.69 279 5.45 319 6.21 359 40 0.83 80 1.62 120 2.40 160 3.18 200 3.95 240 4.71 280 5.47 320 6.23 360 

Table 3. Acute Water Quality Standards for dissolved Cadmium Chronic Water Quality Standards for Dissolved Cadmium

Aquatic and Wildlife ephemeral Aquatic and Wildlife coldwater

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 NA 41 24.56 81 51.39 121 79.40 161 108.18 201 137.55 241 167.40 281 197.64 321 22 NA 42 25.21 82 52.08 122 80.11 162 108.90 202 138.29 242 168.15 282 198.40 322 23 NA 43 25.86 83 52.77 123 80.82 163 109.63 203 139.03 243 168.90 283 199.17 323 24 NA 44 26.51 84 53.46 124 81.53 164 110.36 204 139.77 244 169.65 284 199.93 324 25 NA 45 27.17 85 54.15 125 82.24 165 111.09 205 140.51 245 170.40 285 200.69 325 26 NA 46 27.82 86 54.84 126 82.96 166 111.82 206 141.25 246 171.16 286 201.45 326 27 NA 47 28.48 87 55.53 127 83.67 167 112.55 207 142.00 247 171.91 287 202.21 327 2
293

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

8 NA 48 29.14 88 56.22 128 84.38 168 113.28 208 142.74 248 172.66 288 202.97 328 29 NA 49 29.80 89 56.92 129 85.10 169 114.01 209 143.48 249 173.41 289 203.74 329 2

10 NA 50 30.46 90 57.61 130 85.81 170 114.74 210 144.22 250 174.17 290 204.50 330 211 NA 51 31.12 91 58.31 131 86.53 171 115.47 211 144.97 251 174.92 291 205.26 331 212 NA 52 31.78 92 59.00 132 87.24 172 116.20 212 145.71 252 175.68 292 206.02 332 213 NA 53 32.44 93 59.70 133 87.96 173 116.93 213 146.46 253 176.43 293 206.79 333 214 NA 54 33.11 94 60.39 134 88.68 174 117.66 214 147.20 254 177.18 294 207.55 334 215 NA 55 33.77 95 61.09 135 89.39 175 118.40 215 147.94 255 177.94 295 208.31 335 216 NA 56 34.44 96 61.79 136 90.11 176 119.13 216 148.69 256 178.69 296 209.08 336 217 NA 57 35.11 97 62.48 137 90.83 177 119.86 217 149.43 257 179.45 297 209.84 337 218 NA 58 35.78 98 63.18 138 91.55 178 120.59 218 150.18 258 180.21 298 210.61 338 219 NA 59 36.45 99 63.88 139 92.26 179 121.33 219 150.93 259 180.96 299 211.37 339 220 NA 60 37.12 100 64.58 140 92.98 180 122.06 220 151.67 260 181.72 300 212.13 340 221 NA 61 37.79 101 65.28 141 93.70 181 122.80 221 152.42 261 182.47 301 212.90 341 222 NA 62 38.46 102 65.98 142 94.42 182 123.53 222 153.16 262 183.23 302 213.66 342 223 NA 63 39.13 103 66.68 143 95.14 183 124.27 223 153.91 263 183.99 303 214.43 343 224 NA 64 39.81 104 67.38 144 95.86 184 125.00 224 154.66 264 184.74 304 215.20 344 225 14.35 65 40.48 105 68.09 145 96.58 185 125.74 225 155.40 265 185.50 305 215.96 345 226 14.98 66 41.16 106 68.79 146 97.31 186 126.47 226 156.15 266 186.26 306 216.73 346 227 15.60 67 41.84 107 69.49 147 98.03 187 127.21 227 156.90 267 187.01 307 217.49 347 2

28 16.23 68 42.51 108 70.20 148 98.75 188 127.95 228 157.65 268 187.77 308 218.26 348 2

29 16.86 69 43.19 109 70.90 149 99.47 189 128.68 229 158.40 269 188.53 309 219.03 349 230 17.49 70 43.87 110 71.61 150 100.20 190 129.42 230 159.14 270 189.29 310 219.79 350 231 18.13 71 44.55 111 72.31 151 100.92 191 130.16 231 159.89 271 190.05 311 220.56 351 232 18.76 72 45.23 112 73.02 152 101.64 192 130.89 232 160.64 272 190.81 312 221.33 352 233 19.40 73 45.91 113 73.72 153 102.37 193 131.63 233 161.39 273 191.56 313 222.09 353 234 20.04 74 46.60 114 74.43 154 103.09 194 132.37 234 162.14 274 192.32 314 222.86 354 2
294

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

35 20.68 75 47.28 115 75.14 155 103.82 195 133.11 235 162.89 275 193.08 315 223.63 355 236 21.32 76 47.96 116 75.85 156 104.54 196 133.85 236 163.64 276 193.84 316 224.40 356 237 21.97 77 48.65 117 76.56 157 105.27 197 134.59 237 164.39 277 194.60 317 225.16 357 238 22.61 78 49.33 118 77.27 158 106.00 198 135.33 238 165.14 278 195.36 318 225.93 358 239 23.26 79 50.02 119 77.97 159 106.72 199 136.07 239 165.89 279 196.12 319 226.70 359 240 23.91 80 50.71 120 78.68 160 107.45 200 136.81 240 166.64 280 196.88 320 227.47 360 2

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 0.01 41 0.13 81 0.21 121 0.28 161 0.34 201 0.40 241 0.45 281 0.50 321 2 0.02 42 0.13 82 0.21 122 0.28 162 0.34 202 0.40 242 0.45 282 0.50 322 3 0.02 43 0.14 83 0.22 123 0.28 163 0.35 203 0.40 243 0.46 283 0.51 323 4 0.03 44 0.14 84 0.22 124 0.29 164 0.35 204 0.40 244 0.46 284 0.51 324 5 0.03 45 0.14 85 0.22 125 0.29 165 0.35 205 0.40 245 0.46 285 0.51 325 6 0.03 46 0.14 86 0.22 126 0.29 166 0.35 206 0.41 246 0.46 286 0.51 326 7 0.04 47 0.15 87 0.22 127 0.29 167 0.35 207 0.41 247 0.46 287 0.51 327 8 0.04 48 0.15 88 0.23 128 0.29 168 0.35 208 0.41 248 0.46 288 0.51 328 9 0.05 49 0.15 89 0.23 129 0.29 169 0.35 209 0.41 249 0.46 289 0.51 329 

10 0.05 50 0.15 90 0.23 130 0.30 170 0.36 210 0.41 250 0.46 290 0.51 330 11 0.05 51 0.15 91 0.23 131 0.30 171 0.36 211 0.41 251 0.47 291 0.52 331 12 0.06 52 0.16 92 0.23 132 0.30 172 0.36 212 0.41 252 0.47 292 0.52 332 13 0.06 53 0.16 93 0.23 133 0.30 173 0.36 213 0.42 253 0.47 293 0.52 333 14 0.06 54 0.16 94 0.24 134 0.30 174 0.36 214 0.42 254 0.47 294 0.52 334 15 0.07 55 0.16 95 0.24 135 0.30 175 0.36 215 0.42 255 0.47 295 0.52 335 16 0.07 56 0.16 96 0.24 136 0.30 176 0.36 216 0.42 256 0.47 296 0.52 336 17 0.07 57 0.17 97 0.24 137 0.31 177 0.37 217 0.42 257 0.47 297 0.52 337 18 0.07 58 0.17 98 0.24 138 0.31 178 0.37 218 0.42 258 0.47 298 0.52 338 
295

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

19 0.08 59 0.17 99 0.24 139 0.31 179 0.37 219 0.42 259 0.48 299 0.53 339 20 0.08 60 0.17 100 0.25 140 0.31 180 0.37 220 0.43 260 0.48 300 0.53 340 21 0.08 61 0.17 101 0.25 141 0.31 181 0.37 221 0.43 261 0.48 301 0.53 341 22 0.09 62 0.18 102 0.25 142 0.31 182 0.37 222 0.43 262 0.48 302 0.53 342 23 0.09 63 0.18 103 0.25 143 0.32 183 0.37 223 0.43 263 0.48 303 0.53 343 24 0.09 64 0.18 104 0.25 144 0.32 184 0.38 224 0.43 264 0.48 304 0.53 344 25 0.09 65 0.18 105 0.25 145 0.32 185 0.38 225 0.43 265 0.48 305 0.53 345 26 0.10 66 0.18 106 0.26 146 0.32 186 0.38 226 0.43 266 0.48 306 0.53 346 27 0.10 67 0.19 107 0.26 147 0.32 187 0.38 227 0.43 267 0.49 307 0.54 347 28 0.10 68 0.19 108 0.26 148 0.32 188 0.38 228 0.44 268 0.49 308 0.54 348 29 0.10 69 0.19 109 0.26 149 0.32 189 0.38 229 0.44 269 0.49 309 0.54 349 30 0.11 70 0.19 110 0.26 150 0.33 190 0.38 230 0.44 270 0.49 310 0.54 350 31 0.11 71 0.19 111 0.26 151 0.33 191 0.39 231 0.44 271 0.49 311 0.54 351 32 0.11 72 0.20 112 0.27 152 0.33 192 0.39 232 0.44 272 0.49 312 0.54 352 33 0.11 73 0.20 113 0.27 153 0.33 193 0.39 233 0.44 273 0.49 313 0.54 353 34 0.12 74 0.20 114 0.27 154 0.33 194 0.39 234 0.44 274 0.50 314 0.54 354 35 0.12 75 0.20 115 0.27 155 0.33 195 0.39 235 0.45 275 0.50 315 0.55 355 36 0.12 76 0.20 116 0.27 156 0.33 196 0.39 236 0.45 276 0.50 316 0.55 356 37 0.12 77 0.21 117 0.27 157 0.34 197 0.39 237 0.45 277 0.50 317 0.55 357 38 0.13 78 0.21 118 0.28 158 0.34 198 0.40 238 0.45 278 0.50 318 0.55 358 39 0.13 79 0.21 119 0.28 159 0.34 199 0.40 239 0.45 279 0.50 319 0.55 359 40 0.13 80 0.21 120 0.28 160 0.34 200 0.40 240 0.45 280 0.50 320 0.55 360 

Table 4. Acute Water Quality Standards for dissolved Cadmium Acute Water Quality Standards for Dissolved Cadmium

Aquatic and Wildlife coldwater, warmwater, and edw Aquatic and Wildlife warmwater, and edw
296

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 NA 41 1.62 81 3.39 121 5.24 161 7.14 201 9.08 241 11.05 281 13.05 321 12 NA 42 1.66 82 3.44 122 5.29 162 7.19 202 9.13 242 11.10 282 13.10 322 13 NA 43 1.71 83 3.48 123 5.34 163 7.24 203 9.18 243 11.15 283 13.15 323 14 NA 44 1.75 84 3.53 124 5.38 164 7.29 204 9.23 244 11.20 284 13.20 324 15 NA 45 1.79 85 3.58 125 5.43 165 7.34 205 9.28 245 11.25 285 13.25 325 16 NA 46 1.84 86 3.62 126 5.48 166 7.38 206 9.33 246 11.30 286 13.30 326 17 NA 47 1.88 87 3.67 127 5.52 167 7.43 207 9.38 247 11.35 287 13.35 327 18 NA 48 1.92 88 3.71 128 5.57 168 7.48 208 9.43 248 11.40 288 13.40 328 19 NA 49 1.97 89 3.76 129 5.62 169 7.53 209 9.47 249 11.45 289 13.45 329 1

10 NA 50 2.01 90 3.80 130 5.67 170 7.58 210 9.52 250 11.50 290 13.50 330 111 NA 51 2.05 91 3.85 131 5.71 171 7.62 211 9.57 251 11.55 291 13.55 331 112 NA 52 2.10 92 3.90 132 5.76 172 7.67 212 9.62 252 11.60 292 13.60 332 113 NA 53 2.14 93 3.94 133 5.81 173 7.72 213 9.67 253 11.65 293 13.65 333 114 NA 54 2.19 94 3.99 134 5.86 174 7.77 214 9.72 254 11.70 294 13.71 334 115 NA 55 2.23 95 4.03 135 5.90 175 7.82 215 9.77 255 11.75 295 13.76 335 116 NA 56 2.27 96 4.08 136 5.95 176 7.87 216 9.82 256 11.80 296 13.81 336 117 NA 57 2.32 97 4.13 137 6.00 177 7.91 217 9.87 257 11.85 297 13.86 337 118 NA 58 2.36 98 4.17 138 6.05 178 7.96 218 9.92 258 11.90 298 13.91 338 119 NA 59 2.41 99 4.22 139 6.09 179 8.01 219 9.97 259 11.95 299 13.96 339 120 NA 60 2.45 100 4.26 140 6.14 180 8.06 220 10.02 260 12.00 300 14.01 340 121 NA 61 2.50 101 4.31 141 6.19 181 8.11 221 10.06 261 12.05 301 14.06 341 122 NA 62 2.54 102 4.36 142 6.24 182 8.16 222 10.11 262 12.10 302 14.11 342 123 NA 63 2.58 103 4.40 143 6.28 183 8.21 223 10.16 263 12.15 303 14.16 343 124 NA 64 2.63 104 4.45 144 6.33 184 8.25 224 10.21 264 12.20 304 14.21 344 125 0.95 65 2.67 105 4.50 145 6.38 185 8.30 225 10.26 265 12.25 305 14.26 345 126 0.99 66 2.72 106 4.54 146 6.43 186 8.35 226 10.31 266 12.30 306 14.31 346 127 1.03 67 2.76 107 4.59 147 6.47 187 8.40 227 10.36 267 12.35 307 14.36 347 1
297

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

28 1.07 68 2.81 108 4.64 148 6.52 188 8.45 228 10.41 268 12.40 308 14.41 348 129 1.11 69 2.85 109 4.68 149 6.57 189 8.50 229 10.46 269 12.45 309 14.46 349 130 1.16 70 2.90 110 4.73 150 6.62 190 8.55 230 10.51 270 12.50 310 14.51 350 131 1.20 71 2.94 111 4.77 151 6.66 191 8.59 231 10.56 271 12.55 311 14.56 351 132 1.24 72 2.99 112 4.82 152 6.71 192 8.64 232 10.61 272 12.60 312 14.61 352 133 1.28 73 3.03 113 4.87 153 6.76 193 8.69 233 10.66 273 12.65 313 14.67 353 134 1.32 74 3.08 114 4.91 154 6.81 194 8.74 234 10.71 274 12.70 314 14.72 354 135 1.37 75 3.12 115 4.96 155 6.86 195 8.79 235 10.76 275 12.75 315 14.77 355 136 1.41 76 3.17 116 5.01 156 6.90 196 8.84 236 10.81 276 12.80 316 14.82 356 137 1.45 77 3.21 117 5.06 157 6.95 197 8.89 237 10.86 277 12.85 317 14.87 357 138 1.49 78 3.26 118 5.10 158 7.00 198 8.94 238 10.90 278 12.90 318 14.92 358 139 1.54 79 3.30 119 5.15 159 7.05 199 8.98 239 10.95 279 12.95 319 14.97 359 140 1.58 80 3.35 120 5.20 160 7.10 200 9.03 240 11.00 280 13.00 320 15.02 360 1

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 0.09 41 3.30 81 6.41 121 9.47 161 12.50 201 15.51 241 18.49 281 21.47 321 22 0.17 42 3.38 82 6.49 122 9.55 162 12.58 202 15.58 242 18.57 282 21.54 322 23 0.26 43 3.46 83 6.57 123 9.62 163 12.65 203 15.66 243 18.64 283 21.61 323 24 0.34 44 3.54 84 6.64 124 9.70 164 12.73 204 15.73 244 18.72 284 21.69 324 25 0.42 45 3.62 85 6.72 125 9.78 165 12.80 205 15.81 245 18.79 285 21.76 325 26 0.51 46 3.70 86 6.80 126 9.85 166 12.88 206 15.88 246 18.87 286 21.84 326 27 0.59 47 3.77 87 6.87 127 9.93 167 12.95 207 15.96 247 18.94 287 21.91 327 28 0.67 48 3.85 88 6.95 128 10.00 168 13.03 208 16.03 248 19.02 288 21.98 328 29 0.75 49 3.93 89 7.03 129 10.08 169 13.10 209 16.11 249 19.09 289 22.06 329 2

10 0.83 50 4.01 90 7.10 130 10.16 170 13.18 210 16.18 250 19.16 290 22.13 330 211 0.92 51 4.09 91 7.18 131 10.23 171 13.25 211 16.26 251 19.24 291 22.21 331 2
298

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

12 1.00 52 4.17 92 7.26 132 10.31 172 13.33 212 16.33 252 19.31 292 22.28 332 213 1.08 53 4.24 93 7.33 133 10.38 173 13.40 213 16.40 253 19.39 293 22.35 333 214 1.16 54 4.32 94 7.41 134 10.46 174 13.48 214 16.48 254 19.46 294 22.43 334 215 1.24 55 4.40 95 7.49 135 10.53 175 13.56 215 16.55 255 19.54 295 22.50 335 216 1.32 56 4.48 96 7.56 136 10.61 176 13.63 216 16.63 256 19.61 296 22.58 336 217 1.40 57 4.55 97 7.64 137 10.69 177 13.71 217 16.70 257 19.68 297 22.65 337 218 1.48 58 4.63 98 7.72 138 10.76 178 13.78 218 16.78 258 19.76 298 22.72 338 219 1.56 59 4.71 99 7.79 139 10.84 179 13.86 219 16.85 259 19.83 299 22.80 339 220 1.64 60 4.79 100 7.87 140 10.91 180 13.93 220 16.93 260 19.91 300 22.87 340 221 1.72 61 4.87 101 7.95 141 10.99 181 14.01 221 17.00 261 19.98 301 22.95 341 222 1.80 62 4.94 102 8.02 142 11.07 182 14.08 222 17.08 262 20.06 302 23.02 342 223 1.88 63 5.02 103 8.10 143 11.14 183 14.16 223 17.15 263 20.13 303 23.09 343 224 1.96 64 5.10 104 8.18 144 11.22 184 14.23 224 17.23 264 20.20 304 23.17 344 225 2.04 65 5.18 105 8.25 145 11.29 185 14.31 225 17.30 265 20.28 305 23.24 345 226 2.12 66 5.25 106 8.33 146 11.37 186 14.38 226 17.38 266 20.35 306 23.32 346 227 2.20 67 5.33 107 8.40 147 11.44 187 14.46 227 17.45 267 20.43 307 23.39 347 228 2.28 68 5.41 108 8.48 148 11.52 188 14.53 228 17.53 268 20.50 308 23.46 348 229 2.36 69 5.49 109 8.56 149 11.59 189 14.61 229 17.60 269 20.58 309 23.54 349 230 2.44 70 5.56 110 8.63 150 11.67 190 14.68 230 17.67 270 20.65 310 23.61 350 231 2.52 71 5.64 111 8.71 151 11.75 191 14.76 231 17.75 271 20.72 311 23.69 351 232 2.60 72 5.72 112 8.79 152 11.82 192 14.83 232 17.82 272 20.80 312 23.76 352 233 2.67 73 5.79 113 8.86 153 11.90 193 14.91 233 17.90 273 20.87 313 23.83 353 234 2.75 74 5.87 114 8.94 154 11.97 194 14.98 234 17.97 274 20.95 314 23.91 354 235 2.83 75 5.95 115 9.01 155 12.05 195 15.06 235 18.05 275 21.02 315 23.98 355 236 2.91 76 6.03 116 9.09 156 12.12 196 15.13 236 18.12 276 21.09 316 24.05 356 237 2.99 77 6.10 117 9.17 157 12.20 197 15.21 237 18.20 277 21.17 317 24.13 357 238 3.07 78 6.18 118 9.24 158 12.27 198 15.28 238 18.27 278 21.24 318 24.20 358 2
299

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

39 3.15 79 6.26 119 9.32 159 12.35 199 15.36 239 18.35 279 21.32 319 24.28 359 240 3.23 80 6.33 120 9.40 160 12.43 200 15.43 240 18.42 280 21.39 320 24.35 360 2

Table 5. Chronic Water Quality Standards for dissolved Cadmium Chronic Water Quality Standards for Dissolved Cadmium

Aquatic and Wildlife coldwater, warmwater, and edw Aquatic and Wildlife warmwater and edw

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 NA 41 1.16 81 1.92 121 2.58 161 3.18 201 3.75 241 4.28 281 4.80 321 2 NA 42 1.18 82 1.93 122 2.59 162 3.20 202 3.76 242 4.30 282 4.81 322 3 NA 43 1.20 83 1.95 123 2.61 163 3.21 203 3.77 243 4.31 283 4.82 323 4 NA 44 1.22 84 1.97 124 2.62 164 3.23 204 3.79 244 4.32 284 4.84 324 5 NA 45 1.24 85 1.98 125 2.64 165 3.24 205 3.80 245 4.34 285 4.85 325 6 NA 46 1.26 86 2.00 126 2.65 166 3.25 206 3.82 246 4.35 286 4.86 326 7 NA 47 1.28 87 2.02 127 2.67 167 3.27 207 3.83 247 4.36 287 4.87 327 8 NA 48 1.30 88 2.04 128 2.69 168 3.28 208 3.84 248 4.38 288 4.89 328 9 NA 49 1.32 89 2.05 129 2.70 169 3.30 209 3.86 249 4.39 289 4.90 329 

10 NA 50 1.34 90 2.07 130 2.72 170 3.31 210 3.87 250 4.40 290 4.91 330 11 NA 51 1.36 91 2.09 131 2.73 171 3.33 211 3.88 251 4.41 291 4.92 331 12 NA 52 1.38 92 2.10 132 2.75 172 3.34 212 3.90 252 4.43 292 4.94 332 13 NA 53 1.40 93 2.12 133 2.76 173 3.35 213 3.91 253 4.44 293 4.95 333 14 NA 54 1.42 94 2.14 134 2.78 174 3.37 214 3.92 254 4.45 294 4.96 334 15 NA 55 1.44 95 2.15 135 2.79 175 3.38 215 3.94 255 4.47 295 4.97 335 16 NA 56 1.46 96 2.17 136 2.81 176 3.40 216 3.95 256 4.48 296 4.98 336 17 NA 57 1.48 97 2.19 137 2.82 177 3.41 217 3.97 257 4.49 297 5.00 337 18 NA 58 1.50 98 2.20 138 2.84 178 3.43 218 3.98 258 4.50 298 5.01 338 19 NA 59 1.51 99 2.22 139 2.85 179 3.44 219 3.99 259 4.52 299 5.02 339 
300

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

20 NA 60 1.53 100 2.24 140 2.87 180 3.45 220 4.01 260 4.53 300 5.03 340 21 NA 61 1.55 101 2.25 141 2.88 181 3.47 221 4.02 261 4.54 301 5.05 341 22 NA 62 1.57 102 2.27 142 2.90 182 3.48 222 4.03 262 4.56 302 5.06 342 23 NA 63 1.59 103 2.29 143 2.91 183 3.50 223 4.05 263 4.57 303 5.07 343 24 NA 64 1.61 104 2.30 144 2.93 184 3.51 224 4.06 264 4.58 304 5.08 344 25 0.80 65 1.63 105 2.32 145 2.94 185 3.53 225 4.07 265 4.59 305 5.10 345 26 0.83 66 1.65 106 2.34 146 2.96 186 3.54 226 4.09 266 4.61 306 5.11 346 27 0.85 67 1.66 107 2.35 147 2.97 187 3.55 227 4.10 267 4.62 307 5.12 347 28 0.87 68 1.68 108 2.37 148 2.99 188 3.57 228 4.11 268 4.63 308 5.13 348 29 0.89 69 1.70 109 2.39 149 3.00 189 3.58 229 4.13 269 4.65 309 5.15 349 30 0.92 70 1.72 110 2.40 150 3.02 190 3.60 230 4.14 270 4.66 310 5.16 350 31 0.94 71 1.74 111 2.42 151 3.03 191 3.61 231 4.15 271 4.67 311 5.17 351 32 0.96 72 1.76 112 2.43 152 3.05 192 3.62 232 4.17 272 4.68 312 5.18 352 33 0.98 73 1.77 113 2.45 153 3.06 193 3.64 233 4.18 273 4.70 313 5.19 353 34 1.01 74 1.79 114 2.47 154 3.08 194 3.65 234 4.19 274 4.71 314 5.21 354 35 1.03 75 1.81 115 2.48 155 3.09 195 3.66 235 4.21 275 4.72 315 5.22 355 36 1.05 76 1.83 116 2.50 156 3.11 196 3.68 236 4.22 276 4.73 316 5.23 356 37 1.07 77 1.84 117 2.51 157 3.12 197 3.69 237 4.23 277 4.75 317 5.24 357 38 1.09 78 1.86 118 2.53 158 3.14 198 3.71 238 4.24 278 4.76 318 5.26 358 39 1.11 79 1.88 119 2.54 159 3.15 199 3.72 239 4.26 279 4.77 319 5.27 359 40 1.14 80 1.90 120 2.56 160 3.17 200 3.73 240 4.27 280 4.78 320 5.28 360 

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 0.02 41 0.30 81 0.48 121 0.64 161 0.78 201 0.91 241 1.03 281 1.15 321 2 0.04 42 0.31 82 0.49 122 0.64 162 0.78 202 0.91 242 1.04 282 1.15 322 3 0.05 43 0.31 83 0.49 123 0.65 163 0.79 203 0.92 243 1.04 283 1.16 323 
301

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

4 0.06 44 0.32 84 0.50 124 0.65 164 0.79 204 0.92 244 1.04 284 1.16 324 5 0.07 45 0.32 85 0.50 125 0.66 165 0.79 205 0.92 245 1.05 285 1.16 325 6 0.08 46 0.33 86 0.51 126 0.66 166 0.80 206 0.93 246 1.05 286 1.16 326 7 0.09 47 0.33 87 0.51 127 0.66 167 0.80 207 0.93 247 1.05 287 1.17 327 8 0.10 48 0.34 88 0.51 128 0.67 168 0.80 208 0.93 248 1.05 288 1.17 328 9 0.10 49 0.34 89 0.52 129 0.67 169 0.81 209 0.94 249 1.06 289 1.17 329 

10 0.11 50 0.35 90 0.52 130 0.67 170 0.81 210 0.94 250 1.06 290 1.17 330 11 0.12 51 0.35 91 0.53 131 0.68 171 0.81 211 0.94 251 1.06 291 1.18 331 12 0.13 52 0.36 92 0.53 132 0.68 172 0.82 212 0.95 252 1.07 292 1.18 332 13 0.14 53 0.36 93 0.53 133 0.68 173 0.82 213 0.95 253 1.07 293 1.18 333 14 0.14 54 0.37 94 0.54 134 0.69 174 0.82 214 0.95 254 1.07 294 1.19 334 15 0.15 55 0.37 95 0.54 135 0.69 175 0.83 215 0.95 255 1.07 295 1.19 335 16 0.16 56 0.38 96 0.55 136 0.69 176 0.83 216 0.96 256 1.08 296 1.19 336 17 0.16 57 0.38 97 0.55 137 0.70 177 0.83 217 0.96 257 1.08 297 1.19 337 18 0.17 58 0.38 98 0.55 138 0.70 178 0.84 218 0.96 258 1.08 298 1.20 338 19 0.18 59 0.39 99 0.56 139 0.71 179 0.84 219 0.97 259 1.09 299 1.20 339 20 0.18 60 0.39 100 0.56 140 0.71 180 0.84 220 0.97 260 1.09 300 1.20 340 21 0.19 61 0.40 101 0.57 141 0.71 181 0.85 221 0.97 261 1.09 301 1.21 341 22 0.20 62 0.40 102 0.57 142 0.72 182 0.85 222 0.98 262 1.10 302 1.21 342 23 0.20 63 0.41 103 0.57 143 0.72 183 0.85 223 0.98 263 1.10 303 1.21 343 24 0.21 64 0.41 104 0.58 144 0.72 184 0.86 224 0.98 264 1.10 304 1.21 344 25 0.21 65 0.42 105 0.58 145 0.73 185 0.86 225 0.99 265 1.10 305 1.22 345 26 0.22 66 0.42 106 0.58 146 0.73 186 0.86 226 0.99 266 1.11 306 1.22 346 27 0.23 67 0.42 107 0.59 147 0.73 187 0.87 227 0.99 267 1.11 307 1.22 347 28 0.23 68 0.43 108 0.59 148 0.74 188 0.87 228 0.99 268 1.11 308 1.22 348 29 0.24 69 0.43 109 0.60 149 0.74 189 0.87 229 1.00 269 1.12 309 1.23 349 30 0.24 70 0.44 110 0.60 150 0.74 190 0.88 230 1.00 270 1.12 310 1.23 350 
302

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

31 0.25 71 0.44 111 0.60 151 0.75 191 0.88 231 1.00 271 1.12 311 1.23 351 32 0.25 72 0.45 112 0.61 152 0.75 192 0.88 232 1.01 272 1.12 312 1.24 352 33 0.26 73 0.45 113 0.61 153 0.75 193 0.89 233 1.01 273 1.13 313 1.24 353 34 0.26 74 0.46 114 0.61 154 0.76 194 0.89 234 1.01 274 1.13 314 1.24 354 35 0.27 75 0.46 115 0.62 155 0.76 195 0.89 235 1.02 275 1.13 315 1.24 355 36 0.28 76 0.46 116 0.62 156 0.76 196 0.90 236 1.02 276 1.14 316 1.25 356 37 0.28 77 0.47 117 0.63 157 0.77 197 0.90 237 1.02 277 1.14 317 1.25 357 38 0.29 78 0.47 118 0.63 158 0.77 198 0.90 238 1.02 278 1.14 318 1.25 358 39 0.29 79 0.48 119 0.63 159 0.77 199 0.91 239 1.03 279 1.14 319 1.26 359 40 0.30 80 0.48 120 0.64 160 0.78 200 0.91 240 1.03 280 1.15 320 1.26 360 

Table 6. Acute Water Quality Standards for Dissolved Cadmium

Aquatic and Wildlife ephemeral

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

1 0.25 41 9.58 81 18.58 121 27.45 161 36.23 201 44.94 241 53.59 281 62.21 321 72 0.50 42 9.80 82 18.80 122 27.67 162 36.45 202 45.15 242 53.81 282 62.42 322 73 0.75 43 10.03 83 19.03 123 27.89 163 36.66 203 45.37 243 54.03 283 62.64 323 74 0.99 44 10.26 84 19.25 124 28.11 164 36.88 204 45.59 244 54.24 284 62.85 324 75 1.23 45 10.49 85 19.47 125 28.33 165 37.10 205 45.81 245 54.46 285 63.06 325 76 1.47 46 10.71 86 19.69 126 28.55 166 37.32 206 46.02 246 54.67 286 63.28 326 77 1.71 47 10.94 87 19.92 127 28.77 167 37.54 207 46.24 247 54.89 287 63.49 327 78 1.95 48 11.17 88 20.14 128 28.99 168 37.76 208 46.46 248 55.10 288 63.71 328 79 2.18 49 11.39 89 20.36 129 29.21 169 37.97 209 46.67 249 55.32 289 63.92 329 7

10 2.42 50 11.62 90 20.58 130 29.43 170 38.19 210 46.89 250 55.54 290 64.14 330 711 2.65 51 11.84 91 20.81 131 29.65 171 38.41 211 47.11 251 55.75 291 64.35 331 7
303

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

12 2.89 52 12.07 92 21.03 132 29.87 172 38.63 212 47.32 252 55.97 292 64.57 332 713 3.13 53 12.30 93 21.25 133 30.09 173 38.85 213 47.54 253 56.18 293 64.78 333 714 3.36 54 12.52 94 21.47 134 30.31 174 39.06 214 47.76 254 56.40 294 65.00 334 715 3.59 55 12.75 95 21.70 135 30.53 175 39.28 215 47.97 255 56.61 295 65.21 335 716 3.83 56 12.97 96 21.92 136 30.75 176 39.50 216 48.19 256 56.83 296 65.42 336 717 4.06 57 13.20 97 22.14 137 30.97 177 39.72 217 48.41 257 57.04 297 65.64 337 718 4.29 58 13.42 98 22.36 138 31.19 178 39.94 218 48.62 258 57.26 298 65.85 338 719 4.53 59 13.65 99 22.58 139 31.41 179 40.15 219 48.84 259 57.48 299 66.07 339 720 4.76 60 13.87 100 22.81 140 31.63 180 40.37 220 49.06 260 57.69 300 66.28 340 721 4.99 61 14.10 101 23.03 141 31.85 181 40.59 221 49.27 261 57.91 301 66.50 341 722 5.22 62 14.32 102 23.25 142 32.07 182 40.81 222 49.49 262 58.12 302 66.71 342 723 5.45 63 14.55 103 z23.47 143 32.29 183 41.03 223 49.71 263 58.34 303 66.93 343 724 5.68 64 14.77 104 23.69 144 32.50 184 41.24 224 49.92 264 58.55 304 67.14 344 725 5.91 65 15.00 105 23.91 145 32.72 185 41.46 225 50.14 265 58.77 305 67.35 345 726 6.14 66 15.22 106 24.13 146 32.94 186 41.68 226 50.35 266 58.98 306 67.57 346 727 6.37 67 15.45 107 24.36 147 33.16 187 41.90 227 50.57 267 59.20 307 67.78 347 728 6.60 68 15.67 108 24.58 148 33.38 188 42.11 228 50.79 268 59.41 308 68.00 348 729 6.83 69 15.90 109 24.80 149 33.60 189 42.33 229 51.00 269 59.63 309 68.21 349 730 7.06 70 16.12 110 25.02 150 33.82 190 42.55 230 51.22 270 59.84 310 68.42 350 731 7.29 71 16.34 111 25.24 151 34.04 191 42.77 231 51.44 271 60.06 311 68.64 351 732 7.52 72 16.57 112 25.46 152 34.26 192 42.98 232 51.65 272 60.27 312 68.85 352 733 7.75 73 16.79 113 25.68 153 34.48 193 43.20 233 51.87 273 60.49 313 69.07 353 734 7.98 74 17.02 114 25.90 154 34.70 194 43.42 234 52.08 274 60.70 314 69.28 354 735 8.21 75 17.24 115 26.12 155 34.91 195 43.63 235 52.30 275 60.92 315 69.49 355 736 8.44 76 17.46 116 26.34 156 35.13 196 43.85 236 52.52 276 61.13 316 69.71 356 737 8.67 77 17.69 117 26.57 157 35.35 197 44.07 237 52.73 277 61.35 317 69.92 357 738 8.89 78 17.91 118 26.79 158 35.57 198 44.29 238 52.95 278 61.56 318 70.14 358 7
304

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

Std.

