Fact Sheet for NPDES Permit No.WA0023451

Lakehaven Utility District

Redondo Wastewater Treatment Plant

August 27, 2013

Purpose of this fact sheet

This fact sheet explains and documents the decisions the Department of Ecology (Ecology) made 

in drafting the proposed National Pollutant Discharge Elimination System (NPDES) permit for 

Lakehaven Utility District’s Redondo Wastewater Treatment Plant (WWTP).

This fact sheet complies with Section 173-220-060 of the Washington Administrative Code 

(WAC), which requires Ecology to prepare a draft permit and accompanying fact sheet for public 

evaluation before issuing an NPDES permit. 

Ecology makes the draft permit and fact sheet available for public review and comment at least 

thirty (30) days before issuing the final permit. Copies of the fact sheet and draft permit for 

Redondo WWTP, NPDES permit No.WA0023451, were available for public review and 

comment from July 22, 2013 until August 21, 2013. For more details on preparing and filing 

comments about these documents, please see Appendix A - Public Involvement Information.

Lakehaven Utility District reviewed the draft permit and fact sheet for factual accuracy. Ecology 

corrected any errors or omissions regarding the facility’s location, history, wastewater 

discharges, or receiving water prior to publishing this draft fact sheet for public notice. 

After the public comment period closed, Ecology summarizes substantive comments and 

provides responses to them. Ecology includes the summary and responses to comments in this 

fact sheet as Appendix E - Response to Comments, and publishes it when issuing the final 

NPDES permit. Ecology did not revise the rest of the fact sheet, but the full document becomes

part of the legal history contained in the facility’s permit file.

Summary

The Lakehaven Utility District (the District) operates a 5.6 MGD trickling filter wastewater 

treatment plant that discharges to Poverty Bay in mid-Puget Sound. Ecology issued the previous 

permit for this facility on July 31, 2008 and modified it on November 1, 2008. The proposed 

permit contains the same effluent limits for Carbonaceous Biochemical Oxygen Demand 

(CBOD5), Total Suspended Solids (TSS), Fecal Coliform Bacteria, pH, and chlorine as the 

permit amended on November 1, 2008.
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Redondo Wastewater Treatment Plant

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Table of Contents

I. Introduction............................................................................................................ 5

II. Background Information....................................................................................... 6

A. Facility description................................................................................................ 7

History ................................................................................................................................7

Collection system status......................................................................................................7

Treatment processes............................................................................................................8

Staff.....................................................................................................................................8

Solid wastes/Residual Solids..............................................................................................8

Discharge outfall.................................................................................................................8

B. Description of the receiving water....................................................................... 9

C. Wastewater influent characterization................................................................. 9

D. Wastewater effluent characterization................................................................. 9

E. Summary of compliance with previous permit issued July 31, 2008 ............. 10

F. State environmental policy act (SEPA) compliance ........................................ 11

III. Proposed Permit Limits........................................................................................ 11

A. Design criteria ..................................................................................................... 11

B. Technology-based effluent limits....................................................................... 12

C. Surface water quality-based effluent limits...................................................... 13

Numerical criteria for the protection of aquatic life and recreation..................................13

Numerical criteria for the protection of human health......................................................14

Narrative criteria ...............................................................................................................14

Antidegradation ................................................................................................................14

Mixing zones.....................................................................................................................15

D. Designated uses and surface water quality criteria ......................................... 19

E. Water quality impairments................................................................................ 20

F. Evaluation of surface water quality-based effluent limits for numeric criteria

............................................................................................................................... 20

Reasonable Potential Analysis..........................................................................................24

G. Human health...................................................................................................... 24

H. Sediment quality.................................................................................................. 25

I. Whole effluent toxicity........................................................................................ 25

J. Groundwater quality limits................................................................................ 26

K. Comparison of effluent limits with the previous permit modified on 

November 1, 2008................................................................................................ 26

IV. Monitoring Requirements.................................................................................... 27

A. Wastewater monitoring ...................................................................................... 27
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B. Lab accreditation ................................................................................................ 28

V. Other Permit Conditions...................................................................................... 28

A. Reporting and record keeping ........................................................................... 28

B. Prevention of facility overloading...................................................................... 29

C. Operation and maintenance............................................................................... 29

D. Pretreatment........................................................................................................ 30

Duty to enforce discharge prohibitions.............................................................................30

Federal and state pretreatment program requirements......................................................30

Routine identification and reporting of industrial users....................................................31

E. Solid wastes.......................................................................................................... 31

F. General conditions.............................................................................................. 31

VI. Permit Issuance Procedures................................................................................ 31

A. Permit modifications........................................................................................... 31

B. Proposed permit issuance................................................................................... 32

VII. References for Text and Appendices................................................................... 32

Appendix A -- Public Involvement Information ......................................................................... 33

Appendix B -- Your Right to Appeal ........................................................................................... 34

Appendix C -- Glossary................................................................................................................ 35

Appendix D -- Technical Calculations........................................................................................ 43

Appendix E -- Response to Comments........................................................................................ 70

Table 1. General Facility Information ........................................................................................... 6

Table 2. Ambient Background Data .............................................................................................. 9

Table 3. Wastewater Influent Characterization ............................................................................. 9

Table 4. Wastewater Effluent Characterization ............................................................................. 9

Table 5. Violations/Permit Triggers ............................................................................................ 10

Table 6. Permit Submittals........................................................................................................... 10

Table 7. Design Criteria for Redondo WWTP............................................................................. 12

Table 8. Technology-based Limits .............................................................................................. 12

Table 9. Technology-based Mass Limits..................................................................................... 13

Table 10. Critical Conditions Used to Model the Discharge ....................................................... 17

Table 11. Marine Aquatic Life Uses and Associated Criteria ..................................................... 20

Table 12. Recreational Uses ........................................................................................................ 20
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Table 13. Dilution Factors (DF)................................................................................................... 21

Table 14. Comparison of Previous and Proposed Effluent Limits .............................................. 27

Table 15. Accredited Parameters................................................................................................. 28

Figure 1. Facility Location Map .................................................................................................... 7

Figure 2. Dilution Necessary to Meet Criteria at Edge of Mixing Zone ...................................... 24
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I. Introduction

The Federal Clean Water Act (FCWA, 1972, and later amendments in 1977, 1981, and 1987) 

established water quality goals for the navigable (surface) waters of the United States. One 

mechanism for achieving the goals of the Clean Water Act is the National Pollutant Discharge 

Elimination System (NPDES), administered by the federal Environmental Protection Agency 

(EPA). The EPA authorized the state of Washington to manage the NPDES permit program in 

our state. Our state legislature accepted the delegation and assigned the power and duty for 

conducting NPDES permitting and enforcement to Ecology. The Legislature defined Ecology's 

authority and obligations for the wastewater discharge permit program in 90.48 RCW (Revised 

Code of Washington). 

The following regulations apply to domestic wastewater NPDES permits:

 Procedures Ecology follows for issuing NPDES permits (chapter 173-220 WAC).

 Technical criteria for discharges from municipal wastewater treatment facilities (chapter 

173-221 WAC).

 Water quality criteria for surface waters (chapter 173-201A WAC).

 Water quality criteria for groundwaters (chapter 173-200 WAC).

 Whole effluent toxicity testing and limits (chapter 173-205 WAC).

 Sediment management standards (chapter 173-204 WAC).

 Submission of plans and reports for construction of wastewater facilities (chapter 173-240 

WAC).

These rules require any treatment facility owner/operator to obtain an NPDES permit before 

discharging wastewater to state waters. They also help define the basis for limits on each 

discharge and for requirements imposed by the permit. 

Under the NPDES permit program and in response to a complete and accepted permit 

application, Ecology must prepare a draft permit and accompanying fact sheet, and make them

available for public review before final issuance. Ecology must also publish an announcement 

(public notice) telling people where they can read the draft permit, and where to send their 

comments, during a period of thirty days (WAC 173-220-050). (See Appendix A - Public

Involvement Information for more detail about the public notice and comment procedures). After 

the public comment period ends, Ecology may make changes to the draft NPDES permit in 

response to comment(s). Ecology will summarize the responses to comments and any changes to 

the permit in Appendix E.
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II. Background Information

Table 1. General Facility Information

Facility Information

Applicant Lakehaven Utility District

31627 First Avenue South

Federal Way, WA 98023

Facility Name and Address Redondo WWTP

515 S. 288th Street

Des Moines, WA 98198

Contact at Facility Name: Mr. Chris McCalib

Title: WWTP Operations Manager

Telephone #: 253-945-1621

Responsible Official Name: Mr. John Bowman

Title: General Manager

Lakehaven Utility District

Address: PO Box 4249

Federal Way, WA 98063

Telephone #: 253-946-5401

FAX #: 253-839-9310

Type of Treatment Trickling Filter (Secondary Treatment)

Facility Location

(NAD83/WGS84 reference datum)

Latitude: 47.34346

Longitude: -122.3279

Discharge Waterbody Name and Location

(NAD83/WGS84 reference datum)

Puget Sound – Poverty Bay

Outfall Location No.001:

Latitude: 47.34941

Longitude: -122.338038

Permit Status

Issuance Date of Previous Permit 7/31/08

Modification Date of Previous Permit 11/1/08

Application for Permit Renewal Submittal Date 1/8/13

Date of Ecology Acceptance of Application 2/8/13

Inspection Status

Date of Last Sampling Inspection 5/12/09

Date of Last Non-sampling Inspection Date 7/23/13
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Figure 1. Facility Location Map

A. Facility description

History

Lakehaven Utility District, formerly known as Federal Way Water and Sewer District, owns and 

operates two wastewater treatment plants, Lakota WWTP and Redondo WWTP, which discharge 

to the Puget Sound. The Redondo WWTP is the smaller of the two with a maximum month 

average design flow of 5.6 million gallons per day (mgd). The District built the original plant in 

1962 for primary treatment and upgraded the plant with secondary treatment in 1983. The District 

installed new odor control facilities and a solids handling facility with a belt filter press in 1988 

and a UV disinfection process in 2000. The belt filter press was removed and replaced with a 

rotary press in 2010.

Collection system status

The Redondo plant collection system includes approximately 114 miles of pipe and serves

residential and associated commercial development. The sanitary collection system is separate 

from the storm drainage system. In the past during wet weather periods, flow increased from a 

monthly average base flow of around 2-mgd up to 10-mgd maximum daily flow. The District 

completed a comprehensive wastewater system plan in 1999. A collection system analysis found 

that Infiltration/Inflow (I/I) is a significant problem at this plant, and it recommended various I/I 

and flow reduction programs. The District incorporated an I/I rehab program focusing on the 

Redondo basin areas. No significant industrial users discharge to Redondo’s collection system.
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Treatment processes

The Redondo WWTP treatment process includes screening with mechanically cleaned bar 

screens, grit removal and comminution, primary clarification, biological treatment using 

plastic media trickling filters, secondary clarification, and ultra violet disinfection. Solids are 

processed with primary and secondary anaerobic digesters and a rotary press. The facility 

heats several buildings onsite with digester off-gas. A schematic of the treatment processes 

is shown in Appendix D.

You can find basic information describing wastewater treatment processes included in a 

booklet at the Water Environment Federation website at: 

http://www.wef.org/publicinformation/default.aspx

Staff

The Redondo plant is staffed five days a week from 6:30 a.m. to 5:00 p.m. Weekend 

coverage consists of one operator for a period of two hours to conduct a facility inspection 

and routine tasks. Redondo is a Class III plant. There are five (5) certified operators and one 

(1) operator-in-training located at the Redondo WWTP. There are an additional five (5)

certified operators in support roles that are available to work at Redondo WWTP if 

necessary. Applicable monitoring data for Redondo WWTP are prepared by the laboratory at 

the District’s Lakota facility. The Lakota laboratory is currently staffed from 6:30 a.m. to 

3:00 p.m., five days per week and weekends as needed.

Solid wastes/Residual Solids

The treatment facilities remove solids during the treatment of the wastewater at the 

headworks (grit and screenings), and at the primary and secondary clarifiers, in addition to 

incidental solids (rags, scum, and other debris) removed as part of the routine maintenance of 

the equipment. Redondo WWTP drains grit, rags, and screenings which are transported for 

ultimate disposal at an approved local landfill. Waste solids and scum removed from the

primary and secondary clarifiers are treated by anaerobic digesters and dewatered by rotary 

press. Dewatered sludge is normally trucked to a beneficial reuse facility in Eastern 

Washington for land application under a permit from the Department of Ecology (Permit No. 

BA0023451). Dewatered sludge can also be periodically trucked to a beneficial reuse 

composting facility in Kent, Washington. The composting facility is kept as a backup site

when the disposal of Redondo WWTP biosolids via land application is not possible.

Discharge outfall

The secondary treated and disinfected effluent discharges from the facility into Puget 

Sound – Poverty Bay through outfall No.001. The Lakehaven Utility District extended the 

Redondo WWTP outfall in 2008. The existing 30-inch outfall pipe extends 1,030 feet 

offshore to a depth of -123 feet MLLW and is connected to a new outfall line extension made 

of a 24-inch diameter high density polyethylene (HDPE). The effluent discharges through a 

single port (open-ended pipe) at a distance of 2,670 feet offshore and a depth of -400 feet 

MLLW. The primary incentives for the outfall extension were to fix existing leaks and to 

provide enhanced protection for the nearby geoduck beds.
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B. Description of the receiving water

Redondo WWTP effluent discharges to Puget Sound – Poverty Bay. Other nearby point source 

outfalls include the Lakota WWTP, located 2.6 miles southwest of Redondo, Midway (Des Moines) 

Sewer District WWTP located 5 miles north of Redondo WWTP, and various stormwater outfalls. 

The ambient background data used for this permit includes the following from the ambient water 

quality monitoring station (EAP001) at East Passage – SW of Three Tree Point just north of 

Redondo (link: http://www.ecy.wa.gov/apps/eap/marinewq/mwdataset.asp):

Table 2. Ambient Background Data

Parameter Value Used

Temperature (90th percentile 1-DADMax) 12.2 oC

Temperature (highest annual 1-DADMax) 15.3 oC

pH (minimum, 90th percentile, maximum) 6.6, 8.1, 9 standard units

Dissolved Oxygen (average, 5th percentile) 7.0 mg/L, 5.1 mg/L

Total Ammonia-N (max.) 0.05 mg/L

Fecal Coliform (90th percentile, maximum) 1/100 mL, 5/100 mL

C. Wastewater influent characterization

Redondo WWTP reported the concentration of influent pollutants in discharge monitoring reports. 

The influent wastewater (data from January 2008 to December 2012) is characterized as follows:

Table 3. Wastewater Influent Characterization

Parameter Units Monthly Average Value Maximum Value

Biochemical Oxygen Demand (BOD5) mg/L 247 325

BOD5 lbs/day 5,334 7,670

Total Suspended Solids (TSS) mg/L 252 400

TSS lbs/day 5,497 9,900

D. Wastewater effluent characterization

Redondo WWTP reported the concentration of pollutants in the discharge in the permit application 

and in discharge monitoring reports. The tabulated data represents the quality of the wastewater 

effluent discharged from January 2008 to December 2012. The wastewater effluent is characterized 

as follows:

Table 4. Wastewater Effluent Characterization

Parameter Units Monthly Average Value Maximum Value

Carbonaceous Biochemical 

Oxygen Demand (CBOD5)

mg/L 10 15

CBOD5 lbs/day 237 590

TSS mg/L 19 26

TSS lbs/day 453 1,046
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Parameter Units Maximum Monthly 

Geometric Mean

Maximum Weekly 

Geometric Mean

Fecal Coliforms #/100 mL 179 443

Parameter Units Minimum Value Maximum Value

pH standard units 6 8

E. Summary of compliance with previous permit issued July 31, 2008

The previous permit placed effluent limits on CBOD5, TSS, fecal coliform, pH, and chlorine.

Redondo WWTP has not consistently complied with the effluent limits and permit conditions

throughout the duration of the permit issued on July 31, 2008. Ecology assessed compliance 

based on its review of the facility’s information in Ecology’s Permitting and Reporting 

Information System (PARIS), discharge monitoring reports (DMRs) and on inspections.

The following table summarizes the violations and permit triggers that occurred during the 

permit term. Permit triggers are not violations but rather when triggered require the permit 

holder to take an action defined in the permit.

Table 5. Violations/Permit Triggers

Date Parameter Unit Value Max Limit Violation

Category

Violation

1/1/09 Effluent TSS Lbs/day 2,279 2,102 Permit Violation Numeric effluent 

violation

1/1/09 Effluent

TSS Removal

% 82.2 85 Permit Violation Numeric effluent 

violation

12/1/10 Effluent Fecal 

Coliform

#/100 mL 443 400 Permit Violation Numeric effluent 

violation

The following table summarizes compliance with report submittal requirements over the 

permit term. There was one late submittal.

Table 6. Permit Submittals

Submittal ‘Name Due Date Received Date

Toxicity - Chronic Summary Report 6/30/12 6/1/12

Toxicity - Chronic Summary Report 12/15/12 12/3/12

Infiltration and Inflow Evaluation 3/31/11 5/24/11

Toxicity - Acute Summary Report 9/30/12 9/1/12

Application for Permit Renewal 1/31/13 1/8/13

Operation and Maintenance Manual 10/31/10 10/29/10

Sediment Sampling and Analysis Plan 3/31/10 3/2/10

Signatory Requirements 9/10/08 9/10/08
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F. State environmental policy act (SEPA) compliance

State law exempts the issuance, reissuance or modification of any wastewater discharge 

permit from the SEPA process as long as the permit contains conditions are no less stringent 

than federal and state rules and regulations (RCW 43.21C.0383). The exemption applies 

only to existing discharges, not to new discharges.

III. Proposed Permit Limits

Federal and state regulations require that effluent limits in an NPDES permit must be either 

technology- or water quality-based.

 Technology-based limits are based upon the treatment methods available to treat specific 

pollutants. Technology-based limits are set by the EPA and published as a regulation, or 

Ecology develops the limit on a case-by-case basis (40 CFR 125.3, and chapter 173-220 

WAC). 

 Water quality-based limits are calculated so that the effluent will comply with the Surface 

Water Quality Standards (chapter 173-201A WAC), Ground Water Standards (chapter 

173-200 WAC), Sediment Quality Standards (chapter 173-204 WAC), or the National Toxics 

Rule (40 CFR 131.36). 

 Ecology must apply the most stringent of these limits to each parameter of concern. These 

limits are described below.

The limits in this permit reflect information received in the application and from supporting 

reports (engineering, hydrogeology, etc.). Ecology evaluated the permit application and 

determined the limits needed to comply with the rules adopted by the state of Washington. 

Ecology does not develop effluent limits for all reported pollutants. Some pollutants are not 

treatable at the concentrations reported, are not controllable at the source, are not listed in 

regulation, and do not have a reasonable potential to cause a water quality violation. 

Ecology does not usually develop limits for pollutants not reported in the permit application but 

may be present in the discharge. The permit does not authorize discharge of the non-reported 

pollutants. During the five-year permit term, the facility’s effluent discharge conditions may 

change from those conditions reported in the permit application. The facility must notify Ecology 

if significant changes occur in any constituent [40 CFR 122.42(a)]. Until Ecology modifies the 

permit to reflect additional discharge of pollutants, a permitted facility could be violating its

permit.

A. Design criteria

Under WAC 173-220-150 (1)(g), flows and waste loadings must not exceed approved design 

criteria. Ecology approved design criteria for this facility’s treatment plant in the design 

drawings (HDR Engineering, November, 1987). The table below includes design criteria 

from the referenced report.
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Table 7. Design Criteria for Redondo WWTP

Parameter Design Quantity

Maximum Month Design Flow (MMDF) 5.6 MGD

BOD5 Loading for Maximum Month 9,760 lb/day

TSS Loading for Maximum Month 11,710 lb/day

B. Technology-based effluent limits

Federal and state regulations define technology-based effluent limits for municipal 

wastewater treatment plants. These effluent limits are given in 40 CFR Part 133 (federal) 

and in chapter 173-221 WAC (state). These regulations are performance standards that 

constitute all known, available, and reasonable methods of prevention, control, and treatment 

(AKART) for municipal wastewater.

The table below identifies technology-based limits for pH, fecal coliform, CBOD5, and TSS, 

as listed in chapter 173-221 WAC. Section III.F this fact sheet describes the potential for 

water quality-based limits. 

Table 8. Technology-based Limits

Parameter Average Monthly Limit Average Weekly Limit

CBOD5

(concentration)

25 mg/L 40 mg/L

CBOD5

(concentration)

In addition, the CBOD5 effluent concentration must not exceed fifteen 

percent (15%) of the average influent concentration.

TSS

(concentration)

30 mg/L 45 mg/L

TSS

(concentration)

In addition, the TSS effluent concentration must not exceed fifteen percent 

(15%) of the average influent concentration.

