1

National Pollutant Discharge Elimination 

System (NPDES): Use of Sufficiently 

Sensitive Test Methods for Permit 

Applications and Reporting:

EPA’s Response to Public Comments

U.S. Environmental Protection Agency

Water Permits Division

Office of Wastewater Management

Office of Water

1200 Pennsylvania Avenue, NW

Washington, D.C. 20460

August 6, 2014
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FOREWORD

This document provides responses to all comments submitted on EPA’s Proposed 

National Pollutant Discharge Elimination System (NPDES): Use of Sufficiently Sensitive Test 

Methods for Permit Applications and Reporting Rulemaking. EPA’s Notice of Proposed 

Rulemaking was published in the Federal Register on June 23, 2010 (75 FR 35712). Submitted 

comments are available electronically through http://www.regulations.gov by searching Docket 

ID No. EPA-HQ-OW-2009-1019 and in hard copy at the EPA Docket Center Public Reading 

Room. The telephone number for the Water Docket is (202) 566-2426 and the telephone number 

for the Public Reading Room is (202) 566-1744. The Water Docket assigned a unique Document 

Control Number (DCN) to each comment submittal.

To organize the comments and to facilitate EPA’s responses, comments or portions of 

comments are broken into comment excerpts. The comment experts are organized in a table at 

the end of this document, and EPA’s corresponding response code is provided immediately 

following the comment excerpt. EPA notes that many commenters raised similar or related 

issues. In order to assist commenters, EPA’s comment responses are organized into 18 different 

responses. Each comment excerpt is assigned a comment response code. EPA notes that the full 

record and response to comments for this action consists of all relevant information found 

throughout the response to comment document, preamble, and other supporting documentation. 

EPA thus cautions commenters to read all of these materials to ensure that they are viewing the 

full Agency response to the issue raised.

The primary contacts regarding questions or comments on this document are:

Kathryn Kelley (202) 564-7004 (telephone)

David Hair (202) 564-2287 (telephone)

U.S. Environmental Protection Agency

Office of Water

Office of Wastewater Management

Mail Code 4203M

1200 Pennsylvania Avenue, NW

Washington, DC 20460
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Table of Contents

FOREWORD.................................................................................................................................. 2

Part I: List of Commenters.............................................................................................................. 4

Part II. Response Essays................................................................................................................. 5

Part III. Comment Excerpts with Response Codes....................................................................... 23
Part I: List of Commenters 

Docket 

Assignment

Number

Commenter Name Total No. 

Comments Comment ID

0005 Department of the Navy 2 A-B

0006/0008 Pennsylvania Department of Environmental Protection (PADEP) 3 C-E

0007 American Bottoms Regional Wastewater Treatment Facility 19 F-X

0009 Anonymous Public Comment 1 Y

0010 King County Water and Land Resources Division 1 Z

0011 National Council for Air and Stream Improvement, Inc. 8 AA-AH

0012 American Water 2 AI-AJ

0013 Hampton Roads Sanitation District 17 AK-BA

0014 Environmental Laboratory Advisory Board Federal Advisory 

Commission 1 BB

0015 The Inter Industry Analytical Group 7 BC-BI

0016 Metro Wastewater Reclamation District 6 BJ-BO

0017 New Jersey Department of Environmental Protection 4 BP-BS

0018 American Petroleum Institute 1 BT

0019 Ford Motor Company 5 BU-BY

0020 Albuquerque Bernalillo County 7 BZ-CF

0021 Oklahoma Department of Environmental Quality 12 CG-CR

0022 West Virginia Municipal Water Quality Association 1 CS

0023 Alaska Oil and Gas Association 5 CT-CX

0024 Virginia Association of Municipal Wastewater Agencies, Inc. 1 CY

0025 The Dow Chemical Company 6 CZ-DE

0026 Wisconsin Department of Natural Resources 1 DF

0027 National Association of Clean Water Agencies 21 DG-EA

0028 South Carolina Water Quality Association 1 EB

0029 Federal Water Quality Coalition 37 EC-FM

0030 North Carolina Water Quality Association, Inc. 1 FN

0031 Maryland Association of Municipal Wastewater Agencies, Inc. 1 FO
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Part II. Response Essays 

Response 1: 

A few commenters indicated that site-specific situations might increase the implementation costs of the rule beyond those costs 

outlined in the proposed rule. Some of these commenters provided examples of when site-specific conditions might result in increased 

costs. EPA recognizes that the burden estimated is a national average and that the cost for an individual facility could be higher or 

lower than that average. However, EPA does not believe that the information provided by the commenters is representative of the 

impact for a typical facility affected by this rule, nor does it alter the Agency’s original burden estimates. To assess the impact of this 

final rule, EPA assessed the cost information for 40 CFR Part 136 methods found in the National Environmental Methods Index 

(NEMI). The NEMI site describes the “relative cost” as the cost per procedure of a typical analytical measurement using the specified 

methods (i.e., the cost of analyzing a single sample). Additional considerations affect total project costs (e.g., labor and 

equipment/supplies for a typical sample preparation, quality assurance/quality control requirements to validate results reported, 

number of samples being analyzed). EPA’s review of the cost ranges provided in NEMI indicated that there was generally little 

difference in the cost ranges across the EPA-approved analytical methods for a particular pollutant. A table with the NEMI cost ranges 

is included in the record. While EPA acknowledges that there are cost differentials for some facilities based on case-specific 

situations, on the basis of the analytical cost ranges provided in NEMI, and the assumptions used in the current ICRs (i.e., that 

applicants and permittees will use a range of available approved methods), the final rule is expected to result in little or no new or 

increased analytical burden to applicants or permittees. 

EPA also recognizes that in some cases, use of a more sensitive method could have the practical effect of requiring a facility to 

adopt additional pollution control measures, even if the permit limit remained unchanged. This is because a more sensitive method 

may detect the presence of a pollutant that was previously undetected. EPA emphasizes that this rule would not be responsible for any 
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change in stringency of the permit requirements in such a case, but acknowledges that a facility may incur additional pollution control 

costs if a previously undetected pollutant is later detected by the use of a sufficiently sensitive method, and additional treatment is 

required to meet the existing permit limit. In general, when EPA develops a cost analysis for a new regulation, there is an assumption 

made of full compliance with existing requirements. EPA does not have data that would allow it to predict in advance where or how 

often this situation might occur, or what a facility would be required to do to address it. Therefore, EPA has not attempted to quantify 

any such costs, as they are outside the scope of this rulemaking 

A few commenters claimed that EPA did not comply with its requirements under the statutory and Executive Order reviews 

contained in the proposed rule at 75 FR 35718. EPA believes that there was a misunderstanding on the part of the commenters 

regarding the intent of the rule that led the commenters to believe that the rule would result in a higher cost of implementation than 

that estimated by EPA. EPA believes that the Agency has met its responsibilities under the following: (a) Executive Order 12866: 

Regulatory Planning and Review, (b) Paperwork Reduction Act, (c) Regulatory Flexibility Act, (d) Unfunded Mandates Reform Act, 

(e) Executive Order 13132: Federalism, (f) Executive Order 13175: Consultation and Coordination With Indian Tribal Governments, 

(g) Executive Order 13045: Protection of Children From Environmental Health and Safety Risks, (i) National Technology Transfer 

and Advancement Act, and (j) Executive Order 12898 (Federal Actions to Address Environmental Justice in Minority Populations and 

Low Income Populations). 