μg/L

Hard.

mg/L

μ

39 9.12 79 18.13 119 27.01 159 35.79 199 44.50 239 53.16 279 61.78 319 70.35 359 740 9.35 80 18.36 120 27.23 160 36.01 200 44.72 240 53.38 280 61.99 320 70.56 360 7

Table 7. Acute Water Quality Standards for dissolved Dissolved Chromium III 

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

m 

1 NA 13 41 275 81 479 121 666 161 842 201 1009 241 1171 281 1328 321 12 NA 23 42 280 82 484 122 671 162 846 202 1013 242 1175 282 1332 322 13 NA 32 43 285 83 489 123 675 163 850 203 1017 243 1179 283 1336 323 14 NA 41 44 291 84 494 124 680 164 854 204 1022 244 1183 284 1340 324 15 NA 49 45 296 85 499 125 684 165 859 205 1026 245 1187 285 1343 325 16 NA 57 46 302 86 504 126 688 166 863 206 1030 246 1191 286 1347 326 17 NA 65 47 307 87 508 127 693 167 867 207 1034 247 1195 287 1351 327 18 NA 72 48 312 88 513 128 697 168 871 208 1038 248 1199 288 1355 328 19 NA 79 49 318 89 518 129 702 169 876 209 1042 249 1203 289 1359 329 1

10 NA 86 50 323 90 523 130 706 170 880 210 1046 250 1207 290 1363 330 111 NA 93 51 328 91 527 131 711 171 884 211 1050 251 1211 291 1367 331 112 

NA 

100

52 334 92 532 132 715 172 888 212 1054 252 1215 292 1370 332 1

13 

NA 

107

53 339 93 537 133 720 173 893 213 1058 253 1219 293 1374 333 1

14 

NA 

114

54 344 94 542 134 724 174 897 214 1062 254 1223 294 1378 334 1

15 

NA 

120

55 349 95 546 135 729 175 901 215 1067 255 1226 295 1382 335 1

16 NA 56 354 96 551 136 733 176 905 216 1071 256 1230 296 1386 336 1
305

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

m 

127

17 

NA 

133

57 360 97 556 137 737 177 909 217 1075 257 1234 297 1390 337 1

18 

NA 

140

58 365 98 560 138 742 178 914 218 1079 258 1238 298 1393 338 1

19 

NA 

146

59 370 99 565 139 746 179 918 219 1083 259 1242 299 1397 339 1

20 

NA 

152

60 375 100 570 140 751 180 922 220 1087 260 1246 300 1401 340 1

21 

NA 

159

61 380 101 574 141 755 181 926 221 1091 261 1250 301 1405 341 1

22 

NA 

165

62 385 102 579 142 759 182 930 222 1095 262 1254 302 1409 342 1

23 

NA 

171

63 390 103 584 143 764 183 935 223 1099 263 1258 303 1413 343 1

24 

NA 

177

64 395 104 588 144 768 184 939 224 1103 264 1262 304 1416 344 1

25 183 65 400 105 593 145 772 185 943 225 1107 265 1266 305 1420 345 126 189 66 405 106 598 146 777 186 947 226 1111 266 1270 306 1424 346 127 195 67 410 107 602 147 781 187 951 227 1115 267 1274 307 1428 347 128 201 68 415 108 607 148 785 188 955 228 1119 268 1277 308 1432 348 129 207 69 420 109 611 149 790 189 960 229 1123 269 1281 309 1435 349 130 213 70 425 110 616 150 794 190 964 230 1127 270 1285 310 1439 350 131 218 71 430 111 621 151 799 191 968 231 1131 271 1289 311 1443 351 132 224 72 435 112 625 152 803 192 972 232 1135 272 1293 312 1447 352 133 230 73 440 113 630 153 807 193 976 233 1139 273 1297 313 1451 353 134 235 74 445 114 634 154 811 194 980 234 1143 274 1301 314 1454 354 1
306

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

m 

35 241 75 450 115 639 155 816 195 985 235 1147 275 1305 315 1458 355 136 247 76 455 116 643 156 820 196 989 236 1151 276 1309 316 1462 356 137 252 77 460 117 648 157 824 197 993 237 1155 277 1312 317 1466 357 138 258 78 465 118 652 158 829 198 997 238 1159 278 1316 318 1470 358 139 263 79 470 119 657 159 833 199 1001 239 1163 279 1320 319 1473 359 140 269 80 475 120 662 160 837 200 1005 240 1167 280 1324 320 1477 360 1

Table 8. Chronic Water Quality Standards for dissolved Dissolved Chromium III 

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

1 

NA 

1.71

41 35.71 81 62.37 121 86.64 161 109.47 201 131.29 241 152.33 281 172.74 321 1

2 

NA 

3.01

42 36.42 82 63.00 122 87.22 162 110.03 202 131.82 242 152.84 282 173.24 322 1

3 

NA 

4.19

43 37.13 83 63.63 123 87.81 163 110.58 203 132.36 243 153.36 283 173.75 323 1

4 

NA 

5.31

44 37.83 84 64.25 124 88.39 164 111.14 204 132.89 244 153.88 284 174.25 324 1

5 

NA 

6.37

45 38.54 85 64.88 125 88.98 165 111.69 205 133.42 245 154.39 285 174.75 325 1

6 

NA 

7.40

46 39.24 86 65.50 126 89.56 166 112.25 206 133.96 246 154.91 286 175.25 326 1

7 

NA 

8.40

47 39.93 87 66.13 127 90.14 167 112.80 207 134.49 247 155.43 287 175.76 327 1

8 

NA 

9.37

48 40.63 88 66.75 128 90.72 168 113.35 208 135.02 248 155.94 288 176.26 328 1
307

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

9 

NA 

10.31

49 41.32 89 67.37 129 91.30 169 113.90 209 135.55 249 156.46 289 176.76 329 1

10 

NA 

11.24

50 42.01 90 67.99 130 91.88 170 114.46 210 136.08 250 156.97 290 177.26 330 1

11 

NA 

12.16

51 42.70 91 68.61 131 92.46 171 115.01 211 136.61 251 157.48 291 177.76 331 1

12 

NA 

13.05

52 43.38 92 69.22 132 93.04 172 115.56 212 137.14 252 158.00 292 178.26 332 1

13 

NA 

13.94

53 44.06 93 69.84 133 93.61 173 116.11 213 137.67 253 158.51 293 178.76 333 1

14 

NA 

14.81

54 44.74 94 70.45 134 94.19 174 116.66 214 138.20 254 159.02 294 179.26 334 1

15 

NA 

15.67

55 45.42 95 71.07 135 94.76 175 117.21 215 138.73 255 159.54 295 179.76 335 1

16 

NA 

16.52

56 46.10 96 71.68 136 95.34 176 117.75 216 139.26 256 160.05 296 180.26 336 1

17 

NA 

17.36

57 46.77 97 72.29 137 95.91 177 118.30 217 139.79 257 160.56 297 180.76 337 2

18 

NA 

18.20

58 47.44 98 72.90 138 96.49 178 118.85 218 140.31 258 161.07 298 181.25 338 2

19 

NA 

19.02

59 48.11 99 73.51 139 97.06 179 119.40 219 140.84 259 161.58 299 181.75 339 2

20 

NA 

19.84

60 48.78 100 74.11 140 97.63 180 119.94 220 141.37 260 162.09 300 182.25 340 2

21 

NA 

20.64

61 49.44 101 74.72 141 98.20 181 120.49 221 141.89 261 162.60 301 182.75 341 2

22 NA 62 50.10 102 75.33 142 98.77 182 121.03 222 142.42 262 163.11 302 183.24 342 2
308

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

21.45

23 

NA 

22.24

63 50.76 103 75.93 143 99.34 183 121.58 223 142.94 263 163.62 303 183.74 343 2

24 

NA 

23.03

64 51.42 104 76.53 144 99.91 184 122.12 224 143.47 264 164.13 304 184.24 344 2

25 23.81 65 52.08 105 77.14 145 100.48 185 122.66 225 143.99 265 164.64 305 184.73 345 226 24.59 66 52.74 106 77.74 146 101.04 186 123.21 226 144.52 266 165.15 306 185.23 346 227 25.36 67 53.39 107 78.34 147 101.61 187 123.75 227 145.04 267 165.66 307 185.72 347 228 26.13 68 54.04 108 78.94 148 102.18 188 124.29 228 145.56 268 166.17 308 186.22 348 229 26.89 69 54.69 109 79.53 149 102.74 189 124.83 229 146.09 269 166.67 309 186.72 349 230 27.65 70 55.34 110 80.13 150 103.31 190 125.37 230 146.61 270 167.18 310 187.21 350 231 28.40 71 55.99 111 80.73 151 103.87 191 125.91 231 147.13 271 167.69 311 187.70 351 232 29.15 72 56.63 112 81.32 152 104.43 192 126.45 232 147.65 272 168.20 312 188.20 352 233 29.89 73 57.27 113 81.92 153 104.99 193 126.99 233 148.17 273 168.70 313 188.69 353 234 30.63 74 57.92 114 82.51 154 105.56 194 127.53 234 148.69 274 169.21 314 189.19 354 235 31.37 75 58.56 115 83.10 155 106.12 195 128.07 235 149.21 275 169.71 315 189.68 355 236 32.10 76 59.20 116 83.69 156 106.68 196 128.61 236 149.73 276 170.22 316 190.17 356 237 32.83 77 59.83 117 84.28 157 107.24 197 129.14 237 150.25 277 170.72 317 190.66 357 238 33.55 78 60.47 118 84.87 158 107.80 198 129.68 238 150.77 278 171.23 318 191.16 358 239 34.28 79 61.10 119 85.46 159 108.35 199 130.22 239 151.29 279 171.73 319 191.65 359 240 34.99 80 61.74 120 86.05 160 108.91 200 130.75 240 151.81 280 172.24 320 192.14 360 2

Table 6. 9. Acute Water Quality Standards for dissolved Dissolved Chromium III 

Aquatic and Wildlife ephemeral

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ
309

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

1 NA 44 41 921 81 1609 121 2235 161 2824 201 3386 241 3929 281 4456 321 42 NA 78 42 939 82 1625 122 2250 162 2838 202 3400 242 3942 282 4469 322 43 

NA 

108

43 958 83 1641 123 2265 163 2852 203 3414 243 3956 283 4481 323 4

4 

NA 

137

44 976 84 1657 124 2280 164 2867 204 3428 244 3969 284 4494 324 5

5 

NA 

164

45 994 85 1673 125 2295 165 2881 205 3441 245 3982 285 4507 325 5

6 

NA 

191

46 1012 86 1690 126 2310 166 2895 206 3455 246 3996 286 4520 326 5

7 

NA 

217

47 1030 87 1706 127 2325 167 2909 207 3469 247 4009 287 4533 327 5

8 

NA 

242

48 1048 88 1722 128 2340 168 2924 208 3483 248 4022 288 4546 328 5

9 

NA 

266

49 1066 89 1738 129 2355 169 2938 209 3496 249 4035 289 4559 329 5

10 

NA 

290

50 1084 90 1754 130 2370 170 2952 210 3510 250 4049 290 4572 330 5

11 

NA 

314

51 1101 91 1770 131 2385 171 2966 211 3524 251 4062 291 4585 331 5

12 

NA 

337

52 1119 92 1785 132 2400 172 2981 212 3537 252 4075 292 4598 332 5

13 

NA 

360

53 1137 93 1801 133 2415 173 2995 213 3551 253 4088 293 4611 333 5

14 

NA 

382

54 1154 94 1817 134 2429 174 3009 214 3565 254 4102 294 4624 334 5

15 NA 55 1172 95 1833 135 2444 175 3023 215 3578 255 4115 295 4637 335 5
310

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

404

16 

NA 

426

56 1189 96 1849 136 2459 176 3037 216 3592 256 4128 296 4649 336 5

17 

NA 

448

57 1206 97 1865 137 2474 177 3051 217 3606 257 4141 297 4662 337 5

18 

NA 

469

58 1224 98 1880 138 2489 178 3066 218 3619 258 4155 298 4675 338 5

19 

NA 

491

59 1241 99 1896 139 2503 179 3080 219 3633 259 4168 299 4688 339 5

20 

NA 

512

60 1258 100 1912 140 2518 180 3094 220 3646 260 4181 300 4701 340 5

21 

NA 

532

61 1275 101 1927 141 2533 181 3108 221 3660 261 4194 301 4714 341 5

22 

NA 

553

62 1292 102 1943 142 2548 182 3122 222 3673 262 4207 302 4726 342 5

23 

NA 

574

63 1309 103 1958 143 2562 183 3136 223 3687 263 4220 303 4739 343 5

24 

NA 

594

64 1326 104 1974 144 2577 184 3150 224 3701 264 4234 304 4752 344 5

25 614 65 1343 105 1990 145 2592 185 3164 225 3714 265 4247 305 4765 345 526 634 66 1360 106 2005 146 2606 186 3178 226 3728 266 4260 306 4778 346 527 654 67 1377 107 2021 147 2621 187 3192 227 3741 267 4273 307 4790 347 528 674 68 1394 108 2036 148 2635 188 3206 228 3755 268 4286 308 4803 348 529 694 69 1411 109 2051 149 2650 189 3220 229 3768 269 4299 309 4816 349 530 713 70 1427 110 2067 150 2665 190 3234 230 3781 270 4312 310 4829 350 531 733 71 1444 111 2082 151 2679 191 3248 231 3795 271 4325 311 4841 351 532 752 72 1461 112 2098 152 2694 192 3262 232 3808 272 4338 312 4854 352 5
311

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

33 771 73 1477 113 2113 153 2708 193 3276 233 3822 273 4351 313 4867 353 534 790 74 1494 114 2128 154 2723 194 3289 234 3835 274 4364 314 4880 354 535 809 75 1510 115 2143 155 2737 195 3303 235 3849 275 4377 315 4892 355 536 828 76 1527 116 2159 156 2752 196 3317 236 3862 276 4390 316 4905 356 537 847 77 1543 117 2174 157 2766 197 3331 237 3875 277 4404 317 4918 357 538 865 78 1560 118 2189 158 2780 198 3345 238 3889 278 4417 318 4931 358 539 884 79 1576 119 2204 159 2795 199 3359 239 3902 279 4430 319 4943 359 540 903 80 1592 120 2220 160 2809 200 3372 240 3916 280 4443 320 4956 360 5

Table 11. 10. Acute Water Quality Standards for dissolved Dissolved Copper 

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

1 

NA 

0.18

41 5.80 81 11.02 121 16.08 161 21.05 201 25.94 241 30.78 281 35.57 321 4

2 

NA 

0.34

42 5.93 82 11.15 122 16.21 162 21.17 202 26.07 242 30.90 282 35.69 322 4

3 

NA 

0.49

43 6.07 83 11.28 123 16.33 163 21.30 203 26.19 243 31.02 283 35.81 323 4

4 

NA 

0.65

44 6.20 84 11.40 124 16.46 164 21.42 204 26.31 244 31.14 284 35.93 324 4

5 

NA 

0.80

45 6.33 85 11.53 125 16.58 165 21.54 205 26.43 245 31.26 285 36.05 325 4

6 

NA 

0.95

46 6.47 86 11.66 126 16.71 166 21.66 206 26.55 246 31.38 286 36.17 326 4

7 

NA 

1.10

47 6.60 87 11.79 127 16.83 167 21.79 207 26.67 247 31.50 287 36.29 327 4
312

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

8 

NA 

1.24

48 6.73 88 11.91 128 16.96 168 21.91 208 26.79 248 31.62 288 36.41 328 4

9 

NA 

1.39

49 6.86 89 12.04 129 17.08 169 22.03 209 26.92 249 31.74 289 36.53 329 4

10 

NA 

1.54

50 6.99 90 12.17 130 17.21 170 22.16 210 27.04 250 31.86 290 36.65 330 4

11 

NA 

1.68

51 7.13 91 12.30 131 17.33 171 22.28 211 27.16 251 31.98 291 36.77 331 4

12 

NA 

1.82

52 7.26 92 12.42 132 17.46 172 22.40 212 27.28 252 32.10 292 36.89 332 4

13 

NA 

1.97

53 7.39 93 12.55 133 17.58 173 22.52 213 27.40 253 32.22 293 37.00 333 4

14 

NA 

2.11

54 7.52 94 12.68 134 17.71 174 22.65 214 27.52 254 32.34 294 37.12 334 4

15 

NA 

2.25

55 7.65 95 12.81 135 17.83 175 22.77 215 27.64 255 32.46 295 37.24 335 4

16 

NA 

2.39

56 7.78 96 12.93 136 17.96 176 22.89 216 27.76 256 32.58 296 37.36 336 4

17 

NA 

2.53

57 7.91 97 13.06 137 18.08 177 23.02 217 27.89 257 32.70 297 37.48 337 4

18 

NA 

2.67

58 8.04 98 13.19 138 18.20 178 23.14 218 28.01 258 32.82 298 37.60 338 4

19 

NA 

2.81

59 8.17 99 13.31 139 18.33 179 23.26 219 28.13 259 32.94 299 37.72 339 4

20 

NA 

2.95

60 8.31 100 13.44 140 18.45 180 23.38 220 28.25 260 33.06 300 37.84 340 4

21 NA 61 8.44 101 13.57 141 18.58 181 23.50 221 28.37 261 33.18 301 37.96 341 4
313

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

3.09

22 

NA 

3.23

62 8.57 102 13.69 142 18.70 182 23.63 222 28.49 262 33.30 302 38.07 342 4

23 

NA 

3.37

63 8.70 103 13.82 143 18.82 183 23.75 223 28.61 263 33.42 303 38.19 343 4

24 

NA 

3.50

64 8.83 104 13.95 144 18.95 184 23.87 224 28.73 264 33.54 304 38.31 344 4

25 3.64 65 8.96 105 14.07 145 19.07 185 23.99 225 28.85 265 33.66 305 38.43 345 426 3.78 66 9.09 106 14.20 146 19.20 186 24.12 226 28.97 266 33.78 306 38.55 346 427 3.91 67 9.22 107 14.32 147 19.32 187 24.24 227 29.09 267 33.90 307 38.67 347 428 4.05 68 9.34 108 14.45 148 19.44 188 24.36 228 29.22 268 34.02 308 38.79 348 429 4.19 69 9.47 109 14.58 149 19.57 189 24.48 229 29.34 269 34.14 309 38.91 349 430 4.32 70 9.60 110 14.70 150 19.69 190 24.60 230 29.46 270 34.26 310 39.02 350 431 4.46 71 9.73 111 14.83 151 19.82 191 24.73 231 29.58 271 34.38 311 39.14 351 432 4.59 72 9.86 112 14.95 152 19.94 192 24.85 232 29.70 272 34.50 312 39.26 352 433 4.73 73 9.99 113 15.08 153 20.06 193 24.97 233 29.82 273 34.62 313 39.38 353 434 4.86 74 10.12 114 15.20 154 20.19 194 25.09 234 29.94 274 34.74 314 39.50 354 435 5.00 75 10.25 115 15.33 155 20.31 195 25.21 235 30.06 275 34.86 315 39.62 355 436 5.13 76 10.38 116 15.46 156 20.43 196 25.34 236 30.18 276 34.98 316 39.74 356 437 5.27 77 10.51 117 15.58 157 20.56 197 25.46 237 30.30 277 35.10 317 39.85 357 438 5.40 78 10.63 118 15.71 158 20.68 198 25.58 238 30.42 278 35.22 318 39.97 358 439 5.53 79 10.76 119 15.83 159 20.80 199 25.70 239 30.54 279 35.34 319 40.09 359 440 5.67 80 10.89 120 15.96 160 20.93 200 25.82 240 30.66 280 35.46 320 40.21 360 4

Table 9. 11. Chronic Water Quality Standards for dissolved Dissolved Copper 

Aquatic and Wildlife coldwater, warmwater, and edw
314

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

1 

NA 

0.18

41 4.18 81 7.48 121 10.54 161 13.45 201 16.26 241 18.99 281 21.65 321 2

2 

NA 

0.32

42 4.27 82 7.56 122 10.61 162 13.52 202 16.33 242 19.06 282 21.72 322 2

3 

NA 

0.45

43 4.35 83 7.64 123 10.69 163 13.60 203 16.40 243 19.13 283 21.78 323 2

4 

NA 

0.57

44 4.44 84 7.72 124 10.76 164 13.67 204 16.47 244 19.19 284 21.85 324 2

5 

NA 

0.69

45 4.53 85 7.79 125 10.84 165 13.74 205 16.54 245 19.26 285 21.92 325 2

6 

NA 

0.81

46 4.61 86 7.87 126 10.91 166 13.81 206 16.61 246 19.33 286 21.98 326 2

7 

NA 

0.92

47 4.70 87 7.95 127 10.99 167 13.88 207 16.68 247 19.39 287 22.05 327 2

8 

NA 

1.03

48 4.78 88 8.03 128 11.06 168 13.95 208 16.75 248 19.46 288 22.11 328 2

9 

NA 

1.14

49 4.87 89 8.11 129 11.13 169 14.02 209 16.81 249 19.53 289 22.18 329 2

10 

NA 

1.25

50 4.95 90 8.18 130 11.21 170 14.09 210 16.88 250 19.59 290 22.24 330 2

11 

NA 

1.36

51 5.04 91 8.26 131 11.28 171 14.16 211 16.95 251 19.66 291 22.31 331 2

12 

NA 

1.46

52 5.12 92 8.34 132 11.35 172 14.24 212 17.02 252 19.73 292 22.38 332 2

13 

NA 

1.57

53 5.21 93 8.42 133 11.43 173 14.31 213 17.09 253 19.80 293 22.44 333 2

14 NA 54 5.29 94 8.49 134 11.50 174 14.38 214 17.16 254 19.86 294 22.51 334 2
315

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

1.67

15 

NA 

1.77

55 5.37 95 8.57 135 11.57 175 14.45 215 17.23 255 19.93 295 22.57 335 2

16 

NA 

1.87

56 5.46 96 8.65 136 11.65 176 14.52 216 17.29 256 20.00 296 22.64 336 2

17 

NA 

1.97

57 5.54 97 8.73 137 11.72 177 14.59 217 17.36 257 20.06 297 22.70 337 2

18 

NA 

2.07

58 5.62 98 8.80 138 11.79 178 14.66 218 17.43 258 20.13 298 22.77 338 2

19 

NA 

2.17

59 5.71 99 8.88 139 11.87 179 14.73 219 17.50 259 20.20 299 22.83 339 2

20 

NA 

2.26

60 5.79 100 8.96 140 11.94 180 14.80 220 17.57 260 20.26 300 22.90 340 2

21 

NA 

2.36

61 5.87 101 9.03 141 12.01 181 14.87 221 17.64 261 20.33 301 22.96 341 2

22 

NA 

2.46

62 5.95 102 9.11 142 12.08 182 14.94 222 17.70 262 20.40 302 23.03 342 2

23 

NA 

2.55

63 6.03 103 9.18 143 12.16 183 15.01 223 17.77 263 20.46 303 23.09 343 2

24 

NA 

2.65

64 6.12 104 9.26 144 12.23 184 15.08 224 17.84 264 20.53 304 23.16 344 2

25 2.74 65 6.20 105 9.34 145 12.30 185 15.15 225 17.91 265 20.60 305 23.22 345 226 2.83 66 6.28 106 9.41 146 12.37 186 15.22 226 17.98 266 20.66 306 23.29 346 227 2.93 67 6.36 107 9.49 147 12.45 187 15.29 227 18.04 267 20.73 307 23.35 347 228 3.02 68 6.44 108 9.56 148 12.52 188 15.36 228 18.11 268 20.79 308 23.42 348 229 3.11 69 6.52 109 9.64 149 12.59 189 15.43 229 18.18 269 20.86 309 23.48 349 230 3.20 70 6.60 110 9.72 150 12.66 190 15.50 230 18.25 270 20.93 310 23.55 350 2
316

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

31 3.29 71 6.68 111 9.79 151 12.74 191 15.57 231 18.32 271 20.99 311 23.61 351 232 3.38 72 6.76 112 9.87 152 12.81 192 15.64 232 18.38 272 21.06 312 23.68 352 233 3.47 73 6.84 113 9.94 153 12.88 193 15.71 233 18.45 273 21.13 313 23.74 353 234 3.56 74 6.92 114 10.02 154 12.95 194 15.78 234 18.52 274 21.19 314 23.81 354 235 3.65 75 7.00 115 10.09 155 13.02 195 15.85 235 18.59 275 21.26 315 23.87 355 236 3.74 76 7.08 116 10.17 156 13.10 196 15.92 236 18.65 276 21.32 316 23.94 356 237 3.83 77 7.16 117 10.24 157 13.17 197 15.99 237 18.72 277 21.39 317 24.00 357 238 3.92 78 7.24 118 10.32 158 13.24 198 16.05 238 18.79 278 21.46 318 24.07 358 239 4.01 79 7.32 119 10.39 159 13.31 199 16.12 239 18.86 279 21.52 319 24.13 359 240 4.09 80 7.40 120 10.47 160 13.38 200 16.19 240 18.92 280 21.59 320 24.20 360 2

Table 10. 12. Acute Water Quality Standards for dissolved Dissolved Copper 

Aquatic and Wildlife ephemeral

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

1 

NA 

0.30

41 10.04 81 19.07 121 27.84 161 36.43 201 44.91 241 53.28 281 61.57 321 6

2 

NA 

0.58

42 10.27 82 19.29 122 28.05 162 36.65 202 45.12 242 53.49 282 61.78 322 7

3 

NA 

0.85

43 10.50 83 19.52 123 28.27 163 36.86 203 45.33 243 53.70 283 61.99 323 7

4 

NA 

1.12

44 10.73 84 19.74 124 28.49 164 37.07 204 45.54 244 53.90 284 62.19 324 7

5 

NA 

1.38

45 10.96 85 19.96 125 28.70 165 37.29 205 45.75 245 54.11 285 62.40 325 7

6 

NA 

1.64

46 11.19 86 20.18 126 28.92 166 37.50 206 45.96 246 54.32 286 62.61 326 7
317

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

7 

NA 

1.90

47 11.42 87 20.40 127 29.14 167 37.71 207 46.17 247 54.53 287 62.81 327 7

8 

NA 

2.15

48 11.65 88 20.62 128 29.35 168 37.92 208 46.38 248 54.74 288 63.02 328 7

9 

NA 

2.41

49 11.88 89 20.84 129 29.57 169 38.14 209 46.59 249 54.94 289 63.22 329 7

10 

NA 

2.66

50 12.11 90 21.06 130 29.78 170 38.35 210 46.80 250 55.15 290 63.43 330 7

11 

NA 

2.91

51 12.33 91 21.28 131 30.00 171 38.56 211 47.01 251 55.36 291 63.64 331 7

12 

NA 

3.16

52 12.56 92 21.50 132 30.22 172 38.77 212 47.22 252 55.57 292 63.84 332 7

13 

NA 

3.40

53 12.79 93 21.72 133 30.43 173 38.99 213 47.43 253 55.78 293 64.05 333 7

14 

NA 

3.65

54 13.02 94 21.94 134 30.65 174 39.20 214 47.64 254 55.98 294 64.25 334 7

15 

NA 

3.89

55 13.24 95 22.16 135 30.86 175 39.41 215 47.85 255 56.19 295 64.46 335 7

16 

NA 

4.14

56 13.47 96 22.38 136 31.08 176 39.62 216 48.06 256 56.40 296 64.67 336 7

17 

NA 

4.38

57 13.70 97 22.60 137 31.29 177 39.84 217 48.27 257 56.61 297 64.87 337 7

18 

NA 

4.62

58 13.92 98 22.82 138 31.51 178 40.05 218 48.48 258 56.81 298 65.08 338 7

19 

NA 

4.86

59 14.15 99 23.04 139 31.72 179 40.26 219 48.68 259 57.02 299 65.28 339 7

20 NA 60 14.37 100 23.26 140 31.94 180 40.47 220 48.89 260 57.23 300 65.49 340 7
318

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

5.11

21 

NA 

5.35

61 14.60 101 23.48 141 32.15 181 40.68 221 49.10 261 57.44 301 65.69 341 7

22 

NA 

5.59

62 14.83 102 23.70 142 32.37 182 40.89 222 49.31 262 57.64 302 65.90 342 7

23 

NA 

5.82

63 15.05 103 23.92 143 32.58 183 41.11 223 49.52 263 57.85 303 66.11 343 7

24 

NA 

6.06

64 15.28 104 24.14 144 32.80 184 41.32 224 49.73 264 58.06 304 66.31 344 7

25 6.30 65 15.50 105 24.36 145 33.01 185 41.53 225 49.94 265 58.26 305 66.52 345 726 6.54 66 15.73 106 24.57 146 33.23 186 41.74 226 50.15 266 58.47 306 66.72 346 727 6.77 67 15.95 107 24.79 147 33.44 187 41.95 227 50.36 267 58.68 307 66.93 347 728 7.01 68 16.17 108 25.01 148 33.65 188 42.16 228 50.57 268 58.89 308 67.13 348 729 7.25 69 16.40 109 25.23 149 33.87 189 42.37 229 50.78 269 59.09 309 67.34 349 730 7.48 70 16.62 110 25.45 150 34.08 190 42.59 230 50.99 270 59.30 310 67.54 350 731 7.72 71 16.85 111 25.66 151 34.30 191 42.80 231 51.19 271 59.51 311 67.75 351 732 7.95 72 17.07 112 25.88 152 34.51 192 43.01 232 51.40 272 59.71 312 67.95 352 733 8.18 73 17.29 113 26.10 153 34.72 193 43.22 233 51.61 273 59.92 313 68.16 353 734 8.42 74 17.52 114 26.32 154 34.94 194 43.43 234 51.82 274 60.13 314 68.36 354 735 8.65 75 17.74 115 26.53 155 35.15 195 43.64 235 52.03 275 60.33 315 68.57 355 736 8.88 76 17.96 116 26.75 156 35.37 196 43.85 236 52.24 276 60.54 316 68.77 356 737 9.12 77 18.18 117 26.97 157 35.58 197 44.06 237 52.45 277 60.75 317 68.98 357 738 9.35 78 18.41 118 27.19 158 35.79 198 44.27 238 52.65 278 60.95 318 69.18 358 739 9.58 79 18.63 119 27.40 159 36.01 199 44.48 239 52.86 279 61.16 319 69.39 359 740 9.81 80 18.85 120 27.62 160 36.22 200 44.69 240 53.07 280 61.37 320 69.59 360 7