Parameter Monthly Geometric Mean Limit Weekly Geometric Mean Limit

Fecal Coliform 200 organisms/100 mL 400 organisms/100 mL

Parameter Daily Minimum Daily Maximum

pH 6.0 standard units 9.0 standard units

Ecology derived the technology-based monthly average limit for chlorine from standard 

operating practices. The Water Pollution Control Federation's Chlorination of Wastewater

(1976) states that a properly designed and maintained wastewater treatment plant can achieve 

adequate disinfection if a 0.5 mg/L chlorine residual is maintained after fifteen minutes of 

contact time. See also Metcalf and Eddy, Wastewater Engineering, Treatment, Disposal and 

Reuse, Third Edition, 1991. A treatment plant that provides adequate chlorination contact 

time can meet the 0.5 mg/L chlorine limit on a monthly average basis. According to WAC 

173-221-030(11)(b), the corresponding weekly average is 0.75 mg/L.
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Redondo WWTP disinfects with UV and only uses chlorine as a backup. The previous 

permit had water-quality based chlorine limits of 120 g/L (average monthly limit) and 312 

g/L (maximum daily limit) based on dilution factors (24 acute and 225 chronic) associated 

with the old outfall diffuser design, and the facility was able to comply with these limits. 

The water-quality based chlorine limits associated with the dilution factors (79 acute and 182 

chronic) of the new outfall are 394 g/L (average monthly limit) and 1,031 g/L (maximum 

daily limit). Since the WWTP could comply with the more stringent limits in the previous 

permit, and to avoid anti-backsliding, the chlorine limits in the previous permit 120 g/L 

(average monthly limit) and 312 g/L (maximum daily limit) will be retained for the 

proposed permit. The chlorine limits only apply when chlorine is being used as a 

disinfectant. 

Technology-based mass limits are based on WAC 173-220-130(3)(b) and 173-221-030(11)(b). 

Ecology calculated the monthly and weekly average mass limits for CBOD5 and Total 

Suspended Solids as follows:

Mass Limit = CL x DF x CF

where:

CL = Technology-based concentration limits listed in the above table

DF = Maximum Monthly Average Design flow (MGD)

CF = Conversion factor of 8.34

Table 9. Technology-based Mass Limits

Parameter Concentration Limit 

(mg/L)

Mass Limit 

(lbs/day)

CBOD5 Monthly Average 25 1,168

CBOD5 Weekly Average 40 1,868

TSS Monthly Average 30 1,401

TSS Weekly Average 45 2,102

C. Surface water quality-based effluent limits

The Washington State surface water quality standards (chapter 173-201A WAC) are 

designed to protect existing water quality and preserve the beneficial uses of Washington's 

surface waters. Waste discharge permits must include conditions that ensure the discharge 

will meet the surface water quality standards (WAC 173-201A-510). Water quality-based 

effluent limits may be based on an individual waste load allocation or on a waste load 

allocation developed during a basin wide total maximum daily load study (TMDL).

Numerical criteria for the protection of aquatic life and recreation

Numerical water quality criteria are listed in the water quality standards for surface waters 

(chapter 173-201A WAC). They specify the maximum levels of pollutants allowed in 

receiving water to protect aquatic life and recreation in and on the water. Ecology uses 
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numerical criteria along with chemical and physical data for the wastewater and receiving 

water to derive the effluent limits in the discharge permit. When surface water quality-based 

limits are more stringent or potentially more stringent than technology-based limits, the 

discharge must meet the water quality-based limits.

Numerical criteria for the protection of human health 

The U.S. EPA has published 91 numeric water quality criteria for the protection of human 

health that are applicable to dischargers in Washington State (EPA, 1992). These criteria are 

designed to protect humans from exposure to pollutants linked to cancer and other diseases, 

based on consuming fish and shellfish and drinking contaminated surface waters. The water 

quality standards also include radionuclide criteria to protect humans from the effects of 

radioactive substances.

Narrative criteria

Narrative water quality criteria (e.g., WAC 173-201A-240(1); 2006) limit the toxic, 

radioactive, or other deleterious material concentrations that the facility may discharge to 

levels below those which have the potential to:

• Adversely affect designated water uses. 

• Cause acute or chronic toxicity to biota. 

• Impair aesthetic values. 

• Adversely affect human health.

Narrative criteria protect the specific designated uses of all fresh waters 

(WAC 173-201A-200, 2006) and of all marine waters (WAC 173-201A-210, 2006) in the

state of Washington.

Antidegradation 

Description--The purpose of Washington's Antidegradation Policy

(WAC 173-201A-300-330; 2006) is to:

• Restore and maintain the highest possible quality of the surface waters of Washington.

• Describe situations under which water quality may be lowered from its current condition.

• Apply to human activities that are likely to have an impact on the water quality of surface

water.

• Ensure that all human activities likely to contribute to a lowering of water quality, at a 

minimum, apply all known, available, and reasonable methods of prevention, control, and 

treatment (AKART).

• Apply three tiers of protection (described below) for surface waters of the state.

Tier I ensures existing and designated uses are maintained and protected and applies to all 

waters and all sources of pollutions. Tier II ensures that waters of a higher quality than the 

criteria assigned are not degraded unless such lowering of water quality is necessary and in 

the overriding public interest. Tier II applies only to a specific list of polluting activities. 

Tier III prevents the degradation of waters formally listed as "outstanding resource waters," 

and applies to all sources of pollution.
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A facility must prepare a Tier II analysis when all three of the following conditions are met: 

• The facility is planning a new or expanded action.

• Ecology regulates or authorizes the action.

• The action has the potential to cause measurable degradation to existing water quality at 

the edge of a chronic mixing zone.

Facility Specific Requirements--This facility must meet Tier I requirements. 

• Dischargers must maintain and protect existing and designated uses. Ecology must not 

allow any degradation that will interfere with, or become injurious to, existing or 

designated uses, except as provided for in chapter 173-201A WAC. 

Ecology’s analysis described in this section of the fact sheet demonstrates that the proposed 

permit conditions will protect existing and designated uses of the receiving water.

Mixing zones

A mixing zone is the defined area in the receiving water surrounding the discharge port(s), 

where wastewater mixes with receiving water. Within mixing zones the pollutant 

concentrations may exceed water quality numeric standards, so long as the discharge doesn’t 

interfere with designated uses of the receiving water body (for example, recreation, water 

supply, and aquatic life and wildlife habitat, etc.) The pollutant concentrations outside of the 

mixing zones must meet water quality numeric standards.

State and federal rules allow mixing zones because the concentrations and effects of most 

pollutants diminish rapidly after discharge, due to dilution. Ecology defines mixing zone 

sizes to limit the amount of time any exposure to the end-of-pipe discharge could harm water 

quality, plants, or fish.

The state’s water quality standards allow Ecology to authorize mixing zones for the facility’s 

permitted wastewater discharges only if those discharges already receive all known, 

available, and reasonable methods of prevention, control, and treatment (AKART). Mixing 

zones typically require compliance with water quality criteria within a specified distance 

from the point of discharge and must not use more than 25% of the available width of the 

water body for dilution [WAC 173-201A-400 (7)(a)(ii-iii)]. 

Ecology uses modeling to estimate the amount of mixing within the mixing zone. Through 

modeling Ecology determines the potential for violating the water quality standards at the 

edge of the mixing zone and derives any necessary effluent limits. Steady-state models are 

the most frequently used tools for conducting mixing zone analyses. Ecology chooses values 

for each effluent and for receiving water variables that correspond to the time period when 

the most critical condition is likely to occur (see Ecology’s Permit Writer’s Manual). Each 

critical condition parameter, by itself, has a low probability of occurrence and the resulting 

dilution factor is conservative. The term “reasonable worst-case” applies to these values.

The mixing zone analysis produces a numerical value called a dilution factor (DF). A 

dilution factor represents the amount of mixing of effluent and receiving water that occurs at 

the boundary of the mixing zone. For example, a dilution factor of 10 means the effluent is 

10% and the receiving water is 90% of the total volume of water at the boundary of the 

mixing zone. Ecology uses dilution factors with the water quality criteria to calculate
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reasonable potentials and effluent limits. Water quality standards include both aquatic lifebased criteria and human health-based criteria. The former are applied at both the acute and 

chronic mixing zone boundaries; the latter are applied only at the chronic boundary. The 

concentration of pollutants at the boundaries of any of these mixing zones may not exceed 

the numerical criteria for that zone. 

Each aquatic life acute criterion is based on the assumption that organisms are not exposed to 

that concentration for more than one hour and more often than one exposure in three years. 

Each aquatic life chronic criterion is based on the assumption that organisms are not exposed 

to that concentration for more than four consecutive days and more often than once in three 

years. 

The two types of human health-based water quality criteria distinguish between those 

pollutants linked to non-cancer effects (non-carcinogenic) and those linked to cancer effects 

(carcinogenic). The human health-based water quality criteria incorporate several exposure 

and risk assumptions. These assumptions include:

• A 70-year lifetime of daily exposures.

• An ingestion rate for fish or shellfish measured in kg/day.

• An ingestion rate of two liters/day for drinking water.

• A one-in-one-million cancer risk for carcinogenic chemicals.

This permit authorizes a small acute mixing zone, surrounded by a chronic mixing zone 

around the point of discharge (WAC 173-201A-400). The water quality standards impose 

certain conditions before allowing the discharger a mixing zone: 

1. Ecology must specify both the allowed size and location in a permit. 

The proposed permit specifies the size and location of the allowed mixing zone (as 

specified below).

2. The facility must fully apply “all known, available, and reasonable methods of 

prevention, control and treatment” (AKART) to its discharge.

Ecology has determined that the treatment provided at Redondo WWTP meets the 

requirements of AKART (see “Technology-based Limits”).

3. Ecology must consider critical discharge conditions.

Surface water quality-based limits are derived for the water body’s critical condition (the 

receiving water and waste discharge condition with the highest potential for adverse 

impact on the aquatic biota, human health, and existing or designated waterbody uses). 

The critical discharge condition is often pollutant-specific or waterbody-specific.

Critical discharge conditions are those conditions that result in reduced dilution or 

increased effect of the pollutant. Factors affecting dilution include the depth of water, the 

density stratification in the water column, the currents, and the rate of discharge. Density 

stratification is determined by the salinity and temperature of the receiving water. 

Temperatures are warmer in the surface waters in summer. Therefore, density 

stratification is generally greatest during the summer months. Density stratification 

affects how far up in the water column a freshwater plume may rise. The rate of mixing 
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is greatest when an effluent is rising. The effluent stops rising when the mixed effluent is 

the same density as the surrounding water. After the effluent stops rising, the rate of 

mixing is much more gradual. Water depth can affect dilution when a plume might rise 

to the surface when there is little or no stratification. Ecology uses the water depth at 

mean lower low water (MLLW) for marine waters. Ecology’s Permit Writer’s Manual 

describes additional guidance on criteria/design conditions for determining dilution 

factors. The manual can be obtained from Ecology’s website at: 

https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html.

Table 10. Critical Conditions Used to Model the Discharge

Critical Condition Value

Water depth at MLLW 400 feet

Density profile with a difference of 0.76 sigma-t units between - 400

(MLLW) feet and the surface

10th percentile current speeds for acute mixing zone 0.38 ~ 0.54 cm/sec

50th percentile current speeds for chronic and human health mixing zones 1.96 ~ 2.81 cm/sec

Maximum average monthly effluent flow for chronic and human health 

non-carcinogen

5.6 MGD

Maximum daily flow for acute mixing zone 10 MGD

1 DAD MAX effluent temperature 20.9 degrees C

Ecology obtained ambient data at critical conditions in the vicinity of the outfall from an 

outfall engineering report by Cosmopolitan Engineering Group in 2005.

4. Supporting information must clearly indicate the mixing zone would not: 

• Have a reasonable potential to cause the loss of sensitive or important habitat.

• Substantially interfere with the existing or characteristic uses.

• Result in damage to the ecosystem.

• Adversely affect public health.

Ecology established Washington State water quality criteria for toxic chemicals using 

EPA criteria. EPA developed the criteria using toxicity tests with numerous organisms

and set the criteria to generally protect the species tested and to fully protect all 

commercially and recreationally important species. 

EPA sets acute criteria for toxic chemicals assuming organisms are exposed to the 

pollutant at the criteria concentration for one hour. They set chronic standards assuming 

organisms are exposed to the pollutant at the criteria concentration for four days. 

Dilution modeling under critical conditions generally shows that both acute and chronic 

criteria concentrations are reached within minutes of discharge. 

The discharge plume does not impact drifting and non-strong swimming organisms 

because they cannot stay in the plume close to the outfall long enough to be affected. 

Strong swimming fish could maintain a position within the plume, but they can also 

avoid the discharge by swimming away. Mixing zones generally do not affect benthic 

organisms (bottom dwellers) because the buoyant plume rises in the water column. 
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Ecology has additionally determined that the effluent will not exceed 33 degrees C for 

more than two seconds after discharge; and that the temperature of the water will not 

create lethal conditions or blockages to fish migration. 

Ecology evaluates the cumulative toxicity of an effluent by testing the discharge with 

whole effluent toxicity (WET) testing. 

5. The discharge/receiving water mixture must not exceed water quality criteria 

outside the boundary of a mixing zone.

Ecology conducted a reasonable potential analysis, using procedures established by the 

EPA and by Ecology, for each pollutant and concluded the discharge/receiving water 

mixture will not violate water quality criteria outside the boundary of the mixing zone if 

permit limits are met.

6. The size of the mixing zone and the concentrations of the pollutants must be 

minimized.

At any given time, the effluent plume uses only a portion of the acute and chronic mixing 

zone, which minimizes the volume of water involved in mixing. Because tidal currents 

change direction, the plume orientation within the mixing zone changes. The plume 

mixes as it rises through the water column therefore much of the receiving water volume 

at lower depths in the mixing zone is not mixed with discharge. Similarly, because the 

discharge may stop rising at some depth due to density stratification, waters above that 

depth will not mix with the discharge. Ecology determined it is impractical to specify in 

the permit the actual, much more limited volume in which the dilution occurs as the 

plume rises and moves with the current. 

Ecology minimizes the size of mixing zones by requiring dischargers to install diffusers 

when they are appropriate to the discharge and the specific receiving waterbody. When a 

diffuser is installed, the discharge is more completely mixed with the receiving water in a 

shorter time. Ecology also minimizes the size of the mixing zone (in the form of the 

dilution factor) using design criteria with a low probability of occurrence. For example, 

Ecology uses the expected 95th percentile pollutant concentration, the 90th percentile 

background concentration, the centerline dilution factor, and the lowest flow occurring 

once in every ten years to perform the reasonable potential analysis. 

Because of the above reasons, Ecology has effectively minimized the size of the mixing 

zone authorized in the proposed permit.

7. Maximum size of mixing zone.

The authorized mixing zone does not exceed the maximum size restriction.

8. Acute mixing zone.

• The discharge/receiving water mixture must comply with acute criteria as near 

to the point of discharge as practicably attainable.

Ecology determined the acute criteria will be met at 10% of the distance of the 

chronic mixing zone.
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• The pollutant concentration, duration, and frequency of exposure to the 

discharge will not create a barrier to migration or translocation of indigenous 

organisms to a degree that has the potential to cause damage to the ecosystem.

As described above, the toxicity of any pollutant depends upon the exposure, the 

pollutant concentration, and the time the organism is exposed to that concentration. 

Authorizing a limited acute mixing zone for this discharge assures that it will not 

create a barrier to migration. The effluent from this discharge will rise as it enters the 

receiving water, assuring that the rising effluent will not cause translocation of 

indigenous organisms near the point of discharge (below the rising effluent).

• Comply with size restrictions.

The mixing zone authorized for this discharge complies with the size restrictions 

published in chapter 173-201A WAC.

9. Overlap of mixing zones.

This mixing zone does not overlap another mixing zone.

D. Designated uses and surface water quality criteria

Applicable designated uses and surface water quality criteria are defined in chapter 

173-201A WAC. In addition, the U.S. EPA set human health criteria for toxic pollutants 

(EPA 1992). The tables included below summarize the criteria applicable to the receiving 

water’s designated uses.

• Aquatic life uses are designated using the following general categories. All indigenous 

fish and non-fish aquatic species must be protected in waters of the state.

a. Extraordinary quality salmonid and other fish migration, rearing, and spawning; clam, 

oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs, 

shrimp, crayfish, scallops, etc.) rearing and spawning.

b. Excellent quality salmonid and other fish migration, rearing, and spawning; clam, 

oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs, 

shrimp, crayfish, scallops, etc.) rearing and spawning.

c. Good quality salmonid migration and rearing; other fish migration, rearing, and 

spawning; clam, oyster, and mussel rearing and spawning; crustaceans and other 

shellfish (crabs, shrimp, crayfish, scallops, etc.) rearing and spawning. 

d. Fair quality salmonid and other fish migration.

The Aquatic Life Uses and the associated criteria for this receiving water are identified 

below.
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Table 11. Marine Aquatic Life Uses and Associated Criteria

Extraordinary Quality

Temperature Criteria – Highest 1D MAX 13°C (55.4°F)

Dissolved Oxygen Criteria – Lowest 1-Day 

Minimum

7.0 mg/L

Turbidity Criteria • 5 NTU over background when the background 

is 50 NTU or less; or 

• A 10 percent increase in turbidity when the 

background turbidity is more than 50 NTU.

pH Criteria pH must be within the range of 7.0 to 8.5 with a 

human-caused variation within the above range of 

less than 0.2 units.

• To protect shellfish harvesting, fecal coliform organism levels must not exceed a 

geometric mean value of 14 colonies/100 mL, and not have more than 10 percent of all 

samples (or any single sample when less than ten sample points exist) obtained for 

calculating the geometric mean value exceeding 43 colonies/100 mL.

• The recreational uses are primary contact recreation and secondary contact recreation. 

The recreational use for this receiving water is primary contact recreation as identified below.

Table 12. Recreational Uses

Recreational Use Criteria

Primary Contact 

Recreation

Fecal coliform organism levels must not exceed a geometric mean value of 14 

colonies/100 mL, with not more than 10 percent of all samples (or any single 

sample when less than ten sample points exist) obtained for calculating the 

geometric mean value exceeding 43 colonies /100 mL.

• The miscellaneous marine water uses are wildlife habitat, harvesting, commerce and 

navigation, boating, and aesthetics.

E. Water quality impairments

Ecology has not documented any water quality impairments in the receiving water in the 

vicinity of the outfall.

F. Evaluation of surface water quality-based effluent limits for numeric criteria

Pollutants in an effluent may affect the aquatic environment near the point of discharge 

(near-field) or at a considerable distance from the point of discharge (far-field). Toxic 

pollutants, for example, are near-field pollutants; their adverse effects diminish rapidly with 

mixing in the receiving water. Conversely, a pollutant such as biochemical oxygen demand 

(BOD5) is a far-field pollutant whose adverse effect occurs away from the discharge even 

after dilution has occurred. Thus, the method of calculating surface water quality-based 

effluent limits varies with the point at which the pollutant has its maximum effect.
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With technology-based controls (AKART), predicted pollutant concentrations in the 

discharge exceed water quality criteria. Ecology therefore authorizes a mixing zone in 

accordance with the geometric configuration, flow restriction, and other restrictions imposed 

on mixing zones by chapter 173-201A WAC.

The Outfall No.001 has 2,670 feet long outfall pipe with a diameter of 24 inches, and is

open-ended. The mean lower low water (MLLW) depth is 400 feet. Ecology obtained this 

information from the Outfall Engineering Report submitted by Cosmopolitan Engineering 

Group in 2005. 

Chronic Mixing Zone--WAC 173-201A-400(7)(b) specifies that mixing zones must not 

extend in any horizontal direction from the discharge ports for a distance greater than 200 

feet plus the depth of water over the discharge ports and may not occupy more than 25% of 

the width of the water body as measured during MLLW. 

The horizontal distance of the chronic mixing zone is 1,200 feet. The mixing zone extends 

from the top of the discharge ports to the water surface.

Acute Mixing Zone--WAC 173-201A-400(8)(b) specifies that in estuarine waters a zone 

where acute criteria may be exceeded must not extend beyond 10% of the distance 

established for the chronic zone. The acute mixing zone for Outfall No.001 extends 60 feet

in any direction from any discharge port. 

Ecology reviewed the dilution factors that occur within these zones at the critical condition 

using U.S. EPA’s UM3 Model. The dilution factors are listed below.

Table 13. Dilution Factors (DF)

Criteria Acute Chronic

Aquatic Life 79:1 182:1

Human Health, Carcinogen 182:1

Human Health, Non-carcinogen 182:1

Ecology determined the impacts of dissolved oxygen deficiency, nutrients, pH, fecal 

coliform, ammonia, metals, other toxics, and temperature as described below, using the 

dilution factors in the above table. The derivation of surface water quality-based limits also 

takes into account the variability of pollutant concentrations in both the effluent and the 

receiving water. 