Response 2:

One commenter raised a concern about the potential costs to states to establish minimum levels. The rule does not require states to 

develop or establish minimum levels as a result of the rule. EPA is aware that some states and regions, including EPA region 6, have 

specified minimum levels in guidance or policy to assist their NPDES applicants and permittees. EPA, however, did not survey 

regions or states to determine the exact numbers that have issued such guidance or policy. Because the rule does not require states to 

develop minimum levels, EPA believes the issue raised by the commenter is outside the scope of this rulemaking. 
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Response 3: 

Effect of the Rule on Current Practices

EPA received several comments that indicated the approach outlined in the proposed rule would force applicants and permittees to 

make decisions regarding the selection of an appropriate method without adequate information upon which to base a decision. 

Specifically, commenters indicated that issues related to the definition of the method minimum level (ML) would make this rule 

difficult to implement and that method sensitivity should not be the sole factor in deciding which method should be used in the 

permitting process. They indicated that there are other factors including accuracy, precision, selectivity, and whether the method has 

been validated that should be considered. 

In response, EPA notes that applicants for NPDES permits have always needed to make decisions regarding which EPA-approved 

methods are the most appropriate for use when performing the screening analyses required under the various permit application 

regulations at 40 CFR 122.21. Similarly, NPDES permitting authorities, even before today’s rulemaking, have had to consider which 

of the EPA-approved methods are the most appropriate for permittees to use to meet their monitoring and reporting requirements 

under a NPDES permit. Today’s rule does not change the basic NPDES permit application or permit issuance process. Under 40 CFR 

122.21, permittees seeking permit renewal or new applicants must provide the Director with adequate information to determine 

whether an NPDES application is complete. Once the Director makes this determination, the Director determines the applicable permit 

requirements, including any sampling or monitoring that must be taken that is “representative of the monitored activity.” See 40 CFR 

122.41(j)(1). The effect of today’s final rulemaking is to codify that where EPA-approved methods exist, only “sufficiently sensitive” 

EPA-approved methods may be used in connection with permit applications and to conduct monitoring and reporting under a permit. 

To determine whether an EPA-approved analytical method is “sufficiently sensitive” in any particular case, NPDES 

applicants/permittees and permit authorities should use the best information available on what the ML is for the method, and EPA 

believes that in general a method’s accurate ML will be readily ascertainable. Where the ML is explicitly listed in the EPA-approved 
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method, applicants may reference the published ML when determining whether a method selected to provide data for their permit 

application is sufficiently sensitive. Alternatively, applicants have always had the option of providing matrix specific method 

detection limits and minimum levels rather than the published minimum levels and nothing in today’s rule changes that flexibility, 

including with respect to selecting a sufficiently sensitive EPA-approved method. For these cases the laboratory should be able to 

show that a reasonable effort (e.g., published cleanup procedures) was attempted to achieve as low a minimum level as possible for 

those samples. For EPA-approved methods that do not explicitly list MLs, the ML can be obtained or derived by the applicant or 

permitting authority. Indeed, many permitting authorities have developed guidance, policies or regulations that establish MLs for 

various methods, or specify specific methods to be used by applicants and permittees. Where applicable, these policies and 

regulations will continue to affect method selection, although at the same time, States must ensure that such policies and regulations 

conform with the criteria established in today’s rulemaking that, where they exist, only “sufficiently sensitive” EPA-approved 

methods are being used when completing an NPDES permit application and when performing sampling and analysis pursuant to 

monitoring requirements in an NPDES permit. If the applicant does not provide data using a sufficiently sensitive EPA-approved 

analytical method where one exists, the Director may determine that the application is “incomplete” per 40 CFR 122.21(e), The 

Director may require that the applicant provide new screening data obtained using a sufficiently sensitive EPA-approved analytical 

method before making a completeness determination and moving forward with permit development. Thus, to avoid having the 

permitting authority reject data provided in an application because the data were not collected by means of a “sufficiently sensitive” 

method, the NPDES applicant should work closely with the permitting authority prior to conducting the required analyses. In addition, 

the permitting authority must ensure the permit includes a requirement to use a sufficiently sensitive EPA-approved analytical test 

method, where they exist, where necessary to perform sampling and analysis, consistent with 40 CFR 122.41(j) and 122.44(i). 

Development of New or Alternate Test Procedures

EPA received several comments that indicated the proposed rule would require the development of new analytical methods where 

no EPA-approved methods exist or where existing EPA-approved methods would not quantify the pollutant concentration at or below 
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the level of the criterion or permit limit. Other commenters indicated that the rule would alter the existing requirements for developing 

Alternate Test Procedures under 40 CFR part 136. EPA has modified the proposal to address these comments as explained below. 

EPA has modified the proposed language for this final rule so that it does not change existing regulatory requirements with respect 

to unapproved methods. Where no EPA-approved analytical methods exist, an applicant will need to select a method from another 

source of available analytical methods (e.g. Standard Methods for the Examination of Water and Wastewater) to measure that 

pollutant or pollutant parameter. Today’s final rule does not require the applicant to develop new methods. The situation in which 

there are no EPA approved methods is uncommon because there are EPA-approved methods for most pollutants or pollutant 

parameters screened and regulated under the NPDES program. Under the existing regulations at 40 CFR 122.21(g)(7) the NPDES 

applicant has the flexibility to use any suitable analytical method when no EPA-approved analytical method exists for that pollutant or 

pollutant parameter. Additionally, under the existing regulations at 40 CFR 122.44(i)(1)(iv) the NPDES permitting authority specifies 

a method in the permit when there is no EPA-approved method. 

Where EPA-approved methods exist, but none of the available methods will quantify the pollutant concentration at or below the 

level of the criterion or permit limit, today’s rulemaking does not require the development of any new analytical methods. However, in 

this situation, the rule will now require the use of the most sensitive of the EPA-approved methods. 

Finally, today’s rulemaking does not alter any of the existing requirements related to the development or approval of alternative 

test procedures under 40 CFR 136.4 and 136.5. 

Consideration of Matrix Effects in Selecting a Sufficiently Sensitive Method

EPA received several comments that indicated the approach outlined in the proposed rule would force applicants and permittees to 

make decisions regarding the selection of an appropriate method without adequate information upon which to base a decision. 

Specifically, commenters indicated that issues related to the definition of the method minimum level (ML) would make this rule 

difficult to implement and that method sensitivity should not be the sole factor in deciding which method should be used in the permit 
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process. They believe there are other critical factors including accuracy, precision, selectivity, and whether the method has been 

validated. 