Table 14. 13. Acute Water Quality Standards for dissolved Dissolved Lead 
319

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

1 

NA 

0.34

41 24.17 81 51.30 121 79.43 161 108.02 201 136.86 241 165.82 281 194.81 321 2

2 

NA 

0.76

42 24.82 82 52.00 122 80.14 162 108.74 202 137.59 242 166.55 282 195.54 322 2

3 

NA 

1.22

43 25.48 83 52.69 123 80.85 163 109.46 203 138.31 243 167.27 283 196.26 323 2

4 

NA 

1.71

44 26.14 84 53.39 124 81.56 164 110.18 204 139.03 244 167.99 284 196.99 324 2

5 

NA 

2.21

45 26.81 85 54.08 125 82.27 165 110.90 205 139.76 245 168.72 285 197.71 325 2

6 

NA 

2.73

46 27.47 86 54.78 126 82.98 166 111.62 206 140.48 246 169.44 286 198.44 326 2

7 

NA

3.26

47 28.13 87 55.48 127 83.69 167 112.34 207 141.20 247 170.17 287 199.16 327 2

8 

NA 

3.80

48 28.80 88 56.17 128 84.41 168 113.06 208 141.93 248 170.89 288 199.89 328 2

9 

NA 

4.35

49 29.47 89 56.87 129 85.12 169 113.78 209 142.65 249 171.62 289 200.61 329 2

10 

NA 

4.91

50 30.14 90 57.57 130 85.83 170 114.50 210 143.37 250 172.34 290 201.34 330 2

11 

NA 

5.47

51 30.81 91 58.27 131 86.54 171 115.22 211 144.10 251 173.07 291 202.06 331 2

12 

NA 

6.04

52 31.48 92 58.97 132 87.26 172 115.94 212 144.82 252 173.79 292 202.79 332 2

13 

NA 

6.62

53 32.15 93 59.67 133 87.97 173 116.66 213 145.54 253 174.52 293 203.51 333 2
320

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

14 

NA 

7.20

54 32.82 94 60.37 134 88.68 174 117.38 214 146.27 254 175.24 294 204.24 334 2

15 

NA 

7.79

55 33.49 95 61.07 135 89.40 175 118.10 215 146.99 255 175.97 295 204.96 335 2

16 

NA 

8.38

56 34.17 96 61.77 136 90.11 176 118.82 216 147.71 256 176.69 296 205.69 336 2

17 

NA 

8.98

57 34.84 97 62.47 137 90.83 177 119.54 217 148.44 257 177.42 297 206.41 337 2

18 

NA 

9.58

58 35.52 98 63.18 138 91.54 178 120.26 218 149.16 258 178.14 298 207.13 338 2

19 

NA 

10.18

59 36.20 99 63.88 139 92.25 179 120.98 219 149.89 259 178.87 299 207.86 339 2

20 

NA 

10.79

60 36.88 100 64.58 140 92.97 180 121.70 220 150.61 260 179.59 300 208.58 340 2

21 

NA 

11.40

61 37.56 101 65.28 141 93.68 181 122.42 221 151.33 261 180.32 301 209.31 341 2

22 

NA 

12.02

62 38.24 102 65.99 142 94.40 182 123.14 222 152.06 262 181.04 302 210.03 342 2

23 

NA 

12.64

63 38.92 103 66.69 143 95.12 183 123.87 223 152.78 263 181.77 303 210.76 343 2

24 

NA 

13.26

64 39.60 104 67.40 144 95.83 184 124.59 224 153.51 264 182.49 304 211.48 344 2

25 13.88 65 40.28 105 68.10 145 96.55 185 125.31 225 154.23 265 183.22 305 212.21 345 226 14.51 66 40.97 106 68.81 146 97.26 186 126.03 226 154.95 266 183.94 306 212.93 346 227 15.14 67 41.65 107 69.51 147 97.98 187 126.75 227 155.68 267 184.67 307 213.65 347 228 15.77 68 42.33 108 70.22 148 98.70 188 127.47 228 156.40 268 185.39 308 214.38 348 229 16.40 69 43.02 109 70.93 149 99.41 189 128.20 229 157.13 269 186.12 309 215.10 349 2
321

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

μ

30 17.04 70 43.71 110 71.63 150 100.13 190 128.92 230 157.85 270 186.84 310 215.83 350 231 17.68 71 44.39 111 72.34 151 100.85 191 129.64 231 158.58 271 187.57 311 216.55 351 232 18.32 72 45.08 112 73.05 152 101.56 192 130.36 232 159.30 272 188.29 312 217.28 352 233 18.96 73 45.77 113 73.75 153 102.28 193 131.08 233 160.02 273 189.02 313 218.00 353 234 19.61 74 46.46 114 74.46 154 103.00 194 131.81 234 160.75 274 189.74 314 218.72 354 235 20.25 75 47.15 115 75.17 155 103.72 195 132.53 235 161.47 275 190.47 315 219.45 355 236 20.90 76 47.84 116 75.88 156 104.43 196 133.25 236 162.20 276 191.19 316 220.17 356 237 21.55 77 48.53 117 76.59 157 105.15 197 133.97 237 162.92 277 191.92 317 220.90 357 238 22.20 78 49.22 118 77.30 158 105.87 198 134.70 238 163.65 278 192.64 318 221.62 358 239 22.86 79 49.92 119 78.01 159 106.59 199 135.42 239 164.37 279 193.36 319 222.34 359 240 23.51 80 50.61 120 78.72 160 107.31 200 136.14 240 165.10 280 194.09 320 223.07 360 2
322

Table 15. 14. Chronic Water Quality Standards for dissolved Dissolved Lead 

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

1 

NA

0.01

41 0.94 81 2.00 121 3.10 161 4.21 201 5.33 241 6.46 281 7.59 321 

2 

NA

0.03

42 0.97 82 2.03 122 3.12 162 4.24 202 5.36 242 6.49 282 7.62 322 

3 

NA

0.05

43 0.99 83 2.05 123 3.15 163 4.27 203 5.39 243 6.52 283 7.65 323 

4 

NA

0.07

44 1.02 84 2.08 124 3.18 164 4.29 204 5.42 244 6.55 284 7.68 324 

5 

NA

0.09

45 1.04 85 2.11 125 3.21 165 4.32 205 5.45 245 6.57 285 7.70 325 

6 

NA

0.11

46 1.07 86 2.13 126 3.23 166 4.35 206 5.47 246 6.60 286 7.73 326 

7 

NA

0.13

47 1.10 87 2.16 127 3.26 167 4.38 207 5.50 247 6.63 287 7.76 327 

8 

NA

0.15

48 1.12 88 2.19 128 3.29 168 4.41 208 5.53 248 6.66 288 7.79 328 

9 

NA

0.17

49 1.15 89 2.22 129 3.32 169 4.43 209 5.56 249 6.69 289 7.82 329 

10 

NA

0.19

50 1.17 90 2.24 130 3.34 170 4.46 210 5.59 250 6.72 290 7.85 330 

11 

NA

0.21

51 1.20 91 2.27 131 3.37 171 4.49 211 5.62 251 6.74 291 7.87 331 

12 

NA

0.24

52 1.23 92 2.30 132 3.40 172 4.52 212 5.64 252 6.77 292 7.90 332 

13 

NA

0.26

53 1.25 93 2.33 133 3.43 173 4.55 213 5.67 253 6.80 293 7.93 333 
323

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

14 

NA

0.28

54 1.28 94 2.35 134 3.46 174 4.57 214 5.70 254 6.83 294 7.96 334 

15 

NA

0.30

55 1.31 95 2.38 135 3.48 175 4.60 215 5.73 255 6.86 295 7.99 335 

16 

NA

0.33

56 1.33 96 2.41 136 3.51 176 4.63 216 5.76 256 6.89 296 8.02 336 

17 

NA

0.35

57 1.36 97 2.43 137 3.54 177 4.66 217 5.78 257 6.91 297 8.04 337 

18 

NA

0.37

58 1.38 98 2.46 138 3.57 178 4.69 218 5.81 258 6.94 298 8.07 338 

19 

NA

0.40

59 1.41 99 2.49 139 3.60 179 4.71 219 5.84 259 6.97 299 8.10 339 

20 

NA

0.42

60 1.44 100 2.52 140 3.62 180 4.74 220 5.87 260 7.00 300 8.13 340 

21 

NA

0.44

61 1.46 101 2.54 141 3.65 181 4.77 221 5.90 261 7.03 301 8.16 341 

22 

NA

0.47

62 1.49 102 2.57 142 3.68 182 4.80 222 5.93 262 7.05 302 8.18 342 

23 

NA

0.49

63 1.52 103 2.60 143 3.71 183 4.83 223 5.95 263 7.08 303 8.21 343 

24 

NA

0.52

64 1.54 104 2.63 144 3.73 184 4.85 224 5.98 264 7.11 304 8.24 344 

25 0.54 65 1.57 105 2.65 145 3.76 185 4.88 225 6.01 265 7.14 305 8.27 345 26 0.57 66 1.60 106 2.68 146 3.79 186 4.91 226 6.04 266 7.17 306 8.30 346 27 0.59 67 1.62 107 2.71 147 3.82 187 4.94 227 6.07 267 7.20 307 8.33 347 28 0.61 68 1.65 108 2.74 148 3.85 188 4.97 228 6.09 268 7.22 308 8.35 348 29 0.64 69 1.68 109 2.76 149 3.87 189 5.00 229 6.12 269 7.25 309 8.38 349 30 0.66 70 1.70 110 2.79 150 3.90 190 5.02 230 6.15 270 7.28 310 8.41 350 31 0.69 71 1.73 111 2.82 151 3.93 191 5.05 231 6.18 271 7.31 311 8.44 351 
324

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

32 0.71 72 1.76 112 2.85 152 3.96 192 5.08 232 6.21 272 7.34 312 8.47 352 33 0.74 73 1.78 113 2.87 153 3.99 193 5.11 233 6.24 273 7.37 313 8.50 353 34 0.76 74 1.81 114 2.90 154 4.01 194 5.14 234 6.26 274 7.39 314 8.52 354 35 0.79 75 1.84 115 2.93 155 4.04 195 5.16 235 6.29 275 7.42 315 8.55 355 36 0.81 76 1.86 116 2.96 156 4.07 196 5.19 236 6.32 276 7.45 316 8.58 356 37 0.84 77 1.89 117 2.98 157 4.10 197 5.22 237 6.35 277 7.48 317 8.61 357 38 0.87 78 1.92 118 3.01 158 4.13 198 5.25 238 6.38 278 7.51 318 8.64 358 39 0.89 79 1.95 119 3.04 159 4.15 199 5.28 239 6.41 279 7.54 319 8.66 359 40 0.92 80 1.97 120 3.07 160 4.18 200 5.31 240 6.43 280 7.56 320 8.69 360 

Table 13. 15. Acute Water Quality Standards for dissolved Dissolved Lead 

Aquatic and Wildlife ephemeral

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

1 

NA 

0.72

41 51.00 81 108.27 121 167.63 161 227.98 201 288.85 241 349.96 281 411.15 321 

2 

NA 

1.61

42 52.39 82 109.74 122 169.13 162 229.50 202 290.37 242 351.49 282 412.68 322 

3 

NA 

2.58

43 53.78 83 111.21 123 170.63 163 231.01 203 291.90 243 353.02 283 414.21 323 

4 

NA 

3.61

44 55.18 84 112.67 124 172.13 164 232.53 204 293.42 244 354.54 284 415.73 324 

5 

NA 

4.67

45 56.57 85 114.14 125 173.63 165 234.05 205 294.95 245 356.07 285 417.26 325 

6 

NA 

5.76

46 57.97 86 115.61 126 175.13 166 235.57 206 296.48 246 357.60 286 418.79 326 

7 

NA 

6.88

47 59.38 87 117.08 127 176.63 167 237.08 207 298.00 247 359.13 287 420.32 327 
325

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

8 

NA 

8.02

48 60.78 88 118.55 128 178.13 168 238.60 208 299.53 248 360.66 288 421.85 328 

9 

NA 

9.18

49 62.19 89 120.03 129 179.64 169 240.12 209 301.05 249 362.19 289 423.38 329 

10 

NA 

10.35

50 63.60 90 121.50 130 181.14 170 241.64 210 302.58 250 363.72 290 424.91 330 

11 

NA 

11.54

51 65.01 91 122.98 131 182.65 171 243.16 211 304.11 251 365.25 291 426.44 331 

12 

NA 

12.75

52 66.43 92 124.45 132 184.15 172 244.68 212 305.64 252 366.78 292 427.97 332 

13 

NA 

13.97

53 67.85 93 125.93 133 185.66 173 246.20 213 307.16 253 368.31 293 429.50 333 

14 

NA 

15.20

54 69.26 94 127.41 134 187.16 174 247.72 214 308.69 254 369.84 294 431.03 334 

15 

NA 

16.44

55 70.69 95 128.89 135 188.67 175 249.24 215 310.22 255 371.37 295 432.56 335 

16 

NA 

17.69

56 72.11 96 130.37 136 190.17 176 250.76 216 311.74 256 372.90 296 434.09 336 

17 

NA 

18.95

57 73.54 97 131.85 137 191.68 177 252.28 217 313.27 257 374.43 297 435.62 337 

18 

NA 

20.21

58 74.96 98 133.33 138 193.19 178 253.80 218 314.80 258 375.96 298 437.15 338 

19 

NA 

21.49

59 76.39 99 134.81 139 194.70 179 255.32 219 316.33 259 377.49 299 438.68 339 

20 

NA 

22.77

60 77.83 100 136.30 140 196.21 180 256.85 220 317.85 260 379.02 300 440.20 340 

21 

NA 

24.07

61 79.26 101 137.78 141 197.72 181 258.37 221 319.38 261 380.55 301 441.73 341 

22 NA 62 80.70 102 139.27 142 199.23 182 259.89 222 320.91 262 382.08 302 443.26 342 
326

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

25.36

23 

NA 

26.67

63 82.13 103 140.75 143 200.74 183 261.41 223 322.44 263 383.61 303 444.79 343 

24 

NA 

27.98

64 83.57 104 142.24 144 202.25 184 262.93 224 323.97 264 385.14 304 446.32 344 

25 29.30 65 85.01 105 143.73 145 203.76 185 264.46 225 325.49 265 386.67 305 447.85 345 26 30.62 66 86.46 106 145.21 146 205.27 186 265.98 226 327.02 266 388.20 306 449.38 346 27 31.95 67 87.90 107 146.70 147 206.78 187 267.50 227 328.55 267 389.73 307 450.91 347 28 33.28 68 89.35 108 148.19 148 208.29 188 269.03 228 330.08 268 391.26 308 452.44 348 29 34.62 69 90.79 109 149.68 149 209.80 189 270.55 229 331.61 269 392.79 309 453.96 349 30 35.96 70 92.24 110 151.18 150 211.32 190 272.07 230 333.14 270 394.32 310 455.49 350 31 37.31 71 93.69 111 152.67 151 212.83 191 273.60 231 334.67 271 395.85 311 457.02 351 32 38.66 72 95.14 112 154.16 152 214.34 192 275.12 232 336.19 272 397.38 312 458.55 352 33 40.02 73 96.60 113 155.65 153 215.86 193 276.65 233 337.72 273 398.91 313 460.08 353 34 41.38 74 98.05 114 157.15 154 217.37 194 278.17 234 339.25 274 400.44 314 461.61 354 35 42.74 75 99.51 115 158.64 155 218.89 195 279.69 235 340.78 275 401.97 315 463.13 355 36 44.11 76 100.97 116 160.14 156 220.40 196 281.22 236 342.31 276 403.50 316 464.66 356 37 45.48 77 102.43 117 161.64 157 221.92 197 282.74 237 343.84 277 405.03 317 466.19 357 38 46.86 78 103.89 118 163.13 158 223.43 198 284.27 238 345.37 278 406.56 318 467.72 358 39 48.24 79 105.35 119 164.63 159 224.95 199 285.79 239 346.90 279 408.09 319 469.25 359 40 49.62 80 106.81 120 166.13 160 226.46 200 287.32 240 348.43 280 409.62 320 470.77 360 

Table 16. Acute Water Quality Standards for dissolved Dissolved Nickel 

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

1 NA 10 41 220 81 392 121 550 161 701 201 845 241 985 281 1122 321 2 NA 17 42 225 82 396 122 554 162 704 202 849 242 989 282 1126 322 
327

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

3 NA 24 43 229 83 400 123 558 163 708 203 852 243 992 283 1129 323 4 NA 31 44 234 84 404 124 562 164 712 204 856 244 996 284 1132 324 5 NA 37 45 238 85 408 125 566 165 715 205 859 245 999 285 1136 325 6 NA 43 46 243 86 412 126 569 166 719 206 863 246 1003 286 1139 326 7 NA 49 47 247 87 416 127 573 167 723 207 867 247 1006 287 1142 327 8 NA 55 48 252 88 420 128 577 168 726 208 870 248 1010 288 1146 328 9 NA 61 49 256 89 424 129 581 169 730 209 874 249 1013 289 1149 329 

10 NA 67 50 260 90 428 130 585 170 734 210 877 250 1017 290 1153 330 11 NA 72 51 265 91 432 131 588 171 737 211 881 251 1020 291 1156 331 12 NA 78 52 269 92 436 132 592 172 741 212 884 252 1023 292 1159 332 13 NA 83 53 274 93 440 133 596 173 744 213 888 253 1027 293 1163 333 14 NA 89 54 278 94 444 134 600 174 748 214 891 254 1030 294 1166 334 15 NA 94 55 282 95 448 135 604 175 752 215 895 255 1034 295 1169 335 16 NA 99 56 287 96 452 136 607 176 755 216 898 256 1037 296 1173 336 17 

NA 

105

57 291 97 456 137 611 177 759 217 902 257 1041 297 1176 337 

18 

NA 

110

58 295 98 460 138 615 178 763 218 905 258 1044 298 1179 338 

19 

NA 

115

59 300 99 464 139 619 179 766 219 909 259 1047 299 1183 339 

20 

NA 

120

60 304 100 468 140 622 180 770 220 912 260 1051 300 1186 340 

21 

NA 

125

61 308 101 472 141 626 181 774 221 916 261 1054 301 1189 341 

22 

NA 

130

62 312 102 476 142 630 182 777 222 919 262 1058 302 1193 342 

23 

NA 

135

63 317 103 480 143 634 183 781 223 923 263 1061 303 1196 343 
328

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

24 

NA 

140

64 321 104 484 144 637 184 784 224 926 264 1064 304 1199 344 

25 145 65 325 105 488 145 641 185 788 225 930 265 1068 305 1203 345 26 150 66 329 106 492 146 645 186 792 226 933 266 1071 306 1206 346 27 155 67 334 107 496 147 649 187 795 227 937 267 1075 307 1209 347 28 159 68 338 108 500 148 652 188 799 228 940 268 1078 308 1213 348 29 164 69 342 109 504 149 656 189 802 229 944 269 1082 309 1216 349 30 169 70 346 110 508 150 660 190 806 230 947 270 1085 310 1219 350 31 174 71 350 111 511 151 664 191 810 231 951 271 1088 311 1223 351 32 179 72 355 112 515 152 667 192 813 232 954 272 1092 312 1226 352 33 183 73 359 113 519 153 671 193 817 233 958 273 1095 313 1229 353 34 188 74 363 114 523 154 675 194 820 234 961 274 1099 314 1233 354 35 193 75 367 115 527 155 678 195 824 235 965 275 1102 315 1236 355 36 197 76 371 116 531 156 682 196 827 236 968 276 1105 316 1239 356 37 202 77 375 117 535 157 686 197 831 237 972 277 1109 317 1243 357 38 207 78 379 118 539 158 689 198 835 238 975 278 1112 318 1246 358 39 211 79 384 119 542 159 693 199 838 239 979 279 1115 319 1249 359 40 216 80 388 120 546 160 697 200 842 240 982 280 1119 320 1253 360 

Table 17. Chronic Water Quality Standards for dissolved Dissolved Nickel 

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

1 

NA

1.06

41 24.46 81 43.51 121 61.11 161 77.81 201 93.88 241 109.46 281 124.64 321 

2 

NA

1.90

42 24.96 82 43.97 122 61.53 162 78.22 202 94.27 242 109.84 282 125.02 322 

3 NA 43 25.47 83 44.42 123 61.96 163 78.63 203 94.67 243 110.23 283 125.39 323 
329

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

2.68

4 

NA

3.42

44 25.97 84 44.87 124 62.39 164 79.03 204 95.06 244 110.61 284 125.77 324 

5 

NA

4.12

45 26.47 85 45.33 125 62.81 165 79.44 205 95.46 245 110.99 285 126.14 325 

6 

NA

4.81

46 26.96 86 45.78 126 63.24 166 79.85 206 95.85 246 111.38 286 126.52 326 

7 

NA

5.48

47 27.46 87 46.23 127 63.66 167 80.26 207 96.24 247 111.76 287 126.89 327 

8 

NA

6.14

48 27.95 88 46.68 128 64.09 168 80.66 208 96.64 248 112.14 288 127.26 328 

9 

NA

6.78

49 28.44 89 47.12 129 64.51 169 81.07 209 97.03 249 112.52 289 127.64 329 

10 

NA

7.41

50 28.93 90 47.57 130 64.93 170 81.47 210 97.42 250 112.91 290 128.01 330 

11 

NA

8.04

51 29.42 91 48.02 131 65.35 171 81.88 211 97.81 251 113.29 291 128.38 331 

12 

NA

8.65

52 29.91 92 48.46 132 65.78 172 82.28 212 98.21 252 113.67 292 128.76 332 

13 

NA

9.26

53 30.39 93 48.91 133 66.20 173 82.69 213 98.60 253 114.05 293 129.13 333 

14 

NA

9.86

54 30.88 94 49.35 134 66.62 174 83.09 214 98.99 254 114.43 294 129.50 334 

15 

NA

10.45

55 31.36 95 49.80 135 67.04 175 83.50 215 99.38 255 114.81 295 129.88 335 

16 

NA

11.03

56 31.84 96 50.24 136 67.46 176 83.90 216 99.77 256 115.19 296 130.25 336 

17 

NA

11.61

57 32.32 97 50.68 137 67.88 177 84.30 217 100.16 257 115.57 297 130.62 337 
330

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

18 

NA

12.19

58 32.80 98 51.13 138 68.30 178 84.71 218 100.55 258 115.95 298 130.99 338 

19 

NA

12.76

59 33.28 99 51.57 139 68.71 179 85.11 219 100.94 259 116.33 299 131.36 339 

20 

NA

13.33

60 33.76 100 52.01 140 69.13 180 85.51 220 101.33 260 116.71 300 131.74 340 

21 

NA

13.89

61 34.23 101 52.45 141 69.55 181 85.91 221 101.72 261 117.09 301 132.11 341 

22 

NA

14.45

62 34.71 102 52.89 142 69.97 182 86.31 222 102.11 262 117.47 302 132.48 342 

23 

NA

15.00

63 35.18 103 53.32 143 70.38 183 86.71 223 102.50 263 117.85 303 132.85 343 

24 

NA

15.55

64 35.65 104 53.76 144 70.80 184 87.12 224 102.89 264 118.23 304 133.22 344 

25 16.10 65 36.12 105 54.20 145 71.22 185 87.52 225 103.28 265 118.61 305 133.59 345 26 16.64 66 36.59 106 54.63 146 71.63 186 87.92 226 103.67 266 118.99 306 133.96 346 27 17.18 67 37.06 107 55.07 147 72.05 187 88.32 227 104.05 267 119.37 307 134.33 347 28 17.72 68 37.53 108 55.51 148 72.46 188 88.71 228 104.44 268 119.75 308 134.70 348 29 18.25 69 37.99 109 55.94 149 72.87 189 89.11 229 104.83 269 120.12 309 135.07 349 30 18.78 70 38.46 110 56.37 150 73.29 190 89.51 230 105.22 270 120.50 310 135.44 350 31 19.31 71 38.92 111 56.81 151 73.70 191 89.91 231 105.60 271 120.88 311 135.81 351 32 19.83 72 39.39 112 57.24 152 74.11 192 90.31 232 105.99 272 121.26 312 136.18 352 33 20.36 73 39.85 113 57.67 153 74.53 193 90.71 233 106.38 273 121.63 313 136.55 353 34 20.88 74 40.31 114 58.10 154 74.94 194 91.10 234 106.76 274 122.01 314 136.92 354 35 21.40 75 40.77 115 58.53 155 75.35 195 91.50 235 107.15 275 122.39 315 137.29 355 36 21.91 76 41.23 116 58.96 156 75.76 196 91.90 236 107.53 276 122.76 316 137.66 356 37 22.43 77 41.69 117 59.39 157 76.17 197 92.29 237 107.92 277 123.14 317 138.02 357 38 22.94 78 42.15 118 59.82 158 76.58 198 92.69 238 108.30 278 123.52 318 138.39 358 
331

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

39 23.45 79 42.60 119 60.25 159 76.99 199 93.09 239 108.69 279 123.89 319 138.76 359 40 23.96 80 43.06 120 60.68 160 77.40 200 93.48 240 109.07 280 124.27 320 139.13 360 

Table 18. Water Quality Standards for dissolved Silver

Aquatic and Wildlife coldwater, warmwater, edw, and ephemeral

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard

mg/L

1 NA 41 0.74 81 2.40 121 4.79 161 7.83 201 11.46 241 15.66 281 20.40 321 2 NA 42 0.78 82 2.45 122 4.86 162 7.91 202 11.56 242 15.78 282 20.52 322 3 NA 43 0.81 83 2.50 123 4.93 163 7.99 203 11.66 243 15.89 283 20.65 323 4 NA 44 0.84 84 2.56 124 4.99 164 8.08 204 11.76 244 16.00 284 20.77 324 5 NA 45 0.87 85 2.61 125 5.06 165 8.16 205 11.86 245 16.11 285 20.90 325 6 NA 46 0.91 86 2.66 126 5.13 166 8.25 206 11.96 246 16.23 286 21.03 326 7 NA 47 0.94 87 2.72 127 5.20 167 8.33 207 12.06 247 16.34 287 21.15 327 8 NA 48 0.98 88 2.77 128 5.27 168 8.42 208 12.16 248 16.45 288 21.28 328 9 NA 49 1.01 89 2.82 129 5.35 169 8.51 209 12.26 249 16.57 289 21.41 329 

10 NA 50 1.05 90 2.88 130 5.42 170 8.59 210 12.36 250 16.68 290 21.53 330 11 NA 51 1.08 91 2.93 131 5.49 171 8.68 211 12.46 251 16.80 291 21.66 331 12 NA 52 1.12 92 2.99 132 5.56 172 8.77 212 12.56 252 16.91 292 21.79 332 13 NA 53 1.16 93 3.05 133 5.63 173 8.86 213 12.67 253 17.03 293 21.92 333 14 NA 54 1.20 94 3.10 134 5.71 174 8.94 214 12.77 254 17.14 294 22.05 334 15 NA 55 1.23 95 3.16 135 5.78 175 9.03 215 12.87 255 17.26 295 22.18 335 16 NA 56 1.27 96 3.22 136 5.85 176 9.12 216 12.97 256 17.38 296 22.31 336 17 NA 57 1.31 97 3.27 137 5.93 177 9.21 217 13.08 257 17.49 297 22.44 337 18 NA 58 1.35 98 3.33 138 6.00 178 9.30 218 13.18 258 17.61 298 22.57 338 19 NA 59 1.39 99 3.39 139 6.08 179 9.39 219 13.29 259 17.73 299 22.70 339 20 NA 60 1.43 100 3.45 140 6.15 180 9.48 220 13.39 260 17.85 300 22.83 340 21 NA 61 1.47 101 3.51 141 6.23 181 9.57 221 13.50 261 17.97 301 22.96 341 
332

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard

mg/L

22 NA 62 1.52 102 3.57 142 6.31 182 9.66 222 13.60 262 18.08 302 23.09 342 23 NA 63 1.56 103 3.63 143 6.38 183 9.76 223 13.71 263 18.20 303 23.22 343 24 NA 64 1.60 104 3.69 144 6.46 184 9.85 224 13.81 264 18.32 304 23.35 344 25 0.32 65 1.64 105 3.75 145 6.54 185 9.94 225 13.92 265 18.44 305 23.49 345 26 0.34 66 1.69 106 3.81 146 6.61 186 10.03 226 14.02 266 18.56 306 23.62 346 27 0.36 67 1.73 107 3.88 147 6.69 187 10.12 227 14.13 267 18.68 307 23.75 347 28 0.39 68 1.78 108 3.94 148 6.77 188 10.22 228 14.24 268 18.80 308 23.89 348 29 0.41 69 1.82 109 4.00 149 6.85 189 10.31 229 14.35 269 18.92 309 24.02 349 30 0.43 70 1.87 110 4.06 150 6.93 190 10.41 230 14.45 270 19.04 310 24.15 350 31 0.46 71 1.91 111 4.13 151 7.01 191 10.50 231 14.56 271 19.17 311 24.29 351 32 0.49 72 1.96 112 4.19 152 7.09 192 10.59 232 14.67 272 19.29 312 24.42 352 33 0.51 73 2.01 113 4.26 153 7.17 193 10.69 233 14.78 273 19.41 313 24.56 353 34 0.54 74 2.06 114 4.32 154 7.25 194 10.79 234 14.89 274 19.53 314 24.69 354 35 0.57 75 2.10 115 4.39 155 7.33 195 10.88 235 15.00 275 19.65 315 24.83 355 36 0.60 76 2.15 116 4.45 156 7.41 196 10.98 236 15.11 276 19.78 316 24.96 356 37 0.62 77 2.20 117 4.52 157 7.49 197 11.07 237 15.22 277 19.90 317 25.10 357 38 0.65 78 2.25 118 4.59 158 7.58 198 11.17 238 15.33 278 20.03 318 25.23 358 39 0.68 79 2.30 119 4.65 159 7.66 199 11.27 239 15.44 279 20.15 319 25.37 359 40 0.71 80 2.35 120 4.72 160 7.74 200 11.37 240 15.55 280 20.27 320 25.51 360 