Dissolved Oxygen--BOD5 and Ammonia Effects--Natural decomposition of organic 

material in wastewater effluent impacts dissolved oxygen in the receiving water at distances 

far outside of the regulated mixing zone. The 5-day Biochemical Oxygen Demand (BOD5) 

of an effluent sample indicates the amount of biodegradable material in the wastewater and 

estimates the magnitude of oxygen consumption the wastewater will generate in the receiving 

water. The amount of ammonia-based nitrogen in the wastewater also provides an indication 

of oxygen demand potential in the receiving water.

With technology-based limits, this discharge results in a small amount of biochemical 

oxygen demand (BOD5) relative to the large amount of dilution in the receiving water at 

critical conditions. Technology-based limits will ensure that dissolved oxygen criteria are 

met in the receiving water.
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pH--Compliance with the technology-based limits of 6.0 to 9.0 will assure compliance with 

the water quality standards of surface waters because of the high buffering capacity of marine 

water. 

Fecal Coliform--Ecology modeled the numbers of fecal coliform by simple mixing analysis 

using the technology-based limit of 400 organisms per 100 mL and a dilution factor of 182. 

Under critical conditions, modeling predicts no violation of the water quality criterion for 

fecal coliform. Therefore, the proposed permit includes the technology-based effluent limit 

for fecal coliform bacteria.

Turbidity--Ecology evaluated the impact of turbidity based on the range of total suspended 

solids in the effluent and turbidity of the receiving water. Ecology expects no violations of 

the turbidity criteria outside the designated mixing zone provided the facility meets its 

technology-based total suspended solids permit limits.

Toxic Pollutants--Federal regulations (40 CFR 122.44) require Ecology to place limits in 

NPDES permits on toxic chemicals in an effluent whenever there is a reasonable potential for 

those chemicals to exceed the surface water quality criteria. Ecology does not exempt facilities 

with technology-based effluent limits from meeting the surface water quality standards.

The following toxic pollutants are present in the discharge: chlorine, ammonia, and heavy 

metals (arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc), bis

(2-ethylhexyl phthalate), and butyl benzyl phthalate. Ecology conducted a reasonable 

potential analysis (See Appendix D) on these parameters to determine whether it would 

require effluent limits in this permit. 

Ammonia's toxicity depends on that portion which is available in the unionized form. The 

amount of unionized ammonia depends on the temperature, pH, and salinity of the receiving 

marine water. To evaluate ammonia toxicity, Ecology used the available receiving water 

information for ambient station, the Ecology Marine Water Quality Monitoring Station 

EAP001 and Ecology spreadsheet tools.

No valid ambient background data were available for chlorine and heavy metals (arsenic, 

cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc), bis (2-ethylhexyl 

phthalate), and butyl benzyl phthalate. Ecology used zero for background. 

Ecology determined that chlorine, ammonia, and heavy metals (arsenic, cadmium, chromium, 

copper, lead, mercury, nickel, selenium, and zinc), bis (2-ethylhexyl phthalate) and butyl benzyl 

phthalate pose no reasonable potential to exceed the water quality criteria at the critical condition 

using procedures given in EPA, 1991 (Appendix D) and as described above. Ecology’s 

determination assumes that this facility meets the other effluent limits of this permit.

Temperature--The state temperature standards [WAC 173-201A-200-210 and 600-612]

include multiple elements:

• Annual summer maximum threshold criteria (June 15 to September 15).

• Supplemental spawning and rearing season criteria (September 15 to June 15).

• Incremental warming restrictions.

• Protections against acute effects.
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Ecology evaluates each criterion independently to determine reasonable potential and derive 

permit limits. 

• Annual summer maximum and supplementary spawning/rearing criteria

Each water body has an annual maximum temperature criterion [WAC 173-201A-200(1)(c), 

210(1)(c), and Table 602]. These threshold criteria (e.g., 12, 16, 17.5, 20°C) protect specific 

categories of aquatic life by controlling the effect of human actions on summer 

temperatures. 

Some waters have an additional threshold criterion to protect the spawning and incubation of 

salmonids (9°C for char and 13°C for salmon and trout) [WAC 173-201A-602, Table 602]. 

These criteria apply during specific date-windows.

The threshold criteria apply at the edge of the chronic mixing zone. Criteria for most fresh 

waters are expressed as the highest 7-Day average of daily maximum temperature

(7-DADMax). The 7-DADMax temperature is the arithmetic average of seven consecutive 

measures of daily maximum temperatures. Criteria for marine waters and some fresh waters 

are expressed as the highest 1-Day annual maximum temperature (1-DMax). 

• Incremental warming criteria

The water quality standards limit the amount of warming human sources can cause under 

specific situations [WAC 173-201A-200(1)(c)(i)-(ii), 210(1)(c)(i)-(ii)]. The incremental 

warming criteria apply at the edge of the chronic mixing zone.

At locations and times when background temperatures are cooler than the assigned 

threshold criterion, point sources are permitted to warm the water by only a defined 

increment. These increments are permitted only to the extent doing so does not cause 

temperatures to exceed either the annual maximum or supplemental spawning criteria.

At locations and times when a threshold criterion is being exceeded due to natural 

conditions, all human sources, considered cumulatively, must not warm the water more 

than 0.3°C above the naturally warm condition. 

When Ecology has not yet completed a TMDL, our policy allows each point source to 

warm water at the edge of the chronic mixing zone by 0.3°C. This is true regardless of 

the background temperature and even if doing so would cause the temperature at the edge 

of a standard mixing zone to exceed the numeric threshold criteria. Allowing a 0.3°C 

warming for each point source is reasonable and protective where the dilution factor is 

based on 25% or less of the critical flow. This is because the fully mixed effect on 

temperature will only be a fraction of the 0.3°C cumulative allowance (0.075°C or less) 

for all human sources combined.

• Protections for temperature acute effects

Instantaneous lethality to passing fish: The upper 99th percentile daily maximum effluent 

temperature must not exceed 33°C, unless a dilution analysis indicates ambient 

temperatures will not exceed 33°C two seconds after discharge.

General lethality and migration blockage: Measurable (0.3°C) increases in temperature at 

the edge of a chronic mixing zone are not allowed when the receiving water temperature 

exceeds either a 1DMax of 23°C or a 7DADMax of 22°C.
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Lethality to incubating fish: Human actions must not cause a measurable (0.3°C) 

warming above 17.5°C at locations where eggs are incubating. 

Reasonable Potential Analysis

Annual summer maximum and incremental warming criteria: Ecology calculated the 

reasonable potential for the discharge to exceed the annual summer maximum and the 

incremental warming criteria at the edge of the chronic mixing zone during critical condition. 

No reasonable potential exists to exceed the temperature criterion where:

(Criterion + 0.3) > [Criterion + (Teffluent95 – Criterion)/DF].

The figure below graphically portrays the above equation and shows the conditions when a 

permit limit will apply. 

Figure 2. Dilution Necessary to Meet Criteria at Edge of Mixing Zone

(13 + 0.3) > (13 + (23– 13)/282) => 13.3 > 13.035

Therefore, the proposed permit does not include a temperature limit. The permit requires 

additional monitoring of the effluent. Ecology will reevaluate the reasonable potential during 

the next permit cycle. 

G. Human health

Washington’s water quality standards include 91 numeric human health-based criteria that

Ecology must consider when writing NPDES permits. These criteria were established in 

1992 by the U.S. EPA in its National Toxics Rule (40 CFR 131.36). The National Toxics 

Rule allows states to use mixing zones to evaluate whether discharges comply with human 

health criteria.

0

10

20

30

40

50

60

70

9 11 13 15 17 19 21 23 25 27 29 31 33

Minimum Chronic Dilution Factor needed to 

meet numeric WQ criteria

95th Percentile Effluent Temperature, °C

WQ Criteria = 

9

WQ Criteria = 

12

Calculation based on:
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Ecology determined the effluent may contain chemicals of concern for human health, based 

on (1) the facility’s status as an EPA major discharger and (2) data or information indicating

the discharge contains regulated chemicals.

Ecology evaluated the discharge's potential to violate the water quality standards as required 

by 40 CFR 122.44(d) by following the procedures published in the Technical Support 

Document for Water Quality-Based Toxics Control (EPA/505/2-90-001) and Ecology's 

Permit Writer's Manual to make a reasonable potential determination. The evaluation 

showed that the discharge has no reasonable potential to cause a violation of water quality 

standards, and an effluent limit is not needed.

H. Sediment quality

The aquatic sediment standards (chapter 173-204 WAC) protect aquatic biota and human 

health. Under these standards Ecology may require a facility to evaluate the potential for its 

discharge to cause a violation of sediment standards (WAC 173-204-400). You can obtain 

additional information about sediments at the Ecology Aquatic Lands Cleanup Unit website. 

http://www.ecy.wa.gov/programs/tcp/smu/sediment.html

In August 2009, a sampling event occurred to provide baseline sediment data near the new 

outfall which was installed in 2008. No SMS chemical exceedances were found in the six 

samples analyzed and the one bioassay sample passed the SMS biological criteria. Ecology’s 

Aquatic Lands Cleanup Unit recommends sampling at Redondo’s new outfall again to assess 

sediment conditions from the baseline conditions. The proposed permit requires a sediment 

sampling and analysis plan and a subsequent sediment data report. According to Ecology’s 

Aquatic Cleanup Lands Unit, if no SMS exceedances are found during this permit cycle, 

monitoring would continue at a rate of every other permit cycle.

I. Whole effluent toxicity

The water quality standards for surface waters forbid discharge of effluent that has the 

potential to cause toxic effects in the receiving waters. Many toxic pollutants cannot be 

measured by commonly available detection methods. However, laboratory tests can measure 

toxicity directly by exposing living organisms to the wastewater and measuring their 

responses. These tests measure the aggregate toxicity of the whole effluent, so this approach 

is called whole effluent toxicity (WET) testing. Some WET tests measure acute toxicity and 

other WET tests measure chronic toxicity.

• Acute toxicity tests measure mortality as the significant response to the toxicity of the 

effluent. Dischargers who monitor their wastewater with acute toxicity tests find early 

indications of any potential lethal effect of the effluent on organisms in the receiving water.

• Chronic toxicity tests measure various sublethal toxic responses, such as reduced growth 

or reproduction. Chronic toxicity tests often involve either a complete life cycle test on 

an organism with an extremely short life cycle, or a partial life cycle test during a critical 

stage of a test organism's life. Some chronic toxicity tests also measure survival.

Laboratories accredited by Ecology for WET testing know how to use the proper WET testing 

protocols, fulfill the data requirements, and submit results in the correct reporting format. 

Accredited laboratory staff know how to calculate an NOEC, LC50, EC50, IC25, etc. Ecology 

gives all accredited labs the most recent version of Ecology Publication No. WQ-R-95-80, 
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Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria

(https://fortress.wa.gov/ecy/publications/SummaryPages/9580.html) which is referenced in the 

permit. Ecology recommends that each regulated facility send a copy of the acute or chronic 

toxicity sections(s) of its NPDES permit to the laboratory.

Acute Toxicity

The previous permit required the Redondo WWTP to perform acute WET tests twice during

the permit term. Both of the July 2012 acute tests (fathead minnow and daphnid) had less 

than 65% survival in 100% effluent. Therefore, Redondo needs another effluent 

characterization for acute WET. 

Chronic Toxicity

The previous permit required the Redondo WWTP to perform chronic WET tests twice 

during the permit term. WET testing conducted during effluent characterization showed no 

reasonable potential for effluent discharges to cause receiving water chronic toxicity because 

there was no statistically significant toxicity at the ACEC of 4.17% effluent. Therefore, the 

proposed permit will not impose a chronic WET limit. Redondo WWTP must re-test the 

effluent before submitting an application for permit renewal. 

• If this facility makes process or material changes which, in Ecology's opinion, increase 

the potential for effluent toxicity, then Ecology may (in a regulatory order, by permit 

modification, or in the permit renewal) require the facility to conduct additional effluent 

characterization. Redondo WWTP may demonstrate to Ecology that effluent toxicity has 

not increased by performing additional WET testing after the process or material changes 

have been made.

• If WET testing conducted for submittal with a permit application fails to meet the 

performance standards in WAC 173-205-020, Ecology will assume that effluent toxicity 

has increased and require another effluent characterization in accordance with WAC 

173-205-060(3)(a). 

J. Groundwater quality limits

The groundwater quality standards (chapter 173-200 WAC) protect beneficial uses of 

groundwater. Permits issued by Ecology must not allow violations of those standards 

(WAC 173-200-100).

The Redondo WWTP does not discharge wastewater to the ground. No permit limits are 

required to protect groundwater.

K. Comparison of effluent limits with the previous permit modified on 

November 1, 2008

The proposed effluent limits are the same as the previous limits.
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Table 14. Comparison of Previous and Proposed Effluent Limits

Previous Effluent Limits: 

Outfall No. 001

Proposed Effluent Limits: 

Outfall No. 001

Parameter Basis of 

Limit

Average 

Monthly

Average 

Weekly

Average 

Monthly

Average 

Weekly

CBOD5 Technology

25 mg/L

1168 lbs/day

85% removal

40 mg/L

1868 lbs/day

25 mg/L

1168 lbs/day

85% removal

40 mg/L

1868 lbs/day

TSS Technology

30 mg/L

1401 lbs/day

85% removal

45 mg/L

2102 lbs/day

30 mg/L

1401 lbs/day

85% removal

45 mg/L

2102 lbs/day

Parameter

Monthly 

Geometric 

Mean Limit

Weekly 

Geometric 

Mean Limit

Monthly 

Geometric 

Mean Limit

Weekly 

Geometric 

Mean Limit

Fecal Coliform 

Bacteria Technology 200/100 mL 400/100 mL 200/100 mL 400/100 mL

Parameter Limit Limit

pH Technology 6.0-9.0 6.0-9.0

Parameter Average 

Monthly

Maximum 

Daily

Average 

Monthly

Maximum 

Daily

Total Residual 

Chlorine WQ 120 μg/L 312 μg/L 120 μg/L 312 μg/L

IV. Monitoring Requirements

Ecology requires monitoring, recording, and reporting (WAC 173-220-210 and 40 CFR 122.41) 

to verify that the treatment process is functioning correctly and that the discharge complies with 

the permit’s effluent limits.

If a facility uses a contract laboratory to monitor wastewater, it must ensure that the laboratory 

uses the methods and meets or exceeds the method detection levels required by the permit. The 

permit describes when facilities may use alternative methods. It also describes what to do in 

certain situations when the laboratory encounters matrix effects. When a facility uses an 

alternative method as allowed by the permit, it must report the test method, DL, and QL on the 

discharge monitoring report or in the required report.

A. Wastewater monitoring

The monitoring schedule is detailed in the proposed permit under Special Condition S.2. 

Specified monitoring frequencies take into account the quantity and variability of the 

discharge, the treatment method, past compliance, significance of pollutants, and cost of 

monitoring. The required monitoring frequency is consistent with agency guidance given in 

the current version of Ecology’s Permit Writer's Manual (Publication Number 92-09) for 

trickling filter facilities > 2.0 MGD. 
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Ecology has included some additional monitoring of nutrients in the proposed permit to 

establish a baseline for this discharger. It will use this data in the future as it develops 

TMDLs for dissolved oxygen and establishes WLAs for nutrients. 

Monitoring of sludge quantity and quality is necessary to determine the appropriate uses of 

the sludge. Biosolids monitoring is required by the current state and local solid waste 

management program and also by EPA under 40 CFR 503.

B. Lab accreditation

Ecology requires that facilities must use a laboratory registered or accredited under the 

provisions of chapter 173-50 WAC, Accreditation of Environmental Laboratories, to prepare 

all monitoring data (with the exception of certain parameters). Applicable monitoring data 

for Redondo WWTP will be prepared by the laboratory at the District’s Lakota facility. It 

should be noted that the Redondo WWTP staff perform analysis of pH and DO. Ecology 

accredited the laboratory at the Lakota facility for BOD5/CBOD5, chlorine (residual), DO, 

pH, TSS, turbidity, and fecal coliform. The lab accreditation number is M674.

Table 15. Accredited Parameters

General Chemistry

Parameter name Analyte code Method description NELAC code Matrix *

Turbidity 2055 SM 2130 B-01 20048219 N

Solids, Total Suspended 1960 SM 2540 D-97 20051201 N

Chlorine (Residual), Total 1940 SM 4500-Cl G-00 20081612 N

pH 1900 SM 4500-H+ B-00 20105219 N

Dissolved Oxygen 1880 SM 4500-O G-01 20121408 N

Biochemical Oxygen Demand 1530 SM 5210 B-01 20135006 N

Solids, Total, Fixed and Volatile 1725 SM 2540 G-97 WM920420 S

Microbiology

Parameter name Analyte code Method description NELAC code Matrix *

Fecal coliform-count 2530 SM 9222 D (m-FC)-97 20210008 N

* Matrix key: N = non-potable water; S = solids and chemical materials

V. Other Permit Conditions

A. Reporting and record keeping

Ecology based Special Condition S3 on its authority to specify any appropriate reporting and 

record keeping requirements to prevent and control waste discharges (WAC 173-220-210).
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B. Prevention of facility overloading

Overloading of the treatment plant is a violation of the terms and conditions of the permit. 

To prevent this from occurring, RCW 90.48.110 and WAC 173-220-150 require Redondo 

WWTP to:

• Take the actions detailed in proposed permit Special Condition S.4.

• Design and construct expansions or modifications before the treatment plant reaches 

existing capacity.

• Report and correct conditions that could result in new or increased discharges of pollutants. 

Special Condition S.4 restricts the amount of flow.

If a municipality intends to apply for Ecology-administered funding for the design or 

construction of a facility project, the plan must meet the standard of a “Facility Plan”, as defined 

in WAC 173-98-030. A complete “Facility Plan” includes all elements of an “Engineering 

Report” along with State Environmental Review Process (SERP) documentation to demonstrate 

compliance with 40 CFR 35.3140 and 40 CFR 35.3145, and a cost effectiveness analysis as 

required by WAC 173-98-730. The municipality should contact Ecology’s regional office as 

early as practical before planning a project that may include Ecology-administered funding.

C. Operation and maintenance 

The proposed permit contains Special Condition S.5 as authorized under RCW 90.48.110, 

WAC 173-220-150, chapter 173-230 WAC, and WAC 173-240-080. Ecology included it to 

ensure proper operation and regular maintenance of equipment, and to ensure that Redondo 

WWTP takes adequate safeguards so that it uses constructed facilities to their optimum

potential in terms of pollutant capture and treatment. 

Significant portions of the collection system are 35 years old, were constructed using 

techniques such as concrete pipes with oakum packing and/or have numerous manholes,

which were not installed using modern materials. Ecology expects leaks are present in the 

collection system due to its age, materials used, and, construction methods for its installation. 

Therefore, the proposed permit requires the Redondo WWTP to characterize the collection 

system for the presence of leaks by providing the following information: 

• Volume of the annual average and peak daily flow under worst conditions (inflow or 

infiltration) attributed to leaks.

• Location of each individual leaks.

• Size of each leak and/or volume of excess flow contributed by a run of sewer.

• Whether exfiltration occurs in the system’s force mains and/or inverted siphons.

Three good references to aid in these tasks include:

• American Society of Civil Engineers and Water Environment Federation Manual of

Practice FD-6, Existing Sewer Evaluation and Rehabilitation. 

• U.S. Environmental Protection Agency, Handbook for Sewer System Infrastructure 

Analysis and Rehabilitation, EPA/625/6-91/030, 1991.
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• Washington State Department of Transportation, Standard Specifications for Road, 

Bridge, and Municipal Construction, 2002.

Following characterization of the leaks, Ecology may require corrective actions by issuing an 

administrative order following review of the assessment.

D. Pretreatment

Duty to enforce discharge prohibitions

This provision prohibits the publicly owned treatment works (POTW) from authorizing or 

permitting an industrial discharger to discharge certain types of waste into the sanitary sewer. 

• The first section of the pretreatment requirements prohibits the POTW from accepting 

pollutants which causes “pass-through” or “interference.” This general prohibition is 

from 40 CFR §403.5(a). Appendix C of this fact sheet defines these terms.

• The second section reinforces a number of specific state and federal pretreatment 

prohibitions found in WAC 173-216-060 and 40 CFR §403.5(b). These reinforce that the 

POTW may not accept certain wastes, which:

a. Are prohibited due to dangerous waste rules.

b. Are explosive or flammable. 

c. Have too high or low of a pH (too corrosive, acidic or basic). 

d. May cause a blockage such as grease, sand, rocks, or viscous materials. 

e. Are hot enough to cause a problem.

f. Are of sufficient strength or volume to interfere with treatment.

g. Contain too much petroleum-based oils, mineral oil, or cutting fluid. 

h. Create noxious or toxic gases at any point. 

40 CFR Part 403 contains the regulatory basis for these prohibitions, with the exception of 

the pH provisions which are based on WAC 173-216-060.