In response, as noted above, EPA has clarified that the requirement to use a “sufficiently sensitive” EPA-approved method does 

not apply where no-EPA approved method exits. EPA agrees that other factors beyond the ML can also be important in determining 

method performance, including a method’s selectivity, resolution, accuracy, and precision. EPA has added language in the rule text 

that clarifies where no EPA-approved methods exist, permit applicants may consider these other factors, in conjunction with 

sensitivity, when selecting an appropriate method. 

For EPA-approved methods, however, these factors have already been considered during the method validation and approval 

process. As explained above, EPA evaluates method performance in a wide variety of wastewater matrices and approves those 

methods that have selectivity, sensitivity, precision and accuracy that are appropriate for wastewater compliance monitoring. 40 CFR 

136.6 also allows flexibility to tailor approved methods to more challenging wastewater matrices. EPA notes that applicants have 

always had the option of providing matrix or sample specific minimum levels rather than the published levels and nothing in today’s 

rule changes that flexibility, including with respect to selecting a sufficiently sensitive EPA-approved method. For these cases the 

laboratory should be able to show that a reasonable effort (e.g., published cleanup procedures) was attempted to achieve as low a 

minimum level as possible for those samples. 

If the most sensitive method listed in 40 CFR Part 136 is not performing adequately in a given wastewater matrix (e.g., sensitivity, 

accuracy, and precision), several options are available and should be pursued. Dilution is often a good option if it does not drive the 

sample specific minimum level above the permit requirements. Cleanup procedures included in the method can also be utilized. If 

those cleanups do not prove adequate for a particular matrix, the analyst should consult “Solutions to Analytical Chemistry Problems 

with Clean Water Act Methods,” EPA 821-R-07-002 (or more recent revisions) to determine if another cleanup procedure may be 

appropriate. If a solution is still not apparent, the permittee should consult EPA or the permitting authority. 
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Based on data and information provided to EPA by analytical laboratories, EPA finds that experienced laboratories are often 

capable of achieving minimum levels below those published with a method while maintaining the precision and accuracy specified in 

the method. However, EPA acknowledges that while rare, situations may exist where a method cannot perform adequately in a 

specific matrix. In response, EPA added a note in the regulation to clarify this issue. In such rare situations, the Director may 

consider additional technical factors when determining whether the method is still “sufficiently sensitive.” Specifically, where a the 

permit applicant or permittees can demonstrate to the Director that despite a good faith effort to overcome these methodological 

problems due to challenging wastewater matrices, either (1)the method’s minimum level is higher than originally anticipated, or (2) 

the method results no longer meet the methods QA/QC specification, the Director may take these factors into account when 

determining whether the permit applicant has met the requirements to use a “sufficiently sensitive” method or in prescribing a 

“sufficiently sensitive” method in the permit. In the first situation, the matrix or sample-specific minimum level should be used to 

evaluate which of the EPA-approved methods is “sufficiently sensitive.” In the second situation, if the method’s results are no longer 

consistent with the QA/QC specifications, then the method is not performing adequately and a “sufficiently sensitive” method should 

be selected from the remaining EPA-approved methods. In either case, the permit applicant or permittee is responsible for 

demonstrating that a published minimum level is unachievable or a reasonable effort was applied to bring the original sufficiently 

sensitive method within the QA/QC specifications in the given matrix before selecting another EPA-approved method (e.g., cleanup 

procedures, dilution when appropriate, etc.). To illustrate the type of situations where this provision would be appropriate, EPA 

provides two examples below. 

EPA received comments about the situation where there are multiple EPA-approved methods for an organic pollutant and the 

methods employ different technologies (i.e., gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS)). These

commenters raised concern that, in some instances, while the GC method may provide a lower detection limit, the GC/MS method 

provides a greater degree of confidence in the correct identification of the regulated parameter. As explained above, this is not an 

issue if the laboratory has demonstrated that it can achieve an ML for GC/MS that is lower than the NPDES permit limit for the 
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regulated parameter, in which case GC/MS would be considered “sufficiently sensitive”. EPA agrees that GC/MS is more selective 

than GC, but several options are available to remove the interferences from difficult matrices before using a dual-column GC method, 

(e.g., solid-phase extraction as a cleanup procedure, Florisil cleanup, alumina cleanup, sulfur removal with copper or TBA sulfite, gel 

permeation chromatography, etc.). Generally, a result from a dual-column GC method would only be questioned if the 

chromatograms from the two columns did not yield similar numerical results or if the chromatograms contained many extraneous 

peaks that suggest interferences are present. If the permit applicant or permittee is still concerned that the peaks may be caused by a 

different contaminant, and is a false positive for the GC method, the permit applicant or permittee could use a GC/MS to confirm the

presence of the contaminant. However, since the GC/MS is less sensitive, it may not be able to confirm low level dual column GC 

results. Then more sensitive GC/MS method options (e.g., larger sample volume, smaller final extract volume, selected ion 

monitoring techniques, or high resolution GC/MS) may be necessary to prove whether the dual column GC result is a false positive. 

The permittee should also consult with EPA and/or its permitting authority for potential solutions. In this case, if the permittee has 

exhausted all practical options (e.g., solid-phase extraction as a cleanup procedure, Florisil cleanup, alumina cleanup, sulfur removal 

with copper or TBA sulfite, gel permeation chromatography, etc.) and has documentation to demonstrate that the dual-column GC 

creates false positive results for that specific matrix, then the Director would appropriately approve the selection of a different EPAapproved method that would then be considered a sufficiently sensitive method (e.g., GC/MS). 

As another example, EPA also received comments specific to Method 1631 for mercury. These commenters noted the “clean” 

sampling methods associated with this method to minimize potential contamination from the sampling technique itself are not possible 

in many industrial settings. They noted that EPA’s documentation of the sampling technique acknowledges it is not intended for 

treated and untreated discharges from industrial uses. EPA notes that since approval of this method and the associated clean sampling 

techniques, these techniques have been successfully used in some industrial settings. For example, sewage treatment plants accepting 

industrial wastewater have successfully eliminated permit exceedances for mercury as measured by Method 1631 by employing the

clean sampling procedures. Where the permittee has documentation that clean sampling techniques cannot be adopted for the site-
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specific application, the Director would appropriately approve the selection of a different EPA-approved method that meets the 

definition of a sufficiently sensitive method (e.g., the one with the lowest ML of the remaining EPA-approved methods). If the 

ambient level of mercury contamination at the site is too high to use clean sampling methods, then using a less sensitive EPAapproved method can meet the definition of a sufficiently sensitive method. 

Another commenter raised concerns specific to Method 1631. They questioned the method’s suggestion to minimize laboratory 

contamination by soaking laboratory air filters in gold chloride solution so that mercury in incoming air will amalgamize with the 

filter’s gold. This commenter questioned whether or not it was EPA’s expectation that laboratories go to such lengths to employ such 

a sufficiently sensitive method where required under this rule. EPA notes the procedure described by the commenter is only a 

suggestion if laboratories are having problems with laboratory contamination. There are now many laboratories that perform Method 

1631 without undue difficulty. In this case, where necessary to meet the definition of “sufficiently sensitive” in today’s final rule, EPA 

would expect that the permittee use Method 1631 as the permittee should send their sample to a laboratory that can demonstrate it has 

control over sources of mercury within its own environment. 