Table 12. 18. Acute Water Quality Standards for dissolved Dissolved Nickel 

Aquatic and Wildlife ephemeral

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

1 NA 85 41 1956 81 3479 121 4886 161 6221 201 7506 241 8752 281 9966 321 2 

NA 

152

42 1996 82 3516 122 4920 162 6254 202 7538 242 8783 282 9996 322 

3 NA 43 2036 83 3552 123 4954 163 6287 203 7569 243 8813 283 10026 323 
333

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

214

4 

NA 

273

44 2076 84 3588 124 4988 164 6319 204 7601 244 8844 284 10056 324 

5 

NA 

330

45 2116 85 3624 125 5022 165 6352 205 7632 245 8875 285 10086 325 

6 

NA 

385

46 2156 86 3660 126 5056 166 6385 206 7664 246 8905 286 10116 326 

7 

NA 

438

47 2195 87 3696 127 5090 167 6417 207 7695 247 8936 287 10146 327 

8 

NA 

491

48 2235 88 3732 128 5124 168 6450 208 7727 248 8967 288 10176 328 

9 

NA 

542

49 2274 89 3768 129 5158 169 6482 209 7758 249 8997 289 10206 329 

10 

NA 

593

50 2313 90 3804 130 5192 170 6514 210 7790 250 9028 290 10235 330 

11 

NA 

643

51 2352 91 3839 131 5226 171 6547 211 7821 251 9058 291 10265 331 

12 

NA 

692

52 2391 92 3875 132 5259 172 6579 212 7852 252 9089 292 10295 332 

13 

NA 

740

53 2430 93 3911 133 5293 173 6612 213 7884 253 9119 293 10325 333 

14 

NA 

788

54 2469 94 3946 134 5327 174 6644 214 7915 254 9150 294 10355 334 

15 

NA 

835

55 2508 95 3982 135 5360 175 6676 215 7946 255 9180 295 10385 335 

16 

NA 

882

56 2546 96 4017 136 5394 176 6708 216 7978 256 9211 296 10414 336 

17 

NA 

929

57 2585 97 4053 137 5427 177 6741 217 8009 257 9241 297 10444 337 
334

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

18 

NA 

975

58 2623 98 4088 138 5461 178 6773 218 8040 258 9272 298 10474 338 

19 

NA 

1020

59 2661 99 4123 139 5494 179 6805 219 8071 259 9302 299 10504 339 

20 

NA 

1066

60 2699 100 4158 140 5528 180 6837 220 8102 260 9332 300 10533 340 

21 

NA 

1110

61 2737 101 4193 141 5561 181 6869 221 8133 261 9363 301 10563 341 

22 

NA 

1155

62 2775 102 4229 142 5594 182 6901 222 8165 262 9393 302 10593 342 

23 

NA 

1199

63 2813 103 4264 143 5628 183 6934 223 8196 263 9423 303 10622 343 

24 

NA 

1243

64 2851 104 4299 144 5661 184 6966 224 8227 264 9454 304 10652 344 

25 1287 65 2888 105 4334 145 5694 185 6998 225 8258 265 9484 305 10682 345 26 1330 66 2926 106 4368 146 5727 186 7030 226 8289 266 9514 306 10711 346 27 1374 67 2963 107 4403 147 5761 187 7062 227 8320 267 9544 307 10741 347 28 1416 68 3001 108 4438 148 5794 188 7093 228 8351 268 9575 308 10770 348 29 1459 69 3038 109 4473 149 5827 189 7125 229 8382 269 9605 309 10800 349 30 1502 70 3075 110 4508 150 5860 190 7157 230 8413 270 9635 310 10830 350 31 1544 71 3112 111 4542 151 5893 191 7189 231 8444 271 9665 311 10859 351 32 1586 72 3149 112 4577 152 5926 192 7221 232 8475 272 9695 312 10889 352 33 1628 73 3186 113 4611 153 5959 193 7253 233 8506 273 9726 313 10918 353 34 1669 74 3223 114 4646 154 5992 194 7285 234 8536 274 9756 314 10948 354 35 1711 75 3260 115 4680 155 6025 195 7316 235 8567 275 9786 315 10977 355 36 1752 76 3297 116 4715 156 6058 196 7348 236 8598 276 9816 316 11007 356 37 1793 77 3333 117 4749 157 6090 197 7380 237 8629 277 9846 317 11036 357 38 1834 78 3370 118 4783 158 6123 198 7411 238 8660 278 9876 318 11066 358 
335

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard. 

mg/L 

Std. 

μg/L 

Hard.

mg/L 

Std. 

μg/L 

Hard

mg/L 

39 1875 79 3407 119 4818 159 6156 199 7443 239 8691 279 9906 319 11095 359 40 1915 80 3443 120 4852 160 6189 200 7475 240 8721 280 9936 320 11124 360 

Table 19. Acute Water Quality Standards for Dissolved Silver

Aquatic and Wildlife coldwater, warmwater, edw, and ephemeral

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard

mg/L

1 0.001 41 0.69 81 2.24 121 4.46 161 7.30 201 10.69 241 14.60 281 19.02 321 2 0.004 42 0.72 82 2.29 122 4.53 162 7.38 202 10.78 242 14.71 282 19.14 322 3 0.01 43 0.75 83 2.33 123 4.59 163 7.45 203 10.87 243 14.81 283 19.25 323 4 0.01 44 0.78 84 2.38 124 4.66 164 7.53 204 10.96 244 14.92 284 19.37 324 5 0.02 45 0.81 85 2.43 125 4.72 165 7.61 205 11.06 245 15.02 285 19.49 325 6 0.03 46 0.85 86 2.48 126 4.79 166 7.69 206 11.15 246 15.13 286 19.61 326 7 0.03 47 0.88 87 2.53 127 4.85 167 7.77 207 11.24 247 15.24 287 19.72 327 8 0.04 48 0.91 88 2.58 128 4.92 168 7.85 208 11.34 248 15.34 288 19.84 328 9 0.05 49 0.94 89 2.63 129 4.98 169 7.93 209 11.43 249 15.45 289 19.96 329 

10 0.06 50 0.98 90 2.68 130 5.05 170 8.01 210 11.52 250 15.56 290 20.08 330 11 0.07 51 1.01 91 2.74 131 5.12 171 8.09 211 11.62 251 15.66 291 20.20 331 12 0.08 52 1.04 92 2.79 132 5.19 172 8.18 212 11.71 252 15.77 292 20.32 332 13 0.10 53 1.08 93 2.84 133 5.25 173 8.26 213 11.81 253 15.88 293 20.44 333 14 0.11 54 1.11 94 2.89 134 5.32 174 8.34 214 11.91 254 15.99 294 20.56 334 15 0.12 55 1.15 95 2.95 135 5.39 175 8.42 215 12.00 255 16.09 295 20.68 335 16 0.14 56 1.19 96 3.00 136 5.46 176 8.51 216 12.10 256 16.20 296 20.80 336 17 0.15 57 1.22 97 3.05 137 5.53 177 8.59 217 12.19 257 16.31 297 20.92 337 18 0.17 58 1.26 98 3.11 138 5.60 178 8.67 218 12.29 258 16.42 298 21.04 338 19 0.18 59 1.30 99 3.16 139 5.67 179 8.76 219 12.39 259 16.53 299 21.16 339 20 0.20 60 1.34 100 3.22 140 5.74 180 8.84 220 12.48 260 16.64 300 21.28 340 21 0.22 61 1.37 101 3.27 141 5.81 181 8.93 221 12.58 261 16.75 301 21.41 341 
336

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard.

mg/L

Std.

ug/L

Hard

mg/L

22 0.24 62 1.41 102 3.33 142 5.88 182 9.01 222 12.68 262 16.86 302 21.53 342 23 0.26 63 1.45 103 3.38 143 5.95 183 9.10 223 12.78 263 16.97 303 21.65 343 24 0.28 64 1.49 104 3.44 144 6.02 184 9.18 224 12.88 264 17.08 304 21.78 344 25 0.30 65 1.53 105 3.50 145 6.09 185 9.27 225 12.98 265 17.19 305 21.90 345 26 0.32 66 1.57 106 3.56 146 6.17 186 9.35 226 13.08 266 17.31 306 22.02 346 27 0.34 67 1.62 107 3.61 147 6.24 187 9.44 227 13.18 267 17.42 307 22.15 347 28 0.36 68 1.66 108 3.67 148 6.31 188 9.53 228 13.28 268 17.53 308 22.27 348 29 0.38 69 1.70 109 3.73 149 6.39 189 9.61 229 13.38 269 17.64 309 22.39 349 30 0.41 70 1.74 110 3.79 150 6.46 190 9.70 230 13.48 270 17.76 310 22.52 350 31 0.43 71 1.78 111 3.85 151 6.54 191 9.79 231 13.58 271 17.87 311 22.64 351 32 0.45 72 1.83 112 3.91 152 6.61 192 9.88 232 13.68 272 17.98 312 22.77 352 33 0.48 73 1.87 113 3.97 153 6.68 193 9.97 233 13.78 273 18.10 313 22.90 353 34 0.50 74 1.92 114 4.03 154 6.76 194 10.06 234 13.88 274 18.21 314 23.02 354 35 0.53 75 1.96 115 4.09 155 6.84 195 10.15 235 13.98 275 18.33 315 23.15 355 36 0.55 76 2.01 116 4.15 156 6.91 196 10.24 236 14.09 276 18.44 316 23.27 356 37 0.58 77 2.05 117 4.21 157 6.99 197 10.33 237 14.19 277 18.56 317 23.40 357 38 0.61 78 2.10 118 4.28 158 7.06 198 10.42 238 14.29 278 18.67 318 23.53 358 39 0.64 79 2.14 119 4.34 159 7.14 199 10.51 239 14.40 279 18.79 319 23.66 359 40 0.67 80 2.19 120 4.40 160 7.22 200 10.60 240 14.50 280 18.90 320 23.78 360 

Table 20. Acute and Chronic Water Quality Standards for dissolved Dissolved Zinc 

Aquatic and Wildlife coldwater, warmwater, and edw

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard

mg/L 

1 NA 2.4 41 55.1 81 98.0 121 137.7 161 175.4 201 211.7 241 246.9 281 281.2 321 2 NA 4.3 42 56.2 82 99.0 122 138.7 162 176.4 202 212.6 242 247.8 282 282.1 322 3 NA 6.0 43 57.3 83 100.1 123 139.6 163 177.3 203 213.5 243 248.6 283 282.9 323 4 NA 7.7 44 58.4 84 101.1 124 140.6 164 178.2 204 214.4 244 249.5 284 283.8 324 
337

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard

mg/L 

5 NA 9.3 45 59.6 85 102.1 125 141.6 165 179.1 205 215.3 245 250.4 285 284.6 325 6 

NA

10.8

46 60.7 86 103.1 126 142.5 166 180.0 206 216.2 246 251.2 286 285.5 326 

7 

NA

12.3

47 61.8 87 104.1 127 143.5 167 181.0 207 217.1 247 252.1 287 286.3 327 

8 

NA

13.8

48 62.9 88 105.2 128 144.4 168 181.9 208 217.9 248 253.0 288 287.1 328 

9 

NA

15.2

49 64.0 89 106.2 129 145.4 169 182.8 209 218.8 249 253.8 289 288.0 329 

10 

NA

16.7

50 65.1 90 107.2 130 146.4 170 183.7 210 219.7 250 254.7 290 288.8 330 

11 

NA

18.1

51 66.2 91 108.2 131 147.3 171 184.6 211 220.6 251 255.6 291 289.7 331 

12 

NA

19.4

52 67.3 92 109.2 132 148.3 172 185.5 212 221.5 252 256.4 292 290.5 332 

13 

NA

20.8

53 68.4 93 110.2 133 149.2 173 186.4 213 222.4 253 257.3 293 291.4 333 

14 

NA

22.1

54 69.5 94 111.2 134 150.2 174 187.4 214 223.3 254 258.1 294 292.2 334 

15 

NA

23.5

55 70.6 95 112.2 135 151.1 175 188.3 215 224.1 255 259.0 295 293.0 335 

16 

NA

24.8

56 71.7 96 113.2 136 152.1 176 189.2 216 225.0 256 259.9 296 293.9 336 

17 

NA

26.1

57 72.8 97 114.2 137 153.0 177 190.1 217 225.9 257 260.7 297 294.7 337 

18 

NA

27.4

58 73.9 98 115.2 138 153.9 178 191.0 218 226.8 258 261.6 298 295.6 338 

19 

NA

28.7

59 74.9 99 116.2 139 154.9 179 191.9 219 227.7 259 262.4 299 296.4 339 
338

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard

mg/L 

20 

NA

30.0

60 76.0 100 117.2 140 155.8 180 192.8 220 228.6 260 263.3 300 297.2 340 

21 

NA

31.2

61 77.1 101 118.2 141 156.8 181 193.7 221 229.4 261 264.2 301 298.1 341 

22 

NA

32.5

62 78.2 102 119.2 142 157.7 182 194.6 222 230.3 262 265.0 302 298.9 342 

23 

NA

33.7

63 79.2 103 120.2 143 158.7 183 195.5 223 231.2 263 265.9 303 299.8 343 

24 

NA

35.0

64 80.3 104 121.1 144 159.6 184 196.4 224 232.1 264 266.7 304 300.6 344 

25 36.2 65 81.3 105 122.1 145 160.5 185 197.3 225 232.9 265 267.6 305 301.4 345 26 37.4 66 82.4 106 123.1 146 161.5 186 198.3 226 233.8 266 268.4 306 302.3 346 27 38.6 67 83.5 107 124.1 147 162.4 187 199.2 227 234.7 267 269.3 307 303.1 347 28 39.9 68 84.5 108 125.1 148 163.3 188 200.1 228 235.6 268 270.2 308 304.0 348 29 41.1 69 85.6 109 126.1 149 164.3 189 201.0 229 236.5 269 271.0 309 304.8 349 30 42.2 70 86.6 110 127.0 150 165.2 190 201.9 230 237.3 270 271.9 310 305.6 350 31 43.4 71 87.7 111 128.0 151 166.2 191 202.8 231 238.2 271 272.7 311 306.5 351 32 44.6 72 88.7 112 129.0 152 167.1 192 203.7 232 239.1 272 273.6 312 307.3 352 33 45.8 73 89.8 113 130.0 153 168.0 193 204.6 233 239.9 273 274.4 313 308.1 353 34 47.0 74 90.8 114 130.9 154 168.9 194 205.5 234 240.8 274 275.3 314 309.0 354 35 48.1 75 91.8 115 131.9 155 169.9 195 206.3 235 241.7 275 276.1 315 309.8 355 36 49.3 76 92.9 116 132.9 156 170.8 196 207.2 236 242.6 276 277.0 316 310.6 356 37 50.5 77 93.9 117 133.9 157 171.7 197 208.1 237 243.4 277 277.8 317 311.5 357 38 51.6 78 94.9 118 134.8 158 172.7 198 209.0 238 244.3 278 278.7 318 312.3 358 39 52.8 79 96.0 119 135.8 159 173.6 199 209.9 239 245.2 279 279.5 319 313.1 359 40 53.9 80 97.0 120 136.8 160 174.5 200 210.8 240 246.0 280 280.4 320 314.0 360 

Table 19. 21. Acute Water Quality Standards for dissolved Dissolved Zinc 

Aquatic and Wildlife ephemeral
339

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard

mg/L 

1 NA 22 41 522 81 930 121 1307 161 1665 201 2009 241 2343 281 2669 321 2 NA 40 42 533 82 940 122 1316 162 1674 202 2018 242 2351 282 2677 322 3 NA 57 43 544 83 950 123 1325 163 1682 203 2026 243 2360 283 2685 323 4 NA 73 44 555 84 959 124 1334 164 1691 204 2034 244 2368 284 2693 324 5 NA 88 45 565 85 969 125 1343 165 1700 205 2043 245 2376 285 2701 325 6 

NA

103

46 576 86 979 126 1353 166 1708 206 2051 246 2384 286 2709 326 

7 

NA

117

47 587 87 988 127 1362 167 1717 207 2060 247 2392 287 2717 327 

8 

NA

131

48 597 88 998 128 1371 168 1726 208 2068 248 2401 288 2725 328 

9 

NA

145

49 608 89 1007 129 1380 169 1735 209 2077 249 2409 289 2733 329 

10 

NA

158

50 618 90 1017 130 1389 170 1743 210 2085 250 2417 290 2741 330 

11 

NA

171

51 629 91 1027 131 1398 171 1752 211 2093 251 2425 291 2749 331 

12 

NA

184

52 639 92 1036 132 1407 172 1761 212 2102 252 2433 292 2757 332 

13 

NA

197

53 649 93 1046 133 1416 173 1769 213 2110 253 2442 293 2765 333 

14 

NA

210

54 660 94 1055 134 1425 174 1778 214 2119 254 2450 294 2773 334 

15 

NA

223

55 670 95 1065 135 1434 175 1787 215 2127 255 2458 295 2781 335 

16 

NA

235

56 680 96 1074 136 1443 176 1795 216 2135 256 2466 296 2789 336 

17 

NA

248

57 691 97 1084 137 1452 177 1804 217 2144 257 2474 297 2797 337 
340

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard

mg/L 

18 

NA

260

58 701 98 1093 138 1461 178 1813 218 2152 258 2482 298 2805 338 

19 

NA

272

59 711 99 1103 139 1470 179 1821 219 2161 259 2491 299 2813 339 

20 

NA

284

60 721 100 1112 140 1479 180 1830 220 2169 260 2499 300 2821 340 

21 

NA

296

61 732 101 1121 141 1488 181 1838 221 2177 261 2507 301 2829 341 

22 

NA

308

62 742 102 1131 142 1497 182 1847 222 2186 262 2515 302 2837 342 

23 

NA

320

63 752 103 1140 143 1506 183 1856 223 2194 263 2523 303 2845 343 

24 

NA

332

64 762 104 1150 144 1515 184 1864 224 2202 264 2531 304 2853 344 

25 344 65 772 105 1159 145 1523 185 1873 225 2211 265 2539 305 2861 345 26 355 66 782 106 1168 146 1532 186 1881 226 2219 266 2547 306 2869 346 27 367 67 792 107 1178 147 1541 187 1890 227 2227 267 2556 307 2876 347 28 378 68 802 108 1187 148 1550 188 1898 228 2236 268 2564 308 2884 348 29 390 69 812 109 1196 149 1559 189 1907 229 2244 269 2572 309 2892 349 30 401 70 822 110 1206 150 1568 190 1916 230 2252 270 2580 310 2900 350 31 412 71 832 111 1215 151 1577 191 1924 231 2260 271 2588 311 2908 351 32 423 72 842 112 1224 152 1586 192 1933 232 2269 272 2596 312 2916 352 33 435 73 852 113 1233 153 1594 193 1941 233 2277 273 2604 313 2924 353 34 446 74 862 114 1243 154 1603 194 1950 234 2285 274 2612 314 2932 354 35 457 75 871 115 1252 155 1612 195 1958 235 2294 275 2620 315 2940 355 36 468 76 881 116 1261 156 1621 196 1967 236 2302 276 2628 316 2948 356 37 479 77 891 117 1270 157 1630 197 1975 237 2310 277 2636 317 2956 357 38 490 78 901 118 1279 158 1638 198 1984 238 2318 278 2645 318 2964 358 
341

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard. 

mg/L 

Std. 

ug/L 

Hard.

mg/L 

Std. 

ug/L 

Hard

mg/L 

39 501 79 911 119 1289 159 1647 199 1992 239 2327 279 2653 319 2971 359 40 512 80 920 120 1298 160 1656 200 2001 240 2335 280 2661 320 2979 360 

Table 21. 22. Acute Water Quality Standards for 

Pentachlorophenol Acute Aquatic and Wildlife coldwater, 

warmwater, and edw

Table 22. 23. Chronic Water Quality Standards for Pentachlorophenol Chronic Aquatic and Wildlife coldwater, warmwater, and edw

Table 23. 24. Acute Water Q

Pentachlorophenol Acute Aquatic and Wildlife e

pH ug/L pH ug/L pH ug/L pH ug/L pH ug/L 

3 0.163 7 9.070 3 0.103 7 5.726 3 0.660 

3.1 0.180 7.1 10.029 3.1 0.114 7.1 6.331 3.1 0.730 3.2 0.199 7.2 11.090 3.2 0.126 7.2 7.001 3.2 0.807 3.3 0.220 7.3 12.262 3.3 0.139 7.3 7.741 3.3 0.892 3.4 0.243 7.4 13.558 3.4 0.154 7.4 8.559 3.4 0.986 3.5 0.269 7.5 14.992 3.5 0.170 7.5 9.464 3.5 1.091 3.6 0.298 7.6 16.577 3.6 0.188 7.6 10.465 3.6 1.206 3.7 0.329 7.7 18.329 3.7 0.208 7.7 11.571 3.7 1.334 3.8 0.364 7.8 20.267 3.8 0.230 7.8 12.794 3.8 1.475 3.9 0.402 7.9 22.410 3.9 0.254 7.9 14.147 3.9 1.631 

4 0.445 8 24.779 4 0.281 8 15.643 4 1.803 

4.1 0.492 8.1 27.399 4.1 0.311 8.1 17.296 4.1 1.994 4.2 0.544 8.2 30.296 4.2 0.343 8.2 19.125 4.2 2.204 4.3 0.601 8.3 33.498 4.3 0.380 8.3 21.147 4.3 2.437 4.4 0.665 8.4 37.040 4.4 0.420 8.4 23.383 4.4 2.695 4.5 0.735 8.5 40.956 4.5 0.464 8.5 25.855 4.5 2.980 4.6 0.813 8.6 45.286 4.6 0.513 8.6 28.588 4.6 3.295 4.7 0.899 8.7 50.074 4.7 0.568 8.7 31.611 4.7 3.643 4.8 0.994 8.8 55.368 4.8 0.628 8.8 34.953 4.8 4.029 4.9 1.099 8.9 61.222 4.9 0.694 8.9 38.648 4.9 4.454 
342

pH ug/L pH ug/L pH ug/L pH ug/L pH ug/L 

5 1.215 9 67.694 5 0.767 9 42.734 5 4.925 

5.1 1.344 9.1 74.851 5.1 0.848 9.1 47.252 5.1 5.446 5.2 1.486 9.2 82.765 5.2 0.938 9.2 52.248 5.2 6.022 5.3 1.643 9.3 91.515 5.3 1.037 9.3 57.772 5.3 6.659 5.4 1.817 9.4 101.190 5.4 1.147 9.4 63.880 5.4 7.363 5.5 2.009 9.5 111.888 5.5 1.268 9.5 70.633 5.5 8.141 5.6 2.221 9.6 123.717 5.6 1.4022 9.6 78.101 5.6 9.002 5.7 2.456 9.7 136.797 5.7 1.550 9.7 86.358 5.7 9.953 5.8 2.716 9.8 151.260 5.8 1.714 9.8 95.488 5.8 11.006 5.9 3.003 9.9 167.252 5.9 1.896 9.9 105.583 5.9 12.169 

6 3.320 10 184.934 6 2.096 10 116.746 6 13.456 

6.1 3.671 10.1 204.486 6.1 2.318 10.1 129.089 6.1 14.878 6.2 4.059 10.2 226.105 6.2 2.563 10.2 142.736 6.2 16.451 6.3 4.488 10.3 250.010 6.3 2.833 10.3 157.827 6.3 18.191 6.4 4.963 10.4 276.442 6.4 3.133 10.4 174.513 6.4 20.114 6.5 5.488 10.5 305.668 6.5 3.464 10.5 192.963 6.5 22.240 6.6 6.068 10.6 337.984 6.6 3.831 10.6 213.364 6.6 24.591 6.7 6.709 10.7 373.717 6.7 4.235 10.7 235.922 6.7 27.191 6.8 7.419 10.8 413.228 6.8 4.683 10.8 260.864 6.8 30.066 6.9 8.203 10.9 456.916 6.9 5.178 10.9 288.444 6.9 33.245 

11 505.223 11 318.939 

Table 24. 25. Acute Criteria for Total Ammonia (in mg N / L mg/L as N) 

Aquatic and Wildlife coldwater, warmwater, and edw

pH A&Wc 

A&Ww and 

A&W edw

6.5 32.6 48.8 6.6 31.3 46.8 6.7 29.8 44.6 
343

6.8 28.1 42.0 6.9 26.2 39.1 7.0 24.1 36.1 7.1 22.0 32.8 7.2 19.7 29.5 7.3 17.5 26.2 7.4 15.4 23.0 7.5 13.3 19.9 7.3 11.4 17.0 7.7 9.65 14.4 7.8 8.11 12.1 7.9 6.77 10.1 8.0 5.62 8.40 8.1 4.64 6.95 8.2 3.830 5.72 8.3 3.15 4.71 8.4 2.59 3.88 8.5 2.14 3.20 8.6 1.77 2.65 8.7 1.47 2.20 8.8 1.23 1.84 8.9 1.04 1.56 9.0 0.885 1.32 

Table 25. 26. Chronic Criteria for Total Ammonia (in L / N mg/L as N) for A&Wc, and A&Ww Designated Uses

Aquatic and Wildlife coldwater, warmwater, and edw

Temperature, °C pH 

0 14 16 18 20 22 24 26 28 30 

6.5 6.67 6.67 6.06 5.33 4.68 4.12 3.62 3.18 2.80 2.46 6.6 6.57 6.57 5.97 5.25 4.61 4.05 3.56 3.13 2.75 2.42 
344

Temperature, °C pH 

0 14 16 18 20 22 24 26 28 30 

6.7 6.44 6.44 5.86 5.15 4.52 3.98 3.50 3.07 2.70 2.37 6.8 6.29 6.29 5.72 5.03 4.42 3.89 3.42 3.00 2.64 2.32 6.9 6.12 6.12 5.56 4.89 4.30 3.78 3.32 2.92 2.57 2.25 7.0 5.91 5.91 5.37 4.72 4.15 3.65 3.21 2.82 2.48 2.18 7.1 5.67 5.67 5.15 4.53 3.98 3.50 3.08 2.70 2.38 2.09 7.2 5.39 5.39 4.90 4.31 3.78 3.33 2.92 2.57 2.26 1.99 7.3 5.08 5.08 4.61 4.06 3.57 3.13 2.76 2.42 2.13 1.87 7.4 4.73 4.73 4.30 3.78 3.33 2.92 2.57 2.26 1.98 1.74 7.5 4.36 4.36 3.97 3.49 3.06 2.69 2.37 2.08 1.83 1.61 7.6 3.98 3.98 3.61 3.18 2.79 2.45 2.16 1.90 1.67 1.47 7.7 3.58 3.58 3.25 2.86 2.51 2.21 1.94 1.71 1.50 1.32 7.8 3.18 3.18 2.89 2.54 2.23 1.96 1.73 1.52 1.33 1.17 7.9 2.80 2.80 2.54 2.24 1.96 1.73 1.52 1.33 1.17 1.03 8.0 2.43 2.43 2.21 1.94 1.71 1.50 1.32 1.16 1.02 0.897 8.1 2.10 2.10 1.91 1.68 1.47 1.29 1.14 1.00 0.879 0.773 8.2 1.79 1.79 1.63 1.43 1.26 1.11 0.973 0.855 0.752 0.661 8.3 1.52 1.52 1.39 1.22 1.07 0.941 0.827 0.727 0.639 0.562 8.4 1.29 1.29 1.17 1.03 0.906 0.796 0.700 0.615 0.541 0.475 8.5 1.09 1.09 0.990 0.870 0.765 0.672 0.591 0.520 0.457 0.401 8.6 0.920 0.920 0.836 0.735 0.646 0.568 0.499 0.439 0.386 0.339 8.7 0.778 0.778 0.707 0.622 0.547 0.480 0.422 0.371 0.326 0.287 8.8 0.661 0.661 0.601 0.528 0.464 0.408 0.359 0.315 0.277 0.244 8.9 0.565 0.565 0.513 0.451 0.397 0.349 0.306 0.269 0.237 0.208 9.0 0.486 0.486 0.442 0.389 0.342 0.300 0.264 0.232 0.204 0.179 
345

Appendix B. APPENDIX B. List of Surface Waters and Designated Uses SURFACE WATERS AND DESIGNATED USES

Abbreviations

River Basins

BW = Bill Williams

CM = Colorado Mainstem (includes Red Lake)

LC = Little Colorado

MG = Middle Gila (includes Gila River below San Carlos Indian Reservation, Salt River below Granite Reef Dam and Phoenix area waterb

RM = Rios de Mexico (includes Rio Magdalena, Rio Sonoita, and Rio Yaqui Basins)

SC = Santa Cruz

SP = San Pedro 

SR = Salt River (includes Salt River and tributaries above Granite Reef Dam)

UG = Upper Gila (includes Gila River and tributaries above San Carlos Indian Reservation)

VR = Verde River

WP = Wilcox Playa

Designated Uses

A&Wc = Aquatic and Wildlife cold water

A&Wc = Aquatic and Wildlife warm water

A&We = Aquatic and Wildlife ephemeral

A&Wedw = Aquatic and Wildlife effluent dependent water

FBC = Full-body Contact

PBC = Partial-body Contact

DWS = Domestic Water Source

FC = Fish Consumption

AgI = Agricultural Irrigation

AgL = Agricultural Livestock Watering
346

Other

U = Unique Water

EDW = Effluent-dependent Water

WWTP = Wastewater Treatment Plant

Km = kilometers

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

BW Alamo Lake 34°14'45"/113°35'00" Deep A&Ww FBC BW Big Sandy River Tributary to the Santa Maria River Headwaters to 

confluence at Alamo Lake at 34°18'36"/113°31'34" A&Ww FBC 

BW 

Bill Williams River 

Tributary to the Alamo Lake to confluence with

Colorado River at 34°18'04"/114°08'10" A&Ww FBC 

BW Blue Tank 34°40'14"/112°58'16" A&Ww FBC BW Boulder Creek Headwaters to confluence with unnamed tributary 

at 34°41'14"/113°03'34" A&Wc FBC 

BW 

Boulder Creek Below confluence with unnamed tributary to 

confluence with Burro Creek at 34°36'47"/113°18'00"

 A&Ww FBC 

BW 

Burro Creek (Unique Water) 

(OAW)

Headwaters to confluence with Boulder Creek at 34°36'47"/113°18'00" A&Ww FBC 

BW 

Burro Creek Below confluence with Boulder Creek to 

confluence with Big Sandy River at 34°32'24"/113°34'19.2"

 A&Ww FBC 

BW Conger Creek Headwaters to confluence with unnamed tributary 

at 34°45'13"/113°05'45" A&Wc FBC 

BW Conger Creek Below confluence with unnamed tributary to A&Ww FBC 
347

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

confluence with Burro Creek at 34°46'05"/113°12'54"