• The third section of pretreatment conditions reflects state prohibitions on the POTW 

accepting certain types of discharges unless the discharge has received prior written 

authorization from Ecology. These discharges include: 

a. Cooling water in significant volumes. 

b. Stormwater and other direct inflow sources. 

c. Wastewaters significantly affecting system hydraulic loading, which do not require 

treatment.

Federal and state pretreatment program requirements

Ecology administers the Pretreatment Program under the terms of the addendum to the 

“Memorandum of Understanding between Washington Department of Ecology and the United States 

Environmental Protection Agency, Region 10” (1986) and 40 CFR, part 403. Under this delegation 

of authority, Ecology issues wastewater discharge permits for significant industrial users (SIUs) 

discharging to POTWs which have not been delegated authority to issue wastewater discharge 
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permits. Ecology must approve, condition, or deny new discharges or a significant increase in the 

discharge for existing significant industrial users (SIUs) [40 CFR 403.8 (f)(1)(i) and(iii)].

Industrial dischargers must obtain a permit from Ecology before discharging waste to the 

Redondo WWTP [WAC 173-216-110(5)]. Industries discharging wastewater that is similar in 

character to domestic wastewater do not require a permit.

Routine identification and reporting of industrial users

The permit requires non-delegated POTWs to take “continuous, routine measures to identify all 

existing, new, and proposed significant industrial users (SIUs) and potential significant industrial 

users (PSIUs)” discharging to their sewer system. Examples of such routine measures include 

regular review of water and sewer billing records, business license and building permit 

applications, advertisements, and personal reconnaissance. System maintenance personnel 

should be trained on what to look for so they can identify and report new industrial dischargers 

in the course of performing their jobs. The POTW may not allow SIUs to discharge prior to 

receiving a permit, and must notify all industrial dischargers (significant or not) in writing of 

their responsibility to apply for a State Waste Discharge Permit. The POTW must send a copy of 

this notification to Ecology.

E. Solid wastes

To prevent water quality problems the facility is required in permit Special Condition S7 to 

store and handle all residual solids (grit, screenings, scum, sludge, and other solid waste) in 

accordance with the requirements of RCW 90.48.080 and state water quality standards.

The final use and disposal of sewage sludge from this facility is regulated by U.S. EPA under 

40 CFR 503, and by Ecology under chapter 70.95J RCW, chapter 173-308 WAC “Biosolids 

Management,” and chapter 173-350 WAC “Solid Waste Handling Standards.” The disposal 

of other solid waste is under the jurisdiction of the King County Health Department.

Requirements for monitoring sewage sludge and record keeping are included in this permit. 

Ecology will use this information, required under 40 CFR 503, to develop or update local limits. 

F. General conditions

Ecology bases the standardized General Conditions on state and federal law and regulations. 

They are included in all individual domestic wastewater NPDES permits issued by Ecology.

VI. Permit Issuance Procedures

A. Permit modifications

Ecology may modify this permit to impose numerical limits, if necessary to comply with water 

quality standards for surface waters, with sediment quality standards, or with water quality 

standards for groundwaters, based on new information from sources such as inspections, effluent 

monitoring, outfall studies, and effluent mixing studies.

Ecology may also modify this permit to comply with new or amended state or federal regulations.
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B. Proposed permit issuance

This proposed permit meets all statutory requirements for Ecology to authorize a wastewater 

discharge. The permit includes limits and conditions to protect human health and aquatic 

life, and the beneficial uses of waters of the state of Washington. Ecology proposes to issue 

this permit for a term of 5 years.

VII. References for Text and Appendices

Environmental Protection Agency (EPA) 

1992. National Toxics Rule. Federal Register, V. 57, No. 246, Tuesday, December 22, 1992.

1991. Technical Support Document for Water Quality-based Toxics Control. EPA/505/2-90-001.

1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State 

Modeling. USEPA Office of Water, Washington, D.C.

1985. Water Quality Assessment: A Screening Procedure for Toxic and Conventional 

Pollutants in Surface and Ground Water. EPA/600/6-85/002a.

1983. Water Quality Standards Handbook. USEPA Office of Water, Washington, D.C.

Tsivoglou, E.C., and J.R. Wallace. 

1972. Characterization of Stream Reaeration Capacity. EPA-R3-72-012. (Cited in EPA 

1985 op.cit.) 

Washington State Department of Ecology.

December 2011. Permit Writer’s Manual. Publication Number 92-109 

(https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html)

Laws and Regulations (http://www.ecy.wa.gov/laws-rules/index.html)

Permit and Wastewater Related Information 

(http://www.ecy.wa.gov/programs/wq/permits/guidance.html)

Water Pollution Control Federation.

1976. Chlorination of Wastewater.

Wright, R.M., and A.J. McDonnell.

1979. In-stream Deoxygenation Rate Prediction. Journal Environmental Engineering 

Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.) 
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Appendix A -- Public Involvement Information

Ecology proposes to reissue a permit to Redondo WWTP. The permit includes wastewater 

discharge limits and other conditions. This fact sheet describes the facility and Ecology’s 

reasons for requiring permit conditions. 

Ecology placed a Public Notice of Draft on July 22, 2013, in the Seattle Times to inform the 

public and to invite comment on the proposed draft National Pollutant Discharge Elimination 

System permit and fact sheet.

The notice:

• Told where copies of the draft permit and fact sheet were available for public evaluation (a 

local public library, the closest regional or field office, posted on our website).

• Offered to provide the documents in an alternate format to accommodate special needs.

• Asked people to tell us how well the proposed permit would protect the receiving water.

• Invited people to suggest fairer conditions, limits, and requirements for the permit.

• Invited comments on Ecology’s determination of compliance with antidegradation rules.

• Urged people to submit their comments, in writing, before the end of the comment period.

• Told how to request a public hearing about the proposed NPDES permit.

• Explained the next step(s) in the permitting process.

Ecology has published a document entitled Frequently Asked Questions about Effective Public 

Commenting, which is available on our website at 

https://fortress.wa.gov/ecy/publications/SummaryPages/0307023.html. 

You may obtain further information from Ecology by telephone, 425-649-7000 or by writing to 

the address listed below.

Water Quality Permit Coordinator

Department of Ecology

Northwest Regional Office

3190 160th Avenue SE

Bellevue, WA 98008-5452

During the above-noted public comment period, no comments were received.

The primary author of this permit and fact sheet is Kevin Leung.
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Appendix B -- Your Right to Appeal

You have a right to appeal this permit to the Pollution Control Hearing Board (PCHB) within 30 

days of the date of receipt of the final permit. The appeal process is governed by chapter 43.21B 

RCW and chapter 371-08 WAC. “Date of receipt” is defined in RCW 43.21B.001(2) (see 

glossary).

To appeal you must do the following within 30 days of the date of receipt of this permit:

 File your appeal and a copy of this permit with the PCHB (see addresses below). Filing 

means actual receipt by the PCHB during regular business hours.

 Serve a copy of your appeal and this permit on Ecology in paper form - by mail or in person. 

(See addresses below.) E-mail is not accepted.

You must also comply with other applicable requirements in chapter 43.21B RCW and chapter 

371-08 WAC.

ADDRESS AND LOCATION INFORMATION

.Street Addresses Mailing Addresses

Department of Ecology

Attn: Appeals Processing Desk

300 Desmond Drive SE

Lacey, WA 98503

Department of Ecology

Attn: Appeals Processing Desk

PO Box 47608

Olympia, WA 98504-7608

Pollution Control Hearings Board 

1111 Israel RD SW, STE 301

Tumwater, WA 98501

Pollution Control Hearings Board

PO Box 40903

Olympia, WA 98504-0903
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Appendix C -- Glossary

1-DMax or 1-day maximum temperature -- The highest water temperature reached on any 

given day. This measure can be obtained using calibrated maximum/minimum thermometers 

or continuous monitoring probes having sampling intervals of thirty minutes or less. 

7-DADMax or 7-day average of the daily maximum temperatures -- The arithmetic average 

of seven consecutive measures of daily maximum temperatures. The 7-DADMax for any 

individual day is calculated by averaging that day's daily maximum temperature with the 

daily maximum temperatures of the three days prior and the three days after that date.

Acute toxicity --The lethal effect of a compound on an organism that occurs in a short time 

period, usually 48 to 96 hours. 

AKART -- The acronym for “all known, available, and reasonable methods of prevention, 

control and treatment.” AKART is a technology-based approach to limiting pollutants from 

wastewater discharges, which requires an engineering judgment and an economic judgment. 

AKART must be applied to all wastes and contaminants prior to entry into waters of the state 

in accordance with RCW 90.48.010 and 520, WAC 173-200-030(2)(c)(ii), and WAC 173-

216-110(1)(a).

Alternate point of compliance -- An alternative location in the groundwater from the point of 

compliance where compliance with the groundwater standards is measured. It may be 

established in the groundwater at locations some distance from the discharge source, up to, 

but not exceeding the property boundary and is determined on a site specific basis following 

an AKART analysis. An “early warning value” must be used when an alternate point is 

established. An alternate point of compliance must be determined and approved in 

accordance with WAC 173-200-060(2).

Ambient water quality -- The existing environmental condition of the water in a receiving 

water body.

Ammonia -- Ammonia is produced by the breakdown of nitrogenous materials in wastewater. 

Ammonia is toxic to aquatic organisms, exerts an oxygen demand, and contributes to 

eutrophication. It also increases the amount of chlorine needed to disinfect wastewater. 

Annual average design flow (AADF) – The average of the daily flow volumes anticipated to 

occur over a calendar year.

Average monthly (intermittent) discharge limit -- The average of the measured values 

obtained over a calendar months time taking into account zero discharge days. 

Average monthly discharge limit -- The average of the measured values obtained over a 

calendar month's time.

Background water quality -- The concentrations of chemical, physical, biological or radiological 

constituents or other characteristics in or of groundwater at a particular point in time upgradient of 

an activity that has not been affected by that activity [WAC 173-200-020(3)]. Background water 

quality for any parameter is statistically defined as the 95% upper tolerance interval with a 95% 

confidence based on at least eight hydraulically upgradient water quality samples. The eight 

samples are collected over a period of at least one year, with no more than one sample collected 

during any month in a single calendar year.
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Best management practices (BMPs) -- Schedules of activities, prohibitions of practices, 

maintenance procedures, and other physical, structural and/or managerial practices to prevent 

or reduce the pollution of waters of the state. BMPs include treatment systems, operating 

procedures, and practices to control: plant site runoff, spillage or leaks, sludge or waste 

disposal, or drainage from raw material storage. BMPs may be further categorized as 

operational, source control, erosion and sediment control, and treatment BMPs.

BOD5 -- Determining the five-day Biochemical Oxygen Demand of an effluent is an indirect 

way of measuring the quantity of organic material present in an effluent that is utilized by 

bacteria. The BOD5 is used in modeling to measure the reduction of dissolved oxygen in 

receiving waters after effluent is discharged. Stress caused by reduced dissolved oxygen 

levels makes organisms less competitive and less able to sustain their species in the aquatic 

environment. Although BOD5 is not a specific compound, it is defined as a conventional 

pollutant under the federal Clean Water Act.

Bypass -- The intentional diversion of waste streams from any portion of a treatment facility.

Categorical pretreatment standards -- National pretreatment standards specifying quantities or 

concentrations of pollutants or pollutant properties, which may be discharged to a POTW by 

existing or new industrial users in specific industrial subcategories.

Chlorine -- A chemical used to disinfect wastewaters of pathogens harmful to human health. It is 

also extremely toxic to aquatic life. 

Chronic toxicity -- The effect of a compound on an organism over a relatively long time, often 

1/10 of an organism's lifespan or more. Chronic toxicity can measure survival, reproduction 

or growth rates, or other parameters to measure the toxic effects of a compound or 

combination of compounds. 

Clean water act (CWA) -- The federal Water Pollution Control Act enacted by Public Law 

92-500, as amended by Public Laws 95-217, 95-576, 96-483, 97-117; USC 1251 et seq.

Compliance inspection-without sampling -- A site visit for the purpose of determining the 

compliance of a facility with the terms and conditions of its permit or with applicable statutes 

and regulations.

Compliance inspection-with sampling -- A site visit for the purpose of determining the 

compliance of a facility with the terms and conditions of its permit or with applicable statutes 

and regulations. In addition it includes as a minimum, sampling and analysis for all 

parameters with limits in the permit to ascertain compliance with those limits; and, for 

municipal facilities, sampling of influent to ascertain compliance with the 85 percent removal 

requirement. Ecology may conduct additional sampling.

Composite sample -- A mixture of grab samples collected at the same sampling point at 

different times, formed either by continuous sampling or by mixing discrete samples. May 

be "time-composite" (collected at constant time intervals) or "flow-proportional" (collected 

either as a constant sample volume at time intervals proportional to stream flow, or collected 

by increasing the volume of each aliquot as the flow increased while maintaining a constant 

time interval between the aliquots).
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Construction activity -- Clearing, grading, excavation, and any other activity, which disturbs 

the surface of the land. Such activities may include road building; construction of residential 

houses, office buildings, or industrial buildings; and demolition activity.

Continuous monitoring -- Uninterrupted, unless otherwise noted in the permit.

Critical condition -- The time during which the combination of receiving water and waste 

discharge conditions have the highest potential for causing toxicity in the receiving water 

environment. This situation usually occurs when the flow within a water body is low, thus, 

its ability to dilute effluent is reduced.

Date of receipt – This is defined in RCW 43.21B.001(2) as five business days after the date of 

mailing; or the date of actual receipt, when the actual receipt date can be proven by a 

preponderance of the evidence. The recipient's sworn affidavit or declaration indicating the 

date of receipt, which is unchallenged by the agency, constitutes sufficient evidence of actual 

receipt. The date of actual receipt, however, may not exceed forty-five days from the date of 

mailing.

Detection limit – see Method Detection Level.

Dilution factor (DF) -- A measure of the amount of mixing of effluent and receiving water that 

occurs at the boundary of the mixing zone. Expressed as the inverse of the percent effluent 

fraction, for example, a dilution factor of 10 means the effluent comprises 10% by volume 

and the receiving water 90%.

Distribution uniformity -- The uniformity of infiltration (or application in the case of sprinkle 

or trickle irrigation) throughout the field expressed as a percent relating to the average depth 

infiltrated in the lowest one-quarter of the area to the average depth of water infiltrated.

Early warning value -- The concentration of a pollutant set in accordance with WAC 

173-200-070 that is a percentage of an enforcement limit. It may be established in the 

effluent, groundwater, surface water, the vadose zone or within the treatment process. This 

value acts as a trigger to detect and respond to increasing contaminant concentrations prior to 

the degradation of a beneficial use.

Enforcement limit -- The concentration assigned to a contaminant in the groundwater at the 

point of compliance for the purpose of regulation, [WAC 173-200-020(11)]. This limit 

assures that a groundwater criterion will not be exceeded and that background water quality 

will be protected.

Engineering report -- A document that thoroughly examines the engineering and administrative 

aspects of a particular domestic or industrial wastewater facility. The report must contain the 

appropriate information required in WAC 173-240-060 or 173-240-130.

Fecal coliform bacteria -- Fecal coliform bacteria are used as indicators of pathogenic bacteria 

in the effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are 

controlled by disinfecting the wastewater. The presence of high numbers of fecal coliform 

bacteria in a water body can indicate the recent release of untreated wastewater and/or the 

presence of animal feces.

Grab sample -- A single sample or measurement taken at a specific time or over as short a 

period of time as is feasible.
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Groundwater -- Water in a saturated zone or stratum beneath the surface of land or below a 

surface water body.

Industrial user -- A discharger of wastewater to the sanitary sewer that is not sanitary 

wastewater or is not equivalent to sanitary wastewater in character.

Industrial wastewater -- Water or liquid-carried waste from industrial or commercial processes, 

as distinct from domestic wastewater. These wastes may result from any process or activity 

of industry, manufacture, trade or business; from the development of any natural resource; or 

from animal operations such as feed lots, poultry houses, or dairies. The term includes 

contaminated storm water and, also, leachate from solid waste facilities.

Interference -- A discharge which, alone or in conjunction with a discharge or discharges from 

other sources, both:

 Inhibits or disrupts the POTW, its treatment processes or operations, or its sludge 

processes, use or disposal; and

 Therefore is a cause of a violation of any requirement of the POTW's NPDES permit 

(including an increase in the magnitude or duration of a violation) or of the prevention of 

sewage sludge use or disposal in compliance with the following statutory provisions and 

regulations or permits issued thereunder (or more stringent State or local regulations): 

Section 405 of the Clean Water Act, the Solid Waste Disposal Act (SWDA) (including 

title II, more commonly referred to as the Resource Conservation and Recovery Act 

(RCRA), and including State regulations contained in any State sludge management plan 

prepared pursuant to subtitle D of the SWDA), sludge regulations appearing in 40 CFR 

Part 507, the Clean Air Act, the Toxic Substances Control Act, and the Marine 

Protection, Research and Sanctuaries Act.

Local limits -- Specific prohibitions or limits on pollutants or pollutant parameters developed by 

a POTW.

Major facility -- A facility discharging to surface water with an EPA rating score of > 80 points 

based on such factors as flow volume, toxic pollutant potential, and public health impact.

Maximum daily discharge limit -- The highest allowable daily discharge of a pollutant 

measured during a calendar day or any 24-hour period that reasonably represents the calendar 

day for purposes of sampling. The daily discharge is calculated as the average measurement 

of the pollutant over the day. 

Maximum day design flow (MDDF) -- The largest volume of flow anticipated to occur during a 

one-day period, expressed as a daily average.

Maximum month design flow (MMDF) -- The largest volume of flow anticipated to occur 

during a continuous 30-day period, expressed as a daily average.

Maximum week design flow (MWDF) -- The largest volume of flow anticipated to occur 

during a continuous 7-day period, expressed as a daily average.

Method detection level (MDL) -- The minimum concentration of a substance that can be 

measured and reported with 99 percent confidence that the pollutant concentration is above 

zero and is determined from analysis of a sample in a given matrix containing the pollutant.
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Minor facility -- A facility discharging to surface water with an EPA rating score of < 80 points 

based on such factors as flow volume, toxic pollutant potential, and public health impact.

Mixing zone -- An area that surrounds an effluent discharge within which water quality criteria 

may be exceeded. The permit specifies the area of the authorized mixing zone that Ecology 

defines following procedures outlined in state regulations (chapter 173-201A WAC).

National pollutant discharge elimination system (NPDES) -- The NPDES (Section 402 of the 

Clean Water Act) is the federal wastewater permitting system for discharges to navigable 

waters of the United States. Many states, including the state of Washington, have been 

delegated the authority to issue these permits. NPDES permits issued by Washington State 

permit writers are joint NPDES/State permits issued under both state and federal laws.

pH -- The pH of a liquid measures its acidity or alkalinity. It is the negative logarithm of the 

hydrogen ion concentration. A pH of 7 is defined as neutral and large variations above or 

below this value are considered harmful to most aquatic life.

Pass-through -- A discharge which exits the POTW into waters of the State in quantities or 

concentrations which, alone or in conjunction with a discharge or discharges from other 

sources, is a cause of a violation of any requirement of the POTW's NPDES permit 

(including an increase in the magnitude or duration of a violation), or which is a cause of a 

violation of State water quality standards.

Peak hour design flow (PHDF) -- The largest volume of flow anticipated to occur during a 

one-hour period, expressed as a daily or hourly average.

Peak instantaneous design flow (PIDF) -- The maximum anticipated instantaneous flow.

Point of compliance -- The location in the groundwater where the enforcement limit must not be 

exceeded and a facility must comply with the Ground Water Quality Standards. Ecology 

determines this limit on a site-specific basis. Ecology locates the point of compliance in the 

groundwater as near and directly downgradient from the pollutant source as technically, 

hydrogeologically, and geographically feasible, unless it approves an alternative point of 

compliance.

Potential significant industrial user (PSIU) --A potential significant industrial user is defined 

as an Industrial User that does not meet the criteria for a Significant Industrial User, but 

which discharges wastewater meeting one or more of the following criteria:

a. Exceeds 0.5 % of treatment plant design capacity criteria and discharges <25,000 gallons 

per day; or

b. Is a member of a group of similar industrial users which, taken together, have the 

potential to cause pass through or interference at the POTW (e.g. facilities which develop 

photographic film or paper, and car washes).

Ecology may determine that a discharger initially classified as a potential significant 

industrial user should be managed as a significant industrial user.

Quantitation level (QL) -- Also known as Minimum Level of Quantitation (ML) – The lowest 

level at which the entire analytical system must give a recognizable signal and acceptable 

calibration point for the analyte. It is equivalent to the concentration of the lowest calibration 

standard, assuming that the lab has used all method-specified sample weights, volumes, and 
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cleanup procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the 

result to the number nearest to (1, 2, or 5) x 10n, where n is an integer (64 FR 30417). 