Finally, where a technology based requirement is specified as “zero discharge” or “no detect” the permitting authority may take 

into account the sensitivity of the method used to establish the requirement when determining if a method is “sufficiently sensitive.” 

EPA recognizes that if a more sensitive method is approved after such a requirement has been established, its use may be inconsistent 

with the technological basis of the original requirement. In situations where a technology based requirement reflects a technology that 

eliminates the discharge of the subject pollutant altogether, the newer sensitive method is appropriate. However, where a technologybased limit reflects a technology that may not achieve the minimum level of the newer more sensitive method, the Director may 

determine that the method on which the requirement was originally based is “sufficiently sensitive” to determine compliance, as 

understood at the time the requirement was established. 
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Report of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs

EPA received a number of comments that identified concerns that the proposed rule uses terms, such as minimum level (ML), that 

are not defined in new or existing regulations. Commenters also indicated that the proposed rule fails to address a variety of issues 

regarding detection and quantitation that were raised in the Report of the Federal Advisory Committee on Detection and Quantitation 

Approaches and Uses in Clean Water Act Programs. EPA agrees that there are a variety of related issues raised in the aforementioned 

report, yet notes that the members of the Federal Advisory Committee (FAC) were unable to reach consensus over several key issues 

in the report. While several of these issues, such as the definition of ML, are discussed in today’s rulemaking, applicants and 

permitting authorities must still, on a regular and ongoing basis, choose which of the available analytical methods are most appropriate 

for use when screening effluent for permit applications and as part of permit conditions. This has always been the case, regardless of 

today’s rulemaking.

EPA believes that the requirements of the rule are adequately described and can be implemented without having to address the 

myriad of issues considered by the FAC. For today’s rulemaking, EPA is not redefining or establishing new method detection limits 

(MDLs) or MLs, developing new procedures for determining detection or quantitation, or maintaining a clearinghouse on detection 

and quantitation issues. EPA considers such issues to be outside the scope of today’s rulemaking. 

Other Factors Affecting Selection of Analytical Methods

EPA received several comments that expressed concern that the rule would require the use of only the most sensitive available 

method, and that other factors such as geographical isolation or unique sample collection constraints might preclude the use of certain 

available methods. Some comments also expressed concerns regarding the availability of laboratories qualified to conduct some of 

the more sensitive analytical methods, particularly where the state requires applicants and permittees to use laboratories certified by 

the state to conduct analyses.
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EPA is not requiring the use of any specific analytical technology or practice over others; only that the selected EPA-approved 

method is sufficiently sensitive. EPA expects that in general factors such as geographical isolation, or unique sampling collection 

constraints would not preclude the selection of a sufficiently sensitive method. The definition does not require the use of the most 

sensitive EPA-approved method available, so long as a less sensitive approved method still meets the criteria for being “sufficiently 

sensitive.” In cases where factors beyond a facility’s control render the use of a particular method infeasible, such as extreme 

geographical isolation, the permitting authority could consider such factors in deciding which method best meets the definition of 

“sufficiently sensitive.” EPA expects such situations would be rare.

Issues related to sampling procedures, such as holding times, are frequently prescribed by the test procedures in 40 CFR Part 136, 

and may be contingent on the unique physical, chemical, and biological characteristics of the discharge. Standard practice has been 

and continues to be that if an applicant/permittee or laboratory has questions regarding the appropriateness of using a specific method 

in a given situation, or has technical questions on its use, it should consult with its permitting authority prior to conducting monitoring.

Response 4: 

Three commenters questioned whether EPA had omitted the word “or” when defining the term “sufficiently sensitive” in the 

proposed rule at 40 CFR 122.21(e) (3) (i) (B) and 122.44(i) (1) (iv) (A) (2) (i.e., after the semicolon in the second to last item in the 

series). EPA has corrected these inadvertent omissions in this rulemaking. 

Response 5: 

EPA received a comment recommending that the Agency add the following language to the third criterion for sufficiently sensitive 

at 40 CFR 122.21(e)(3)(i)(C) and 122.44(i)(1)(IV)(3) to read as follows: “The method has the lowest ML of the analytical methods 

approved under 40 CFR part 136 for the measured pollutant or pollutant parameter. The commenter justifies this recommendation by 

noting that EPA provides clarification that this is the case in the preamble to the proposed rule. EPA agrees that the suggested 

language clarifies the Agencies intent. EPA has therefore revised the regulatory language in the final rule.
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Response 6: 

EPA received one comment asking whether a laboratory would need to go through a demonstration pursuant to 40 CFR 136.6 

before using a method for which the lab is able to achieve a lower MDL and ML than specified in the approved method. EPA’s 

response to this inquiry is that the rule does not change any alternative test procedures or requirements under 40 CFR part 136. If a 

laboratory has already documented and received approval pursuant to 40 CFR 136.6 to modify a method and the lab achieves a lower 

MDL and ML than is achieved by the promulgated method, then the MDL and ML from the modified method would be used to 

determine whether the method is sufficiently sensitive as defined in the rule. 

However, if the laboratory has not previously demonstrated the performance of a proposed method modification pursuant to 40 

CFR 136.6, it would be responsible for doing so. The demonstration would be made to the applicable EPA Regional office per the 

application requirements at 40 CFR 136.4. 

Response 7: 

A few commenters asked to what extent the rule would affect recordkeeping and reporting requirements. The rule does not change 

existing recordkeeping and reporting requirements at 40 CFR 122.21(p), 122.41(j) and 122.48. The permitting authority, however, has 

discretionary authority to require its applicants or permittees to provide information under the latter two provisions.

Response 8: 

EPA received a comment relating to the permitting of nutrients when the nonpoint sources exceed point source contributions. 

While EPA appreciates the concerns of the commenter, the issues raised do not relate to the question of what the final provisions of 

the sufficiently sensitive methods rule should be, and so are beyond the scope of this rulemaking.

Response 9: 

A few commenters raised issues pertaining to the rule’s impact on indirect dischargers. The rule affects only direct dischargers 

(those applying for an individual NPDES permit) and state / EPA NPDES permitting authorities. The rule does not apply to indirect 

dischargers. POTWs with approved pretreatment programs may at their discretion (as authorized by their local ordinances and 
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regulations) require their indirect dischargers to achieve specific minimum levels when performing analyses or may require the use of 

specific methods to enable them to better characterize contributions into their system. Where a State or EPA is the pretreatment 

Control Authority, the specific requirements for analytical methods can be specified in the control mechanism issued to the indirect 

discharger.

Response 10: 

One commenter asked how an applicant would select a method where there is no water quality criterion established. If, in fact, 

there is no applicable numeric water quality criterion for the pollutant of concern, then any EPA-approved analytical method would 

meet the definition of "sufficiently sensitive.” While any of the EPA-approved methods would satisfy the regulatory definition in this 

situation, it may be prudent for the applicant to contact the permitting authority to obtain guidance regarding the appropriateness of a 

particular method. 