BW Coors Lake 34°36'20"/113°11'25" Igneous A&Ww FBC BW Copper Basin 

Wash 

Headwaters to confluence with unnamed tributary at 34°28'11"/112°35'31" A&Wc FBC 

BW Copper Basin 

Wash 

Below confluence with unnamed tributary to Skull 

Valley Wash at 34°25'55"/112°41'42" A&We PBC 

BW 

Cottonwood Canyon 

Headwaters to Bear Trap Spring at 34°45'10"/112°52'32" A&Wc FBC 

BW 

Cottonwood Canyon 

Below Bear Trap Spring to confluence at Smith 

Canyon at 34°37'34"/112°54'46.8" A&Ww FBC 

BW 

Date Creek Tributary to the Headwaters to confluence with

Santa Maria River at 34°18'11"/113°29'53" A&Ww FBC 

BW 

Francis Creek (Unique Water) 

OAW

Tributary to Headwaters to confluence with Burro 

Creek at 34°44'28"/113°14'35" A&Ww FBC 

BW Kirkland Creek Tributary to Headwaters to confluence with Santa 

Maria River at 34°32'02"/112°59'38" A&Ww FBC 

BW Knight Creek Tributary to the Headwaters to confluence with Big 

Sandy River at 34°55'16"/113°37'30" A&Ww FBC 

BW 

Peoples PeeplesCanyon (Unique 

Water) (OAW)

Tributary to the Headwaters to confluence with

Santa Maria River at 34°20'35"/113°15'11" A&Ww FBC 

BW 

Santa Maria River 

Tributary to the Bill Williams River Headwaters to 

confluence with Alamo Lake at 

34°18'36"/113°31'34" 

 A&Ww FBC 

BW Trout Creek Headwaters to confluence with unnamed tributary A&Wc FBC 
348

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

at 35°06'47"/113°13'01" 

BW 

Trout Creek Below confluence with unnamed tributary to 

confluence with Knight Creek at 34°55'16"/113°37'30"

 A&Ww FBC 

CM A-10 Backwater 33°31'38"/114°33'19" A&Ww FBC CM A-7 Backwater 33°34'39"/114°39'42" A&Ww FBC CM Adobe Lake 33°02'39"/114°39'19" A&Ww FBC CM

CG

Agate Canyon Creek 

Grand Canyon, tributary to the Headwaters to confluence with the Colorado River at 

36°08'38"/112°16'48" 

 A&Ww FBC 

CM

CG

Beaver Dam Wash 

Tributary to the Headwaters to confluence with the

Virgin River at 36°53'42"/113°55'09" A&Ww FBC 

CM

CG

Big Springs Tank 36°36'10"/112°20'58" A&Wc FBC 

CM

CG

Boucher Creek Grand Canyon, tributary to Headwaters to 

confluence with the Colorado River at 36°06'54"/112°13'44" 

 A&Ww FBC 

CM

CG

Bright Angel Creek 

Headwaters to confluence with Roaring Springs 

Canyon at 36°11'34"/112°01'54" 

 A&Wc FBC 

CM

CG

Bright Angel Creek 

Below confluence with Roaring Spring Canyon to Colorado River at 36°05'56"/112°05'27.6"

 A&Ww FBC 

CG Bright Angel 

Wash

Headwaters to South Rim of Grand Canyon WWTP outfall at 36°02'59"/112°09'02"

 A&We PBC

CM

CG

Bright Angel Wash (EDW) 

South rim Rim Grand Canyon WWTP outfall at 36°00'11"/112°39'06" to Coconino Wash A&Wedw PBC 

CM

CG

Bulrush Canyon Wash 

Tributary to Headwaters to confluence with Kanab 

Creek at 36°46'55"/112°37'08" 

 A&We PBC 
349

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CM

CG

Cataract Creek Headwaters to Santa Fe Reservoir 

 A&Wc FBC 

CM

CG

Cataract Creek Santa Fe Reservoir to Williams WWTP outfall at 

35°15'40"/112°10'40" A&Wc FBC 

CM

CG

Cataract Creek (EDW) 

Williams WWTP outfall to 1 km downstream 

 A&Wedw PBC 

CM

Cataract Creek Below 1 km downstream of Williams WWTP 

outfall to confluence of Red Lake Wash

 A&Wc FBC 

CM

CG

Cataract Creek Red Lake Wash to Havasupai Reservation at 

33°56'52"/112°30'38.3" A&We PBC 

CM

CG

Cataract Lake 35°15'05"/112°12'58" 

Igneous A&Wc FBC 

CM

CG

Chuar Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°11'36"/111°52'17" 

 A&Wc FBC 

CM

CG

Chuar Creek Below confluence with unnamed tributary at 

36°11'36.4"/111°52'17 to confluence with Colorado River at 36°08'20.4"/111°48' 58.7"

 A&Ww FBC 

CM Cibola Lake 33°14'20"/114°40'16" A&Ww FBC CM

CG

City Reservoir 35°13'57"/112°11'23" Igneous A&Wc FBC 

CM

CG

Clear Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°09'12"/111°58'25" 

 A&Wc FBC 

CM

CG

Clear Creek Below confluence with unnamed tributary to 

confluence with Colorado River at 36°04'55"/112°02'09.6"

 A&Ww FBC 
350

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CM Clear Lake 33°01'57"/114°31'26" A&Ww FBC 

CG

Coconino Wash 

(EDW)

South Grand Canyon Sanitary District Tusayan 

WRF outfall at 35°58'39"/112°08'25" to 1km downstream at 35°58'36"/112°08'54"

 A&Wedw PBC

CM

CG

Colorado River Lake Powell to Topock Lake Mead. A&Wc FBC 

CM Colorado River Topock to Morelos Dam A&Ww FBC CM

CG

Cottonwood Creek 

Headwaters to confluence with unnamed tributary at 35°20'45.5"/113°35'31" A&Wc FBC 

CM

CG

Cottonwood Creek 

Below confluence with unnamed tributary to confluence with Colorado River at 35°22'05"/113°40'04.8"

 A&Ww FBC 

CM

CG

Crystal Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°13'42"/112°11'48" 

 A&Wc FBC 

CM

CG

Crystal Creek Below confluence with unnamed tributary to 

Colorado River at 36°08'06"/112°14'34.8"

 A&Ww FBC 

CM

CG

Deer Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°26'16"/112°28'15.5" 

 A&Wc FBC 

CM

CG

Deer Creek Below confluence with unnamed tributary to 

confluence with Colorado River at 36°23'20"/112°30'28.8"

 A&Ww FBC 

CM

CG

Detrital Wash Tributary Headwaters to Lake Mead at 

36°02'20"/114°27'47" 

 A&We PBC 

CM

CG

Dogtown Reservoir 

35°12'40"/112°07'46" 

Igneous A&Wc FBC 
351

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CM

CG

Dragon Creek Grand Canyon; headwaters Headwaters to 

confluence with Milk Creek at 36°12'25"/112°09'33" 

 A&Wc FBC 

CM

CG

Dragon Creek Below confluence with Milk Creek to confluence 

with Crystal Creek at 36°10'12"/112°12'10.8"

 A&Ww FBC 

CM

CG

Garden Creek Grand Canyon, tributary Headwaters to confluence 

with Pipe Creek at 36°05'35"/112°06'40" 

 A&Ww FBC 

CM

CG

Gonzalez Lake 35°15'26"/112°12'07" 

Shallow A&Wc A&Ww FBC 

CM

CG

Grand Wash Tributary Headwaters to Lake Mead at 

36°15'29"/114°00'18" 

 A&We PBC 

CM

CG

Grapevine Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°03'29"/112°00'00" 

 A&Ww FBC 

CM

CG

Grapevine Wash Tributary Headwaters to Lake Mead at 

36°06'29"/114°00'07" 

 A&We PBC 

CM

CG

Hakatai Canyon Creek 

Grand Canyon; tributary Headwaters to the 

Colorado River at 36°14'42"/112°22'59" 

 A&Ww FBC 

CM

CG

Hance Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°02'46"/111°57'07" 

 A&Ww FBC 

CM

CG

Havasu Canyon Creek 

Below From the Havasupai Indian Reservation; 

tributary boundary to confluence with the Colorado 

River at 36°18'29"/112°45'43" 

 A&Ww FBC 

CM

CG

Hermit Creek Grand Canyon; headwaters Headwaters to Hermit 

Pack Trail crossing at 36°03'23"/112°13'25" 

 A&Wc FBC 

CM

CG

Hermit Creek Below Hermit Pack Trail crossing to confluence 

with the Colorado River at 36°06'00"/112°32'04"

 A&Ww FBC 

CM Holy Moses Kingman WWTP outfall to 3 km downstream A&Wedw PBC
352

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Wash (EDW)

CM

CG

Horn Creek Grand Canyon; tributary Headwaters to confluence

with the Colorado River at 36°05'56"/112°07'59" 

 A&Ww FBC 

CM

CG

Hualapai Wash Tributary Headwaters to Lake Mead at 

36°00'40"/114°07'37" 

 A&We PBC 

CM

Hunter's Hole 

Backwater

32°31'15"/114°48'03"

 A&Ww FBC 

CM Imperial 

Reservoir

32°53'04"/114°27'40"

 A&Ww FBC 

CM Island Lake 33°01'52"/114°35'07" A&Ww FBC CM

CG

Jacob Lake 36°42'26"/112°13'48" 

Sedimentary A&Wc A&Ww FBC 

CM

CG

Kaibab Lake 35°17'04"/112°09'17" 

Igneous A&Wc FBC 

CM

CG

Kanab Creek Kanab Plateau; tributary Headwaters to confluence 

with the Colorado River at 36°23'31"/112°37'44" A&Ww FBC 

CM

CG

Kwagunt Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°13'29"/111°55'24" 

 A&Wc FBC 

CM

CG

Kwagunt Creek Below confluence with unnamed tributary to 

confluence with the Colorado River at 36°15'47"/111°49'40.8"

 A&Ww FBC 

CM Laguna Reservoir 32°51'15"/114°28'38" A&Ww FBC CM Lake Havasu 34°18'15"/114°08'15" A&Ww FBC CM

CG

Lake Mead 36°01'00"/114°44'15" 

Deep A&Wc FBC 

CM Lake Mohave 35°11'45"/114°34'00" A&Wc FBC 
353

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CM

CG

Lake Powell 36°57'00"/111°29'15" 

Deep A&Wc FBC 

CM

CG

Lonetree Canyon Creek 

Grand Canyon; tributary Headwaters to the 

Colorado River at 36°04'48"/112°01'52" 

 A&Ww FBC 

CM Martinez Lake 32°58'52"/114°28'23" A&Ww FBC CM

CG

Matkatamiba Creek 

Below Havasupai Indian Reservation; tributary to 

confluence with the Colorado River at 

36°20'38"/112°40'19" 

 A&Ww FBC 

CM Mittry Lake 32°49'11"/114°27'41" A&Ww FBC CM Mohave Wash Tributary to Lake Havasu at 33°28'55"/114°35'56" A&We PBCCM

CG

Monument Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°05'53"/112°10'55" 

 A&Ww FBC 

CM

CG

Nankoweap Creek 

Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°15'30"/111°57'23" 

 A&Wc FBC 

CM

CG

Nankoweap Creek 

Below confluence with unnamed tributary to Colorado River at 36°18'25"/111°51'28.8"

 A&Ww FBC 

CM

CG

National Canyon Creek 

Grand Canyon; those reaches Portion of the creek that flows into the Colorado River at 36°15'25"/112°53'34.8" that is not located on the 

Hualapai Indian Reservation 

 A&Ww FBC 

CM

CG

North Canyon Creek 

Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°33'57"/111°55'39" 

 A&Wc FBC 

CM

CG

North Canyon Creek 

Below confluence with unnamed tributary to Colorado River at 36°37'48"/111°45'46.8"

 A&Ww FBC 

CM Nortons Lake 33°02'35"/114°37'58" A&Ww FBC 
354

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CM

CG

Olo Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°22'16"/112°38'56" 

 A&Ww FBC 

CM

CG

Parashant Canyon Headwaters to confluence with unnamed tributary 

at 36°21'26"/113°28'10" 

 A&Wc FBC 

CM

CG

Parashant Canyon Below confluence with unnamed tributary to the 

Colorado River

 A&Ww FBC 

CM

CG

Paria River Paria Plateau; tributary Utah border to the 

Colorado River at 36°51'29"/111°36'04" 

 A&Ww FBC 

CM

CG

Phantom Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°10'04"/112°07'50" 

 A&Wc FBC 

CM

CG

Phantom Creek Below confluence with unnamed tributary to 

Colorado River at 36°06'58"/112°05'09.6"

 A&Ww FBC 

CM

CG

Pipe Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°05'56"/112°06'36" 

 A&Ww FBC 

CM Pretty Water 

Lake

33°19'45"/114°42'15"

 A&Ww FBC 

CM Quigley Ponds 32°43'00"/113°58'00" A&Ww FBC CM

CG

Red Canyon Creek 

Grand Canyon; tributary Headwaters to the 

Colorado River at 36°02'42"/111°55'08" 

 A&Ww FBC 

CM

CG

Red Lake 35°40'00"/114°03'45" 

 A&Ww FBC 

CM

CG

Redondo Lake 32°44'32"/114°29'02" 

Shallow A&Ww FBC 

CM

CG

Roaring Springs Headwaters of Roaring Springs Creek at 36 

11'35"/112°01'55.2"

 A&Wc FBC 

CM Roaring Springs Grand Canyon; tributary Headwaters to Bright A&Wc FBC 
355

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CG Canyon Angel Creek at 36°11'35"/112°01'55" 

CM

CG

Rock Canyon Tributary to Truxton Wash at 

35°26'56"/113°36'29" 

 A&We PBC 

CM

CG

Royal Arch Creek Grand Canyon; tributary Tributary to the Colorado 

River at 36°11'53"/112°26'56" 

 A&Ww FBC 

CM

CG

Ruby Canyon Creek 

Grand Canyon; tributary Tributary to the Colorado 

River at 36°11'24"/112°18'54" 

 A&Ww FBC 

CM

CG

Russell Tank 34°52'22"/111°52'44" 

 A&Wc FBC 

CM

Sacramento Wash Tributary to Topock Marsh at 

34°43'48"/114°29'13"

 A&We PBC

CM

CG

Saddle Canyon Creek 

Marble Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 36°21'35.5"/112°22'46" 

 A&Wc FBC 

CM

CG

Saddle Canyon Creek 

Below confluence with unnamed tributary to Colorado River at 36°22'52"/112°23'16.8"

 A&Ww FBC 

CM

CG

Santa Fe Reservoir 

35°14'26"/112°11'04" 

Igneous A&Wc FBC 

CM

CG

Sapphire Canyon Creek 

Grand Canyon; tributary Headwaters to the 

Colorado River at 36°08'49"/112°17'28" 

 A&Ww FBC 

CM Sawmill Canyon Headwaters to abandoned gaging station at 

35°09'46.5"/113°57'51"

 A&Ww FBC 

CM Sawmill Canyon Below abandoned gaging station A&We PBC CM

CG

Serpentine Canyon Creek 

Grand Canyon; tributary Headwaters to the 

Colorado River at 36°12'22"/112°19'37" 

 A&Ww FBC 

CM

CG

Shinumo Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 

 A&Wc FBC 
356

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

36°18'21"/112°18'03" 

CM

CG

Shinumo Creek Below confluence with unnamed tributary to the 

Colorado River at 36°14'13"/112°20'52.8"

 A&Ww FBC 

CM

CG

Short Creek Tributary to the Virgin River at 

36°58'23"/113°16'08" 

 A&We PBC 

CM

CG

Slate Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°08'06"/112°14'42" 

 A&Ww FBC 

CM

CG

Spring Canyon Creek 

Grand Canyon; tributary Headwaters to the 

Colorado River at 36°01'08"/113°21'00" 

 A&Ww FBC 

CM

CG

Stone Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°20'49"/112°27'14" 

 A&Ww FBC 

CM

CG

Tapeats Creek Grand Canyon; tributary Headwaters to the 

Colorado River at 36°22'16"/112°28'05" 

 A&Wc FBC 

CM

CG

Thunder River Tributary to Tapeats Creek at 

36°23'31"/112°27'00" 

 A&Wc FBC 

CM Topock Marsh 34°47'30"/114°31'00" A&Ww FBC CM

CG

Trail Canyon Creek 

Grand Canyon; tributary Headwaters to the 

Colorado River at 35°50'20"/113°19'37" 

 A&Ww FBC 

CG Transept Canyon Headwaters to North Rim WWTP outfall at 

36°12'20"/112°03'35"

 A&We PBC

CM

CG

Transept Canyon (EDW) 

North Rim WWTP outfall to 1 km downstream 

 A&Wedw PBC 

CG Transept Canyon 1 km downstream of the North Rim WWTP outfall 

to Bright Angel Creek

 A&We PBC

CM

CG

Travertine Canyon Creek 

Grand Canyon; tributary Tributary to the Colorado 

River at 36°06'11"/112°13'05" 

 A&Ww FBC 

CM Truxton Wash Tributary to Red Lake Playa at A&We PBC 
357

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CG 35°37'23"/114°03'00" 

CM

CG

Turquoise Canyon Creek 

Grand Canyon; tributary Tributary to the Colorado 

River at 36°09'14"/112°18'07" 

 A&Ww FBC 

CG

Unkar Creek Grand Canyon; headwaters to confluence with 

unnamed tributary at 36°07'54"/111°54'03"

 A&Wc FBC 

CM

CG

Unkar Creek Below conf confluence with unnamed tributary to

confluence with Colorado River at 

36°04'48"/111°52'22.8"

 A&Ww FBC 

CG

Unnamed wash 

(EDW)

Grand Canyon NP Desert View WWTP outfall to 

Cedar Canyon

 A&Wedw PBC

CG

Unnamed wash 

(EDW)

Valle Airpark WRF outfall at 

35°38'34"/112°09'22" to confluence with Spring Valley Wash at 35°38'29"/112°10'47"

 A&Wedw PBC

CM

CG

Vasey's Paradise Grand Canyon; A spring at 36°26'49"/111°50'46" A&Wc FBC 

CM

CG

Virgin River Tributary to the Colorado River at 

36°47'28"/114°06'11" A&Ww FBC 

CM

CG

Vishnu Creek Grand Canyon; tributary Tributary to the Colorado 

River at 36°03'18"/111°59'42" 

 A&Ww FBC 

CM

CG

Warm Springs Creek 

Grand Canyon; tributary Tributary to the Colorado 

River at 36°11'49"/113°04'55" 

 A&Ww FBC 

CM Wellton Canal Yuma Canal System CM Wellton Ponds 32°42'15"/114°06'15" A&Ww FBC CM

CG

West Cataract Creek 

Tributary to Cataract Creek at 35°15'40"/112°11'38" A&Wc FBC 

CM

CG

White Creek Grand Canyon; headwaters Headwaters to 

confluence with unnamed tributary at 

 A&Wc FBC 
358

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

36°18'42"/112°21'03" 

CM

CG

White Creek Below confluence with unnamed tributary to the 

Colorado River at 36°15'22"/112°19'30"

 A&Ww FBC 

CM

CG

Wright Canyon Creek 

Headwaters to confluence with unnamed tributary at 35°20'54"/113°30'35" A&Wc FBC 

CM

CG

Wright Canyon Creek 

Below confluence with unnamed tributary to confluence with Truxton Wash A&Ww FBC 

CM YPG Pond 32°50'22"/114°26'25" A&Ww FBC CM

Yuma Area 

Canals

Above municipal water treatment plant intakes 

CM

Yuma Area 

Canals

Below municipal water treatment plant intakes and 

all drains 

CL A-10 Backwater 33°31'38"/114°33'19" Shallow A&Ww FBC CL A-7 Backwater 33°34'39"/114°39'42" Shallow A&Ww FBC CL Adobe Lake 33°02'39"/114°39'19" Shallow A&Ww FBC CL Cibola Lake 33°31'38"/114°33'19" Shallow A&Ww FBC CL Clear Lake 33°01'57"/114°31'26" Shallow A&Ww FBC CL

Columbus Wash Tributary to the Gila River at 

33°00'25"/113°16'08"

 A&We PBC

CL Colorado River Lake Mead to Topock Marsh A&Wc FBC CL Colorado River Topock Marsh to Morelos Dam A&Ww FBC CL

Gila River Painted Rock Dam to the Colorado River at 

32°43'12"/114°33'14"

 A&Ww FBC 

CL Holy Moses 

Wash

Headwaters to Kingman WWTP outfall at 35°10'30"/114°03'43"

 A&We PBC

CL Holy Moses 

Wash (EDW)

Kingman WWTP outfall to 3 km downstream A&Wedw PBC
359

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

CL

Holy Moses 

Wash

3 km downstream of Kingman WWTP outfall to confluence with Sawmill Wash at 35°09'43"/114°04'20"

 A&We PBC

CL

Hunter's Hole 

Backwater

32°31'15"/114°48'03"

Shallow A&Ww FBC 

CL Imperial 

Reservoir

32°53'04"/114°27'40"

Shallow A&Ww FBC 

CL Island Lake 33°01'52/114°35'07" Shallow A&Ww FBC CL Laguna Reservoir 32°51'15"/114°28'38" Shallow A&Ww FBC CL Lake Havasu 34°18'15"/114°08'15" Deep A&Ww FBC CL Lake Mohave 35°11'45"/114°34'00" Deep A&Wc FBC CL Martinez Lake 32°58'52"/114°28'23" Shallow A&Ww FBC CL Mittry Lake 32°49'11"/114°27'41" Shallow A&Ww FBC CL

Mohave Wash Headwaters to Lake Havasu at 

33°28'55"/114°35'56"

 A&We PBC

CL Nortons Lake 33°02'35"/114°37'58" Shallow A&Ww FBC CL

Painted Rock 

(Borrow Pit) Lake

33°05'00"/113°01'20"

Sedimentary A&Ww FBC 

CL Pretty Water 

Lake

33°19'45"/114°42'15"

Shallow A&Ww FBC 

CL Quigley Ponds 32°43'00"/113°58'00" Shallow A&Ww FBC CL

Sacramento Wash Tributary to Topock Marsh at 

34°43'48"/114°29'13"

 A&We PBC

CL Sawmill Canyon Headwaters to abandoned gaging station at 

35°09'46.5"/113°57'51"

 A&Ww FBC 

CL Sawmill Canyon Below abandoned gaging station to confluence A&We PBC 
360

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

with Sacramento Wash at 35°09'43"/113°58'01.2"

CL Topock Marsh 34°47'30"/114°31'00" Shallow A&Ww FBC CL

Tyson Wash 

(EDW)

Town of Quartzsite WWTP outfall at 

33°42'30"/114°13'14" to1 km downstream at 33°42'30"/114°13'45"

 A&Wedw PBC

CL Wellton Canal Wellton-Mohawk Irrigation District CL Wellton Ponds 32°42'15"/114°06'15" A&Ww FBC CL YPG Pond 32°50'22"/114°26'25" A&Ww FBC CL

Yuma Area 

Canals

Above municipal water treatment plant intakes 

CL

Yuma Area 

Canals

Below municipal water treatment plant intakes and 

all drains 

LC Als Lake 35°02'17"/111°25'13" Igneous A&Ww FBC LC Ashurst Lake 35°01'10"/111°24'09" Igneous A&Wc FBC LC 

Atcheson Reservoir 

34°00'00"/109°20'41" 

Igneous A&Ww FBC 

LC Auger Creek Tributary to Nutrioso Creek at 

33°57'22"/109°12'58" A&Wc FBC 

LC Barbershop 

Canyon Creek 

Tributary to East Clear Creek at 34°33'00"/111°09'43" A&Wc FBC 

LC Bear Canyon 

Creek 

Tributary to General Springs Canyon at 34°32'18"/111°12'15" A&Wc FBC 

LC Bear Canyon 

Creek 

Tributary to Willow Creek at 34°27'29"/111°00'00" A&Wc FBC 

LC Bear Canyon 

Lake 

34°24'10"/111°00'09" 

Sedimentary A&Wc FBC 

LC Becker Lake 34°09'16"/109°18'18" Shallow A&Wc FBC 
361

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

LC Billy Creek Tributary to Show Low Creek at 

34°12'25"/110°00'00" A&Wc FBC 

LC Black Canyon 

Creek 

Tributary to Chevelon Creek at 34°47'38"/110°36'22" A&Wc FBC 

LC Black Canyon 

Lake 

34°19'50"/110°41'59" 

Sedimentary A&Wc FBC 

LC Blue Ridge 

Reservoir 

34°33'15"/111°11'01" 

Deep A&Wc FBC 

LC Boot Lake 34°58'53"/111°20'00" Igneous A&Wc A&Ww FBC LC

Bow and Arrow 

Wash (EDW)

Estates at Pine Canyon WWTP outfall #1 at 

35°09'31"/111°38'24" to confluence with Rio de Flag at 35°10'35"/111°36'42"

 A&Wedw PBC

LC Buck Springs 

Canyon Creek 

Tributary to Leonard Canyon Creek at 34°28'52"/111°05'24" A&Wc FBC 

LC Bunch Reservoir 34°02'12"/109°26'45" Igneous A&Wc FBC LC Camillo Tank 34°55'03"/111°22'41" Igneous A&Ww FBC LC Carnero Lake 34°06'57"/109°31'39" Shallow A&Wc FBC LC Chevelon Canyon 

Lake 

34°30'39"/110°49'28" 

Sedimentary A&Wc FBC 

LC Chevelon Creek Tributary to the Little Colorado River at 

34°57'04"/110°31'30" A&Wc FBC 

LC 

Chevelon Creek, West Fork 

Tributary to Chevelon Creek at 34°36'58"/110°46'05" A&Wc FBC 

LC Chilson Tank 34°51'46"/111°22'52" Igneous A&Ww FBC LC Cholla Lake 34°56'00"/110°17'12" A&Ww FBC LC Clear Creek Tributary to the Little Colorado River at 

34°59'13"/110°38'17" A&Wc FBC 
362

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

LC 

Clear Creek Reservoir 

34°58'10"/110°38'33" 

Shallow A&Wc FBC 

LC 

Coconino Reservoir 

35°00'16"/111°23'52" 

Igneous A&Wc FBC 

LC Colter Creek Tributary to Nutrioso Creek at 

33°58'19"/109°12'29" A&Wc FBC 

LC Colter Reservoir 33°56'40"/109°28'50" Shallow A&Wc FBC LC Concho Creek Tributary to Carrizo Wash at 34°36'25"/109°33'54" A&Wc FBC LC Concho Lake 34°26'36"/109°37'40" Shallow A&Wc FBC LC Cow Lake 34°53'19"/111°18'49" Igneous A&Ww FBC LC Coyote Creek Tributary to the Little Colorado River at 

34°18'22"/109°20'53" A&Wc FBC 

LC 

Crisis Lake (Snake Tank #2) 

34°47'51"/111°17'01" 

 A&Ww FBC 

LC Dane Canyon 

Creek 

Tributary to Barbershop Canyon Creek at 34°30'29"/111°09'07" A&Wc FBC 

LC Daves Tank 34°44'23"/111°17'08" A&Ww FBC LC Deep Lake 35°03'30"/111°24'55" Igneous A&Ww FBC LC Dry Lake (EDW) 34°37'52"/110°23'40" Igneous A&Wedw PBC LC Ducksnest Lake 34°59'15"/111°23'53" A&Ww FBC LC East Clear Creek Tributary to Clear Creek at 34°38'31"/110°59'49" A&Wc FBC LC 

Ellis Wiltbank Reservoir 

34°05'25"/109°28'24" 

Igneous A&Wc FBC 

LC Fish Creek Tributary to the Little Colorado River at 

34°04'05"/109°26'49" A&Wc FBC 

LC 

Fool's Hollow Lake 

34°16'14"/110°04'15" 

Igneous A&Wc FBC 
363

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

LC General Springs 

Canyon Creek 

Tributary to East Clear Creek at 34°32'17"/111°12'18" A&Wc FBC 

LC Geneva Reservoir 34°01'44"/109°31'44" Igneous A&Wc FBC LC Hall Creek Tributary to the Little Colorado River at 

34°03'58"/109°27'07" A&Wc FBC 

LC Hart Canyon 

Creek 

Tributary to Willow Creek at 34°30'40"/110°59'28" A&Wc FBC 

LC Hay Lake 34°00'11"/109°25'55" Igneous A&Wc A&Ww FBC LC Hog Wallow 

Lake 

33°58'57"/109°25'38" 

Igneous A&Wc FBC 

LC Horse Lake 35°03'53"/111°27'51" A&Ww FBC LC Huffer Tank 34°27'45"/111°23'09" A&Ww FBC LC Hulsey Creek Tributary to Nutrioso Creek at 

33°56'28"/109°11'28" A&Wc FBC 

LC Hulsey Lake 33°55'57"/109°09'33" Sedimentary A&Wc FBC LC Indian Lake 35°00'38"/111°22'37" A&Ww FBC LC Jack's Canyon 

Creek 

Tributary to the Little Colorado River at 35°00'07"/110°39'07" A&Wc FBC 

LC Jarvis Lake 33°58'59"/109°12'33" Sedimentary A&Wc FBC LC Kinnikinick Lake 34°53'52"/111°18'20" Igneous A&Wc FBC LC Knoll Lake 34°25'38"/111°05'10" Sedimentary A&Wc FBC LC Lake Humphreys 

(EDW) 

35°11'51"/111°35'16" 

 A&Wedw PBC 

LC Lake Mary, 

Lower 

35°06'22"/111°34'20" 

Igneous A&Wc FBC 

LC Lake Mary, 

Upper 

35°04'45"/111°31'56" 

Igneous A&Wc FBC 
364

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

LC 

Lake of the Woods 

34°09'39"/109°58'45" 

Igneous A&Wc FBC 

LC Lee Valley Creek 

(UW) (OAW)

Headwaters to Lee Valley Reservoir A&Wc FBC 

LC Lee Valley Creek From Lee Valley Reservoir to the East Fork of the 

Little Colorado River at 33°56'35"/109°29'06" A&Wc FBC 

LC Lee Valley 

Reservoir 

33°56'30"/109°30'00" 

Igneous A&Wc FBC 

LC Leonard Canyon 

Creek 

Tributary to Clear Creek at 34°37'26"/111°02'20" A&Wc FBC 

LC Leonard Canyon 

Creek, East Fork 

Tributary to Leonard Canyon Creek at 34°25'52"/111°05'06" A&Wc FBC 

LC 

Leonard Canyon Creek, Middle Fork 

Tributary to Leonard Canyon, West Fork at 34°26'17"/111°06'47" A&Wc FBC 

LC Leonard Canyon 

Creek, West Fork 

Tributary to Leonard Canyon, East Fork at 34°28'01"/111°05'28" A&Wc FBC 

LC Lily Creek Tributary to Coyote Creek at 33°59'46"/109°03'58" A&Wc FBC LC 

Little Colorado River 

Headwaters to Lyman Reservoir A&Wc FBC 

LC 

Little Colorado River 

Below Lyman Reservoir, to confluence with the Puerco River at 34°53'20"/110°07'41" A&Wc FBC 

LC 

Little Colorado River 

Below confluence with Puerco River to the 

boundary of the Navajo Nation A&Ww FBC 

LC 

Little Colorado River, East Fork 

Tributary to the Little Colorado River at 34°00'14"/109°27'22" A&Wc FBC 

LC Little Colorado Tributary to the Little Colorado River at A&Wc FBC 
365

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

River, South Fork 34°05'20"/109°24'58" 