ALSO GIVEN AS: 

The smallest detectable concentration of analyte greater than the Detection Limit (DL) where 

the accuracy (precision & bias) achieves the objectives of the intended purpose. (Report of 

the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in 

Clean Water Act Programs Submitted to the US Environmental Protection Agency,

December 2007).

Reasonable potential -- A reasonable potential to cause a water quality violation, or loss of 

sensitive and/or important habitat.

Responsible corporate officer -- A president, secretary, treasurer, or vice-president of the 

corporation in charge of a principal business function, or any other person who performs 

similar policy- or decision-making functions for the corporation, or the manager of one or 

more manufacturing, production, or operating facilities employing more than 250 persons or 

have gross annual sales or expenditures exceeding $25 million (in second quarter 1980 

dollars), if authority to sign documents has been assigned or delegated to the manager in 

accordance with corporate procedures (40 CFR 122.22).

Significant industrial user (SIU) --

1) All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 

40 CFR Chapter I, Subchapter N; and 

2) Any other industrial user that: discharges an average of 25,000 gallons per day or more of 

process wastewater to the POTW (excluding sanitary, noncontact cooling, and boiler 

blow-down wastewater); contributes a process wastestream that makes up 5 percent or 

more of the average dry weather hydraulic or organic capacity of the POTW treatment 

plant; or is designated as such by the Control Authority* on the basis that the industrial 

user has a reasonable potential for adversely affecting the POTW's operation or for 

violating any pretreatment standard or requirement [in accordance with 40 CFR 

403.8(f)(6)].

Upon finding that the industrial user meeting the criteria in paragraph 2, above, has no 

reasonable potential for adversely affecting the POTW's operation or for violating any 

pretreatment standard or requirement, the Control Authority* may at any time, on its own 

initiative or in response to a petition received from an industrial user or POTW, and in 

accordance with 40 CFR 403.8(f)(6), determine that such industrial user is not a significant 

industrial user.

*The term "Control Authority" refers to the Washington State Department of Ecology in the 

case of non-delegated POTWs or to the POTW in the case of delegated POTWs.

Slug discharge -- Any discharge of a non-routine, episodic nature, including but not limited to 

an accidental spill or a non-customary batch discharge to the POTW. This may include any 

pollutant released at a flow rate that may cause interference or pass through with the POTW 

or in any way violate the permit conditions or the POTW’s regulations and local limits.

Soil scientist -- An individual who is registered as a Certified or Registered Professional Soil 

Scientist or as a Certified Professional Soil Specialist by the American Registry of Certified 
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Professionals in Agronomy, Crops, and Soils or by the National Society of Consulting 

Scientists or who has the credentials for membership. Minimum requirements for eligibility 

are: possession of a baccalaureate, masters, or doctorate degree from a U.S. or Canadian 

institution with a minimum of 30 semester hours or 45 quarter hours professional core 

courses in agronomy, crops or soils, and have 5, 3, or 1 year(s), respectively, of professional 

experience working in the area of agronomy, crops, or soils.

Solid waste -- All putrescible and non-putrescible solid and semisolid wastes including, but not 

limited to, garbage, rubbish, ashes, industrial wastes, swill, sewage sludge, demolition and 

construction wastes, abandoned vehicles or parts thereof, contaminated soils and 

contaminated dredged material, and recyclable materials.

Soluble BOD5 -- Determining the soluble fraction of Biochemical Oxygen Demand of an 

effluent is an indirect way of measuring the quantity of soluble organic material present in an 

effluent that is utilized by bacteria. Although the soluble BOD5 test is not specifically 

described in Standard Methods, filtering the raw sample through at least a 1.2 um filter prior 

to running the standard BOD5 test is sufficient to remove the particulate organic fraction.

State waters -- Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, 

and all other surface waters and watercourses within the jurisdiction of the state of 

Washington.

Stormwater -- That portion of precipitation that does not naturally percolate into the ground or 

evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water 

drainage system into a defined surface water body, or a constructed infiltration facility.

Technology-based effluent limit -- A permit limit based on the ability of a treatment method to 

reduce the pollutant.

Total coliform bacteria -- A microbiological test, which detects and enumerates the total 

coliform group of bacteria in water samples.

Total dissolved solids -- That portion of total solids in water or wastewater that passes through a 

specific filter.

Total maximum daily load (TMDL) -- A determination of the amount of pollutant that a water 

body can receive and still meet water quality standards.

Total suspended solids (TSS) -- Total suspended solids is the particulate material in an effluent. 

Large quantities of TSS discharged to a receiving water may result in solids accumulation. 

Apart from any toxic effects attributable to substances leached out by water, suspended solids 

may kill fish, shellfish, and other aquatic organisms by causing abrasive injuries and by 

clogging the gills and respiratory passages of various aquatic fauna. Indirectly, suspended 

solids can screen out light and can promote and maintain the development of noxious 

conditions through oxygen depletion. 

Upset -- An exceptional incident in which there is unintentional and temporary noncompliance 

with technology-based permit effluent limits because of factors beyond the reasonable 

control of the Permittee. An upset does not include noncompliance to the extent caused by 

operational error, improperly designed treatment facilities, lack of preventative maintenance, 

or careless or improper operation.
Fact Sheet for NPDES Permit No.WA0023451

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Water quality-based effluent limit -- A limit imposed on the concentration of an effluent 

parameter to prevent the concentration of that parameter from exceeding its water quality 

criterion after discharge into receiving waters.
Fact Sheet for NPDES Permit No.WA0023451

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Appendix D -- Technical Calculations

Several of the Excel® spreadsheet tools used to evaluate a discharger’s ability to meet 

Washington State water quality standards can be found on Ecology’s homepage at 

http://www.ecy.wa.gov/programs/wq/permits/guidance.html.

Simple Mixing:

Ecology uses simple mixing calculations to assess the impacts of certain conservative pollutants, 

such as the expected increase in fecal coliform bacteria at the edge of the chronic mixing zone 

boundary. Simple mixing uses a mass balance approach to proportionally distribute a pollutant 

load from a discharge into the authorized mixing zone. The approach assumes no decay or 

generation of the pollutant of concern within the mixing zone. The predicted concentration at the 

edge of a mixing zone (MC) is based on the following calculation:

MC = [EC + (AC X DF)]/(1 + DF)

where:

EC = Effluent Concentration

AC = Ambient Concentration

DF = Dilution Factor

Reasonable Potential Analysis:

The spreadsheets in Ecology’s PermitCalc Workbook determine reasonable potential (to violate 

the aquatic life water quality standards) and calculate effluent limits, determine reasonable 

potential and calculate effluent limits for human health pollutants. The process and formulas for 

determining reasonable potential and effluent limits in these spreadsheets are taken directly from 

the Technical Support Document for Water Quality-based Toxics Control, (EPA 505/2-90-001). 

The adjustment for autocorrelation is from EPA (1996a), and EPA (1996b).

Calculation of Water Quality-Based Effluent Limits:

Water quality-based effluent limits are calculated by the two-value wasteload allocation process 

as described on page 100 of the TSD (EPA, 1991) and shown below. 

1. Calculate the acute wasteload allocation WLAa by multiplying the acute criteria by the 

acute dilution factor and subtracting the background factor. Calculate the chronic 

wasteload allocation (WLAc) by multiplying the chronic criteria by the chronic dilution 

factor and subtracting the background factor.

WLAa = (acute criteria x DFa) – [(background conc.x (DFa - 1)]

WLAc = (chronic criteria x DFc) – [(background conc. x (DFc -1)]

where: DFa = Acute Dilution Factor

DFc = Chronic Dilution Factor
Fact Sheet for NPDES Permit No.WA0023451

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2. Calculate the long term averages (LTAa and LTAc) which will comply with the wasteload 

allocations WLAa and WLAc. 

LTAa = WLAa  e

[0.52 - z] where: 2 = ln[CV2 + 1]

z = 2.326

CV = coefficient of variation = std. dev./mean

LTAc = WLAc  e

[0.52 - z] where: 2 = ln[(CV2  4) + 1]

z = 2.326

3. Use the smallest LTA of the LTAa or LTAc to calculate the maximum daily effluent limit 

and the monthly average effluent limit.

Maximum Daily Limit = MDL

MDL= LTAxe

(Z -0.5 )

2  

where: 2 = ln[CV2

+ 1]

z = 2.326 (99th percentile occurrence)

LTA = Limiting long term average

Average Monthly Limit = AML

where: 2 = ln[(CV2  n) + 1]

n = number of samples/month

z = 1.645 (95th % occurrence probability)

LTA = Limiting long term average

AML = LTAxe

(Z -0.5 )

2

 n  n
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Redondo WWTP Process Schematic
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Reasonable Potential Calculations

Dilution Factors: Acute Chronic

Facility 7 9 182

Water Body Type 182

Rec. Water Hardness 182 AMMONIA, Criteria as Total NH3 ARSENIC (dissolved) 7440382 2 MCADMIUM - 7440439 4M Hardness dependent CHLORINE (Total Residual) 7782505 CHROMIUM(HEX) 18540299 COPPER - 744058 6M Hardness dependent LEAD - 7439921 7M Dependent on hardness MERCURY 7439976 8M NICKEL - 7440020 9M - Dependent on hardness SELENIUM 7782492 10M ZINC- 7440666 13M hardness dependent

4 5 5 5 3 0 5 5 3 5 5 5 3

0.55 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

22,400 2.39 0.072 312 0.62 68.7 7.08 0.0851 2.05 0.51 57.4

9900

2 0 0 0 0 0 0 0 0 0 0 0

1 0 0 0 0 0 0

Acute 8,328 6 9 4 2 1 3 1100 4.8 210 1.8 7 4 290 9 0

Chronic 1,251 3 6 9.3 7.5 5 0 3.1 8.1 0.025 8.2 7 1 8 1

- - - - - - - 0.15 4600 4200 -

Acute - 1 0.994 - 0.993 0.83 0.951 0.85 0.99 - 0.946

Chronic - - 0.994 - 0.993 0.83 0.951 - 0.99 - 0.946

N Y N N N N N N N N N

Aquatic Life Reasonable Potential

0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950

s 0.514 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555

Pn 0.936 0.549 0.549 0.905 0.549 0.549 0.368 0.549 0.549 0.549 0.368

1.00 2.32 2.32 1.00 2.32 2.32 3.00 2.32 2.32 2.32 3.00

Acute 303 0.070 0.002 3.949 0.018 1.678 0.256 0.002 0.060 0.015 2.062

Chronic 143 0.031 0.001 1.714 0.008 0.728 0.111 0.001 0.026 0.007 0.895

NO NO NO NO NO NO NO NO NO NO NO

Aquatic Life Limit Calculation

0.55 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

Acute 656374 5451 3318 1027 86900 379.2 16590 142.2 5846 22910 7110

Chronic 224067 6552 1692.6 1365 9100 564.2 1474.2 4.55 1492.4 12922 14742

Acute 226582 1750.2 1065.4 329.75 27902 121.75 5326.8 45.658 1877.1 7356 2282.9

Chronic 124011 3455.7 892.73 719.95 4799.6 297.58 777.54 2.3998 787.14 6815.5 7775.4

124011 1750.2 892.73 329.75 4799.6 121.75 777.54 2.3998 787.14 6815.5 2282.9

1.00 1.00 0.99 1.00 0.99 0.83 0.95 1.00 0.99 1.00 0.95

#DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0!

###### 5451.0 2797.2 1027.0 15053.7 456.9 2546.4 7.5 2476.3 ###### 7515.9

Human Health Reasonable Potential

s 0.514 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545

Pn 0.936 0.549 0.549 0.905 0.549 0.549 0.368 0.549 0.549 0.549 0.368

0.458 0.9336 0.9336 0.4835 0.9336 0.9336 1.2049 0.9336 0.9336 0.9336 1.2049

182 182 182 182 182 182 182 182 182 182 182

64.341 0.0123 0.0004 0.8289 0.0032 3.5E-01 4.7E-02 0.0004 0.0105 0.0026 0.38

n/a n/a n/a n/a n/a n/a n/a NO NO NO n/a

Human Health Limit Calculation

-1810 0 0 0 0 0 0 27.3 837200 764400 0

#DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0!

Comments/Notes:

References: WAC 173-201A,

Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99

Redondo WWTP

Marine

 mg/L

Aquatic Life

Human Health Non-Carcinogenic

Human Health Carcinogenic

WQ Criteria for Protection of 

Human Health, ug/L

Multiplier

Max concentration (ug/L) at edge of...

Reasonable Potential? Limit Required?

Pn=(1-confidence level)1/n

s

2=ln(CV2+1)

Multiplier

Dilution Factor

Maximum Daily Limit (MDL), ug/L

# of Compliance Samples Expected per month

Waste Load Allocations, ug/L

LTA Coeff. Var. (CV), decimal

Permit Limit Coeff. Var. (CV), decimal

s

2=ln(CV2+1)

Pn=(1-confidence level)1/n

Limiting LTA, ug/L

Metal Translator or 1?

Average Monthly Limit (AML), ug/L

Effluent percentile value

Reasonable Potential Calculation

Long Term Averages, ug/L

Effluent Data

# of Samples (n)

Effluent Concentration, ug/L 

(Max. or 95th Percentile)

Pollutant, CAS No. & 

NPDES Application Ref. No.

Aquatic Life Criteria, 

ug/L

Carcinogen?

Water Quality Criteria

Coeff of Variation (Cv)

Calculated 50th percentile 

Effluent Conc. (when n>10)

Receiving Water Data

90th Percentile Conc., ug/L

Geo Mean, ug/L

Metal Criteria 

Translator, decimal

Maximum Daily Effluent Limit, ug/L

Max Conc. at edge of Chronic Zone, ug/L

Reasonable Potential? Limit Required?

# of Compliance Samples Expected per month

Average Monthly Effluent Limit, ug/L
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Calculations for Fecal Coliform

Chronic Dilution Factor 182

Receiving Water Fecal Coliform, #/100 mL 5

Effluent Fecal Coliform - worst case, #/100 mL 400

Surface Water Criteria, #/100 mL 14

Fecal Coliform at Mixing Zone Boundary, #/100 ml 7

Difference between mixed and ambient, #/100 mL 2

Calculation of Fecal Coliform at Chronic Mixing Zone 

Conclusion: At design flow, the discharge has no reasonable potential to 

violate water quality standards for fecal coliform.

INPUT

OUTPUT
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 48 of 73

 

Calculations for Ammonia

1. Receiving Water Temperature, deg C (90th percentile): 12.2

2. Receiving Water pH, (90th percentile): 8.1

3. Receiving Water Salinity, g/kg (10th percentile): 29.1

4. Pressure, atm (EPA criteria assumes 1 atm): 1.0

5. Unionized ammonia criteria (mg un-ionized NH3 per liter) 

from EPA 440/5-88-004:

 Acute: 0.233

 Chronic: 0.035

Using mixed temp and pH at mixing zone boundaries? N o

1. Molal Ionic Strength (not valid if >0.85): 0.597

2. pKa8 at 25 deg C (Whitfield model "B"): 9.314

3. Percent of Total Ammonia Present as Unionized: 2.3%

4. Total Ammonia Criteria (mg/L as N H3):

 Acute: 10.04

 Chronic: 1.51

Total Ammonia Criteria (mg/L as N)

 Acute: 8.26

 Chronic: 1.24

Data source: 

Note: Use total ammonia, not unionized ammonia, in the reasonable potential 

calculation. Criteria is for unionized ammonia but permittees measure total 

ammonia. This spreadsheet calculates the concentration of total ammonia in the 

effluent (as measured by permittee) that will result in the unionized criteria 

concentration in the receiving water.

INPUT

OUTPUT

RESULTS

Calculation of seawater fraction of un-ionized ammonia from Hampson (1977). Unionized ammonia criteria for salt water are from EPA 440/5-88-004. Revised 19-Oct93.

Marine Un-ionized Ammonia Criteria Calculation
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 49 of 73

 

Calculations for Temperature

INPUT Jan-Dec

1. Chronic Dilution Factor at Mixing Zone Boundary 182

2. Annual max 1DADMax Ambient Temperature (Background 90th percentile) 15.3 °C

3. 1DADMax Effluent Temperature (95th percentile) 23.0 °C

4. Aquatic Life Temperature WQ Criterion 13.0 °C

OUTPUT

5. Temperature at Chronic Mixing Zone Boundary: 15.34 °C

6. Incremental Temperature Increase or decrease: 0.04 °C

7. Incremental Temperature Increase 12/(T-2) if T< crit: ---

8. Maximum Allowable Temperature at Mixing Zone Boundary: 15.60 °C

A. If ambient temp is warmer than WQ criterion

9. Does temp fall within this warmer temp range? YES

10. Temp increase allowed at mixing zone boundary, if required: NO LIMIT

B. If ambient temp is cooler than WQ criterion but within 12/(Tamb-2) and 

within 0.3 °C of the criterion 

11. Does temp fall within this incremental temp. range? ---

12. Temp increase allowed at mixing zone boundary, if required: ---

C. If ambient temp is cooler than (WQ criterion-0.3) but within 12/(Tamb-2) of the criterion

13. Does temp fall within this Incremental temp. range? ---

14. Temp increase allowed at mixing zone boundary, if required: ---

D. If ambient temp is cooler than (WQ criterion - 12/(Tamb-2))

15. Does temp fall within this Incremental temp. range? ---

16. Temp increase allowed at mixing zone boundary, if required: ---

RESULTS

17. Do any of the above cells show a temp increase? NO

18. Temperature Limit if Required? NO LIMIT

Marine Temperature Reasonable Potential and Limit Calculation

Based on WAC 173-201A-200(1)(c)(i)--(ii) and Water Quality Program Guidance. All Data inputs must 

meet WQ guidelines. The Water Quality temperature guidance document may be found at: 

http://www.ecy.wa.gov/biblio/0610100.html
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Redondo WWTP Data (2008-2012)

Date

BOD, mg/LBOD, mg/LBOD, ppdBOD, ppdCBOD, mg/LCBOD, mg/LCBOD, ppdCBOD, ppdTSS, mg/LTSS, mg/LTSS, ppdTSS, ppd

Ave Max Ave Max Ave Max Ave Max Ave Max Ave Max

1/1/08 214 260 5712 7117 189 460 5013 12004 207 300 5599 8940

2/1/08 228 250 5621 6870 183 240 4427 5911 225 310 5411 6921

3/1/08 280 360 5661 7479 223 380 4481 7742 258 310 5132 6316

4/1/08 296 440 6323 7992 211 280 4611 5811 255 300 5635 7591

5/1/08 325 370 6052 6888 258 370 4902 7107 322 490 6154 9722

6/1/08 303 340 5802 7089 244 320 4518 6672 278 390 5154 7506

7/1/08 298 340 4947 5777 240 290 4130 5098 313 420 5406 7352

8/1/08 278 310 5091 5749 221 2689 3798 5191 285 350 4887 5934

9/1/08 290 306 4690 5176 235 276 3910 4864 285 384 4755 6767

10/1/08 260 311 4419 5369 220 297 3606 4644 284 373 4649 5838

11/1/08 234 342 5673 6777 185 371 4657 9268 235 344 6169 13599

12/1/08 242 377 5592 7162 183 268 4152 5921 212 280 4804 6568

1/1/09 213 277 7670 14076 131 196 4198 6191 179 314 5995 12555

2/1/09 267 324 5611 6267 205 286 4097 6100 226 268 4507 5592

3/1/09 239 260 5916 6198 175 248 4244 5894 221 354 5512 8765

4/1/09 236 260 5707 6324 163 230 3918 5071 208 254 4982 6444

5/1/09 232 275 5277 5877 172 232 3876 4784 265 374 5968 8457

6/1/09 313 368 5826 7244 243 292 4478 5179 297 392 5490 7003

7/1/09 296 369 5199 6401 207 397 3576 6589 400 576 6928 10037

8/1/09 285 308 4972 5370 248 345 4313 5936 270 310 4704 5414

9/1/09 275 324 4746 5747 213 253 3763 4459 291 393 5143 6892

10/1/09 265 279 4887 5321 207 255 3750 4512 291 388 5341 7624

11/1/09 207 228 6012 6937 134 222 3989 7299 206 375 5973 8100

12/1/09 215 238 5430 5936 182 252 4457 6142 236 361 5809 8357

1/1/10 147 200 4822 5830 101 160 3359 4722 160 210 5547 6956

2/1/10 210 218 5576 5860 158 203 4156 4983 263 518 6878 12186

3/1/10 199 224 5036 5414 144 183 3631 4415 242 330 6157 7801

4/1/10 219 285 5725 6884 151 240 3901 5786 225 311 5810 7467

5/1/10 211 242 4705 5345 167 200 3679 4382 247 320 5440 7283

6/1/10 195 262 5168 5760 141 215 3559 4711 221 288 5638 7017

7/1/10 275 296 5094 5904 191 244 3611 4904 262 303 4922 5975

8/1/10 302 346 5323 6134 231 285 4046 4850 343 478 6002 8316

9/1/10 284 319 4945 5587 218 356 3879 6335 307 800 5508 14245

10/1/10 296 339 5000 5453 212 270 3788 4748 290 402 5236 7031

11/1/10 184 194 4406 4836 148 248 3912 6011 206 246 5492 7378

12/1/10 163 240 5003 6885 116 185 3802 5266 207 319 6797 10634

1/1/11 174 224 5451 6695 118 149 3740 4788 177 236 5507 6815

2/1/11 222 292 5347 6637 155 197 3738 4490 226 285 5494 7062

3/1/11 166 180 5670 7424 114 151 3874 5211 169 230 5836 9607

4/1/11 178 201 5147 5451 119 139 3421 4068 173 215 4973 5907

5/1/11 222 246 5212 5454 181 389 4211 8562 220 518 5096 11408

6/1/11 302 315 5846 6762 196 264 3718 4681 273 356 5183 7378

7/1/11 311 321 5119 5370 218 239 3731 4307 277 332 4720 5609

8/1/11 297 320 4980 5467 216 257 3520 4193 289 368 4723 6130

9/1/11 307 336 4622 5400 225 248 3711 4904 282 347 4639 5993

10/1/11 269 331 4235 5038 219 310 3745 4923 288 367 4941 6972

11/1/11 258 332 5563 7167 201 248 4273 6514 270 591 5861 10763

12/1/11 272 312 5652 6221 194 232 3942 4719 272 555 5490 10697

1/1/12 198 247 5788 6057 132 194 3792 6276 197 369 5608 8773

2/1/12 206 229 6048 8429 128 148 3567 4343 191 248 5398 8060

3/1/12 258 520 7066 11397 136 355 4048 7776 320 983 9900 21545

4/1/12 242 412 5942 9218 136 179 3404 4116 242 493 5947 11036

5/1/12 232 269 4765 5179 162 243 3527 5762 329 608 7171 14411

6/1/12 236 265 4672 5395 166 211 3378 4235 233 310 4737 6875

7/1/12 294 306 5112 5421 225 291 3923 5341 280 406 4878 6855

8/1/12 276 308 4351 5047 233 373 3803 6542 333 ### 5470 19676

9/1/12 293 314 4506 5158 247 307 3853 4999 261 282 4070 4680

10/1/12 266 306 4788 5286 218 298 3736 4534 261 355 4551 5908

11/1/12 189 218 4853 5707 143 184 3730 5838 173 235 4444 6268

12/1/12 146 172 5682 6672 103 124 4071 5711 144 200 5642 7681

AVE: 247 294 5334 6385 184 299 3944 5606 252 386 5497 8445

MIN: 146 172 4235 4836 101 124 3359 4068 144 200 4070 4680

MAX: 325 520 7670 14076 258 2689 5013 12004 400 ### 9900 21545

Influent
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Redondo WWTP Data (2008-2012)