Response 11: 

A few commenters asked whether the rule alters existing permit requirements. The rule itself does not modify the terms or 

conditions of existing NPDES permits. If, under the requirements of this rulemaking, a change needs to occur in the analytical 

methods specified in an existing permit, that change would occur at the time of permit renewal, or could also occur through a permit 

modification (where provided for by 40 CFR 122.62 and the procedures of 40 CFR Part 124, or analogous provisions in the laws and 

regulation of authorized states). 

A few commenters asked whether existing data (collected using insufficiently sensitive methods) will be acceptable for submission 

with an application for permit renewal. NPDES application monitoring data that is collected after the effective date of the rule, or, if 

applicable, after an authorized State has revised its regulations to adopt the provisions of the rule, must be based on the use of 

sufficiently sensitive test methods. However, the rule does not negate the existing requirement for applicants to submit data from 

previous years, even where these data may have been collected using methods that did not conform to the sufficiently sensitive criteria 

established in this rule. Based on all of the data submitted with the permit application, the permitting authority will determine whether 
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it has information adequate to develop an NPDES permit. Where the permitting authority determines that data was collected using 

insufficiently sensitive methods, it may choose to disregard this information and accept only data collected employing sufficiently 

sensitive EPA-approved methods. In addition, even prior to the effective date of today’s rulemaking, the permitting authority has the 

authority under the existing NPDES regulations to request additional data from applicants where insufficient data is provided with the 

application before considering an application complete.

Response 12: 

A few commenters expressed confusion as to the effective date of the rule. EPA’s response is that the effective date of the final 

rule as stated in the preamble, is 30 days after publication in the Federal Register However, authorized states have up to one year to 

revise, as necessary, their NPDES regulations to adopt the requirements of this rule, or two years if statutory changes are needed, as 

provided at 40 CFR 123.62.

Response 13:

EPA received two comments indicating that the reference made on 75 FR 35716 of the proposed rule to EPA’s website as a means 

of keeping permitting authorities and permittees informed of method updates and revised water quality criteria is irrelevant for states 

that have adopted their own water quality criteria. The purpose of this discussion is to keep NPDES permittees and permitting 

authorities informed when there are changes in EPA-approved methods so that sufficiently sensitive methods are used in the NPDES 

application and permit monitoring/reporting processes at all times. EPA agrees that this will not provide updates to state programs 

and recommends that applicants and permittees contact their states for the most up to date information on any state program updates.

Response 14:

EPA received several comments that indicated that while the commenters supported the concept established in the proposed rule, 

they believed additional flexibility should be provided to account for instream dilution. Specifically, the commenters requested that 

the criteria defining sufficiently sensitive be revised such that the ML would be compared to either "the applicable water quality 

criterion, wasteload allocation, permit limit, or other critical regulatory value." 
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The pollutant screening data submitted with an NPDES permit application are used for a variety of purposes by EPA and State 

permitting authorities. One important use of the data is to determine whether any pollutant or pollutant parameter present in the 

discharge will cause, have a reasonable potential to cause, or contribute to an excursion above any state water quality standard [see 40 

CFR §122.44(d) (1)]. This determination is often referred to as the permitting authority’s “reasonable potential” analysis.. 

In conducting a reasonable potential analysis, the permitting authority may consider the dilution of the discharge provided by the 

receiving water [see 40 CFR §122.44(d)(1)(ii)]. However, many factors limit the availability of a dilution consideration, including, 

but not limited to the following: (a) presence of the pollutant or pollutant parameter upstream of the discharge (i.e., the ambient 

concentration of the pollutant), (b) presence of non-motile organisms near the discharge point, (c) proximity of a drinking water intake 

or recreational area, (d) limitations within State water quality standards for certain classes of pollutants (e.g., bioaccumulative 

pollutants), and/or (e) low flow conditions at or near zero. Where these situations exist, little or no dilution may be available, and the 

applicable water quality criteria must be met at the point of the undiluted discharge. 

When performing pollutant analyses for a permit application, a new discharger or a discharger seeking renewal of its permit will 

generally not have information available to know whether, or what quantity of, dilution may be available for consideration by the 

permitting authority during the reasonable potential evaluation. Even if a dilution allowance was quantified and granted during the 

previous permit term, there is no assurance that the conditions noted above are the same as during the previous analysis conducted by 

the permitting authority. Because the pollutant-specific dilution allowance is not generally known prior to sampling for the permit 

application, it is generally necessary that the data provided be at or below the applicable water quality criteria (without accounting for 

any dilution).

EPA believes that the final rule need only require comparison of a method’s ML with the applicable water quality criterion, as 

proposed, and that this language is sufficiently flexible to address the commenters’ concern. Under this language, the permitting 

authority has adequate discretion to determine whether the data provided with a permit application were collected with methods that 

are sufficiently sensitive to measure at the relevant regulatory value. For example, where a permitting authority has conducted a 
20

timely and relevant dilution analysis (including an evaluation of ambient pollutant concentrations) and documented this analysis in the 

permit record, the permitting authority could provide this information to the applicant prior to the applicant sampling for the permit 

application. The applicant would then only need to show that the method it has selected has an ML that is at least as sensitive as 

necessary to determine compliance with the water quality criterion, after accounting for allowable dilution. The water quality criterion 

as adjusted for allowable dilution would be the “applicable water quality criterion” in this case, and the method would be “sufficiently 

sensitive” if it measures at this level. EPA considers this approach consistent with the requirements established in today's rule. For 

these reasons, EPA is not revising the regulatory text to incorporate the language suggested by the commenters.

Response 15:

Two commenters asked EPA to explain what it means by “method is otherwise required by the Director” in 40 CFR § 

122.21(e)(3)(ii) of the proposal. This language is intended to address situations there are no EPA-approved methods, and the State has 

regulations that require NPDES applicants to use a specific analytical method or achieve a specific minimum level for a particular 

pollutant (or they have a state policy or guidance that recommends a specific method or minimum level). In these cases, an applicant 

should consult with the State to ensure they are meeting all existing State requirements. Where an NPDES applicant intends to

perform analyses for a pollutant or a pollutant parameter for which there is no analytical method approved under 40 CFR part 136, and 

the State has not specified a particular method to be used, the existing regulations require that the applicant work with its laboratory to 

identify the methods that are “suitable” for the purposes of the screening effort.

Response 16:

Two commenters indicated that the rule requires the use of “suitable” unapproved methods in some circumstances. The 

commenters asked EPA to define “suitable.” This term is in the existing regulations, and is not redefined or otherwise affected by this 

rulemaking. Therefore, this comment is beyond the scope of this rulemaking. 
21

Response 17:

One commenter asked EPA to add the words “or specified” after “required” at 40 CFR 122.21(e)(3)(ii) and 40 CFR 

122.44(i)(1)(iv)(B) to clarify that test methods that are specified in applicable effluent limitation guidelines, new source performance 

standards, or sludge standards are sufficient for compliance purposes. EPA believes that the existing language already addresses 

situations where a method is specified in an effluent guideline, new source performance standard or sludge standards by indicating that 

an applicant must use a method that has be approved under 40 CFR 136 or “in accordance with another method required under 40 

CFR chapter I, subchapter N or O” and that the suggested revisions are not needed. 