LC 

Little Colorado River, West Fork (Unique Water)

(OAW)

Headwaters to Government Springs at 33°59'33"/109°27'52" 

 A&Wc FBC 

LC 

Little Colorado River, West Fork 

Below Government Springs to the Little Colorado 

River at 34°00'14"/109°27'21.6" A&Wc FBC 

LC Little George 

Reservoir 

34°00'37"/109°19'15" 

Igneous A&Ww FBC 

LC 

Little Mormon Lake 

34°17'00"/109°58'03" 

Igneous A&Wc FBC 

LC Little Ortega 

Lake 

34°22'45"/109°40'00" 

Igneous A&Wc FBC 

LC Long Lake, 

Lower 

34°46'45"/111°12'00" 

Igneous A&Wc FBC 

LC Long Lake, 

Upper 

35°00'00"/111°21'00" 

Igneous A&Wc A&Ww FBC 

LC Long Tom Tank 34°20'37"/110°49'20" A&Wc FBC LC 

Lower Walnut Canyon Lake (EDW) 

35°12'04"/111°34'07" 

 A&Wedw PBC 

LC Lyman Reservoir 34°21'30"/109°21'30" Deep A&Wc FBC LC Mamie Creek Tributary to Coyote Creek at 33°59'24"/109°03'50" A&Wc FBC LC Marshall Lake 35°07'10"/111°32'01" Igneous A&Wc FBC LC McKay Reservoir 34°01'27"/110°29'07" A&Wc FBC LC 

Merritt Draw Creek 

Tributary to Barbershop Canyon Creek at 34°29'38"/111°09'54" A&Wc FBC 
366

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

LC Mexican Hay 

Lake 

34°01'57"/109°21'25" 

Igneous A&Wc FBC 

LC Milk Creek Tributary to Hulsey Creek at 33°56'31"/109°11'17" A&Wc FBC LC Miller Canyon 

Creek 

Tributary to East Clear Creek at 34°33'00"/111°14'17" A&Wc FBC 

LC Miller Canyon 

Creek, East Fork 

Tributary to Miller Canyon Creek at 34°30'18"/111°14'53" A&Wc FBC 

LC Mineral Creek Tributary to Little Ortega Lake at 

34°22'52"/109°39'50" A&Wc FBC 

LC Mormon Lake 34°56'40"/111°27'10" Shallow A&Wc FBC LC Morton Lake 34°53'36"/111°17'39" Igneous A&Wc FBC LC Mud Lake 34°55'24"/111°21'18" Shallow A&Ww FBC LC Ned Lake (EDW) 32°17'18"/110°03'20" EDW A&Wedw PBC LC Nelson Reservoir 34°03'12"/109°11'18" Sedimentary A&Wc FBC LC Norton Reservoir 34°03'57"/109°31'21" Igneous A&Wc FBC LC Nutrioso Creek Tributary to the Little Colorado River at 

34°09'04"/109°17'35" A&Wc FBC 

LC Paddy Creek Tributary to Nutrioso Creek at 

33°54'47"/109°10'16" A&Wc FBC 

LC 

Phoenix Park Wash 

Tributary to Dry Lake at 34°37'30"/110°22'12" A&We PBC 

LC Pierce Seep 34°23'35"/110°31'22" A&Wc PBCLC Pine Tank 34°46'49"/111°17'17" Igneous A&Ww FBC LC 

Pintail Lake (EDW) 

34°18'06"/110°01'17" 

EDW A&Wedw PBC 

LC Pool Corral Lake 33°58'16"/109°24'53" Igneous A&Ww FBC LC Porter Creek Tributary to Show Low Creek at A&Wc FBC 
367

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

34°10'16"/109°58'48" 

LC Potato Lake 34°27'44"/111°20'42" Igneous A&Wc FBC LC Pratt Lake 34°01'31"/109°04'16" Sedimentary A&Wc FBC LC Puerco River Tributary to the Little Colorado River at 

34°53'20"/110°07'41" A&Ww FBC 

LC

Puerco River 

(EDW)

Sanders Unified School District WWTP outfall at 

35°12'52"/109°19'40" to 0.5 km downstream at 35°12'39"/109°19'52"

 A&Wedw PBC

LC 

Rainbow Lake 34°09'03"/109°59'01" Shallow

Igneous A&Wc FBC 

LC Reagan Reservoir 34°02'09"/109°08'43" Igneous A&Wc FBC LC Rio de Flag Headwaters to Flagstaff WWTP outfall at 

35°12'21"/111°39'17

 A&We PBC

LC 

Rio de Flag (EDW) 

Flagstaff WWTP outfall at 35°12'21"/111°39'17 to 

the confluence with San Francisco Wash at 

35°14'04"/111°28'02.5"

 A&Wedw PBC 

LC River Reservoir 34°02'01"/109°26'07" Igneous A&Wc FBC LC Rogers Reservoir 33°58'30"/109°16'18" Igneous A&Wc FBC LC Rudd Creek Tributary to Nutrioso Creek at 

34°04'12"/109°11'56" A&Wc FBC 

LC Russel Reservoir 33°59'29"/109°20'00" Igneous A&Wc FBC LC

San Salvador 

Reservoir

33°58'51"/109°19'51"

 A&Wc FBC 

LC Salt House Lake 33°57'06"/109°20'12" Igneous A&Wc FBC LC

San Salvador 

Reservoir

33°58'51"/109°19'51"

Igneous A&Wc FBC 

LC Scott Reservoir 34°10'27"/109°57'27" Igneous A&Wc FBC 
368

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

LC Show Low Creek Tributary to Silver Creek at 34°25'26"/110°04'05" A&Wc FBC LC Show Low Lake 34°11'25"/109°59'55" Igneous A&Wc FBC LC Silver Creek Tributary to the Little Colorado River at 

34°44'24"/110°02'17" A&Wc FBC 

LC Slade Reservoir 33°59'50"/109°20'00" Igneous A&Wc FBC LC 

Soldiers Annex Lake 

34°47'13"/111°13'48" 

Igneous A&Wc FBC 

LC Soldiers Lake 34°47'49"/110°13'59" Igneous A&Wc FBC LC Spaulding Tank 34°30'17"/111°02'03" A&Ww FBC LC Sponseller Lake 34°14'10"/109°50'42" Igneous A&Wc FBC LC 

St Johns Reservoir (Little Reservoir) 

34°29'14"/109°21'57" 

Igneous A&Wc FBC 

LC Telephone Lake 

(EDW) 

34°17'35"/110°02'39" 

EDW A&Wedw PBC 

LC Tremaine Lake 34°46'00"/111°14'10" Igneous A&Wc FBC LC Tunnel Reservoir 34°01'51"/109°26'32" Igneous A&Wc FBC LC

Turkey Draw 

(EDW)

High Country Pines II WWTP outfall at 

34°25'35"/110°38'13" to confluence of Turkey Draw with Black Canyon Creek at 34°25'20"/110°36'36"

 A&Wedw PBC

LC

Unnamed wash 

(EDW)

Bison Ranch WWTP outfall at 

34°23'31"/110°31'41" to Pierce Seep at 34°23'35"/110°31'22"

 A&Wedw PBC

LC

Unnamed wash 

(EDW)

Black Mesa Ranger Station WWTP outfall at 

34°23'32"/110°53'32" to confluence of Oklahoma Flat Draw with Pierce Wash at 

 A&Wedw PBC
369

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

34°26'47"/110°29'25"

LC

Unnamed wash 

(EDW)

Estates at Pine Canyon WWTP outfall at 

35°09'17"/111°38'22" to confluence of unnamed wash with Bow Wash and Arrow Wash at 35°09'51"/111°37'29"

 A&Wedw PBC

LC

Unnamed Wash 

(EDW)

Estates at Pine Canyon WWTP outfall #3 at 

35°09'45"/111°38'48" to confluence with Rio de Flag at 35°10'05"/111°38'37"

 A&Wedw PBC

LC Vail Lake 35°05'24"/111°30'42" Igneous A&Wc FBC LC Walnut Creek Tributary to Billy Creek at 34°09'50"/109°58'48" A&Wc FBC LC Water Canyon 

Creek 

Tributary to the Little Colorado River at 34°06'47"/109°18'43" A&Wc FBC 

LC Water Canyon 

Reservoir 

34°00'15"/109°20'05" 

Igneous A&Wc FBC 

LC 

Whale Lake (EDW) 

35°12'32"/111°34'42" 

EDW A&Wedw PBC 

LC Whipple Lake 34°16'47"/109°58'28" Igneous A&Wc FBC LC 

White Mountain Lake 

34°21'54"/109°59'38" 

Igneous A&Wc FBC 

LC 

White Mountain Reservoir 

34°00'15"/109°30'48" 

Igneous A&Wc FBC 

LC Willow Creek Tributary to Clear Creek at 34°38'31"/110°59'49" A&Wc FBC LC Willow Springs 

Canyon Creek 

Tributary to Chevelon Creek at 34°21'32"/110°53'20" A&Wc FBC 

LC Willow Springs 

Lake 

34°18'45"/110°52'34" 

Sedimentary A&Wc FBC 

LC Woodland 34°07'36"/109°57'06" Igneous A&Wc FBC 
370

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Reservoir 

LC Woods Canyon 

Creek 

Tributary to Chevelon Creek at 34°21'32"/110°53'20" A&Wc FBC 

LC Woods Canyon 

Lake 

34°20'05"/110°56'35" 

Sedimentary A&Wc FBC 

LC Zuni River Tributary to the Little Colorado River at 

34°38'42"/109°40'26" A&Wc FBC 

LG

Columbus Wash Tributary to the Gila River at 

33°00'25"/113°16'08"

 A&We PBC

LG

Gila River Painted Rock Dam to the Colorado River at 

32°43'12"/114°33'14"

 A&Ww FBC 

LG

Painted Rock 

(Borrow Pit) Lake

33°05'00"/113°01'20"

 A&Ww FBC 

MG 

Agua Fria River Headwaters to confluence with unnamed EDW 

wash at 34°35'43"/112°16'29", receiving treated wastewater from the Prescott Valley WWTP 

 A&We PBC 

MG 

Agua Fria River (EDW) 

Below confluence with unnamed wash receiving treated wastewater from the Prescott Valley WWTP to State Route 169 at 

34°31'43"/112°14'7.5"

 A&Wedw PBC 

MG Agua Fria River State Route 169 to Lake Pleasant at 

34°54'54.7"/112°14'7.5" A&Ww FBC 

MG Agua Fria River Below Lake Pleasant to the El Mirage WWTP at 

33°34'36"/112°48'45" A&We PBC 

MG Agua Fria River 

(EDW) 

El Mirage WWTP to 2 km downstream A&Wedw PBC 
371

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

MG Agua Fria River Below 2 km downstream of the El Mirage WWTP 

to State Highway 85 Avondale WWTP outfall

 A&We PBC 

MG Agua Fria River Below State Highway 85 A&Ww FBC MG 

Agua Fria River Avondale WWTP outfall at 

33°23'24"/112°21'50.4" to Gila River at 33°23'22"/112°21'48"

 A&Wedw PBC

MG Alvord Park Lake Municipal Park Urban Lake: 35th Avenue & 

Baseline Road, Phoenix at 33°22'34"/112°08'11"

Urban A&Ww PBC 

MG

Andorra Wash 

(EDW)

Town of Cave Creek WWTP outfall #1 at 

33°50'00"/111°56'32" to confluence with Cave Creek Wash at 33°49'54"/111°57'57.4"

 A&W edw PBC

MG Antelope Creek Tributary to Martinez Creek at 

34°16'37"/112°08'46" A&Ww FBC 

MG 

Arlington Canal Above Wilson Avenue From Gila River at 

33°20'54"/112°35'39" to Gila River at 33°13'44"/112°46'15"

 

MG Ash Creek Headwaters to confluence with Tex Canyon at 

34°34'44"/112°07'18" A&Wc FBC 

MG Ash Creek Below confluence with Tex Canyon to Agua Fria 

at 34°19'34"/112°04'30" A&Ww FBC 

MG Beehive Tank 32°52'36"/111°02'19" A&Ww FBC MG Big Bug Creek Headwaters to confluence with Eugene Gulch at 

34°27'11"/112°18'28.5" A&Wc FBC 

MG 

Big Bug Creek Below confluence with Eugene Gulch to 

confluence with Agua Fria River at 34°18'54"/112°03'58"

 A&Ww FBC 

MG Black Canyon Tributary to the Agua Fria River at A&Ww FBC 
372

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Creek 34°04'12"/112°09'29" 

MG 

Blind Indian Creek 

Tributary to the Hassayampa River at 34°12'40"/112°32'17" A&Ww FBC 

MG 

Bonsall Park Lake 

Municipal Park Urban Lake; 59th Avenue & 

Bethany Home Road, Phoenix at 33°31'23"/112°11'05"

Urban A&Ww PBC 

MG 

Canal Park Lake Municipal Park Urban Lake; College Avenue & 

Curry Road, Tempe at 33°26'57"/111°56'14"

Urban A&Ww PBC 

MG Cave Creek Headwaters to the Cave Creek Dam A&Ww FBC MG 

Cave Creek Cave Creek Dam to the Arizona Canal at 

33°34'24"/112°06'25" 

 A&We PBC 

MG 

Centennial Wash Tributary to the Gila River at 

33°13'44"/112°46'16" A&We PBC 

MG 

Centennial Wash Ponds 

33°55'10"/113°23'05" 

 A&Ww FBC 

MG 

Chaparral Park Lake 

Municipal Park Urban Lake; Hayden Road & 

Chaparral Road, Scottsdale at 33°30'41"/111°54'25"

Urban A&Ww PBC 

MG Cortez Park Lake Municipal Park Urban Lake; 35th Avenue & 

Dunlap, Glendale at 33°34'13"/112°07'51"

Urban A&Ww PBC 

MG 

Desert Breeze Lake 

Municipal Park Urban Lake; Galaxy Drive, West 

Chandler at 33°18'47.5"/111°55'08"

Urban A&Ww PBC 

MG Devils Canyon Tributary to Mineral Creek at 

33°12'58"/110°59'42" A&Ww FBC 

MG 

Dobson Lake Municipal Park Urban Lake; Dobson Road & Los 

Lagos Vista Avenue, Mesa at 33°22'17"/111°53'12"

Urban A&Ww PBC 
373

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

MG 

Eldorado Park Lake 

Municipal Park Urban Lake; Miller Road & Oak 

Street, Tempe at 33°28'25"/111°54'51"

Urban A&Ww PBC 

MG 

Encanto Park Lake 

Municipal Park Urban Lake; 15th Avenue & 

Encanto Blvd., Phoenix at 33°28'36"/112°05'17"

Urban A&Ww PBC 

MG Fain Lake Park Lake, city City of Prescott Valley Park Lake 

34°34'29"/112°21'03"

Urban A&Ww PBC 

MG French Gulch Headwaters to confluence with Hassayampa River A&Ww PBC MG Galena Gulch Tributary to the Agua Fria River at 

34°28'37"/112°15'14" A&We PBC 

MG

Gallaway Wash 

(EDW)

Town of Cave Creek WWTP outfall #2 at 

33°49'58"/111°57'30"to confluence with Andorra Wash at 33°49'59"/111°57'41"

 A&Wedw PBC

MG 

Gila River San Carlos Indian Reservation to the AshurstHayden Dam at 33°06'01"/111°14'46" A&Ww FBC 

MG Gila River Ashurst-Hayden Dam to the Florence WWTP 

outfall at 33°02'30"/111°24'16" A&We PBC 

MG 

Gila River (EDW) 

Florence WWTP outfall to Felix Road at 

33°01'49"/111°17'16"

 A&Wedw PBC 

MG Gila River Felix Road to the Gila River Indian Reservation A&We PBC MG 

Gila River (EDW) 

From the confluence with the Salt River to the 

Gillespie Dam at 33°13'45"/112°46'07" A&Wedw PBC 

MG Gila River Gillespie Dam to Painted Rock Dam at 

33°04'23"/113°00'40" A&Ww FBC 

MG 

Granada Park Lake 

Municipal Park Urban Lake; 6505 North 20th 

Street, Phoenix at 33°31'58.6"/112°02'06"

Urban A&Ww PBC 

MG Groom Creek Tributary to the Hassayampa River at 

34°27'14"/112°29'24" A&Wc FBC 
374

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

MG Hank Raymond 

Lake 

33°50'18"/112°16'07" 

 A&Ww FBC 

MG Hassayampa 

Lake 

34°25'45"/112°25'29" 

Igneous A&Wc FBC 

MG Hassayampa 

River 

Headwaters to confluence with unnamed tributary at 34°26'09"/112°30'32" A&Wc FBC 

MG Hassayampa 

River 

Below confluence with unnamed tributary to 8 miles south of Wickenberg A&Ww FBC 

MG 

Hassayampa River 

8 miles south of Wickenburg to the Buckeye Irrigation Company Canal at 

33°23'38"/112°22'22.8"

 A&We PBC 

MG Hassayampa 

River 

Buckeye Irrigation Company Canal to the Gila River at 33°19'34"/112°42'39.6" A&Ww FBC 

MG Horsethief Lake 34°09'42"/112°17'56" Igneous A&Wc FBC MG 

Indian Bend Wash 

Tributary to the Salt River at 33°26'13"/111°54'58" A&We PBC 

MG 

Indian Bend Wash Lakes 

Municipal Park Urban Lakes; Scottsdale at 

33°30'31"/111°54'24"

Urban A&Ww PBC 

MG 

Indian School Park Lake 

Municipal Park Urban Lake; Indian School Road 

& Hayden Road, Scottsdale at 33°29'45"/111°54'33"

Urban A&Ww PBC 

MG 

Kiwanis Park Lake 

Municipal Park Urban Lake; 6000 South Mill 

Avenue, Tempe at 33°22'27"/111°56'21"

Urban A&Ww PBC 

MG Lake Pleasant 33°51'15"/112°16'15" Deep A&Ww FBC MG Lion Canyon Tributary to Weaver Creek at 

34°10'12"/112°41'49" A&Ww FBC 

MG Little Ash Creek Tributary to Ash Creek at 34°20'46"/112°04'16" A&Ww FBC 
375

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

MG Lynx Creek Headwaters to confluence with unnamed tributary 

at 34°34'29"/112°21'05" A&Wc FBC 

MG Lynx Creek Below confluence with unnamed tributary to Agua 

Fria River at 34°37'49"/112°14'42" A&Ww FBC 

MG Lynx Lake 34°31'08"/112°23'05" Deep A&Wc FBC MG Maricopa Park 

Lake 

33°35'30"/112°18'16" 

Urban A&Ww PBC 

MG Martinez Canyon Tributary to Box Canyon at 33°06'33"/111°12'48" A&Ww FBC MG Martinez Creek Tributary to the Hassayampa River at 

33°59'56"/112°44'38" A&Ww FBC 

MG 

McKellips Park Lake 

Municipal Park Urban Lake; Miller Road & 

McKellips Road, Scottsdale at 33°27'14"/111°54'45"

Urban A&Ww PBC 

MG

McMicken Wash 

(EDW)

Jomax WWTP outfall at 33°43'30"/112°20'11"to 

confluence of McMicken Wash with Agua Fria River at 33°39'39"/112°18'56"

 A&Wedw PBC

MG Mineral Creek Tributary to the Gila River at 

34°17'42"/112°13'34" A&Ww FBC 

MG Minnehaha Creek Tributary to the Hassayampa River at 

34°11'49"/112°32'24" A&Ww FBC 

MG

Mountain Valley 

Park Ponds (EDW)

Town of Prescott Valley WWTP outfall 002 at 

34°26'07"/112°18'48" to Navajo Wash A&Wedw PBC

MG New River Headwaters to I-17 at 33°54'19.5"/112°08'46" A&Ww FBC MG New River Below I-17 to Agua Fria River at 

33°30'47"/112°18'14" A&We PBC 

MG Painted Rock 33°04'15"/113°00'30" Sedimentary A&Ww FBC 
376

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Reservoir 

MG Papago Park 

Ponds 

Municipal Park Urban Lake; Galvin Parkway, 

Phoenix at 33°26'56"/111°56'50"

Urban A&Ww PBC 

MG Papago Park 

South Pond

Municipal Park Urban Lake; Curry Road, Tempe Urban A&Ww PBC 

MG Perry Mesa Tank 34°11'03"/112°01'59" A&Ww FBC MG 

Phoenix Area Canals 

Granite Reef Dam to all municipal WTP intakes 

MG 

Phoenix Area Canals 

Below municipal WTP intakes and all other locations 

MG 

Picacho Reservoir 

32°51'17"/111°28'49" 

Shallow A&Ww FBC 

MG 

Poland Creek Headwaters to confluence with Lorena Gulch at 

34°12'32"/112°19'07" A&Wc FBC 

MG 

Poland Creek Below confluence with Lorena Gulch to Black 

Canyon Creek at 34°14'20"/112°12'54" A&Ww FBC 

MG Queen Creek Headwaters to the Town of Superior WWTP 

outfall at 33°16'45"/111°17'25"

 A&Ww A&We PBC 

MG 

Queen Creek (EDW) 

Town of Superior WWTP outfall to confluence with Potts Canyon at 33°17'17"/111°11'36"

 A&Wedw PBC 

MG Queen Creek Potts Canyon to Queen Valley golf course at 

33°17'55"/111°17'17" A&Ww FBC 

MG Queen Creek Below Queen Valley golf course to Gila River at 

33°09'50"/111°53'16.8"

 A&We PBC 

MG 

Riverview Park Lake 

Municipal Park Urban Lake; Dobson Road & 8th 

Street, Mesa at 33°25'50"/111°52'29"

Urban A&Ww PBC 

MG Roadrunner Park Municipal Park Urban Lake; 36th Street & Cactus, Urban A&Ww PBC 
377

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Lake Phoenix at 33°35'57"/112°00'18"

MG

Salt River Verde River to 2 km below Granite Reef Dam 

(Granite Reef Dam is at 31°26'23"/111°12'40")

 A&Ww FBC 

MG

Salt River 2 km below Granite Reef Dam to City of Mesa 

NW WRF outfall at 33°26'45"/111°56'35"

 A&We PBC

MG

Salt River (EDW) City of Mesa NW WRF outfall at 

33°26'45"/111°56'35" to Tempe Town Lake at 33°26'01"/111°54'55"

 A&Wedw PBC

MG Salt River Below Tempe Town Lake to I-10 bridge A&We PBCMG

Salt River I-10 bridge to the 23rd Ave WWTP at 

33°25'03"/112°06'41.6"

 A&Ww PBC 

MG

Salt River (EDW) 23rd Ave WWTP to confluence with Gila River at 

33°22'55"/112°18'21.6"

 A&Wedw PBC 

MG

Siphon Draw 

(EDW)

Superstition Mountains WWTP outfall at 

33°21'40"/111°33'30" to 6 km downstream at 32°21'01"/111°36'59"

 A&Wedw PBC

MG Sycamore Creek Headwaters to confluence with Tank Canyon at 

34°19'32"/111°50'12" A&Wc FBC 

MG Sycamore Creek Below confluence with Tank Canyon to the Agua 

Fria River 34°19'30"/112°04'12" A&Ww FBC 

MG Tempe Town 

Lake

At Mill Avenue Bridge at 33°26'30"/111°53'30" Urban A&Ww FBC 

MG Tule Creek Tributary to the Agua Fria River at 

33°57'25"/112°14'13" A&Ww FBC 

MG Turkey Creek Headwaters to confluence with unnamed tributary 

at 34°19'28"/112°21'28" A&Wc FBC 

MG Turkey Creek Below confluence with unnamed tributary to A&Ww FBC 
378

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Poland Creek at 34°14'20"/112°12'54"

MG

Unnamed Wash 

(EDW)

City of Phoenix Cave Creek WRF outfall at 

33°45'20"/112°00'59" to unnamed wash to 0.5 km downstream at 33°35'07"/112°01'12"

 A&Wedw PBC

MG 

Unnamed Wash (EDW) 

Gila Bend WWTP outfall to the Gila River at 

32°58'13"/112°43'46"

 A&Wedw PBC 

MG 

Unnamed Wash (EDW) 

Luke Air Force Base WWTP outfall to the Agua Fria River at 33°32'21"/112°19'15"

 A&Wedw PBC 

MG

Unnamed Wash 

(EDW)

Florence Gardens WWTP outfall at 

33°03'49.54"/111°23'13.28" to confluence with Gila River at 33°02'59"/111°23'15"

 A&Wedw PBC

MG 

Unnamed Wash (EDW) 

Prescott Valley WWTP outfall to the Agua Fria River 34°35'16"/112°16'18"

 A&Wedw PBC 

MG 

Unnamed Wash (EDW) 

Queen Valley Sanitary District WWTP outfall at 

33°17'38"/111°18'31" to the confluence with Queen Creek 

 A&Wedw PBC 

MG Wagner Wash 

(EDW)

Buckeye Festival Ranch WRF outfall at 

33°39'14"/112°40'18" to 2 km downstream

 A&Wedw PBC

MG 

Vista Del Camino Park North 

Municipal Park Urban Lake; 7700 East Roosevelt 

Street, Scottsdale at 33°27'33"/111°54'49.3"

 A&Ww PBC 

MG

Vista Del Camino 

Park South

Municipal Park Lake; 7700 East Roosevelt Street, 

Scottsdale

 A&Ww PBC 

MG Walnut Canyon 

Creek 

Tributary to the Gila River at 33°06'47"/111°05'20" A&Ww FBC 

MG Weaver Creek Tributary to Martinez Creek at 

34°03'18"/112°46'48" A&Ww FBC 

MG White Canyon Tributary to Walnut Canyon Creek at A&Ww FBC 
379

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Creek 33°09'25"/111°04'48" 

RM Abbot Canyon Mule Mountains A&Ww FBC RM Ash Creek Chiricahua Mountains A&Ww FBC RM

Bear Creek Headwaters to U.S./Mexico border at 

31°19'59"/110°22'58.5"

 A&Ww FBC 

RM Blackwater Draw San Bernardino Valley A&Ww FBC RM Buck Canyon Headwaters to Buck Creek Tank at 

31°33'06"/109°52'43"

 A&Ww FBC 

RM Buck Canyon Below Buck Creek Tank A&We PBC RM California Gulch South of Ruby A&Ww FBC RM Dixie Canyon Mule Mountains A&Ww FBC RM Dry Canyon Mule Mountains A&Ww FBC RM Gadwell Canyon Mule Mountains A&Ww FBC RM Glance Creek Mule Mountains A&Ww FBC RM Gold Gulch Mule Mountains A&Ww FBC RM Holden Canyon 

Creek

Coronado National Forest

 A&Ww FBC 

RM Johnson Canyon Chiricahua Mountains A&Ww FBC RM Leslie Canyon 

Creek

Chiricahua Mountains

 A&Ww FBC 

RM Mexican Canyon Mule Mountains A&Ww FBC RM Mule Gulch Headwaters to just above the Lavender Pit A&Ww PBC RM

Mule Gulch Just above the Lavender Pit to the Bisbee WWTP 

outfall

 A&We PBC

RM

Mule Gulch 

(EDW)

Below the Bisbee WWTP outfall, to the Highway 

80 bridge at 31°26'30"/109°49'28"

 A&Wedw PBC
380

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

RM Mule Gulch Below the Highway 80 bridge A&We PBC RM Quitobaquito 

Spring

(Pond and Springs) 31°56'39"/113°01'06" A&Ww FBC 

RM Ruby Lakes Near the town of Ruby A&Ww FBC RM Rucker Canyon 

Creek

Chiricahua Mtns; tributary to Whitewater Draw at 31°44'46"/109°26'06"

 A&Wc FBC 

RM Rucker Canyon 

Lake

31°46'46"/109°18'30"

 A&Wc FBC 

RM Soto Canyon Mule Mountains A&Ww FBC RM Sycamore 

Canyon Creek

Headwaters to the U.S./Mexico border at 31°22'48"/111°13'19"

 A&Ww FBC 

RM

Unnamed Wash 

(EDW)

Bisbee-Douglas International Airport WWTP 

outfall to Whitewater Draw

 A&Wedw PBC

RM

Whitewater Draw Headwaters to confluence with unnamed tributary 

at 31°20'36"/109°34'46"

 A&We PBC 

RM Whitewater Draw Below confluence with unnamed tributary A&Ww FBC 

SC Agua Caliente 

Lake 

Municipal Park Urban Lake; 12325 East Roger Road, Tucson 

Urban A&Ww PBC 

SC Agua Caliente 

Wash 

Headwaters to Soldier Trail at 32°17'48"/110°42'58.5" A&Ww FBC 

SC Agua Caliente 

Wash 

Below Soldier Trail to Tanque Verde Creek at 32°14'35"/110°47'17" A&We PBC 

SC Aguirre Wash Those reaches not located on the Tohono O'odham 

Indian Reservation 

 A&We PBC 

SC Alambre Wash Tributary to Brawley Wash at 

31°57'47"/111°23'28" 

 A&We PBC 

SC Alamo Wash Tributary to Rillito Creek at 32°16'23"/110°54'18" A&We PBC 
381

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SC Altar Wash Tributary to Brawley Wash at 

31°57'47"/111°23'28" 

 A&We PBC 

SC Alum Gulch Headwaters to 31°28'20"/110°43'51" A&We PBC SC 

Alum Gulch From 31°28'20"/110°43'51" to 

31°29'17"/110°44'25" A&Ww FBC 

SC 

Alum Gulch Below 31°29'17"/110°44'25" to Sonoita Creek at 

31°30'58"/110°47'06" A&We PBC 

SC Arivaca Creek Tributary to Altar Wash at 31°43'01"/111°25'41" A&Ww FBC SC Arivaca Lake 31°31'50"/111°15'05" Igneous A&Ww FBC SC Atterbury Wash Tributary to Pantano Wash at 

32°10'52"/110°48'50" A&We PBC 

SC Bear Grass Tank 31°33'01"/111°11'32" A&Ww FBC SC Big Wash Tributary to Cañada del Oro at 

32°24'47"/110°56'28" 

 A&We PBC 

SC

Black Wash 

(EDW)

Pima County WWMD Avra Valley WWTP at 

32°09'50"/111°10'49" to confluence with Brawley Wash at 32°15'00"/111°14'34"

 A&Wedw PBC

SC Bog Hole Tank 31°28'34"/110°37'07" A&Ww FBC SC Brawley Wash Tributary to Los Robles Wash at 

32°21'54"/111°17'31" 

 A&We PBC 

SC California Gulch South of Ruby A&Ww FBC SC Cañada del Oro Headwaters to Highway 89 at 

32°24'48"/110°56'14" A&Ww FBC 

SC Cañada del Oro Below Highway 89 to the Santa Cruz River at 

32°19'30"/111°03'47" A&We PBC 

SC Cienega Creek Headwaters to confluence with Gardner Canyon 

and Spring Water Canyon at R18E, T17S. A&Ww FBC 
382

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

31°47'38"/110°35'17"

SC 

Cienega Creek (Unique Water)

(OAW)

From confluence with Gardner Canyon and Spring Water Canyon at R18E, T17S to USGS gaging 

station at 32°02'09"/110°40'34" (becomes Pantano 

Wash below this point)

 A&Ww FBC 

SC Davidson Canyon Headwaters to unnamed spring at 

31°59'00"/110°38'46" A&We PBC 

SC Davidson Canyon 

(OAW)

Unnamed Spring to confluence with unnamed tributary at 31°59'32.5"/110°38'43.5" A&Ww FBC 