Date Flow, MGD Flow, MGD CBOD, mg/L CBOD, mg/L CBOD, ppd CBOD, ppd CBOD, % Removal TSS, mg/L TSS, mg/L TSS, ppd TSS, ppd TSS, % Removal PHPHFecal Coliform, #/100 ml Fecal Coliform, #/100 ml Ammonia-N mg/L Ammonia-N mg/L TKN-N mg/L TKN-N mg/L NO3+NO2-N, mg/L NO3+NO2-N, mg/L Ortho P, mg/L Ortho P, mg/L Total P, mg/L Total P, mg/L Temperature, C Temperature, C Cl, μg/L Cl, mg/L

Ave

Max 

Day

Mnthly 

Ave

Wkly 

Ave

Mnthly 

Ave

Wkly 

Ave Ave

Mnthly 

Ave

Wkly 

Ave

Mnthly 

Ave

Wkly 

Ave Ave Min Max GEM GM7 Ave Max Ave Max Ave Max Ave Max Ave Max Ave Max Ave Max

1/1/08 3.38 5.51 9 1 1 237 302 9 5 2 1 2 5 589 874 9 0 6.8 7.2 4 9 7 3

2/1/08 3.12 4.82 8 1 0 197 257 9 6 1 4 1 8 350 412 9 4 7.0 7.3 7 0 128

3/1/08 2.64 3.18 1 0 1 1 187 206 9 6 2 0 3 0 375 473 9 2 6.7 7.4 4 0 109

4/1/08 2.68 3.34 9 1 0 205 195 9 6 1 7 1 9 375 388 9 3 6.9 7.3 4 2 6 7

5/1/08 2.31 2.67 9 9 172 181 9 6 2 2 2 6 424 505 9 3 6.7 7.2 3 4 5 5

6/1/08 2.27 2.71 9 1 1 167 196 9 6 2 2 2 4 399 469 9 2 6.4 7.3 3 2 117

7/1/08 2.10 2.35 1 0 1 3 172 232 9 6 2 1 2 4 370 417 9 3 6.3 7.0 9 1 9

8/1/08 2.08 2.48 1 0 1 1 164 188 9 6 2 0 2 2 341 363 9 3 6.4 7.5 2 4 202 1 2 1 2 1 4 1 4 1 1 1 1 4 4 5.2 5.2 2 0 2 1

9/1/08 2.03 2.37 12.2 1 7 203 277 9 5 19.8 2 3 330 367 9 3 7.0 7.6 4 6 290 7.3 7.3 9.9 9.9 8.3 8.3 2.7 2.7 5.5 5.5 2 0 2 1

10/1/08 2.04 2.53 9.7 1 6 160 271 9 5 20.6 2 7 338 427 9 3 6.7 7.5 3 8 6 4 6.1 6.1 1 1 1 1 9.2 9.2 3.7 3.7 5.2 5.2

11/1/08 3.07 7.13 10.6 1 3 304 420 9 4 22.3 3 7 648 1239 9 1 6.6 7.7 7 6 177 1 6 1 6 1 8 1 8 2 0 2 0 3.9 3.9 5.6 5.6

12/1/08 3.07 6.84 1 0 1 2 240 464 9 4 18.1 2 3 438 843 9 1 6.8 7.4 6 0 172 1 2 1 2 1 9 1 9 2 1 2 1 4.5 4.5 5.4 5.4

1/1/09 4.15 9.36 15.1 2 3 590 1124 8 6 25.8 3 2 1046 2279 8 2 6.9 7.6 141 396 1 0 1 0 1 1 1 1 8.2 8.2 2.2 2.2 3.1 3.1

2/1/09 2.44 2.75 9.5 1 0 191 211 9 5 20.4 2 2 411 501 9 1 7.0 7.5 4 7 6 2 7.7 7.7 1 1 1 1 1 2 1 2 3.6 3.6 4.5 4.5

3/1/09 3.06 4.42 9.4 1 2 236 321 9 4 20.2 2 3 513 763 9 0 6.7 7.4 4 2 6 7 1 3 1 3 1 7 1 7 1 2 1 2 4.2 4.2 5.1 5.1 M M

4/1/09 2.99 3.82 7.7 9.1 184 215 9 5 19.2 2 3 465 616 9 1 7.0 7.4 2 8 6 4 1 6 1 6 2 3 2 3 4.1 4.1 3.6 3.6 4.5 4.5 C C

5/1/09 2.70 3.48 7.8 9.5 179 221 9 5 20.9 2 6 475 617 9 2 6.9 7.3 1 7 3 3 5.4 5.4 1 1 1 1 1 7 1 7 3.6 3.6 4.8 4.8 C C

6/1/09 2.25 2.51 7.1 7.8 131 151 9 7 21.3 2 3 396 421 9 3 6.6 7.3 2 2 3 4 3 3 8.4 8.4 1 4 1 4 5 5 5 5 M M

7/1/09 2.10 2.30 7.5 8.7 130 149 9 6 23.5 2 8 406 487 9 4 6.6 7.5 3 6 5 5 9.3 9.3 1 3 1 3 1 5 1 5 5.4 5.4 5.5 5.5 2 1 2 2 M M

8/1/09 2.12 2.47 1 1 1 8 192 298 9 6 16.6 1 2 289 208 9 4 7.0 7.4 101 179 1 1 1 1 1 5 1 5 1 8 1 8 4.4 4.4 5.8 5.8 2 1 2 3 M M

9/1/09 2.17 2.69 9.3 1 2 164 203 9 6 17.2 1 9 305 351 9 4 7.1 7.3 9 2 129 1 4 1 4 2 1 2 1 1 6 1 6 4.5 4.5 5.6 5.6 2 1 2 1 M M

10/1/09 2.29 3.22 9 9.4 165 180 9 6 16.6 1 7 305 346 9 4 7.0 7.4 9 2 290 6.4 6.4 1 2 1 2 1 2 1 2 4.2 4.2 5.1 5.1 C C

11/1/09 3.95 6.66 10.5 1 5 354 662 9 2 20.4 2 4 656 1006 8 9 6.8 7.4 130 397 3.6 3.6 7.4 7.4 2 2 2 2 4.6 4.6 4.9 4.9 M M

12/1/09 3.00 4.09 1 3 1 6 318 347 9 3 24.4 2 8 595 633 9 0 7.0 7.4 8 5 234 7.8 7.8 1 2 1 2 1 4 1 4 3.3 3.3 3.9 3.9 M M

1/1/10 4.36 6.69 9.9 1 2 361 602 8 9 23.8 2 6 867 1349 8 5 6.8 7.4 5 9 9 1 8.4 8.4 1 6 1 6 4.5 4.5 2.5 2.5 3.6 3.6 C C

2/1/10 3.36 4.43 9.4 9.8 249 254 9 4 21.2 2 3 565 604 9 1 7.0 7.3 108 159 1 3 1 3 1 6 1 6 1 0 1 0 3.1 3.1 4.1 4.1 C C

3/1/10 3.21 5.46 8.1 9.7 212 261 9 4 20.2 2 2 535 659 9 1 6.9 7.3 5 1 143 9.9 9.9 1 4 1 4 1 0 1 0 3.2 3.2 3.4 3.4 C C

4/1/10 3.24 4.77 8.9 9.8 235 252 9 4 20.1 2 3 526 578 9 1 7.0 7.4 8 6 197 1 1 1 1 1 3 1 3 1 1 1 1 2.7 2.7 3.2 3.2 c c

5/1/10 2.71 3.52 8.9 9.8 196 210 9 5 21.8 2 3 479 522 9 1 7.0 7.3 5 0 7 1 7 7 9.3 9.3 1 2 1 2 3.1 3.1 3.8 3.8 c c

6/1/10 3.10 4.12 7.9 8.8 207 242 9 4 2 1 2 5 551 744 9 0 6.9 7.2 4 0 6 0 1 3 1 3 1 5 1 5 1 3 1 3 3.8 3.8 4.1 4.1 c c

7/1/10 2.29 2.58 9.4 1 1 177 194 9 5 17.5 2 2 330 411 9 3 6.6 7.2 4 8 8 6 7.4 7.4 1 2 1 2 1 2 1 2 4.1 4.1 4.5 4.5 1 9 2 0 m m

8/1/10 2.12 2.29 11.1 1 2 195 208 9 5 2 0 2 1 350 370 9 4 6.8 7.2 7 3 8 4 1 4 1 4 1 7 1 7 1 3 1 3 4.1 4.1 5.3 5.3 2 1 2 1 M M

9/1/10 2.20 2.82 10.6 1 3 191 233 9 5 15.5 2 0 280 353 9 5 6.8 7.4 136 190 2 0 2 0 2 6 2 6 1 7 1 7 4.4 4.4 4.4 4.4 2 1 2 1 m m

10/1/10 2.30 3.41 11.3 1 3 209 292 9 4 17.6 2 1 327 451 9 4 6.9 7.5 4 8 120 2 0 2 0 2 3 2 3 1 7 1 7 4.9 4.9 4.6 4.6 m m

11/1/10 3.24 4.94 10.6 1 4 278 326 9 3 17.1 2 2 446 531 9 2 6.9 7.2 8 1 135 4.9 4.9 7.7 7.7 1 1 1 1 1.7 1.7 2.3 2.3 m m

12/1/10 4.26 8.43 1 2 1 5 428 768 8 9 21.6 2 7 770 1404 8 9 6.8 7.2 179 443 3.9 3.9 7.5 7.5 1 2 1 2 2.1 2.1 3 3 110 220

1/1/11 4 6.5 10.9 1 3 349 432 9 1 1 7 1 8 550 686 9 0 6.9 7.2 130 230 1 8 1 8 2 4 2 4 1 3 1 3 2.8 2.8 3.7 3.7 m m

2/1/11 3 4.5 9.4 1 1 228 279 9 4 20.3 2 2 497 574 9 1 6.9 7.3 7 9 102 1 3 1 3 1 6 1 6 1 4 1 4 2.8 2.8 3.1 3.1 m m

3/1/11 4.1 6.5 10.6 1 4 378 590 9 1 18.8 2 2 666 954 8 8 6.8 7.3 6 8 117 1 1 1 1 1 3 1 3 1 1 1 1 2.4 2.4 2.8 2.8 m m

4/1/11 3.8 7.1 8.4 9.3 247 328 9 3 17.2 2 0 503 625 9 0 6.5 7.3 2 4 8 3 5.3 5.3 8.6 8.6 8.5 8.5 1.4 1.4 1.9 1.9 m m

5/1/11 3 6.5 8.7 9.5 206 247 9 5 15.4 1 7 361 421 9 2 6.5 7.2 4 1 4 7 6.4 6.4 1 0 1 0 1 4 1 4 3 3 3.4 3.4 m m

6/1/11 2.3 2.6 8.4 9.7 161 194 9 6 22.8 2 8 434 558 9 2 6.6 7.1 1 4 6 9 5.2 5.2 8.4 8.4 1 7 1 7 3.3 3.3 4 4 m m

7/1/11 2.1 2.3 9.1 1 0 155 175 9 6 20.3 2 4 346 406 9 3 6.2 7 1 1 1 6 5.5 5.5 1 1 1 1 1 2 1 2 3.5 3.5 4.4 4.4 1 9 2 0 m m

8/1/11 2 2.2 11.6 1 4 190 218 9 5 21.5 2 2 352 364 9 3 6.6 7.3 1 1 5 9 1 1 1 1 1 7 1 7 1 5 1 5 3.9 3.9 5 5 2 1 2 2 m m

9/1/11 2 2.4 11.3 1 6 188 264 9 5 19.8 2 6 329 433 9 3 6.6 7.3 4 4 126 1 5 1 5 2 1 2 1 2 0 2 0 4.1 4.1 5.2 5.2 2 1 2 1 m m

10/1/11 2.1 2.5 9.3 1 1 159 182 9 6 16.8 2 0 289 331 9 4 6.8 7.2 2 4 236 9 9 1 4 1 4 1 3 1 3 3.7 3.7 4.4 4.4 m m

11/1/11 2.6 5.2 11.3 1 7 280 639 9 4 18.1 2 8 459 1098 9 3 6.8 7.3 1 8 7 3 9.3 9.3 1 3 1 3 1 9 1 9 4.1 4.1 5.1 5.1 m m

12/1/11 2.5 3.8 13.3 1 6 278 427 9 3 2 0 2 5 419 679 9 2 6.6 7.2 3 4 4 1 1 1 1 1 1 5 1 5 1 3 1 3 3.6 3.6 3.9 3.9 m m

1/1/12 3.9 6.9 11.8 1 3 368 507 9 0 20.7 2 5 688 1172 8 8 6.8 7.3 7 0 120 9.4 9.4 1 4 1 4 1 2 1 2 2.5 2.5 3.3 3.3 m m

2/1/12 3.5 5.3 11.1 1 3 320 514 9 1 18.7 2 9 563 1224 9 0 6.9 7.4 7 9 140 7.4 7.4 1 2 1 2 8.1 8.1 1.7 1.7 2.3 2.3 m m

3/1/12 4 6.3 10.7 1 3 358 540 9 1 19.2 3 1 662 1352 9 3 6.7 7.4 8 0 167 9 9 1 3 1 3 9.9 9.9 2.1 2.1 2.9 2.9 m m

4/1/12 3.1 4.6 1 1 1 5 286 463 9 1 15.6 1 9 394 458 9 3 7 7.3 7 6 124 9.9 9.9 1 3 1 3 6.6 6.6 1.9 1.9 2.1 2.1 m m

5/1/12 2.7 3.4 8.1 9.5 177 217 9 5 19.5 2 4 424 524 9 4 6.7 7.3 5 4 230 1 5 1 5 2 0 2 0 1 6 1 6 4.1 4.1 5.7 5.7 m m

6/1/12 2.5 3 7.2 9.4 145 181 9 6 16.3 2 0 329 392 9 3 6.7 7.2 3 1 9 6 1 1 1 1 1 2 1 2 1 3 1 3 3.6 3.6 3.9 3.9 m m

7/1/12 2.1 2.4 1 4 1 6 244 289 9 4 19.4 2 3 337 381 9 3 7 7.5 3 6 4 6 2 3 2 3 2 7 2 7 4.4 4.4 3 3 3.5 3.5 1 9 2 0 m m

8/1/12 2 2.3 14.7 1 7 241 287 9 4 20.6 2 3 337 387 9 3 7.1 7.7 7 5 157 2 7 2 7 3 3 3 3 4.6 4.6 3.4 3.4 4.4 4.4 2 1 2 1 m m

9/1/12 1.9 2.2 13.2 1 7 207 256 9 5 18.3 2 5 284 376 9 3 7.1 7.5 1 9 8 6 3 5 3 5 4 2 4 2 3.4 3.4 4.4 4.4 5.2 5.2 2 1 2 2 m m

10/1/12 2.2 3.9 9.1 1 1 165 272 9 6 14.7 2 0 271 435 9 4 6.9 7.5 9 2 2 2 3 2 3 2 9 2 9 1 1 1 1 3.9 3.9 3.4 3.4 m m

11/1/12 3.5 7.8 1 0 1 2 265 361 9 3 12.6 1 6 323 377 9 3 6.7 7.3 5 6 8 5 1 0 1 0 1 3 1 3 1 1 1 1 2.9 2.9 2.9 2.9 m m

12/1/12 4.6 6.6 10.3 1 3 415 582 9 0 13.1 2 0 526 852 9 1 6.9 7.2 4 2 9 3 4.6 4.6 8.1 8.1 6.3 6.3 1.6 1.6 1.7 1.7 m m

AVE: 2.8 4.2 10.1 12.3 237 326 9 4 19.3 23.3 453 634 9 2 6.8 7.3 5 7 129 11.3 11.3 15.4 15.4 12.2 12.2 3.4 3.4 4.1 4.1 2 0 2 1 110 220

MIN: 1.9 2.2 7.1 7.8 130 149 8 6 12.6 11.8 271 208 8 2 6.2 7.0 9 1 6 3.0 3.0 7.4 7.4 3.4 3.4 1.4 1.4 1.7 1.7 1 9 2 0 110 220

MAX: 4.6 9.4 15.1 22.7 590 1124 9 7 25.8 37.2 1046 2279 9 5 7.1 7.7 179 443 34.6 34.6 42.1 42.1 21.7 21.7 5.4 5.4 5.8 5.8 2 1 2 3 110 220

Effluent
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 52 of 73

 

Redondo WWTP Influent – Flow

Redondo WWTP Effluent – pH

0.0

1.0

2.0

3.0

4.0

5.0

6.0 Jan-08 Apr-08 Jul-08 Oct-08 Jan-09 Apr-09 Jul-09 Oct-09 Jan-10 Apr-10 Jul-10 Oct-10 Jan-11 Apr-11 Jul-11 Oct-11 Jan-12 Apr-12 Jul-12 Oct-12 Influent Flow, MGD

Ave

85% of Max Month Flow

100% of Max Month Flow

5

6

7

8

9

1 0 Dec-07 Feb-08 Apr-08 Jun-08 Aug-08 Oct-08 Dec-08 Feb-09 Apr-09 Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Jan-13 Effluent pH, Std. Units

Min Max

permit range: 6.0 - 9.0
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 53 of 73

 

Redondo WWTP Influent – TSS

0

100

200

300

400

500 Jan-08 Apr-08 Jul-08 Oct-08 Jan-09 Apr-09 Jul-09 Oct-09 Jan-10 Apr-10 Jul-10 Oct-10 Jan-11 Apr-11 Jul-11 Oct-11 Jan-12 Apr-12 Jul-12 Oct-12 Average Influent TSS Concentration, mg/L

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000 Jan-08 Apr-08 Jul-08 Oct-08 Jan-09 Apr-09 Jul-09 Oct-09 Jan-10 Apr-10 Jul-10 Oct-10 Jan-11 Apr-11 Jul-11 Oct-11 Jan-12 Apr-12 Jul-12 Oct-12 Influent TSS, lbs/day

Ave

85% of Design Limit

Design Loading
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 54 of 73

 