Response 18:

One commenter expressed concern regarding the language at 40 CFR 122.21(e)(3)(ii), which states the following: “When there is

no analytical method that has been approved under 40 CFR part 136, required under 40 CFR chapter I, subchapter N or O, or 

otherwise required by the Director, the applicant may use any suitable, sufficiently sensitive method but shall provide a description of 

the method that includes documentation of the ML.” The commenter suggested that, where there is no EPA-approved method the 

Director should specify a suitable, sufficiently sensitive method to applicants. EPA concurs that there are certainly situations in which 

states may aid applicants by specifying a suitable method when there is no 40 CFR part 136 method available. However, this 

regulation does not require the Director to provide a list of methods to an applicant. Where an NPDES applicant intends to perform

analyses for a pollutant or a pollutant parameter for which there is no analytical method approved under 40 CFR part 136, the existing 

regulations require that the applicant work with its laboratory to identify the methods that are “suitable” for the purposes of the 

screening effort.

The commenter also raised a concern regarding the proposed regulatory text at 122.21(e)(3)(ii) and 122.41(i)(iv)(B) for instances 

where there are no EPA-approved methods. The proposed language included additional requirements for situations where there are no 

EPA-approved methods. Specifically, the proposed rule would have required that applicants and permitting authorities select a 

“sufficiently sensitive” non EPA-approved method and that applicants provide a description of the method, including the minimum 
22

level. The situation in which there are no EPA-approved methods is uncommon because there are EPA-approved methods for most 

pollutants or pollutant parameters screened and regulated under the NPDES program. In addition, the existing regulations already 

require that applicants select a suitable method and provide a description of the method. Based these comments, EPA determined that 

this additional requirement was unnecessary and has revised the regulatory text to reflect the existing language in 40 CFR 122.21 and 

122.41. As such, today’s rule does not specify non-EPA approved methods must be sufficiently sensitive. To clarify this point, EPA 

also added language to the introduction of 122.21(e)(3) to specify that the requirement to use a sufficiently sensitive method applies 

“except as specified in 122.21(e)(3)(ii).” Finally, EPA amended 122.21(e)(3)(ii) by adding regulatory text to clarify that in the case 

where there are no EPA-approved methods, applicants may consider other relevant factors to assess the performance of the method 

(e.g., precision, accuracy, or resolution) when selecting an appropriate method.
23

Part III. Comment Excerpts with Response Codes 

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

0005 Department of the Navy

Clean Water Act Services 

Steering Committee (CWA 

SSC)

Donald R. Schregardus

Deputy Assistant Secretary of 

the Navy (Environment)

A Comment #1. EPA's definition and determination procedures for method "sensitivity" 

within the text of the proposed rule may need some revision in order to ensure a high data 

quality. The proposed rule does not require that permittees determine and report that 

determination of precision and bias of the "quantitation limit", "reporting limit", and 

"minimum level". In order for data to be considered reliable enough to utilize in 

comparative analysis and in decision making, "quantitation limits" or "minimum levels" 

should have an associated precision and bias. Additionally, setting a 'quantitation limit" 

or "minimum level" at the lowest calibration standard or multiple of the MDL may not be 

a scientifically valid means of determining test sensitivity. EPA's MDL procedure has 

been criticized as a poor estimator of the Detection Level (DL) for failing to account for 

analytical bias, for assuming uniform variance across all possible spike concentrations, 

failing to account for the fact that variance increases at higher concentrations. To judge 

that sufficiently sensitive test methods are being used, NPDES test methods should be 

robust enough to produce quantifiable data at values less than the required permit limits. 

Given that currently there are no universally accepted statistical procedures for estimating 

test sensitivity, EPA should provide guidance for determining the acceptability of the 

minimum levels in relation to the water quality criterion or permit limit in order to reduce 

confusion in implementation of this proposed rule. 

Recommendations: Recommend that the concept and procedures in EPA's "Guidance on 

Systematic Planning Using the Data Quality Objectives Process" (EPA-QA/G-4) be 

followed to determine sufficient test methods.

(p. 2 of comments)

See Response 

3

0005 Department of the Navy

Clean Water Act Services 

Steering Committee (CWA 

SSC)

Donald R. Schregardus

Deputy Assistant Secretary of 

the Navy (Environment)

B Comment #2. The use of the "most sensitive" approved method is not adequate for data 

quality and usability assessments unless the associated precision and bias data is 

included. In addition, a lower "minimum level" is not necessarily more precise than a 

higher "minimum level". Data precision and bias associated with the "minimum level" 

must be considered when assessing data quality and when using that data to make 

decisions. Specific requirements for method sensitivity should be determined on a caseby-case basis in order to ensure that the test methods meet project requirements for 

reporting quantitative data with known precision and bias. Because of the complexities 

and room for error, EPA should provide guidance to assist permittees in choosing 

scientifically valid methods to determine test sensitivities.

See Response 

3
24

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

Recommendation: Recommend that EPA consider using scientifically valid detection 

and quantitation methods similar to those described in the "DoD Quality Systems Manual 

for Environmental Laboratories (V4.1). (p. 3 of comments)

0006, 0008 Pennsylvania Department of 

Environmental Protection 

(PADEP)

Sean M. Furjanic, MS, 

PE/Chief

NPDES Information Analysis 

Section

C Comment #1 In general, PADEP agrees with the rationale for the rule changes but 

believes EPA should concurrently establish technology-based minimum levels and be 

cognizant of state programmatic issues with laboratory accreditation. (p. 1 of comments)

See Response 

3

0006, 0008 Pennsylvania Department of 

Environmental Protection 

(PADEP)

Sean M. Furjanic, MS, 

PE/Chief

NPDES Information Analysis 

Section

D Comment #2. EPA should establish minimum levels. EPA acknowledges that some 

states have established required minimum levels for parameters. PADEP has not, but is 

wrestling with this issue now. We believe other states are in the same position. As noted 

in the docket, establishing required minimum levels is important for both assessing 

NPDES permit applications and evaluating compliance, including the treatment of "nondetect" results. If the rule changes were to take effect tomorrow, permit writers in PA 

would not have the tools, i.e., method-specific minimum levels, needed to implement the 

new requirements. By default, the practice in PA has often been to use Method Detection 

Limits (MDLs) as published in 40 CFR Part 136 as the minimum levels for permits. To 

change this approach we will need to have published minimum levels.We find no reason 

that EPA could not set method-specific minimum levels on a national level. Determining 

such levels relies not on water quality criteria, which could vary across the states, but on 

analytical technology. We urge you to form a workgroup with state members to develop 

these levels as an amendment to 40 CFR Part 136. We would anticipate delays in 

implementation and inconsistencies between states that confound permit reviews by EPA 

staff if the development of minimum levels is left entirely up to states. (p. 1-2 of 

comments)

See Response 

3

0006, 0008 Pennsylvania Department of 

Environmental Protection 

(PADEP)

Sean M. Furjanic, MS, 

PE/Chief

NPDES Information Analysis 

Section

E Comment #3 - Clarification Requested in Situations Where No EPA-Approved 

Method Exists

PADEP is concerned about how this rule would be applied in instances where no EPAapproved method exists for a parameter, with respect to the accreditation process for 

laboratories analyzing NPDES samples.