SC Davidson Canyon 

(OAW)

From confluence with unnamed tributary to unnamed spring at 32°00'54"/110°38'54" A&We PBC 

SC 

Davidson Canyon (OAW)

From unnamed spring at 32°00'54"/110°38'54" to confluence with Cienega Creek at 

32°01'05"/110°38'32"

 A&Ww FBC 

SC Empire Gulch Headwaters to unnamed spring at 

31°47'14"/110°38'13" 

 A&We PBC 

SC Empire Gulch From 31°47'14"/110°38'13" 

to31°47'11"/110°00'39" 

 A&Ww FBC 

SC Empire Gulch Below 31°47'11"/110°00'39" to 

31°47'18"/110°36'57" A&We PBC 

SC Empire Gulch From 31°47'18"/110°36'57" to confluence with 

Cienega Creek at 31°48'32"/110°35'20"

 A&Ww FBC 

SC Flux Canyon Tributary to Alum Canyon at 31°30'22"/110°46'41" A&We PBC SC Gardner Canyon 

Creek 

Headwaters to confluence with Sawmill Canyon at 31°42'51"/110°44'43" 

 A&Wc FBC 

SC Gardner Canyon 

Creek 

Below Sawmill Canyon To Cienega Creek at 31°47'38"/110°35'17"

 A&Ww FBC 
383

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SC Greene Wash Tributary to the Santa Cruz River at 

33°00'54"/111°59'46" 

 A&We PBC 

SC Harshaw Creek Tributary to Sonoita Creek at 

31°32'35"/110°44'42" A&We PBC 

SC Hit Tank 32°43'57"/111°03'18" A&Ww FBC SC

Holden Canyon 

Creek

Headwaters to Mexico border at 31°23'38"/111°15'54" in the Coronado National Forest

 A&Ww FBC 

SC Huachuca Tank 31°21'11"/110°30'12" A&Ww FBC SC Julian Wash Tributary to the Santa Cruz River at 

32°11'20"/110°59'13" 

 A&We PBC 

SC Kennedy Lake Municipal Park Urban Lake; Mission Road & Ajo 

Road, Tucson at 32°10'48.5"/111°00'27"

Urban A&Ww PBC 

SC Lakeside Lake Municipal Park Urban Lake; 8300 East Stella 

Road, Tucson at 32°11'10.5"/110°49'00"

Urban A&Ww PBC 

SC Lemmon Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 32°23'47"/110°47'46" 

 A&Wc FBC 

SC Lemmon Canyon 

Creek 

Below unnamed tributary to Sabino Canyon Creek at 32°23'02"/110°47'28"

 A&Ww FBC 

SC Los Robles Wash Tributary to the Santa Cruz River at 

32°32'13"/111°23'53" 

 A&We PBC 

SC Madera Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 31°43'42"/110°52'50" A&Wc FBC 

SC Madera Canyon 

Creek 

Below unnamed tributary to the Santa Cruz River at 31°46'55"/111°00'58" A&Ww FBC 

SC Mattie Canyon Tributary to Cienega Creek at 

31°51'31"/110°34'25" A&Ww FBC 
384

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SC Nogales Wash Tributary to Potrero Creek at 31°24'07"/110°57'11" A&Ww PBC SC Oak Tree Canyon Tributary to Cienega Creek at 

31°48'43"/110°35'24" 

 A&We PBC 

SC Palisade Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 32°22'34"/110°45'35" 

 A&Wc FBC 

SC Palisade Canyon 

Creek 

Below unnamed tributary to Sabino Canyon Creek at 32°21'54"/110°46'23"

 A&Ww FBC 

SC Pantano Wash Tributary to Tanque Verde Creek at 

32°16'23"/110°54'18" 

 A&We PBC 

SC Paradise Lake 32°44'18"/111°40'42" Urban A&Ww FBC PBC SC Parker Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 31°24'17"/110°28'44.5" 

 A&Wc FBC 

SC Parker Canyon 

Creek 

Below unnamed tributary to Mexico border at 31°19'59"/110°33'58"

 A&Ww FBC 

SC Parker Canyon 

Lake 

31°25'35"/110°27'15" 

Deep A&Wc FBC 

SC Patagonia Lake 31°29'30"/110°52'00" Deep A&Wc A&Ww FBC SC Peña Blanca Lake 31°24'12"/111°05'04" Igneous A&Wc A&Ww FBC SC 

Potrero Creek Headwaters to Interstate 19 at 

31°23'24"/110°57'30" A&We PBC 

SC 

Potrero Creek Below Interstate 19 to Santa Cruz River at 

31°27'07"/110°57'40" A&Ww FBC 

SC Puertocito Wash Tributary to Altar Wash at 31°43'01"/111°25'41" A&We PBC SC Quitobaquito 

Spring

(Pond and Springs) 31°56'39"/113°01'06" A&Ww FBC 

SC Redrock Canyon 

Creek 

Tributary to Harshaw Creek at 31°32'35"/110°44'13" 

 A&Ww FBC 
385

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SC Rillito Creek Tributary to the Santa Cruz River at 

32°18'50"/111°03'18" A&We PBC 

SC Romero Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 32°24'30"/110°50'35" 

 A&Wc FBC 

SC Romero Canyon 

Creek 

Below unnamed tributary to Sutherland Wash at 32°25'52"/110°53'56"

 A&Ww FBC 

SC Rose Canyon 

Creek 

Tributary to Rose Canyon Lake at 32°23'10"/110°43'01" 

 A&Wc FBC 

SC Rose Canyon 

Lake 

32°23'13"/110°42'38" 

Igneous A&Wc FBC 

SC Ruby Lakes Near the town of Ruby at 31°26'28.5"/111°14'19" Igneous A&Ww fbc SC Sabino Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 32°23'28"/110°47'00" A&Wc FBC 

SC Sabino Canyon 

Creek 

Below unnamed tributary to Tanque Verde River at 32°15'40"/110°49'30" A&Ww FBC 

SC 

Salero Ranch Tank 

31°35'42"/110°53'22" A&Ww FBC 

SC Santa Cruz River Headwaters to the International Boundary at 

31°19'58"/110°35'48" A&Ww FBC 

SC 

Santa Cruz River International Boundary to the Nogales 

International WWTP outfall at 31°27'24"/110°58'05"

 A&Ww FBC 

SC

Santa Cruz River 

(EDW)

Nogales International WWTP outfall to the Tubac 

Bridge at 31°36'25"/111°02'00"

 A&Wedw PBC 

SC Santa Cruz River The Tubac Bridge to Roger Rd Road WWTP 

outfall A&We PBC 

SC Santa Cruz River Roger Road WWTP outfall to Baumgartner Road A&Wedw PBC 
386

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

(EDW) at 32°35'37"/111°28'08"

SC 

Santa Cruz River 

(Wash)

Baumgartner Road to the Gila River Ak Chin

Indian Reservation A&We PBC 

SC 

Santa Cruz River

Wash, West 

Branch 

Tributary to the Santa Cruz River Wash at 32°12'07"/110°59'20" A&We PBC 

SC 

Santa Cruz River

Wash, N. Fork

North Branch

Tributary to the Santa Cruz River Wash at 

32°55'55"/111°53'10" A&We PBC 

SC

Santa Cruz Wash, 

North Branch (EDW)

City of Casa Grande WRF outfall at

32°54'57"/111°47'13" to 1 km downstream at 32°54'49"/111°47'48"

 A&Wedw PBC

SC 

Santa Rosa Wash Below Tohono O'odham Indian Reservation to the 

Santa Cruz Wash at 32°53'49"/111°56'46" Ak Chin Indian Reservation

 A&We PBC 

SC

Santa Rosa Wash

(EDW)

Palo Verde Utilities WWTP outfall at 

33°04'20"/112°01'47" to the Gila River Indian Reservation

 A&Wedw PBC

SC Soldier Lake 32°25'34"/110°44'41" A&Wc FBC SC Sonoita Creek Headwaters to the Town of Patagonia WWTP 

outfall at 31°32'15"/110°45'30" A&We PBC 

SC 

Sonoita Creek (EDW) 

Town of Patagonia WWTP outfall to 750

permanent groundwater upwelling point 

approximately 1600 feet downstream of outfall 

 A&Wedw PBC 

SC 

Sonoita Creek Below 750 1600 feet downstream of Town of 

Patagonia WWTP outfall to the Santa Cruz River 

at 31°29'43"/110°58'37"

 A&Ww FBC 
387

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SC Split Tank 31°28'15"/111°05'15" A&Ww FBC SC Sutherland Wash Tributary to Cañada del Oro at 

32°25'05"/110°55'26" 

 A&Ww FBC 

SC Sycamore 

Canyon 

From 32°21'36"/110°45'21" to Sycamore Reservoir A&Ww FBC 

SC Sycamore 

Canyon Creek

Headwaters to the U.S / Mexico border at 31°22'48"/111°13'19"

 A&Ww FBC 

SC Sycamore 

Reservoir 

32°20'57"/110°44'52" 

 A&Wc FBC 

SC Tanque Verde 

Creek 

Headwaters to Houghton Road at 32°14'13"/110°46'04" A&Ww FBC 

SC Tanque Verde 

Creek 

Below Houghton Road to Rillito Creek at 32°16'08"/110°52'30" A&We PBC 

SC The Lake Tank 32°54'14"/111°04'14" A&Ww FBC SC Three R Canyon Headwaters to Lat/Long: 31°28'35"/110°46'19" A&We PBC SC Three R Canyon From Lat/Long: 31°28'35"/110°46'19" to 

Lat/Long: 31°28'27"/110°47'12" A&Ww FBC 

SC Three R Canyon From Lat/Long: 31°28'27"/110°47'12" to Sonoita 

Creek at 31°29'56"/110°48'54" A&We PBC 

SC Tinaja Wash Eastern foothills, Sierrita Mountains Headwaters to 

the Santa Cruz River at 31°32'58.4"/111°02'45.7" A&We PBC 

SC 

Unnamed Wash (EDW) 

Oracle Sanitary District WWTP outfall at 32°36'54"/110°48'02" to 5 km downstream 

 A&Wedw PBC 

SC

Unnamed Wash 5 km downstream of the Oracle Sanitary District 

WWTP outfall

 A&We PBC

SC

Unnamed Wash 

(EDW)

Arizona City Sanitary District WWTP outfall at 

32°45'47"/111°44'20" to confluence with Santa 

 A&Wedw PBC
388

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Cruz Wash at 35°45'45"/111°46'43"

SC

Unnamed Wash 

(EDW)

Saddlebrooke WWTP outfall at 

32°32'00"/110°52'59"to confluence with Canada del Oro at 32°30'20"/110°52'27"

 A&Wedw PBC

SC 

Vekol Wash Those reaches not located on the Ak-Chin, Tohono 

O'odham and Gila River Indian Reservations 

 A&We PBC 

SC 

Wakefield Canyon 

Headwaters to confluence with unnamed tributary 31°52'47"/110°26'25" A&Wc FBC 

SC 

Wakefield Canyon 

Below confluence with unnamed tributary to Cienega Creek at 31°52'47.5"/110°26'25" A&Ww FBC 

SC 

Wild Burro Canyon 

Headwaters to confluence with unnamed tributary at 32°28'36"/111°05'18" A&Ww FBC 

SC 

Wild Burro Canyon 

Below confluence with unnamed tributary to Santa Cruz River at 32°28'34"/111°05'15.5" A&We PBC 

SC 

Williams Ranch Tanks 

31°55'15"/110°25'30" 

 A&Ww FBC 

SP Abbot Canyon Headwaters to confluence with Whitewater Draw 

at 31°33'32"/109°48'39.6"

 A&Ww FBC 

SP Aravaipa Creek Headwaters to confluence with Stowe Gulch at 

32°52'10"/110°22'00" A&Ww FBC 

SP 

Aravaipa Creek (Unique Water)

(OAW)

Stowe Gulch confluence to downstream boundary of Aravaipa Canyon Wilderness Area at 32°54'23"/110°33'40" 

 A&Ww FBC 

SP 

Aravaipa Creek Below downstream boundary of Aravaipa Canyon 

Wilderness Area to the San Pedro River at 

32°50'20"/110°42'50"

 A&Ww FBC 

SP Ash Creek Chiricahua Mountains, near Whitewater Draw at A&Ww FBC 
389

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

31°50'28"/109°40'01.2"

SP 

Babocomari Creek River

Tributary to the San Pedro River at 31°43'19"/110°11'35" A&Ww FBC 

SP Bass Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 32°26'06"/110°13'18" A&Wc FBC 

SP Bass Canyon 

Creek 

Below confluence with unnamed tributary to Hot 

Springs Canyon Creek at 32°20'53"/110°15'14" A&Ww FBC 

SP Bass Canyon 

Tank 

32°24'00"/110°13'00" 

 A&Ww FBC 

SP

Bear Creek Headwaters to U.S. / Mexico border at 

31°19'59"/110°22'58.5"

 A&Ww FBC 

SP Big Creek Tributary to Pitchfork Canyon at 

32°35'24"/109°57'07"

 A&Wc FBC 

SP Blacktail Pond Fort Huachuca Military Reservation at 

31°24'13"/110°17'21"

 A&Ww FBC 

SP

Blackwater Draw Headwaters to the U.S. / Mexico border at 

31°20'02"/109°15'36" in the San Bernardino Valley

 A&Ww FBC 

SP Booger Canyon 

Creek 

Tributary to Aravaipa Creek at 32°54'54"/110°29'35" A&Ww FBC 

SP Buck Canyon Headwaters to Buck Creek Tank at 

31°33'06"/109°52'43"

 A&Ww FBC 

SP Buck Canyon Below Buck Creek Tank to Dry Creek at 

31°31'08"/109°18'25"

 A&We PBC 

SP 

Buehman Canyon Creek (Unique 

Water) (OAW)

Headwaters to confluence with unnamed tributary at 32°24'31.5"/110°32'08" A&Ww FBC 

SP Buehman Canyon Below confluence with unnamed tributary at A&Ww FBC 
390

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Creek 32°25'41"/110°29'53"

SP Bull Tank 32°31'15"/110°12'45" A&Ww FBC SP Bullock Canyon Tributary to Buehman Canyon at 

32°23'00"/110°33'04" A&Ww FBC 

SP Carr Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 31°27'00"/110°15'45" A&Wc FBC 

SP Carr Canyon 

Creek 

Below confluence with unnamed tributary to the 

San Pedro River at 31°30'32"/110°07'37" A&Ww FBC 

SP Copper Creek Headwaters to confluence with Prospect Canyon at 

32°44'48"/110°30'18" 

A&Ww FBC 

SP Copper Creek Below confluence with Prospect Canyon to the San 

Pedro River at 32°41'17"/110°36'43" A&We PBC 

SP Deer Creek Headwaters to confluence with unnamed tributary 

at 32°59'56"/110°20'09" A&Wc FBC 

SP Deer Creek Below confluence with unnamed tributary to 

Aravaipa Creek at 32°54'25"/110°28'01" A&Ww FBC 

SP Dixie Canyon Heradwaters to Mexican Canyon at 

31°29'02"/109°45'04" in the Mule Mountains

 A&Ww FBC 

SP Double R Canyon 

Creek 

Tributary to Bass Canyon at 32°21'06"/110°14'23" A&Ww FBC 

SP Dry Canyon Headwaters to Abbott Canyon at 

31°33'25"/109°43'23" in the Mule Mountains

 A&Ww FBC 

SP 

East Gravel Pit Pond 

Fort Huachuca Military Reservation at 

31°30'54"/110°19'42" Sedimentary A&Ww FBC 

SP Espiritu Canyon 

Creek 

Tributary to Soza Wash at 32°18'52"/110°28'35" A&Ww FBC 

SP Fly Pond Fort Huachuca Military Reservation at A&Ww FBC 
391

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

31°32'53"/110°21'14"

SP Fourmile Canyon 

Creek 

Tributary to Aravaipa Creek at 32°50'14"/110°20'08" A&Ww FBC 

SP Fourmile Canyon, 

Left Prong 

Headwaters to confluence with unnamed tributary at 32°43'14"/110°23'43" A&Wc FBC 

SP Fourmile Canyon, 

Left Prong 

Below confluence with unnamed tributary to 

Fourmile Canyon Creek at 32°47'33"/110°22'36" A&Ww FBC 

SP Fourmile Canyon, 

Right Prong 

Tributary to Fourmile Canyon at 32°47'33"/110°22'36" A&Ww FBC 

SP Gadwell Canyon Headwaters to Whitewater Draw at 

31°36'50"/109°43'41" in the Mule Mountains

 A&Ww FBC 

SP Garden Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 31°29'00"/110°19'42" A&Wc FBC 

SP Garden Canyon 

Creek 

Below confluence with unnamed tributary to the 

San Pedro River at 31°41'46"/110°12'40" A&Ww FBC 

SP

Glance Creek Headwaters to Whitewater Draw at 

31°27'04"/109°42'29" in the Mule Mountains

 A&Ww FBC 

SP

Gold Gulch Headwaters to U.S. / Mexico border at 

31°20'10"/109°50'06" in the Mule Mountains

 A&Ww FBC 

SP Golf Course Pond Fort Huachuca Military Reservation at 

31°32'14"/110°18'49" Sedimentary A&Ww FBC PBC 

SP Goudy Canyon 

Creek

Headwaters to Grant Creek at 32°35'13"/109°58'37" in the Pinaleno Mountains

 A&Wc FBC 

SP

Grant Creek Headwaters to confluence with unnamed tributary 

at 32°38'09.5"/109°56'35"

 A&Wc FBC 

SP

Grant Creek Below confluence with unnamed tributary to 

terminus near Willcox Playa at 

 A&Ww FBC 
392

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

32°33'43"/109°58'55"

SP Gravel Pit Pond Fort Huachuca Military Reservation at 

31°30'51"/110°19'47.6" Sedimentary A&Ww FBC 

SP

Greenbrush Draw From Mexican border to confluence with San 

Pedro River

 A&We PBC

SP Hidden Pond Fort Huachuca Military Reservation at 

32°30'30"/109°22'17"

 A&Ww FBC 

SP High Creek Headwaters to confluence with unnamed tributary 

at 32°33'07"/110°14'40"

 A&Wc FBC 

SP

High Creek Below confluence with unnamed tributary to 

terminus near Willcox Playa at 32°31'41"/109°02'38"

 A&Ww FBC 

SP Horse Camp 

Canyon Creek 

Tributary to Aravaipa Creek at 32°55'07"/110°30'56" A&Ww FBC 

SP Hot Springs 

Canyon Creek 

Tributary to the San Pedro River at 32°17'24"/110°22'55" A&Ww FBC 

SP Johnson Canyon Headwaters to Whitewater Draw at 

31°32'56"/109°46'19" in the Chiricahua Mountains

 A&Ww FBC 

SP

Lake Cochise 

(EDW)

South of Twin Lakes Municipal Golf Course at 

32°13'58"/109°49'25"

 A&Wedw PBC

SP Leslie Canyon 

Creek

Headwaters to Whitewater Draw at 31°32'10"/109°40'12" in the Chiricahua Mountains

 A&Ww FBC 

SP 

Lower Garden Canyon Pond 

Fort Huachuca Military Reservation A&Ww FBC 

SP Mexican Canyon Headwaters to Whitewater Draw at 

31°29'13"/109°46'30" in the Mule Mountains

 A&Ww FBC 

SP Miller Canyon Headwaters to Broken Arrow Ranch Road at A&Wc FBC 
393

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Creek 31°25'33"/110°15'08" 

SP Miller Canyon 

Creek 

Below Broken Arrow Ranch Road to the San Pedro 

River at 31°29'56"/110°07'37" A&Ww FBC 

SP Moonshine Creek Tributary to Post Creek at 32°40'52"/109°54'25" A&Wc FBC SP

Mule Gulch Headwaters to just above the Lavender Pit at 

31°26'23.7"/109°45'36.7"

 A&Ww PBC 

SP

Mule Gulch Just above the Lavender Pit to the Bisbee WWTP 

outfall at 31°25'30"/109°52'40"

 A&We PBC

SP

Mule Gulch 

(EDW)

Below the Bisbee WWTP outfall to the Highway 

80 bridge at 31°26'30"/109°49'28"

 A&Wedw PBC

SP

Mule Gulch Below the Highway 80 bridge to Whitewater Draw 

at 31°28'03"/109°42'21"

 A&We PBC 

SP Oak Grove Creek Tributary to Turkey Creek at 32°45'32"/110°14'06" A&Ww FBC SP 

Officers Club Pond 

Fort Huachuca Military Reservation at 

31°32'51"/110°21'35" Sedimentary A&Ww FBC PBC 

SP Paige Canyon 

Creek 

Tributary to the San Pedro River at 32°17'10"/110°22'48" A&Ww FBC 

SP Parsons Canyon 

Creek 

Tributary to Aravaipa Creek at 32°54'11"/110°27'40" A&Ww FBC 

SP Pinery Creek Headwaters to State Highway 181 at 

32°00'24"/109°25'16"

 A&Wc FBC 

SP Pinery Creek Below State Highway 181 to terminus near 

Willcox Playa at 32°01'05"/109°34'23"

 A&Ww FBC 

SP Post Creek Tributary to Grant Creek at 32°40'05"/109°54'58" A&Wc FBC SP Ramsey Canyon 

Creek 

Headwaters to Forest Service Road #110 at 31°27'44"/110°17'27" A&Wc FBC 

SP Ramsey Canyon Below Forest Service Road #110 to Carr Wash at A&Ww FBC 
394

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Creek 31°30'04"/110°09'11"

SP 

Rattlesnake Canyon 

Headwaters to confluence with Brush Canyon at 32°38'27"/110°21'24" A&Wc FBC 

SP 

Rattlesnake Canyon 

Below confluence with Brush Canyon to Aravaipa 

Creek at 32°48'00"/110°17'32" A&Ww FBC 

SP Redfield Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 32°33'39"/110°18'41" A&Wc FBC 

SP Redfield Canyon 

Creek 

Below confluence with unnamed tributary to the 

San Pedro River at 32°09'32"/110°17'56" A&Ww FBC 

SP Riggs Flat Lake 32°42'27"/109°57'51" Igneous A&Wc FBC SP

Rock Creek Tributary to Turkey Creek at 

31°53'20"/109°30'00"Alc

 FBC 

SP Rucker Canyon 

Creek

Headwaters to Whitewater Draw at 31°44'46"/109°26'06" Igneous A&Wc FBC 

SP Rucker Canyon 

Lake

31°46'46"/109°18'30"

Shallow A&Wc FBC 

SP San Pedro River U.S. / Mexico Border to Redington at 

32°25'39"/110°29'33" A&Ww FBC 

SP San Pedro River Redington to the Gila River at 

32°59'02"/110°46'55" A&Ww FBC 

SP Snow Flat Lake 32°39'09"/109°51'52" Igneous A&Wc FBC SP Soldier Creek Tributary to Post Creek at 32°40'52"/109°54'40" A&Wc FBC SP

Soldier Creek 

(EDW)

Fort Huachuca WWTP outfall to unnamed wash at 

31°34'48"/110°18'35"to confluence with Soldier Creek to confluence with Babocomari River at 31°39'46"/110°17'24"

 A&Wedw PBC

SP Soto Canyon Headwaters to Dixie Canyon at A&Ww FBC 
395

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

31°29'46"/109°55'37" in the Mule Mountains

SP Swamp Springs 

Canyon Creek 

Tributary to Redfield Canyon at 32°26'10"/110°19'30" A&Ww FBC 

SP Sycamore Pond I Fort Huachuca Military Reservation at 

31°35'12"/110°26'09" Sedimentary A&Ww FBC 

SP Sycamore Pond II Fort Huachuca Military Reservation at 

31°34'38.6"/110°26'07" Sedimentary A&Ww FBC 

SP Turkey Creek Tributary to Aravaipa Creek at 

32°53'49"/110°26'35" A&Ww FBC 

SP Turkey Creek Headwaters to confluence with Rock Creek at 

31°53'20"/109°30'00"

 A&Wc FBC 

SP Turkey Creek Below confluence with Rock Creek to terminus 

near Willcox Playa at 31°59'56"/109°49'01"

 A&Ww FBC 

SP

Unnamed Wash 

(EDW)

Mt. Lemmon WWTP outfall to 0.25 km 

downstream

 A&Wedw PBC

SP Virgus Canyon 

Creek 

Tributary to Aravaipa Creek at 32°54'58"/110°31'16" A&Ww FBC 

SP

Walnut Gulch Headwaters to Tombstone WWTP outfall at 

31°43'47"/110°04'06"

 A&We PBC

SP 

Walnut Gulch (EDW) 

Tombstone WWTP outfall to the confluence of Tombstone Wash at 31°44'02"/110°05'58"

 A&Wedw PBC 

SP

Walnut Gulch Tombstone Wash to San Pedro River at 

31°43'19"/110°11'35"

 A&We PBC

SP Ward Canyon 

Creek

Tributary to Turkey Creek at 31°51'47"/109°20'13" A&Wc FBC 

SP

Whitewater Draw Headwaters to confluence with unnamed tributary 

at 31°20'36"/109°34'46"

 A&We PBC 
396

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SP

Whitewater Draw Below confluence with unnamed tributary to U.S. / 

Mexico border at 31°20'02"/109°34'44"

 A&Ww FBC 

SP Willcox Playa 32°08'19"/109°50'59" in the Sulphur Springs 

Valley Sedimentary A&Ww FBC 

SP 

Woodcutters Pond 

Fort Huachuca Military Reservation at 

31°31'11.5"/110°20'15" Igneous A&Ww FBC 

SR Ackre (Judge) 

Lake 

33°37'00"/109°20'37" 

 A&Wc FBC 

SR Apache Lake 33°35'30"/111°20'30" Deep A&Wc A&Ww FBC SR 

Barnhardt Creek Headwaters to confluence with unnamed tributary 

at 34°05'36"/111°26'38" A&Wc FBC 

SR 

Barnhardt Creek Below confluence with unnamed tributary to Rye 

Creek at 34°06'58"/111°21'32" A&Ww FBC 

SR Basin Lake 33°55'00"/109°26'05" Igneous A&Wc FBC SR Bear Creek Tributary to the Black River at 

33°43'26"/109°22'30" A&Wc FBC 

SR 

Bear Wallow Creek (UW)

(OAW)

Tributary to the Black River at 33°37'44"/109°31'23" A&Wc FBC 

SR 

Bear Wallow Creek, North Fork (UW)

(OAW)

Tributary to Bear Wallow Creek at 33°35'53"/109°26'49" 

 A&Wc FBC 

SR 

Bear Wallow Creek, South Fork (UW)

(OAW)

Tributary to Bear Wallow Creek at 33°35'53"/109°26'49" 

 A&Wc FBC 
397

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SR Beaver Creek Tributary to the Black River at 

33°43'44"/109°21'07" A&Wc FBC 

SR Big Lake 33°52'45"/109°25'00" Igneous A&Wc FBC SR Black River Tributary to the Salt River at 33°44'20"/110°13'30" A&Wc FBC SR 

Black River, East Fork 

Tributary to the Black River at 33°45'07"/109°21'43" A&Wc FBC 

SR 

Black River, N

North Fork of E

East Fork 

Tributary to Black River, East Fork at 33°56'17"/109°24'11" A&Wc FBC 

SR 

Black River, West Fork 

Tributary to the Black River at 33°45'07"/109°21'43" A&Wc FBC 

SR Bloody Tanks 

Wash 

Headwaters to Schultze Ranch at 33°22'29"/110°54'39" A&We PBC 

SR Bloody Tanks 

Wash 

Schultze Ranch to Miami Wash at 33°25'05"/110°50'02"

 A&We PBC 

SR Boggy Creek Tributary to the Black River at 

33°44'31"/109°26'20" A&Wc FBC 

SR Boneyard Creek Tributary to Black River, East Fork at 

33°51'22"/109°18'50" A&Wc FBC 

SR Boulder Creek Tributary to LaBarge Creek at 

33°30'54"/111°24'40" 

 A&Ww FBC 

SR Campaign Creek Tributary to Roosevelt Lake at 

33°37'30"/111°00'04" A&Ww FBC 

SR Canyon Creek Headwaters to the White Mountain Apache 

Reservation at 33°57'53"/110°47'00" A&Wc FBC 

SR Canyon Lake 33°33'15"/111°26'30" Deep A&Wc A&Ww FBC SR Centerfire Creek Tributary to the Black River at A&Wc FBC 
398

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

33°42'47"/109°26'17" 

SR 

Chambers Draw Creek 

Tributary to North Fork of the East Fork of Black 

River, N Fork of E Fork at 33°53'03"/109°20'13" A&Wc FBC 

SR Cherry Creek Headwaters to confluence with unnamed tributary 

at 34°05'09"/110°56'04" A&Wc FBC 

SR Cherry Creek Below unnamed tributary to the Salt River at 

33°40'16"/110°48'03.6" A&Ww FBC 

SR Christopher 

Creek 

Tributary to Tonto Creek at 34°18'36"/111°04'23" A&Wc FBC 

SR Cold Spring 

Canyon Creek 

Headwaters to confluence with unnamed tributary at 33°49'50"/110°52'55" A&Wc FBC 

SR Cold Spring 

Canyon Creek 

Below confluence with unnamed tributary to Cherry Creek at 33°50'06/110°51'28.8" A&Ww FBC 

SR Conklin Creek Tributary to the Black River at 

33°41'49"/109°27'36" A&Wc FBC 

SR Coon Creek Headwaters to confluence with unnamed tributary 

at 33°46'42"/110°54'25" A&Wc FBC 

SR Coon Creek Below confluence with unnamed tributary to Salt 

River at 33°39'47"/110°50'24" A&Ww FBC 

SR Corduroy Creek Tributary to Fish Creek at 33°59'46"/110°17'31" A&Wc FBC SR Coyote Creek Tributary to the Black River, East Fork at 

33°50'53"/109°18'18" A&Wc FBC 

SR Crescent Lake 33°54'36"/109°25'08" Shallow A&Wc FBC SR Deer Creek Tributary to the Black River, East Fork at 

33°48'07"/109°19'26" A&Wc FBC 

SR Del Shay Creek Tributary to Gun Creek at 34°00'22"/111°15'43" A&Ww FBC SR Devils Chasm Headwaters to confluence with unnamed tributary A&Wc FBC 
399

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

Creek at 33°48'46"/110°52'33" 

SR 

Devils Chasm Creek 

Below confluence with unnamed tributary to Cherry Creek at 33°49'34"/110°54'18" A&Ww FBC 

SR Dipping Vat 

Reservoir 

33°55'54"/109°25'15" 

Igneous A&Wc FBC 

SR Double Cienega 

Creek 

Tributary to Fish Creek at 33°38'35"/109°22'08" A&Wc FBC 

SR Fish Creek Tributary to the Black River at 

33°42'40"/109°26'31" A&Wc FBC 

SR Fish Creek Tributary to the Salt River at 33°34'37"/111°21'11" A&Ww FBC SR Gold Creek Headwaters to confluence with unnamed tributary 

at 33°59'47"/111°25'07" A&Wc FBC 

SR Gold Creek Below confluence with unnamed tributary to Tonto 

Creek at 33°58'55"/111°18'03.6" A&Ww FBC 

SR Gordon Canyon 

Creek 

Headwaters to confluence with Hog Canyon at 34°13'49"/111°00'27" A&Wc FBC 

SR Gordon Canyon 

Creek 

Below confluence with Hog Canyon to Haigler Creek at 34°11'56"/111°03'21" A&Ww FBC 