Redondo WWTP Influent – BOD

0

100

200

300

400

500 Jan-08 Apr-08 Jul-08 Oct-08 Jan-09 Apr-09 Jul-09 Oct-09 Jan-10 Apr-10 Jul-10 Oct-10 Jan-11 Apr-11 Jul-11 Oct-11 Jan-12 Apr-12 Jul-12 Oct-12 Influent BOD, mg/L

0

2,000

4,000

6,000

8,000

10,000 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Influent BOD, lbs/day

Ave

85% of Design Limit

Design Loading
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 55 of 73

 

Redondo WWTP Effluent – TSS

0

5

10

15

20

25

30

35

40

45

50 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Effluent TSS, mg/L

Mnthly Ave

Wkly Ave

Monthly Ave permit limit

Weekly Ave permit limit

0

500

1000

1500

2000

2500 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Effluent TSS, lbs/day

Mnthly Ave

Wkly Ave

Monthly Ave permit limit

Weekly Ave permit limit
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 56 of 73

 

Redondo WWTP Effluent – CBOD5

0

5

10

15

20

25

30

35

40

45 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Effluent CBOD5, mg/L

Mnthly Ave

Wkly Ave

Monthly Ave permit limit

Weekly Ave permit limit

0

500

1000

1500

2000

2500 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Effluent CBOD5, lbs/day

Mnthly Ave

Wkly Ave

Monthly Ave permit limit

Weekly Ave permit limit

Permitted Monthly Ave Max = 1868 

lb/day
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 57 of 73

 

Redondo WWTP Effluent – Fecal Coliform

0

100

200

300

400

500

600 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Effluent Fecal Coliform, #/100 mL

GEM

GM7

GEM permit limit

GM7 permit limit
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 58 of 73

 

Redondo WWTP Effluent – Priority Pollutants

flow mgd 2.172 2.013 2.741 max avg count

11/2/09 11/7/11 11/5/12 ML/MDL units

CYANIDE < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 3 0.005 mg/L

< 0.091 < 0.084 < 0.114 < 0.114 < 0.096

TOTAL PHENOLIC COMPOUNDS < 0.04 < 0.04 < 0.04 < 0.04 < 0.04 3 0.04 mg/L

< 0.725 < 0.672 < 0.914 < 0.914 < 0.770

HARDNESS (AS CaCO3) 0

CYANIDE WEAK ACID DISSOCIABLE < 0.005 0.0062 < 0.005 0.0062 0.0054 3 0.005 mg/L

< 0.091 0.104 < 0.114 < 0.114 0.103

ACROLEIN < 5 < 5 < 5 < 5 < 5 3 5 ug/L

< 0.091 < 0.084 < 0.114 < 0.114 < 0.096

ACRYLONITRILE < 5 < 1 < 1 < 5 < 2 3 5/1 ug/L

0.091 0.017 0.023 < 0.091 < 0.043

BENZENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

BROMOFORM < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

CARBON TETRACHLORIDE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

CHLORBENZENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

CHLOROBIDBROMOMETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

CHLOROETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

2-CHLOROETHYLVINYL ETHER < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

CHOLOROFORM < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

DICHLOROBROMOMETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,1-DICHLOROETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,2-DICHLOROETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,2-DICHLOROETHYLENE 0

TRANS-1,2-DICHLORO-ETHYLENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,1-DICHLOROETHYLENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,2-DICHLOROPROPANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,3-DICHLOROPROPYLENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

ETHYLBENZENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

METHYL BROMIDE < 5 < 5 < 5 < 5 < 5 3 5 ug/L

< 0.091 < 0.084 < 0.114 < 0.114 < 0.096

METHYL CHLORIDE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

METHYLENE CHLORIDE < 5 < 5 < 5 < 5 < 5 3 5 ug/L

< 0.091 < 0.084 < 0.114 < 0.114 < 0.096

1,1,2,2-TETRACHLOROETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

TETRACHLOROETHYLENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

TOLUENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,1,1-TRICHLOROETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

420.1

624

624

ANALYTICAL 

METHOD

sm4500-cn-c,e

624

624

624

624

624

624

624

624

624

sm4500-cn-i,e

624

624

624

624

624

624

624

624

624

624

624

624

624

624
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 59 of 73

 

Redondo WWTP Effluent – Priority Pollutants (Continued)

flow mgd 2.172 2.013 2.741 max avg count

11/2/09 11/7/11 11/5/12 ML/MDL units

1,1,2-TRICHLOROETHANE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

TRICHLORETHYLENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

VINYL CHLORIDE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

P-CHLORO-M-CRESOL < 0.95 < 0.94 < 0.48 < 0.95 < 0.79 3 0.95/0.94/0.48 ug/L

< 0.017 < 0.016 < 0.011 < 0.017 < 0.015

2-CHLOROPHENOL < 0.95 < 0.94 < 0.48 < 0.95 < 0.79 3 0.95/0.94/0.48 ug/L

< 0.017 < 0.016 < 0.011 < 0.017 < 0.015

2,4-DICHLOROPHENOL < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

2,4-DIMETHYLPHENOL < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

4,6-DINITRO-O-CRESOL < 0.95 < 0.94 < 0.48 < 0.95 < 0.79 3 0.95/0.94/0.48 ug/L

< 0.017 < 0.016 < 0.011 < 0.017 < 0.015

2,4-DINITROPHENOL < 0.95 < 0.94 < 0.48 < 0.95 < 0.79 3 0.95/0.94/0.48 ug/L

< 0.017 < 0.016 < 0.011 < 0.017 < 0.015

2-NITROPHENOL < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

4-NITROPHENOL < 0.95 < 0.94 < 0.48 < 0.95 < 0.79 3 0.95/0.94/0.48 ug/L

< 0.017 < 0.016 < 0.011 < 0.017 < 0.015

PENTACHLOROPHENOL < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

PHENOL < 1.9 < 1.9 < 0.95 < 1.90 < 1.58 3 1.9/0.95 ug/L

< 0.034 < 0.032 < 0.022 < 0.034 < 0.029

2,4,6-TRICHLOROPHENOL < 1.9 < 1.9 < 0.95 < 1.9 < 1.58 3 1.9/0.95 ug/L

< 0.034 < 0.032 < 0.022 < 0.034 < 0.029

ACENAPHTHENE < 0.19 < 0.19 < 0.1 < 0.19 < 0.16 3 0.19/0.1 ug/L

< 0.0034 < 0.0032 < 0.0023 < 0.003 < 0.003

ACENAPHTYLENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.0053 < 0.0047 < 0.0032 < 0.005 < 0.004

ANTHRACENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.0053 < 0.0047 < 0.0032 < 0.005 < 0.004

BENZIDINE < 11 < 11 < 5.7 < 11 < 9.23 3 11/5.7 ug/L

< 0.199 < 0.185 < 0.130 < 0.199 < 0.171

BENZO(A) ANTHRACENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.0053 < 0.0047 < 0.0032 < 0.005 < 0.004

BENZO(J)FLUORANTHENE 0

BENZO(r,s.t)PENTAPHENE 0

BENZO(A)PYRENE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

3.4 BENZO-FLUORANTHENE < 0.76 < 0.75 < 0.38 < 0.76 < 0.63 3 0.76/0.75/0.38 ug/L

< 0.014 < 0.013 < 0.009 < 0.014 < 0.012

BENZO(GHI)PERYLENE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

BENZO(K)FLOURANTHENE < 0.76 < 0.75 < 0.38 < 0.76 < 0.63 3 0.76/0.75/0.38 ug/L

< 0.014 < 0.013 < 0.009 < 0.014 < 0.012

BIS (2-CHLOROETHOXY) METHANE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

BIS (2-CHLOROETHYL)-ETHER < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

BIS (2-CHLOROISOPROPYL) ETHER < 0.95 < 0.94 < 0.48 < 0.95 < 0.79 3 0.95/0.94/0.48 ug/L

< 0.017 < 0.016 < 0.011 < 0.017 < 0.015

BIS (2-ETHYLHEXYL) PHTHALATE 2.23 2.71 3.69 3.69 2.88 3 0.29/0.28/0.14 ug/L

0.040 0.045 0.084 0.084 0.057

4-BROMOPHENYL PHENYL ETHER < 0.19 < 0.19 < 0.1 < 0.19 < 0.16 3 0.19/0.1 ug/L

< 0.003 < 0.003 < 0.002 < 0.003 < 0.003

625

625

625

625

625

625

624

624

624

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METHOD

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Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 60 of 73

 

Redondo WWTP Effluent – Priority Pollutants (Continued)

flow mgd 2.172 2.013 2.741 max avg count

11/2/09 11/7/11 11/5/12 ML/MDL units

BUTYL BENZYL PHTHALATE 0.76 < 0.28 < 0.14 0.76 0.39 3 0.29/0.28/0.14 ug/L

0.014 0.005 0.003 0.014 0.007

2-CHLORONAPHTHALENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

4-CHLORPHENYL PHENYL ETHER < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

CHRYSENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

DIBENZO(a,j)ACRIDINE 0

DIBENZO(a,h)ACRIDINE 0

DI-N-BUTYL PHTHALATE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

DI-N-OCTYL PHTHALATE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

DIBENZO(A,H) ANTHRACENE < 0.76 < 0.75 < 0.38 < 0.76 < 0.63 3 0.76/0.75/0.38 ug/L

< 0.014 < 0.013 < 0.009 < 0.014 < 0.012

1,2-DICHLOROBENZENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,3-DICHLOROBENZENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

1,4-DICHLOROBENZENE < 1 < 1 < 1 < 1 < 1 3 1 ug/L

< 0.018 < 0.017 < 0.023 < 0.023 < 0.019

3,3-DICHLOROBENZIDINE < 0.48 < 0.48 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

DIETHYL PHTHALATE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

DIMETHYL PHTHALATE < 0.19 < 0.19 < 0.1 < 0.19 < 0.16 3 0.19/0.1 ug/L

< 0.003 < 0.003 < 0.002 < 0.003 < 0.003

2,4-DINITROTOLUENE < 0.19 < 0.19 < 0.1 < 0.19 < 0.16 3 0.19/0.1 ug/L

< 0.003 < 0.003 < 0.002 < 0.003 < 0.003

2,6-DINITROTOLUENE < 0.19 < 0.19 < 0.1 < 0.19 < 0.16 3 0.19/0.1 ug/L

< 0.003 < 0.003 < 0.002 < 0.003 < 0.003

1,2-DIPHENYLHYDRAZINE < 0.95 < 0.94 < 0.48 < 0.95 < 0.79 3 0.95/0.94/0.48 ug/L

< 0.017 < 0.016 < 0.011 < 0.017 < 0.015

FLUORANTHENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

FLUORENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

HEXACHLOROBENZENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

HEXACHLOROBUTADIENE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

HEXACHLOROCYCLOPENTADIENE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

HEXACHLOROETHANE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

INDENO(1,2,3-CD) PYRENE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

ISOPHORONE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

3-METHYL CHOLANTHRENE 0

NAPHTHALENE < 0.76 < 0.75 < 0.38 < 0.76 < 0.63 3 0.76/0.75/0.38 ug/L

< 0.014 < 0.013 < 0.009 < 0.014 < 0.012

NITROBENZENE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

N-NITROSODI-N-PROPYLAMINE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

625

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METHOD

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Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 61 of 73

 

Redondo WWTP Effluent – Priority Pollutants (Continued)

flow mgd 2.172 2.013 2.741 max avg count

11/2/09 11/7/11 11/5/12 ML/MDL units

N-NITROSODIMETHYLAMINE < 1.9 < 1.9 < 0.24 < 1.9 < 1.35 3 1.9/0.24 ug/L

< 0.034 < 0.032 < 0.005 < 0.034 < 0.024

N-NITROSODIPHENYLAMINE < 0.48 < 0.47 < 0.24 < 0.48 < 0.40 3 0.48/0.47/0.24 ug/L

< 0.009 < 0.008 < 0.005 < 0.009 < 0.007

PERYLENE 0

PHENANTHRENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

PYRENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

1,2,4-TRICHLOROBENZENE < 0.29 < 0.28 < 0.14 < 0.29 < 0.24 3 0.29/0.28/0.14 ug/L

< 0.005 < 0.005 < 0.003 < 0.005 < 0.004

Aldrin < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

alpha-BHC < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

beta-BHC < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

gamma-BHC < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

delta-BHC < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Chlordane < 0.12 < 0.12 < 0.02 < 0.12 < 0.09 3 0.12/0.02 ug/L

< 0.002 < 0.002 < 0.000 < 0.0022 < 0.0015

4,4’-DDD < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

4,4’-DDE < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

4,4’ DDT < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Dieldrin < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.0004 < 0.0004 < 0.0005 < 0.0005 < 0.0004

alpha-Endosulfan < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.0004 < 0.0004 < 0.0005 < 0.0005 < 0.0004

beta-Endosulfan < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Endosulfan Sulfate < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Endrin < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Endrin Aldehyde < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Heptachlor < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Heptachlor Epoxide < 0.024 < 0.024 < 0.02 < 0.024 < 0.023 3 0.024/0.02 ug/L

< 0.000 < 0.000 < 0.000 < 0.0005 < 0.0004

Toxaphene < 0.24 < 0.24 < 0.38 < 0.38 < 0.29 3 0.24/0.38 ug/L

< 0.004 < 0.004 < 0.009 < 0.009 < 0.006

PCB-1016 < 0.24 < 0.24 < 0.09 < 0.24 < 0.19 3 0.24/0.09 ug/L

< 0.004 < 0.004 < 0.002 < 0.004 < 0.003

PCB-1221 < 0.24 < 0.24 < 0.09 < 0.24 < 0.19 3 0.24/0.09 ug/L

< 0.004 < 0.004 < 0.002 < 0.004 < 0.003

PCB-1232 < 0.24 < 0.24 < 0.09 < 0.24 < 0.19 3 0.24/0.09 ug/L

< 0.004 < 0.004 < 0.002 < 0.004 < 0.003

PCB-1242 < 0.24 < 0.24 < 0.09 < 0.24 < 0.19 3 0.24/0.09 ug/L

< 0.004 < 0.004 < 0.002 < 0.004 < 0.003

PCB-1248 < 0.24 < 0.24 < 0.09 < 0.24 < 0.19 3 0.24/0.09 ug/L

< 0.004 < 0.004 < 0.002 < 0.004 < 0.003

PCB-1254 < 0.24 < 0.24 < 0.09 < 0.24 < 0.19 3 0.24/0.09 ug/L

< 0.004 < 0.004 < 0.002 < 0.004 < 0.003

PCB-1260 < 0.24 < 0.24 < 0.09 < 0.24 < 0.19 3 0.24/0.09 ug/L

< 0.004 < 0.004 < 0.002 < 0.004 < 0.003

625

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METHOD

608

608

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608

608

608

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608

608

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Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 62 of 73

 

Redondo WWTP Effluent – Metals

11/3/08 11/2/09 11/1/10 11/8/10 11/7/11 11/5/12 max avg count MDL units

ANALYTICAL 

METHOD

flow (mgd) 2.377 2.172 4.944 3.428 2.013 2.741

ANTIMONY < 0.3 < 0.3 < 0.3 < 0.3 < 0.3 3 0.3 ug/L 200.8

lbs < 0.0054 < 0.0050 < 0.0069 < 0.0069 < 0.0058 3

ARSENIC 1.51 2.39 1.53 1.43 1.2 2.39 1.61 5 0.1 ug/L 200.8

lbs 0.030 0.043 0.063 0.024 0.027 0.063 0.038 5

BERYLLIUM < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 3 0.1 ug/L 200.8

lbs < 0.0018 < 0.0017 < 0.0023 < 0.0023 < 0.0019 3

CADMIUM 0.072 < 0.05 < 0.05 < 0.05 < 0.05 0.072 0.05 5 0.05 ug/L 200.8

lbs 0.0014 < 0.0009 < 0.0021 < 0.0008 < 0.0011 < 0.0021 0.0013 5

CHROMIUM 0.6 0.53 0.62 0.42 0.46 0.62 0.53 5 0.2 ug/L 200.8

lbs 0.0119 0.0096 0.0256 0.0071 0.0105 0.0256 0.0129 5

COPPER 68.7 33.8 33.9 39.5 34.8 68.7 42.1 5 0.4 ug/L 200.8

lbs 1.362 0.612 1.398 0.663 0.796 1.40 0.966 5

LEAD 0.888 0.49 0.54 7.08 0.564 7.08 1.91 5 0.075/0.1 ug/L 200.8

lbs 0.018 0.009 0.022 0.119 0.013 0.119 0.036 5

MERCURY 26.2 16.9 85.1 17.7 11.1 85.1 31.4 5 0.15/0.25/0.3 ng/L 1631

lbs 0.0005 0.0003 0.0024 0.0003 0.0003 0.0024 0.0008 5

NICKEL 2.05 1.53 1.32 1.67 1.44 2.05 1.60 5 0.1 ug/L 200.8

lbs 0.041 0.028 0.054 0.028 0.033 0.054 0.037 5

SELENIUM 0.51 < 0.5 < 0.5 0.51 0.50 3 0.5 ug/L 200.8

lbs 0.009 < 0.008 < 0.011 < 0.011 0.010 3

SILVER < 0.05 < 0.04 < 0.04 < 0.05 < 0.04 3 0.05/0.04 ug/L 200.8

lbs < 0.0009 < 0.0007 < 0.0009 < 0.0009 < 0.0008 3

THALLIUM < 0.04 < 0.04 < 0.04 < 0.04 < 0.04 3 0.04 ug/L 200.8

lbs < 0.0007 < 0.0007 < 0.0009 < 0.0009 < 0.0008 3

ZINC 57.4 50.7 46.6 55 45.3 57.4 51.0 5 0.5 ug/L 200.8

lbs 1.138 0.918 1.921 0.923 1.036 1.92 1.19 5
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 63 of 73

 

Redondo WWTP Effluent - Nutrient Data

DATE N02-NO3 N02-NO3 NH3-N NH3-N TKN TKN OP OP TP TP

mg/L LBS mg/L LBS mg/L LBS mg/L LBS mg/L LBS

max 21.7 544 34.6 546 42.1 696 5.41 110 5.81 160

average 12.3 275 11.3 255 15.4 352 3.41 76 4.08 92

min 3.4 53 3.0 60 7.4 133 1.4 54 1.9 62

count 45 45 45 45 45 45 45 45 45 45

50th percentile 12.3 280 9.9 253 13.4 339 3.6 73 4.1 89

90th percentile 17.3 353 19.0 419 23.8 547 4.5 96 5.3 111

95th percentile 18.7 394 22.4 446 26.9 610 4.9 99 5.6 126

S.D. 4.3 90 6.2 117 6.9 140 1.0 13 1.0 19

GEOMEAN 11.3 255 9.9 226 14.2 326 3.3 75 3.9 90

C.V. 0.35 0.33 0.55 0.46 0.45 0.40 0.28 0.18 0.25 0.21

data from July 2008 to September 2012

EFFLUENT
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 64 of 73

 