PADEP's Laboratory Accreditation Program evaluates and accredits all laboratories 

analyzing samples for NPDES facilities in PA. We are concerned that PADEP laboratory 

accreditation officers could be forced to make determinations of a method's suitability for

See Response 

3 and 

Response 18
25

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

meeting the "sufficiently sensitive" definition where no EPA-approved method exists. If 

such determinations must be made by PADEP staff, then we are concerned that this 

would present an increased workload on already strained resources.

In addition, PADEP seeks clarification on how the use of sufficiently sensitive methods 

by a laboratory will impact the process of the laboratory's accreditation. (p. 2 of 

comments)

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

F Comment #1 - Desirability of quantitative data for the purposes of permitting and 

compliance reporting.

We support the concept that data used for the purposes of permitting and compliance 

should be adequate to provide quantitative results to provide meaningful permits and 

reliable compliance determinations. (p. 1 of comments)

EPA 

acknowledges 

the comment. 

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

G Comment #2 - Use of minimum level (ML) as threshold for quantitative 

determinations. We note that NELAC requires the use of limit of quantitation (LOQ), 

not ML, for laboratory certification requirement and these LOQs are often displayed on 

the laboratory report. While the purposes of the LOQ and ML are similar, the method of 

determining the value of an LOQ is different. (http://www.nelacinstitute.org/docs/2003nelacstandard.pdf, appendix C and D of section 5.) The use of two 

methods for determining the quantitation threshold is likely to create confusion. We 

request that EPA clarify whether MLs must also be provided on the laboratory's report or 

whether LOQs can be used in lieu of MLs. (p. 1 of comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

H Comment #3 - Non-applicability to whole effluent toxicity methods. We support the 

non-applicability to whole effluent toxicity testing. (p. 1 of comments)

EPA 

acknowledges 

the comment.

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

I Comment #4 - Applicability to indirect dischargers. It's not entirely clear whether the 

ML requirement is intended to apply to indirect discharges to POTWs. The description in 

Table I-1 does not refer to indirect dischargers, but the preamble refers to subchapter N 

which includes pretreatment standards for direct and indirect discharge standards. The 

rule or preamble should be clear as to whether the rule applies to the pretreatment 

program monitoring conducted for compliance with Part 403. Because of the challenges 

associated with industrial discharge matrices, we believe that the option to require the 

achievement of MLs below regulatory limits should be left to the discretion of the 

POTW. (p. 1-2 of comments)

See Response 

9
26

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

J Comment #5 - Applicability for non-WQBEL parameters. Monitoring is sometimes 

required in an NPDES permit for parameters for which numeric WQBELs are not 

specified in the permit. A condition may be included in the permit which states that the 

permittee may not cause a violation of instream standards. In the case of our facility's 

NPDES permit, there are dozens of compounds for which quarterly monitoring is 

required and which have state water quality standards but for which no numeric 

WQBELs are included in the permit. In such a case, does the ML requirement apply or 

does the ML requirement apply only to those parameters which have specific numerical 

effluent limits and for which monitoring results are required to be reported on the DMR? 

Our view is that the ML requirement should only apply to parameters with explicit 

numerical limits which are reported on the DMR. (p. 2 of comments)

See Response 

3 and 

Response 11

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

K Comment #6 - Applicability for NPDES permit application. We understand that EPA 

intends that the data required to be collected for the NPDES Permit application--typically 

three pollutant scans--should meet ML requirements. However, more data than the 

required three scans is often available from the four and one-half year period of record 

used for permitting. If non-detectable data or data below the ML is collected during the 

term of a permit, but the most sensitive method is not used, must that data be excluded 

from consideration for NPDES re-permitting if the water quality standard is below the 

ML of the method used? We believe that it is appropriate to allow the permit writer to 

use all the data collected during the term of the permit in addition to the data required to 

meet the minimum data requirements for the permit application and request that EPA 

clarify in the rule or preamble that this is allowed. (p. 2 of comments)

See Response 

11

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

L Comment #7 - Location of definitions. The definition of ML is provided in a footnote. 

Since the definition of ML is central to the application of the rule, the definition should 

be clearly established within the body of the rule. (p. 2 of comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

M Comment #8 - Definition of ML. The first sentence of the definition in footnote 4 

provides that the ML is the maximum of (1) the lowest calibration standard and the (2) 

MDL multiplied by a factor. The second sentence provides four options: (1) ML 

published in a method, (2) lowest calibration point used in the laboratory, (3) published 

MDL multiplied by a factor, (4) laboratory MDL multiplied by a factor. In the second 

sentence, there is no indication of how the maximum is to be applied when the published 

ML is used. We interpret this language to mean that the ML can be either the ML 

published in the method or the maximum of the lowest calibration standard and the MDL 

(either laboratory specific or method) multiplied by a factor. We support the flexibility 

See Response 

3
27

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

that EPA intends to provide in determining the ML, but request that EPA clarify the 

language in the ML definition in the final rule. (p. 2-3 of comments)

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

N Comment #9 - MDL multiplied by a factor. The reference to the factor to be applied to 

the MDL to calculation the ML is obscure. It should not be necessary to refer to 

footnotes to Federal Register publications from more than ten years ago to determine how

to perform this calculation. The documents do not appear to be in the rule docket. EPA 

should incorporate the information explicitly in Part 136. (p. 3 of comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

O Comment # 10 - Lowest acceptable calibration point. The definition in footnote 4 

refers to the lowest "acceptable" calibration point. EPA should provide clarification as to 

the criteria it intends to be applied to a calibration point to make it "acceptable". (p. 3 of 

comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

P Comment #11 - Different determinations of ML. Due to the flexibility EPA provides 

in the determination of ML, more than one ML can be determined for a method. As a 

permittee, we are concerned about the potential for being "second-guessed" by others 

after the fact. We request that EPA clarify in the preamble to the final rule that it is 

expected that the party doing the monitoring will make the determination. (p. 3 of 

comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

Q Comment #12 - Reporting levels/dilution adjusted MLs. Laboratories often use the 

term "reporting level" to refer to dilution-adjusted MDLs or LOQs. In determining 

compliance with the requirements of this rule for NPDES purposes, is sample dilution to 

be considered? The definitions refer to the "method" minimum level. If the method ML 

is sufficiently low, but a particular sample is diluted after an analysis was attempted 

undiluted (perhaps for the removal of interferences) such that the dilution-adjusted ML is 

above the regulatory limit, are the requirements of the rule met? (p. 3 of comments)

See Response 

3
28

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

R Comment #13 - Preferential use of GC vs GC/MS data. In many cases--PCBs, 

pesticides and other organics--the GC/MS MDLs are not sufficiently sensitive to detect 

the level of the water quality standard. In the case of most organics, there is an approved 

gas chromatography (GC) method which provides a lower detection limit than the 

approved GC/MS method. In the case of many organic parameters, the ML rule could 

trigger a requirement to change from GC/MS to GC methods. This would be undesirable. 