SR Greenback Creek Tributary to Tonto Creek at 33°47'38"/111°15'22" A&Ww FBC SR Haigler Creek Headwaters to confluence with unnamed tributary 

at 34°12'23.5"/111°00'11" A&Wc FBC 

SR Haigler Creek Below confluence with unnamed tributary to Tonto 

Creek at 34°12'54"/111°05'45.6" A&Ww FBC 

SR Hannagan Creek Tributary to Beaver Creek at 33°42'07"/109°14'46" A&Wc FBC SR Hay Creek (UW)

(OAW)

Tributary to the Black River, West Fork at 33°48'32"/109°25'16" A&Wc FBC 

SR Home Creek Tributary to the Black River, West Fork at A&Wc FBC 
400

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

33°45'43"/109°22'48" 

SR Horse Creek Tributary to the Black River, West Fork at 

33°45'11"/109°21'50" A&Wc FBC 

SR Horse Camp 

Creek 

Headwaters to confluence with unnamed tributary at 33°53'53"/110°50'10" A&Wc FBC 

SR Horse Camp 

Creek 

Below confluence with unnamed tributary to Cherry Creek at 33°52'08"/110°52'33.6" A&Ww FBC 

SR Horton Creek Tributary to Tonto Creek at 34°20'24"/111°05'42" A&Wc FBC SR Houston Creek Tributary to Tonto Creek at 34°07'30"/111°15'25" A&Ww FBC SR Hunter Creek Tributary to Christopher Creek at 

34°18'29"/111°01'55" A&Wc FBC 

SR 

LaBarge Creek Superstition Wilderness Area; tributary

Headwaters to Canyon Lake at 

33°31'34"/111°25'15.6"

 A&Ww FBC 

SR 

Lake Sierra Blanca 

33°52'25"/109°16'05" 

 A&Wc FBC 

SR Miami Wash Tributary to Pinal Creek at 33°27'04"/110°50'17" A&We PBC SR Mule Creek Tributary to Canyon Creek at 

34°16'34"/110°48'00" A&Wc FBC 

SR Open Draw Creek Tributary to the East Fork of Black River, East 

Fork at 33°49'52"/109°18'18" A&Wc FBC 

SR 

P B Creek Headwaters to Forest Service Road #203 at 

33°57'08"/110°56'09" A&Wc FBC 

SR P B Creek Below Forest Service Road #203 to Cherry Creek 

at 33°55'34"/110°54'18" A&Ww FBC 

SR 

Pinal Creek Headwaters to confluence with unnamed EDW 

wash (Globe WWTP) at 33°25'29"/110°48'18" A&We PBC 
401

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SR 

Pinal Creek (EDW) 

Below unnamed EDW wash to Radium Globe WWTP outfall on unnamed wash at 33°25'46"/110°47'28" to confluence with Pinal Creek to Radium at 33°26'54"/110°49'02"

 A&Wedw PBC 

SR 

Pinal Creek Radium to Setka Ranch lower Pinal Creek water 

treatment plant discharge at 33°32'05"/110°52'17" A&We PBC 

SR 

Pinal Creek Setka Ranch Lower Pinal Creek WTP outfall #1 at 

33°31'56"/110°52'14" to See Ranch Crossing at 33°32'25"/110°52'28"

 A&Ww A&Wedw FBC PBC 

SR Pinal Creek See Ranch Crossing to 33°35'33"/110°54'33" A&Ww FBCSR Pinal Creek From 33°35'33"/110°54'33" to Salt River A&Ww FBC SR Pine Creek Tributary to the Salt River at 33°36'04"/111°12'36" A&Ww FBC SR Pinto Creek Headwaters to confluence with unnamed tributary 

at 33°19'27"/110°54'56" A&Wc FBC 

SR 

Pinto Creek Below confluence with unnamed tributary to 

Roosevelt Lake at 33°39'11"/111°00'43" A&Ww FBC 

SR Pueblo Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 33°50'30"/110°53'13" A&Wc FBC 

SR Pueblo Canyon 

Creek 

Below confluence with unnamed tributary to Cherry Creek at 33°52'30"/110°52'55" A&Ww FBC 

SR Reevis Creek Tributary to Pine Creek at 33°33'07"/111°09'40" A&Ww FBC SR 

Reservation Creek 

Tributary to the Black River at 33°41'42"/109°28'26" A&Wc FBC 

SR Reynolds Creek Tributary to Workman Creek at 

33°52'16"/111°00'14" A&Wc FBC 

SR Roosevelt Lake 33°40'45"/111°09'15" Deep A&Ww FBC SR Russell Gulch From headwaters to confluence with Miami Wash A&We PBC
402

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SR Rye Creek Tributary to Tonto Creek at 34°01'41"/111°17'06" A&Ww FBC SR Saguaro Lake 33°34'00"/111°32'06" Deep A&Wc A&Ww FBC SR Salome Creek Tributary to the Salt River at 33°41'56"/111°05'46" A&Ww FBC SR 

Salt River Above Roosevelt Lake Confluence of White River 

and Black River to Roosevelt Lake A&Ww FBC 

SR 

Salt River Theodore Roosevelt Dam to the Verde River 2 km 

below Granite Reef Dam

 A&Wc A&Ww FBC 

SR Salt River Verde River to 2 km below Granite Reef Dam A&Ww FBC SR Salt River 2 km below Granite Reef Dam to I-10 bridge A&We PBCSR Salt River I-10 bridge to the 23rd Ave WWTP A&We PBCSR Salt River (EDW) 23rd Ave WWTP to confluence with Gila River A&Wedw PBC SR Slate Creek Tributary to Tonto Creek at 33°56'24"/111°18'25" A&Ww FBC SR 

Snake Creek (UW) (OAW)

Tributary to the Black River at 33°40'30"/109°28'55" A&Wc FBC 

SR Spring Creek Tributary to Tonto Creek at 34°09'54"/111°10'08" A&Ww FBC SR Stinky Creek 

(UW) (OAW)

Tributary to the Black River, West Fork at 33°51'22"/109°27'07" A&Wc FBC 

SR Tempe Town 

Lake

At Mill Avenue Bridge A&Ww FBC 

SR Thomas Creek Tributary to Beaver Creek at 33°42'29"/109°15'11" A&Wc FBC SR Thompson Creek Tributary to the West Fork of the Black River, 

West Fork at 33°53'24"/109°28'48" A&Wc FBC 

SR Tonto Creek Headwaters to confluence with unnamed tributary 

at 34°18'10"/111°04'14" A&Wc FBC 

SR Tonto Creek Below confluence with unnamed tributary to 

Roosevelt Lake at 33°45'14"/111°14'17" A&Ww FBC 

SR Turkey Creek Tributary to Rock Creek at 33°58'30"/111°06'47" A&Wc FBC 
403

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

SR 

Unnamed Wash (EDW) 

Globe WWTP outfall to Pinal Creek Cobre Valley Plaza WWTP at 33°24'56"/110°49'43" to confluence with Russell Gulch

 A&Wedw PBC 

SR Wildcat Creek Tributary to Centerfire Creek at 

33°43'41"/109°26'28" A&Wc FBC 

SR Willow Creek Tributary to Beaver Creek at 33°43'52"/109°18'04" A&Wc FBC SR Workman Creek Headwaters to confluence with Reynolds Creek at 

33°52'17"/111°00'14.5" A&Wc FBC 

SR Workman Creek Below confluence with Reynolds Creek to Salome 

Creek at 33°52'37"/111°02'20" A&Ww FBC 

UG Apache Creek Tributary to the Gila River at 

32°52'08"/109°11'53" A&Ww FBC 

UG Ash Creek Headwaters to confluence with unnamed tributary 

at 32°45'37"/109°52'22" A&Wc FBC 

UG Ash Creek Below confluence with unnamed tributary to Gila 

River at 32°53'35"/109°47'34.8" A&Ww FBC 

UG 

Bennett Wash (EDW) 

ADOC-Safford WWTP outfall at 

32°50'20"/109°34'44" to the Gila River 

 A&Wedw PBC 

UG Bitter Creek Tributary to the Gila River at 

32°50'17"/109°10'59" 

 A&Ww FBC 

UG Blue River Headwaters to confluence with Strayhorse Creek at 

33°29'02"/110°12'12" A&Wc FBC 

UG Blue River Below confluence with Strayhorse Creek to San 

Francisco River at 33°12'36"/109°11'27.6" A&Ww FBC 

UG 

Bonita Creek (Unique Water)

(OAW)

San Carlos Indian Reservation to the Gila River at 32°53'35"/109°28'41" A&Ww FBC 
404

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

UG Buckalou Creek Tributary to Castle Creek at 33°43'34"/109°09'07" A&Wc FBC UG Campbell Blue 

Creek 

Tributary to the Blue River at 33°43'30"/109°02'46" A&Wc FBC 

UG Castle Creek Tributary to Campbell Blue Creek at 

33°44'06"/109°08'10" A&Wc FBC 

UG 

Cave Creek (Unique Water)

(OAW)

Headwaters to confluence with South Fork Cave Creek at 31°53'04"/109°10'27" A&Wc FBC 

UG 

Cave Creek (Unique Water)

(OAW)

Below confluence with South Fork Cave Creek to Coronado NF Boundary National Forest boundary A&Ww FBC 

UG Cave Creek Below Coronado NF Boundary to New Mexico 

border at 31°58'19"/109°03'00" A&Ww FBC 

UG 

Cave Creek, South Fork 

Tributary to Cave Creek at 31°53'04"/109°10'27" A&Wc FBC 

UG Chase Creek Headwaters to the Phelps-Dodge Morenci Mine A&Ww FBC UG Chase Creek Below the Phelps-Dodge Morenci Mine to San 

Francisco River

 A&We PBC 

UG Chitty Canyon 

Creek 

Tributary to Salt House Creek at 33°30'32"/109°24'04" A&Wc FBC 

UG Cima Creek Tributary to Cave Creek at 31°52'19"/109°14'02" A&Wc FBC UG 

Cluff Ranch Pond #1 

32°48'55"/109°49'15" 

Sedimentary A&Ww FBC 

UG 

Cluff Ranch Pond #2 

32°49'15"/109°50'33" 

Sedimentary A&Ww FBC 

UG 

Cluff Ranch Pond #3 

32°48'20"/109°51'43" 

Sedimentary A&Ww FBC 
405

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

UG Coleman Creek Tributary to Campbell Blue Creek at 

33°44'20"/109°09'32" A&Wc FBC 

UG Dankworth Ponds 32°43'15"/109°42'15" Sedimentary A&Wc FBC UG Deadman Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 32°43'50"/109°49'01" A&Wc FBC 

UG 

Deadman Canyon Creek 

Below confluence with unnamed tributary to 

confluence with Graveyard Wash at 32°46'48"/109°44'13"

 A&Ww FBC 

UG Eagle Creek Headwaters to confluence with unnamed tributary 

at 33°23'24"/109°29'35" A&Wc FBC 

UG Eagle Creek Below confluence with unnamed tributary to Eagle 

Creek at 32°57'36"/109°24'21.6" A&Ww FBC 

UG East Eagle Creek Tributary to Eagle Creek at 33°29'38"/109°28'05" A&Wc FBC UG East Turkey 

Creek 

Headwaters to confluence with unnamed tributary at 31°58'22"/109°12'17" A&Wc FBC 

UG 

East Turkey Creek 

Below confluence with unnamed tributary to 

terminus near San Simon River at 31°59'53"/109°07'37"

 A&Ww FBC 

UG 

East Whitetail Headwaters to terminus near San Simon River at 

32°08'52"/109°09'25" in the Chiricahua Mountains A&Ww FBC 

UG 

Emigrant Canyon Headwaters to terminus near San Simon River at 

32°17'02"/109°20'27.6" in the Chiricahua 

Mountains 

 A&Ww FBC 

UG Evans Pond 32°49'15"/109°51'15" Sedimentary A&Ww FBC UG Fishhook Creek Tributary to the Blue River at 

33°35'13"/109°10'01" A&Wc FBC 

UG Foote Creek Tributary to the Blue River at A&Wc FBC 
406

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

33°35'24"/109°08'49" 

UG Frye Canyon 

Creek 

Headwaters to Frye Mesa Reservoir at 32°45'09.5"/109°50'02" A&Wc FBC 

UG 

Frye Canyon Creek 

Below Frye Mesa Reservoir to Highline Canal 

Headwaters to terminus near San Simon River at 32°50'10"/109°45'43"

 A&Ww FBC 

UG Frye Mesa 

Reservoir 

32°45'13"/109°50'00" 

Igneous A&Wc FBC 

UG Gibson Creek Tributary to Marijilda Creek at 

32°41'24"/109°48'11" A&Wc FBC 

UG 

Gila River New Mexico border to the San Carlos Indian 

Reservation at 33°05'37"/110°03'21" A&Ww FBC 

UG Grant Creek Tributary to the Blue River at 

33°34'16"/109°10'37" A&Wc FBC 

UG Judd Lake 33°51'15"/109°09'15" Sedimentary A&Wc FBC UG 

K P Creek (UW)

(OAW)

Tributary to the Blue River at 33°31'44"/109°12'04" A&Wc FBC 

UG Lanphier Canyon 

Creek 

Tributary to the Blue River at 33°35'42"/109°07'52" A&Wc FBC 

UG 

Little Blue Creek Headwaters to confluence with Dutch Blue Creek 

at 33°24'26.5"/109°09'18" A&Wc FBC 

UG 

Little Blue Creek Below confluence with Dutch Blue Creek to Blue 

Creek at 32°22'30"/109°10'30" A&Ww FBC 

UG Little Creek Tributary to the San Francisco River at 

33°49'41"/109°04'26" 

 A&Wc FBC 

UG Lower George's 

Reservoir 

33°51'23.5"/109°08'28" 

Sedimentary A&Wc FBC 
407

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

UG Luna Lake 33°49'45"/109°05'15" Sedimentary A&Wc FBC UG Marijilda Creek Headwaters to confluence with Gibson Creek at 

32°41'23"/109°48'13" A&Wc FBC 

UG Marijilda Creek Below confluence with Gibson Creek to Stockton 

Wash at 32°46'30"/109°40'51.6" A&Ww FBC 

UG Markham Creek Tributary to the Gila River at 

32°56'17"/109°53'13" A&Ww FBC 

UG Pigeon Creek Tributary to the Blue River at 

33°16'08"/109°11'42" A&Ww FBC 

UG Raspberry Creek Tributary to the Blue River at 

33°30'07"/109°12'32" 

 A&Wc FBC 

UG Roper Lake 32°45'20"/109°42'11" Sedimentary A&Ww FBC UG 

San Francisco River 

Headwaters to the New Mexico border at 33°49'24.5"/109°02'46" A&Wc FBC 

UG 

San Francisco River 

New Mexico border to the Gila River at 33°14'25"/109°02'49" A&Ww FBC 

UG San Simon River Tributary to the Gila River at 

32°49'52"/109°38'53" A&We PBC 

UG Sheep Tank 32°46'15"/109°48'08" Sedimentary A&Ww FBC UG Smith Pond 32°49'09"/109°50'26" Sedimentary A&Ww FBC UG Squaw Creek Tributary to Thomas Creek at 

33°23'38"/109°12'22" A&Wc FBC 

UG Stone Creek Tributary to the San Francisco River at 

33°50'38"/109°02'46" A&Wc FBC 

UG Strayhorse Creek Tributary to the Blue River at 

33°29'02"/109°12'11" 

 A&Wc FBC 

UG Thomas Creek Headwaters to confluence with Rousensock Creek A&Wc FBC 
408

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

at 33°23'45"/109°13'13" 

UG 

Thomas Creek Below confluence with Rousensock Creek to Blue 

River at 33°23'20"/109°11'20" A&Ww FBC 

UG Tinny Pond 33°47'49"/109°04'23" Sedimentary A&Ww FBC UG Turkey Creek Tributary to Campbell Blue Creek at 

33°44'10"/109°04'05" A&Wc FBC 

UG 

Unnamed Wash (EDW) 

ADOC-Globe WWTP outfall at 

33°24'55"/110°42'35" to the San Carlos Indian Reservation 

 A&Wedw PBC 

VR 

American Gulch Headwaters to the Northern Gila County Sanitary 

District WWTP outfall (Payson) at 

34°14'05"/111°22'18"

 A&Ww FBC 

VR 

American Gulch (EDW) 

Northern Gila County Sanitary District WWTP outfall (Payson) to the East Verde River at 

34°14'42"/111°25'08"

 A&Wedw PBC 

VR Apache Creek Tributary to Walnut Creek at 34°55'12"/112°50'42" A&Ww FBC VR 

Ashbrook Wash Headwaters to the Ft McDowell Reservation at 

33°36'54"/111°42'06" 

 A&We PBC 

VR Aspen Creek Tributary to Granite Creek at 34°31'55"/112°28'19" A&Ww FBC VR Bar Cross Tank 35°00'40"/112°05'34" A&Ww FBC VR Barrata Tank 35°02'43"/112°24'17" A&Ww FBC VR Bartlett Lake 33°49'00"/111°37'45" Deep A&Ww FBC VR Beaver Creek Tributary to the Verde River at 

34°34'26"/111°51'14" A&Ww FBC 

VR Big Chino Wash Tributary to Sullivan Lake at 34°52'37"/112°28'37" A&We PBC VR 

Bitter Creek Headwaters to the Jerome WWTP outfall at 

34°45'08"/112°06'25" A&We PBC 
409

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

VR 

Bitter Creek (EDW) 

Jerome WWTP outfall to the Yavapai Apache Indian Reservation at 34°45'45.5"/112°04'44" A&Wedw PBC 

VR Bitter Creek Below the Yavapai Apache Indian Reservation to 

the Verde River at 34°46'37"/112°02'53" A&Ww FBC 

VR Black Canyon 

Creek 

Headwaters to confluence with unnamed tributary at 34°39'20"/112°05'05" A&Wc FBC 

VR Black Canyon 

Creek 

Below confluence with unnamed tributary to the 

Verde River at 34°40'59"/111°57'28.8" A&Ww FBC 

VR Bonita Creek Tributary to Ellison Creek at 34°20'56"/111°14'20" A&Wc FBC VR Bray Creek Tributary to Webber Creek at 

34°22'37"/111°20'53" A&Wc FBC 

VR Camp Creek Tributary to the Verde River at 

33°45'32"/111°30'14" A&Ww FBC 

VR Carter Tank 34°52'27"/112°57'28" A&Ww FBC VR 

Cereus Wash Headwaters to the Fort McDowell Indian 

Reservation at 33°34'13"/111°42'28" 

 A&We PBC 

VR Chase Creek Tributary to the East Verde River at 

34°22'48"/111°16'59" 

 A&Wc FBC 

VR Clover Creek Tributary to headwaters of West Clear Creek at 

34°33'04"/111°24'11" A&Wc FBC 

VR 

Coffe Coffee

Creek 

Tributary to Spring Creek at 34°48'18"/111°55'41" A&Ww FBC 

VR Colony Wash Headwaters to the Fort McDowell Indian 

Reservation at 33°35'42"/111°42'15" 

 A&We PBC 

VR Dead Horse Lake 34°45'00"/112°00'30" Shallow A&Wc A&Ww FBC VR Deadman Creek Tributary to Horseshoe Reservoir at 

34°00'00"/111°42'36" A&Ww FBC 
410

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

VR 

Del Rio Dam Lake 

34°48'55"/112°28'00" 

Sedimentary A&Ww FBC 

VR Dry Beaver Creek Tributary to Beaver Creek at 34°37'59"/111°49'34" A&Ww FBC VR

Dry Creek 

(EDW)

Sedona Ventures WWTP outfall at 

34°50'45"/111°52'15" toconfluence with Dry Creek at 34°50'31"/111°52'39"

 A&Wedw PBC

VR Dude Creek Tributary to the East Verde River at 

34°23'06"/111°16'26" A&Wc FBC 

VR 

East Verde River Headwaters to confluence with Ellison Creek at 

34°21'10"/111°16'47.5" A&Wc FBC 

VR 

East Verde River Below confluence with Ellison Creek to the Verde 

River at 34°17'02"/111°40'19" A&Ww FBC 

VR Ellison Creek Tributary to the East Verde River at 

34°21'11"/111°16'48" A&Wc FBC 

VR 

Fossil Creek (OAW)

Tributary to the Verde River at 34°18'22"/111°40'30" A&Ww FBC 

VR Fossil Springs 

(OAW)

34°25'24"/111°34'25" 

 A&Ww FBC 

VR Foxboro Lake 34°53'48"/111°40'00" A&Ww FBC VR Fry Lake 35°03'45"/111°48'02" A&Ww FBC VR Gap Creek Headwaters to Government Spring at 

34°23'23"/111°50'53.5" A&Wc FBC 

VR Gap Creek Below Government Spring to the Verde River at 

34°24'50"/111°46'51.6" A&Ww FBC 

VR Garrett Tank 35°18'57"/112°42'16" A&Ww FBC VR 

Goldwater Lake, Lower 

34°29'55"/112°27'18" 

Sedimentary A&Wc FBC 
411

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

VR 

Goldwater Lake, Upper 

34°29'51"/112°26'55" 

Igneous A&Wc FBC 

VR 

Granite Basin Lake 

34°37'01"/112°42'16" 

Igneous A&Wc A&Ww FBC 

VR 

Granite Creek Headwaters to confluence with Willow Creek

Watson lake at 34°36'55" 34°35'15" /112°25'05" A&Wc FBC 

VR 

Granite Creek Below confluence with Willow Creek Watson lake 

to the Verde River at 34°52'54"/112°25'05" A&Ww FBC 

VR Heifer Tank 35°20'28"/112°32'56" A&Ww FBC VR Hell Canyon 

Tank 

35°05'00"/112°24'06" 

Igneous A&Ww FBC 

VR Homestead Tank 35°21'23"/112°41'32" Igneous A&Ww FBC VR Horse Park Tank 34°58'15"/111°36'29" A&Ww FBC VR 

Horseshoe Reservoir 

33°59'00"/111°42'30" 

Sedimentary A&Ww FBC 

VR Houston Creek Tributary to the Verde River at 

34°16'55"/111°41'06" A&Ww FBC 

VR J.D. Dam Lake 35°04'01"/112°01'40" Shallow A&Wc FBC VR Jacks Canyon 

Wash

Headwaters to Big Park WWTP outfall at 34°45'32"/111°45'10"

 A&We PBC

VR Jacks Canyon 

Wash (EDW) 

Big Park WWTP outfall to Dry Beaver Creek at 

34°44'28"/111°46'01"

 A&Wedw PBC 

VR Lime Creek Tributary to Horseshoe Reservoir at 

33°59'20"/111°44'13" A&Ww FBC 

VR 

McLellan Reservoir 

35°13'15"/112°17'05" 

Igneous A&Ww FBC 

VR Meath Dam Tank 35°07'46"/112°27'35" A&Ww FBC 
412

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

VR 

Mullican Place Tank 

34°44'16"/111°36'08" 

Igneous A&Ww FBC 

VR 

Oak Creek (Unique Water)

(OAW)

Headwaters to confluence with unnamed tributary at 34°57'08.5"/111°45'13" A&Wc FBC 

VR 

Oak Creek (Unique Water)

(OAW)

Below confluence with unnamed tributary at 

34°57'08.5"/111°45'13 to Verde River" A&Ww FBC 

VR 

Oak Creek, West Fork (Unique 

Water) (OAW)

Tributary to Oak Creek at 34°59'13"/111°44'46" 

 A&Wc FBC 

VR Odell Lake 34°56'02"/111°37'52" Igneous A&Wc FBC VR Peck's Lake 34°47'07"/112°02'30" Shallow A&Wc A&Ww FBC VR Perkins Tank 35°06'42"/112°04'08" Shallow A&Wc FBC VR Pine Creek Headwaters to confluence with unnamed tributary 

at 34°21'51"/111°26'46" A&Wc FBC 

VR 

Pine Creek Below confluence with unnamed tributary to East 

Verde River at 34°13'19"/111°29'27.6" A&Ww FBC 

VR Red Creek Tributary to the Verde River at 

34°09'47"/111°43'12" A&Ww FBC 

VR Red Lake 35°12'19"/113°03'55" Sedimentary A&Ww FBC VR Reservoir #1 35°13'05"/111°50'07" Igneous A&Ww FBC VR Reservoir #2 35°13'16"/111°50'36" Igneous A&Ww FBC VR 

Roundtree Canyon Creek 

Tributary to Tangle Creek at 34°09'04"/111°48'18" A&Ww FBC 

VR Scholze Lake 35°11'53"/112°00'31" Igneous A&Wc A&Ww FBC VR Spring Creek Headwaters to confluence with unnamed tributary A&Wc FBC 
413

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

at 34°57'23.5"/111°57'19" 

VR Spring Creek Below confluence with unnamed tributary at 

34°44'38"/111°54'19" to Oak Creek A&Ww FBC 

VR Steel Dam Lake 35°13'36"/112°24'51" Igneous A&Wc FBC VR Stehr Lake 34°21'59"/111°40'00" Sedimentary A&Ww FBC VR Stone Dam Lake 35°13'36"/112°24'16" A&Wc FBC VR Stoneman Lake 34°46'44"/111°31'05" Shallow A&Wc FBC VR Sullivan Lake 34°51'46"/112°27'41" A&Ww FBC VR Sycamore Creek Headwaters to confluence with unnamed tributary 

at 35°03'40"/111°57'28" A&Wc FBC 

VR Sycamore Creek Below confluence with unnamed tributary to Verde 

River at 34°51'47"/112°04'41" A&Ww FBC 

VR Sycamore Creek Tributary to Verde River at 33°37'55"/111°39'58" A&Ww FBC VR Sycamore Creek Tributary to Verde River at 34°04'42"/111°42'14" A&Ww FBC VR Tangle Creek Tributary to the Verde River at 

34°05'06"/111°42'36" A&Ww FBC 

VR Trinity Tank 35°27'44"/112°47'56" A&Ww FBC VR

Unnamed Wash Flagstaff Meadows WWTP outfall at 

36°14'17"/111°49'28" to Volunteer Wash at 35°11'55"/111°49'42"

 A&Wedw PBC

VR 

Verde River Above Bartlett Dam from confluence of Chino 

Wash and Granite Creek to Bartlett Lake A&Ww FBC 

VR Verde River Below Bartlett Lake Dam to Salt River A&Ww FBC VR Walnut Creek Tributary to Big Chino Wash at 

34°58'12"/112°34'55" A&Ww FBC 

VR Watson Lake 34°35'15"/112°25'05" Igneous A&Ww FBC VR Webber Creek Tributary to the East Verde River at A&Wc FBC 
414

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

34°18'50"/111°19'55" 

VR West Clear Creek Headwaters to confluence with Meadow Canyon at 

34°33'40"/111°31'30" A&Wc FBC 

VR West Clear Creek Below confluence with Meadow Canyon to the 

Verde River at 34°30'14"/111°49'41" A&Ww FBC 

VR 

Wet Beaver Creek 

Headwaters to unnamed springs at 34°41'17"/111°34'34" A&Wc FBC 

VR 

Wet Beaver Creek 

Below unnamed springs to Dry Beaver Creek at 

34°37'59"/111°49'33.6" A&Ww FBC 

VR Whitehorse Lake 35°07'00"/112°00'47" Igneous A&Wc FBC VR 

Williamson Valley Wash 

Headwaters to confluence with Mint Wash at 34°49'05"/112°37'55" A&We PBC 

VR 

Williamson Valley Wash 

Confluence of Mint Wash to 10.5 km dwnstm

downstream at 34°49'05"/111°37'55" A&Ww FBC 

VR 

Williamson Valley Wash 

Below 10.5 km downstream of Mint Wash confluence to Big Chino Wash at 

32°52'52"/112°28'48"

 A&We PBC 

VR Williscraft Tank 35°11'23"/112°35'38" A&Ww FBC VR Willow Creek Tributary to Granite Creek at 34°51'47"/112°25'52"

Above Willow Creek Reservoir 

Shallow A&Wc FBC 

VR

Willow Creek Below Willow Creek Reservoir to confluence with 

Granite Creek

 A&Ww FBC 

VR 

Willow Creek Reservoir 

34°36'17"/112°26'19" 

Shallow A&Ww FBC 

VR Willow Valley 

Lake 

34°41'08"/111°19'57" 

Sedimentary A&Ww FBC 

WP Big Creek Tributary to Pitchfork Canyon at A&Wc FBC 
415

Aquatic and Wildlife Huma

BASIN

Watershed

SEGMENT

Surface Waters

LOCATION

Segment Description and Location

(Latitude and Longitudes are in NAD 27)

Lake Catgory

A&Wc A&Ww A&We A&Wedw FBC PBC 

32°35'24"/109°57'07"

WP Goudy Canyon 

Creek

Pinaleno Mountains

 A&Wc FBC 

WP

Grant Creek Headwaters to confluence with unnamed tributary 

at 32°38'09.5"/109°56'35"

 A&Wc FBC 

WP Grant Creek Below confluence with unnamed tributary A&Ww FBC WP High Creek Headwaters to confluence with unnamed tributary 

at 32°33'07"/110°14'40"

 A&Wc FBC 

WP High Creek Below confluence with unnamed tributary A&Ww FBC WP

Lake Cochise South of Twin Lakes Municipal Golf Course at 

32°14' N/109°11' W

 A&Wedw PBC

WP Moonshine Creek Tributary to Post Creek at 32°40'52"/109°54'25" A&Wc FBC WP Pinery Creek Headwaters to State Highway 181 at 

32°00'24"/109°25'16"

 A&Wc FBC 

WP Pinery Creek Below State Highway 181 A&Ww FBC WP Post Creek Tributary to Grant Creek at 32°40'05"/109°54'58" A&Wc FBC WP Riggs Flat Lake 32°42'27"/109°57'51" A&Wc FBC WP Rock Creek Tributary to Turkey Creek at 31°53'20"/109°30'00" A&Wc FBC WP Snow Flat Lake 32°39'09"/109°51'52" A&Wc FBC WP Soldier Creek Tributary to Post Creek at 32°40'52"/109°54'40" A&Wc FBC WP Turkey Creek Headwaters to confluence with Rock Creek at 

31°53'20"/109°30'00"

 A&Wc FBC 

WP Turkey Creek Below confluence with Rock Creek A&Ww FBC WP Ward Canyon 

Creek

Tributary to Turkey Creek at 31°51'47"/109°20'13" A&Wc FBC 

WP Willcox Playa Sulphur Springs Valley A&Ww FBC 
416

Watersheds

BW = Bill Williams

CG = Colorado – Grand Canyon

CL = Colorado – Lower Gila

LC = Little Colorado

MG = Middle Gila

SC = Santa Cruz – Rio Magdalena – Rio Sonoyta

SP = San Pedro – Willcox Playa – Rio Yaqui

SR = Salt River

UG = Upper Gila

VR = Verde River

Other Abbreviations

WWTP = Wastewater Treatment Plant

Km = kilometers
 417

Appendix C. APPENDIX C. Repealed SITE-SPECIFIC STANDARDS

Watershed Surface Water Surface Water Description & Location Parameter Site-Specific 

Criterion

LC Rio de Flag (EDW) Flagstaff WWTP outfall to the confluence with 

San Francisco Wash at 35°14'04"/111°28'02.5"

Copper (D) 36 μg/L

CL

Yuma East Wetlands From inlet culvert from Colorado River into 

restored channel to Ocean bridge

Selenium (T)

Total residual 

chlorine

2.2 μg/L

33 μg/L

(A&Ww acute)

20 μg/L

(A&Ww chronic)