Redondo WWTP Effluent - Acute NOEC

Test Code Collected Start Date Organism Endpoint NOECLOEC PMSD

RMAR0072 2/23/1989 Daphnia magna 48-hour Survival 100 > 100

RMAR0071 2/23/1989 fathead minnow 48-hour Survival 100 > 100

RMAR0075 5/16/1989 Daphnia pulex 48-hour Survival 100 > 100

RMAR0074 5/16/1989 fathead minnow 48-hour Survival 100 > 100

RMAR0073 5/16/1989 rainbow trout 96-hour Survival 65 100

RMAR0076 8/14/1989 rainbow trout 96-hour Survival 100 > 100

RMAR0078 8/19/1989 Daphnia pulex 48-hour Survival 100 > 100

RMAR0077 8/19/1989 fathead minnow 48-hour Survival < 100 100 32.9%

RMAR0079 8/21/1989 fathead minnow 48-hour Survival 65 100

RMAR0080 12/13/1989 12/13/1989 fathead minnow 48-hour Survival 100 > 100

RMAR0082 3/7/1990 3/7/1990 fathead minnow 48-hour Survival 100 > 100

RMAR0083 6/13/1990 6/13/1990 fathead minnow 48-hour Survival 100 > 100 4.9%

RMAR0084 9/19/1990 9/19/1990 fathead minnow 48-hour Survival 100 > 100

RMAR0085 12/28/1990 12/28/1990 fathead minnow 48-hour Survival 100 > 100

RMAR0086 3/26/1991 3/27/1991 fathead minnow 48-hour Survival 100 > 100

RMAR0087 6/19/1991 6/19/1991 fathead minnow 48-hour Survival 100 > 100

RMAR0088 9/25/1991 9/25/1991 fathead minnow 48-hour Survival 100 > 100

RMAR0089 12/13/1991 12/16/1991 fathead minnow 48-hour Survival 100 > 100

RMAR0090 1/23/1992 1/24/1992 fathead minnow 48-hour Survival 100 > 100 2.5%

RMAR0091 6/3/1992 6/4/1992 fathead minnow 48-hour Survival 100 > 100

RMAR0092 8/5/1992 8/5/1992 fathead minnow 48-hour Survival 100 > 100 7.4%

RMAR0093 12/8/1992 12/10/1992 fathead minnow 48-hour Survival 100 > 100

aSSIN362 3/10/1993 3/11/1993 fathead minnow 48-hour Survival 100 > 100

KJOH455 5/12/1993 5/12/1993 fathead minnow 48-hour Survival 100 > 100 4.9%

RMAR0081 9/30/1993 10/1/1993 fathead minnow 48-hour Survival 100 > 100

KJOH454 12/6/1993 12/8/1993 fathead minnow 48-hour Survival 100 > 100

KJOH722 3/1/1994 3/3/1994 fathead minnow 48-hour Survival 100 > 100 13.6%

RMAR0094 3/2/1994 3/3/1994 fathead minnow 48-hour Survival 100 > 100 13.6%

AQTX0050 6/2/1994 6/8/1994 fathead minnow 48-hour Survival 100 > 100 4.9%

RMAR0095 9/21/1994 9/22/1994 fathead minnow 48-hour Survival 100 > 100

AQTX0110 12/14/1994 12/15/1994 fathead minnow 48-hour Survival < 100 100

AQTX0229 2/7/1995 2/8/1995 fathead minnow 48-hour Survival 100 > 100

AQTX0387 5/22/1995 5/24/1995 fathead minnow 48-hour Survival 100 > 100 10.9%

RMAR0096 5/23/1995 5/24/1995 fathead minnow 48-hour Survival 100 > 100 10.9%

AQTX0648 8/7/1995 8/9/1995 fathead minnow 96-hour Survival < 100 100 13.8%

AQTX0649 8/7/1995 8/10/1995 fathead minnow 96-hour Survival 50 100 10.8%

AQTX0652 8/17/1995 8/18/1995 fathead minnow 96-hour Survival < 100 100 14.3%

AQTX0700 11/14/1995 11/15/1995 fathead minnow 96-hour Survival < 100 100 11.8%

AQTX0701 11/29/1995 11/29/1995 fathead minnow 96-hour Survival 100 > 100

AQTX0842 6/14/1996 5/15/1996 fathead minnow 96-hour Survival 100 > 100 8.0%

AQTX0971 7/23/1996 7/23/1996 fathead minnow 96-hour Survival 100 > 100

AQTX1245 12/11/1996 12/13/1996 fathead minnow 96-hour Survival 100 > 100

AQTX1278 3/17/1997 3/18/1997 fathead minnow 96-hour Survival 100 > 100

AQTX1383 6/19/1997 6/20/1997 fathead minnow 96-hour Survival 100 > 100 2.5%

AQTX1636 9/16/1997 9/16/1997 fathead minnow 96-hour Survival 100 > 100 10.2%

AQTX1649 12/9/1997 12/9/1997 fathead minnow 96-hour Survival 100 > 100

AQTX002670 4/2/2001 4/3/2001 Daphnia pulex 48-hour Survival 100 > 100

AQTX002669 4/2/2001 4/3/2001 fathead minnow 96-hour Survival 100 > 100

AQTX002674 10/8/2001 10/9/2001 Daphnia pulex 48-hour Survival 100 > 100

AQTX002673 10/26/2001 10/26/2001 fathead minnow 96-hour Survival 100 > 100

RMAR0851 1/8/2007 1/9/2007 fathead minnow 96-hour Survival 100 > 100 8.4%

RMAR0849 1/8/2007 1/9/2007 Ceriodaphnia dubia 48-hour Survival 100 > 100 5.0%

RMAR0935 7/9/2007 7/9/2007 Ceriodaphnia dubia 48-hour Survival 100 > 100 5.0%

RMAR0936 7/9/2007 7/10/2007 fathead minnow 96-hour Survival 100 > 100 15.6%

RMAR2470 1/25/2012 1/25/2012 Ceriodaphnia dubia 48-hour Survival 100 > 100 36.6%

RMAR2469 1/25/2012 1/25/2012 fathead minnow 96-hour Survival 100 > 100 2.5%

RMAR2565 7/11/2012 7/11/2012 fathead minnow 96-hour Survival 50 100 6.2%

RMAR2566 7/11/2012 7/11/2012 Ceriodaphnia dubia 48-hour Survival 50 100 23.1%

Redondo WWTP Acute WET Test Results as NOEC/LOEC in % Effluent
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

Page 65 of 73

 

Redondo WWTP Effluent - Acute %Survival

Test Code Collected Start Date Organism Endpoint % Survival

RMAR0072 2/23/1989 Daphnia magna 48-hour Survival 100%

RMAR0071 2/23/1989 fathead minnow 48-hour Survival 100%

RMAR0075 5/16/1989 Daphnia pulex 48-hour Survival 100%

RMAR0074 5/16/1989 fathead minnow 48-hour Survival 100%

RMAR0073 5/16/1989 rainbow trout 96-hour Survival 100%

RMAR0076 8/14/1989 rainbow trout 96-hour Survival 100%

RMAR0078 8/19/1989 Daphnia pulex 48-hour Survival 100%

RMAR0077 8/19/1989 fathead minnow 48-hour Survival 60%

RMAR0079 8/21/1989 fathead minnow 48-hour Survival 60%

RMAR0080 12/13/1989 12/13/1989 fathead minnow 48-hour Survival 100%

RMAR0082 3/7/1990 3/7/1990 fathead minnow 48-hour Survival 100%

RMAR0083 6/13/1990 6/13/1990 fathead minnow 48-hour Survival 97%

RMAR0084 9/19/1990 9/19/1990 fathead minnow 48-hour Survival 100%

RMAR0085 12/28/1990 12/28/1990 fathead minnow 48-hour Survival 100%

RMAR0086 3/26/1991 3/27/1991 fathead minnow 48-hour Survival 100%

RMAR0087 6/19/1991 6/19/1991 fathead minnow 48-hour Survival 100%

RMAR0088 9/25/1991 9/25/1991 fathead minnow 48-hour Survival 100%

RMAR0089 12/13/1991 12/16/1991 fathead minnow 48-hour Survival 100%

RMAR0090 1/23/1992 1/24/1992 fathead minnow 48-hour Survival 100%

RMAR0091 6/3/1992 6/4/1992 fathead minnow 48-hour Survival 100%

RMAR0092 8/5/1992 8/5/1992 fathead minnow 48-hour Survival 100%

RMAR0093 12/8/1992 12/10/1992 fathead minnow 48-hour Survival 100%

aSSIN362 3/10/1993 3/11/1993 fathead minnow 48-hour Survival 100%

KJOH455 5/12/1993 5/12/1993 fathead minnow 48-hour Survival 97%

RMAR0081 9/30/1993 10/1/1993 fathead minnow 48-hour Survival 100%

KJOH454 12/6/1993 12/8/1993 fathead minnow 48-hour Survival 100%

KJOH722 3/1/1994 3/3/1994 fathead minnow 48-hour Survival 90%

RMAR0094 3/2/1994 3/3/1994 fathead minnow 48-hour Survival 90%

AQTX0050 6/2/1994 6/8/1994 fathead minnow 48-hour Survival 97%

RMAR0095 9/21/1994 9/22/1994 fathead minnow 48-hour Survival 100%

AQTX0110 12/14/1994 12/15/1994 fathead minnow 48-hour Survival 90%

AQTX0229 2/7/1995 2/8/1995 fathead minnow 48-hour Survival 100%

AQTX0387 5/22/1995 5/24/1995 fathead minnow 48-hour Survival 93%

RMAR0096 5/23/1995 5/24/1995 fathead minnow 48-hour Survival 93%

AQTX0648 8/7/1995 8/9/1995 fathead minnow 96-hour Survival 10%

AQTX0649 8/7/1995 8/10/1995 fathead minnow 96-hour Survival 13%

AQTX0652 8/17/1995 8/18/1995 fathead minnow 96-hour Survival 47%

AQTX0700 11/14/1995 11/15/1995 fathead minnow 96-hour Survival 60%

AQTX0701 11/29/1995 11/29/1995 fathead minnow 96-hour Survival 100%

AQTX0842 6/14/1996 5/15/1996 fathead minnow 96-hour Survival 100%

AQTX0971 7/23/1996 7/23/1996 fathead minnow 96-hour Survival 97%

AQTX1245 12/11/1996 12/13/1996 fathead minnow 96-hour Survival 100%

AQTX1278 3/17/1997 3/18/1997 fathead minnow 96-hour Survival 97%

AQTX1383 6/19/1997 6/20/1997 fathead minnow 96-hour Survival 100%

AQTX1636 9/16/1997 9/16/1997 fathead minnow 96-hour Survival 97%

AQTX1649 12/9/1997 12/9/1997 fathead minnow 96-hour Survival 100%

AQTX002670 4/2/2001 4/3/2001 Daphnia pulex 48-hour Survival 100%

AQTX002669 4/2/2001 4/3/2001 fathead minnow 96-hour Survival 97%

AQTX002674 10/8/2001 10/9/2001 Daphnia pulex 48-hour Survival 100%

AQTX002673 10/26/2001 10/26/2001 fathead minnow 96-hour Survival 100%

RMAR0851 1/8/2007 1/9/2007 fathead minnow 96-hour Survival 95%

RMAR0849 1/8/2007 1/9/2007 Ceriodaphnia dubia 48-hour Survival 100%

RMAR0935 7/9/2007 7/9/2007 Ceriodaphnia dubia 48-hour Survival 100%

RMAR0936 7/9/2007 7/10/2007 fathead minnow 96-hour Survival 93%

RMAR2470 1/25/2012 1/25/2012 Ceriodaphnia dubia 48-hour Survival 100%

RMAR2469 1/25/2012 1/25/2012 fathead minnow 96-hour Survival 100%

RMAR2565 7/11/2012 7/11/2012 fathead minnow 96-hour Survival 0%

RMAR2566 7/11/2012 7/11/2012 Ceriodaphnia dubia 48-hour Survival 30%

Redondo WWTP Acute WET Test Results as % Survival in 100% Effluent
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Redondo Wastewater Treatment Plant

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Redondo WWTP Effluent – Chronic NOEC

Test Code Collected Start Date Organism Endpoint NOEC LOEC PMSD

AQTX002672 4/2/2001 4/3/2001 Atlantic mysid 7-day Survival 50 100 13.7%

Biomass 25 50 15.1%

Weight 25 50 12.9%

AQTX002671 4/2/2001 4/3/2001 topsmelt 7-day Survival 50 100 22.8%

Biomass 50 100 24.6%

Weight 50 100 15.3%

AQTX002676 10/8/2001 10/9/2001 Atlantic mysid 7-day Survival 31 100 14.7%

Biomass 4.17 12.5 11.9%

Weight 12.5 31 13.0%

AQTX002675 10/8/2001 10/8/2001 topsmelt 7-day Survival 31 100 16.8%

Biomass 31 100 21.6%

Weight 31 100 20.5%

RMAR0850 1/8/2007 1/9/2007 Atlantic mysid 7-day Survival 50 100 10.0%

Biomass 50 100 15.8%

Weight 50 100 15.5%

RMAR0848 1/8/2007 1/9/2007 topsmelt 7-day Survival 100 > 100 10.5%

Biomass 100 > 100 20.2%

Weight 100 > 100 19.1%

RMAR0934 7/9/2007 7/10/2007 Atlantic mysid 7-day Survival 100 > 100 12.6%

Biomass 50 100 16.6%

Weight 50 100 11.8%

RMAR0937 7/9/2007 7/10/2007 topsmelt 7-day Survival 100 > 100 9.7%

Biomass 100 > 100 25.1%

Weight 100 > 100 23.8%

RMAR2513 4/9/2012 4/10/2012 Atlantic mysid 7-day Survival 50 100 13.7%

Biomass 25 50 16.5%

Weight 50 100 16.4%

RMAR2514 4/9/2012 4/10/2012 topsmelt 7-day Survival 50 100 11.0%

Biomass 25 50 20.6%

Weight 50 100 25.2%

RMAR2720 11/5/2012 11/6/2012 Atlantic mysid 7-day Survival 25 100 12.8%

Biomass 12.5 25 14.9%

Weight 12.5 25 13.2%

RMAR2719 11/5/2012 11/6/2012 topsmelt 7-day Survival 25 100 8.4%

Biomass 25 100 23.9%

Weight 25 > 25 21.9%

Redondo WWTP Chronic WET Test Results as NOEC/LOEC in % Effluent
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Redondo Wastewater Treatment Plant

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Mixing Calculation – Outfall

The chronic and acute dilution factors included in the engineering report (Lakehaven, 2005) were 

364:1 and 159:1, respectively, and are included in the tables below. However, the modeling 

procedure did not take reflux (i.e. increases in ambient concentrations due to tidal reversals) into 

consideration. In the previous permit, this was addressed by reducing the predicted dilution 

factors by half to account for tidal reversals. Ecology believes this approach conservatively 

estimates the available dilution. Accordingly, Ecology used the chronic and acute dilution 

factors of 182:1 and 79:1, respectively, in the previous permit. Ecology continues to use these 

dilution factors until the District revises the mixing model and engineering report to model 

reflux.
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Mixing Calculation – Outfall

Acute – Dilution Run
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Redondo Wastewater Treatment Plant

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Mixing Calculation – Outfall

Chronic – Dilution Run
Fact Sheet for NPDES Permit No.WA0023451

Redondo Wastewater Treatment Plant

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Appendix E -- Response to Comments

During the public comment period, no comments were received.

On July 3, 2013, the Lakehaven Utility District submitted comments after their initial review of 

the draft permit and fact sheet, prior to the public notice of draft. The comments and Ecology’s 

responses are as follows:

Draft NPDES Permit (Entity Review)

Comment 1:

Cover page- The plant is a Trickling Filter, not an Activated Sludge Plant.

Response:

The draft permit has been revised to include the correct treatment plant type. 

Comment 2:

Cover Page- The discharge location for the outfall is incorrect and reflects the old outfall. 

The correct coordinates are Latitude 47.34941, Longitude -122.338038.

Response:

The draft permit has been revised to include the correct outfall coordinates.

Comment 3:

Section S1.A, Footnote (e)- The sentence “During normal operations with UV 

disinfection, chlorine limits do not apply” should be revised. It can be interpreted to 

mean that as long as you are using UV disinfection you may also add chlorine and not 

worry about chlorine limits.

Response:

Ecology does not believe that changes to the footnote are necessary. The first sentence of 

this footnote states that chlorine limits apply only during emergency periods when UV 

disinfection is not available and the District uses chlorine for disinfection. During 

periods when UV is used for disinfection and chlorine is used for control of odors or 

filamentous bacteria, it is assumed that any residual chlorine will be oxidized prior to the 

discharge.

Comment 4:

Section S2.A.5- lists Cyanide on two different lines, once as a grab, and once as a 

24-Hour composite. Clarification is needed.

Response:

The line with cyanide monitoring as a grab sample has been deleted. Cyanide monitoring 

is still required under the priority pollutant analysis for “Metals, Cyanide, & Total 

Phenols”.

Comment 5:

Section S2.A., Footnote (g)- states “3/week means three (3) times during each calendar 

week and on a rotational basis throughout the days of the week, except weekends and 

holidays.” Due to the nature of the testing that involves reading the dissolved oxygen 5 
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Redondo Wastewater Treatment Plant

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days later, CBOD5 can only be setup for analysis on Wednesday, Thursday, or Friday and 

avoid turning on a sampler or analyzing on weekends. Likewise to avoid analysis or turning 

on a sampler during a weekend, TSS can only be analyzed on Tuesday, Wednesday, 

Thursday, or Friday, and Fecal Coliform can only be analyzed on Monday, Tuesday, 

Wednesday, and Thursday limiting the ability to rotate throughout the days of the week.

Response:

The footnote has been revised to “3/week means three (3) times during each calendar week.”

Comment 6:

Section S3.E.a.- discusses the conditions that require immediate reporting. Lakehaven 

Utility District would like clarification on what is meant by “collection system 

overflows” and “any other failures of the sewage system (pipe breaks, etc.)”. Is there a 

minimum amount of liquid leaving the collection system that constitutes an overflow? If 

the overflow is minimal and can be cleaned up immediately without any environmental 

damage does it still need to be reported? During construction of a collection system quite 

often the organization must break into an existing pipe, does this need to be immediately 

reported under this section?

Response:

The term “collection system overflows” means any overflows from the collection system 

including, but not limited to, sewage overflows from manholes, pump stations and other

parts of the collection system due to blockages, inadequate conveyance capacity, excessive 

I/I, root intrusion, etc. The term “any other failures of the sewage system (pipe breaks, 

etc.)” means failures of the collection system including, but not limited to, gravity sewer line 

breaks, force main breaks, pump station power failures, etc. All collection system sewage 

overflows need to be reported and there is no minimum quantity of overflow that is exempt 

from reporting. During construction of collection system improvements, Ecology expects 

that the District will take the necessary safeguards to prevent sewage overflows including 

plugging and bypass pumping. For clarification, Ecology has revised the text under 

immediate reporting from “Collection system overflows” to “Collection system overflows 

that may reach surface waters.”

Comment 7:

Section S3.E.b.- discusses twenty-four-hour reporting, Lakehaven would like clarification 

on what is meant by “any overflow prior to the treatment works”.

Response:

Under 24 hour reporting, the term “any overflow prior to the treatment works” means any 

overflow that occurs prior to reaching the WWTP site (i.e. any collection system overflow) 

that is not covered under the immediate reporting section. 

Comment 8:

Section S9.B.- states “Following Ecology approval of the Sediment Sampling and Analysis 

Plan, the Permittee must collect sediments between August 15th and September 15th.” 

Lakehaven assumes that the collection occurs in 2016, but for clarification the year should be 

noted.

Response:

The year 2016 has been added for clarification.
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Redondo Wastewater Treatment Plant

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Draft Fact Sheet (Entity Review)

Comment 9:

II.Table 1- The discharge location for the outfall is incorrect and reflects the old outfall. 

The correct coordinates are Latitude 47.34941, Longitude -122.338038.

Response:

The draft fact sheet has been revised to include the correct outfall coordinates.

Comment 10:

II.A.History- The belt filter press was removed and replaced with a rotary press in 2010.

Response:

The draft fact sheet has been revised to include the updated information.

Comment 11:

II.A. Treatment processes- Replace “manually cleaned bar screen” with “mechanically 

cleaned bar screen”. Replace “belt filter press” with “rotary press”.

Response:

The draft fact sheet has been revised to include the correct information.

Comment 12:

II.A. Staff- There are 5 certified operators and 1 operator-in-training located at the Redondo 

plant. There are an additional 5 certified operators in support roles that are available to work 

at Redondo if necessary.

Response:

The draft fact sheet has been revised to include the updated information.

Comment 13:

II.A. Staff - The Lakota Laboratory operates from 6:30 to 3:00pm.

Response:

The draft fact sheet has been revised to include the updated information.

Comment 14:

II.A. Solid wastes/Residual Solids- Redondo does not transport solids wastes to Lakota, but 

rather disposes of them directly to a landfill.

Response:

The draft fact sheet has been revised to include the correct information.

Comment 15:

II.A. Solid wastes/Residual Solids- Replace “belt filter press” with “rotary press”.

Response:

The draft fact sheet has been revised to include the correct information.

Comment 16:

II.A. Solid wastes/Residual Solids- Dewatered sludge is not normally trucked to a 

beneficial reuse composting facility, the composting facility is kept as a backup site. 
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Redondo Wastewater Treatment Plant

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Normally the dewatered sludge is trucked to a beneficial reuse facility in Eastern 

Washington for land application.

Response:

The draft fact sheet has been revised to include the correct information.

Comment 17:

II.E. Summary of compliance/Table 5- The first row of data shows an Influent TSS permit 

violation for weekly TSS, which should be “Effluent TSS”.

Response:

The draft fact sheet has been revised to include the correct information.

Comment 18:

II.E. Summary of compliance/Table 5- The third row of data shows a permit violation for a 

late submittal of the December 2010 DMR. Lakehaven does not agree that there was a late 

submittal of the Redondo DMR. The Lakota and Redondo DMRs are compiled at the same 

time, signed at the same time, and mailed in the same envelope. The two DMRs were mailed 

on or about January 7, 2011, and there is no indication that the Lakota DMR was late.

Response:

Ecology concurs with the District’s comment that there was not a late DMR submittal. 

Ecology has removed the late DMR submittal from the table.

Comment 19:

III.F. Evaluation of surface water - The third paragraph discusses the diffuser at Outfall 

No.001. There is no diffuser on this outfall, the outfall pipe is 2,670 feet long, and there 

is only one port.

Response:

The draft fact sheet has been revised to include the correct information.

Comment 20:

IV.B. Lab accreditation - The Lakota Laboratory accreditation number is M674, not M028. 

Redondo pH and DO are performed by Redondo staff, not in the Lakota Laboratory. 

Response:

The draft fact sheet has been revised to include the correct information.