GC/MS provides a much greater degree of confidence in the correct identification of the 

regulated parameter. Although use of dual columns in GC methods reduces uncertainty 

in the identification, GC/MS methods provide much greater confidence in the correct 

identification of organic parameters. The value of more sensitive quantitation is lost if 

one is not certain what is being quantified. The tables attached provide examples of some 

organic compounds which would fall into this category. In these cases, USEPA's 

criterion concentrations (http://www.epa.gov/waterscience/criteria/wqctable/) were used 

as the regulatory level and the ML was determined as 3.14 times the published MDL. As 

can be seen, there are numerous cases in which a GC method might be considered the 

most sensitive method and its use required by the proposed rule.We believe that the 

sufficiently sensitive method rule should recognize the superiority of GC/MS methods to 

GC methods and provide an exception to the sufficiently sensitive methods rule for the 

case of less sensitive GC/MS methods. (p. 3-4 of comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

S Comment #14 - Multiparameter methods with similar detection limits. For multiparameter approved methods which utilize similar technology with similar MDL/MLs 

(e.g. 624, 1624, 6210B 18th), is an analyte-by-analyte comparison necessary to determine 

the appropriate method? This would be a significant administrative difficulty and cost 

increase if POTWs would have to divide one analysis into two or three because 

parameters have slightly different MLs. (p. 4 of comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

T Comment #15 - Multi-parameter scans: GC vs GC/MS. Referring to Table 2, there are 

eight separate GC methods (604, 605, 606, 607, 609, 610, 611, 612) for the same 

parameters encompassed into one GC/MS method (625). As discussed above, the 

requirements of the draft rule appear to potentially require the use of multiple GC 

methods instead of or in addition to a single GC/MS method. This represents a 

significant administrative burden and cost increase. We believe the sufficiently sensitive 

methods rule should provide an exception for GC/MS methods. (p. 4 of comments)

See Response 

3
29

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

U Comment #16 - Availability of method. Not all approved methods are available 

commercially. For example, we recently tried without success to identify a laboratory to 

perform method 603 for acrolein since method 603 is more sensitive than method. We 

recommend that the rule should provide an exception for sensitive methods which are not 

commercially available to prevent creating an obligation for regulated entities to fund 

laboratories to provide those analytical services. (p. 4 of comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

V Comment #17 - Centralized source of ML information. We recommend that USEPA 

provide a centralized source of ML information to allow for ready application of the rule.

(p. 4 of comments)

See Response 

3

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

W Comment #18 - Effective date. For NELAC and other laboratories, inclusion of ML 

information in data systems and reports will require significant time and resources to 

implement. We suggest an effective data at least 18 months after publication of the final 

rule. (p. 4 of comments)

See Response 

12

0007 American Bottoms Regional 

Wastewater Treatment 

Facility

Kay E. Anderson

Environmental Compliance 

Manager

X Comment #19 - Reporting of data below ML on DMR reports. Instructions for DMR 

reporting address the reporting of data below the MDL. The rule is silent on the 

communication of ML information on the DMR or NPDES application. We request that 

EPA clarify in the preamble to the rule that there is no ML reporting obligation on the 

DMR or NPDES application. (p. 4 of comments)

See Response 

3 and 

Response 7

0009 Anonymous Public 

Comment

Y Comment #1 Is the EPA going to provide the minimum level (ML) that must be 

achieved for the pollutant or are States required to develop a list of ML [sic] that must be 

obtained by the permittee. The methods availableunder 40 CFR Part 136 do not list a ML 

for each method and pollutant in most cases. (p. 1 of comments)

See Response 

3
30

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

0010 King County Water and 

Land Resources Division

King County Environmental 

Lab

Colin Elliot

QA Officer

Z Comment #1 We understand and agree with the rationale for using methods sensitive enough 

to meet permit requirements. We are however, concerned about how the proposed policy will 

be implemented. In particular, we have concerns with the use of the term Minimum Level 

(ML) and if the descriptions in footnote #4 and #6 in the Federal Register announcement will 

be applied to all chemical-specific NPDES testing. We believe these definitions are 

inadequate or inappropriate for many of the methods approved for NPDES testing. Without 

detailed and appropriate definitions that are widely applicable to methods allowed for NPDES 

testing, it will be difficult for labs and permittees to comply with the proposed policy.

The deficiencies and limitations of the current approved methods for establishing the method 

detection limit (MDL) and the lack of a program-wide definition of a Quantitation Limit or 

Minimum Level have already been well documented by the EPA. There are a number of 

contradictory EPA definitions and conditions of compliance surrounding the ML. For 

instance, the background information in the Federal Register announcement states that the ML 

is NOT a quantitation limit while the ACIL Environmental Services Section Technical 

Committee states that it is. ACIL is also recommending using a different statistical 

calculation to derive MDLs and MLs than the current 40 CFR calculations.

In footnote #4, a calibration standard at or below the ML must be included in the calibration 

curve. This would not be appropriate for some EPA-approved methods. An example is EPA 

Method 200.07 where the ML would be unreasonable high since calibration must be done 

using a high level, single point standard. IF the single point standard were set at the true ML 

concentration, the instrument would not be properly calibrated (see section 11.4.4 of Method 

200.7). The goal should be to prove that the method is valid at the ML. Depending upon the 

method and instrumentation being used, there are a variety of options that should be allowed. 

For instance a good approach to verifying quantitation limits are found in the SW-846 Method 

6020A where a low level standards is used to verify the level and must pass between 70-

130%.

It is our understanding that the most recent efforts to update procedures for determining the 

MDL and ML have not yet been completed. It also isn't clear if a program-wide definition has 

yet been established for the ML. A more-complete definition and approved procedures for 

determining and verifying the ML should be established before the term is implemented for 

regulatory compliance purposes. We suggest that the sufficient sensitivity policy be 

implemented provided that the EPA expedites promulgation of procedures to establish and 

verify MDLs and MLs for all chemical-specific methods. Since all chemical disciplines can 

differ, having options for determining the MDL and ML is key to the success of a programwide procedure. In some cases the MDL/ML determinations must be done by looking at a 

combination of 40 CFR Part 136 Appendix B as well as ACIL method.

See Response 

3
31

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

References:

- Revised Assessment of Detection and Quantitation Approaches, EPA-821-B-04-005. 

October 2004

-Report of the Federal Advisory Committee on Detection and Quantitation Approaches and 

Uses in Clean Water Act Programs, December 2007 (p. 1-2 of comments)
32

Docket 

Assignment

Number

Commenter Comment 

ID

Comment(s) 

Text as it appears in correspondence to EPA

Response 

Code

011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AA Comment #1. In general, although it seems intuitively obvious, it is appropriate to use an 

analytical method that is sufficiently sensitive provided it meets the other performance 

characteristics required of a regulatory compliance method. Thus, clarification of 

sufficient sensitivity is useful, if done correctly. The idea that a permittee or state agency 

does not have to use a more sensitive method if the analyte is present within what is 

considered to be the range of acceptable performance of a method that might otherwise 

be considered less sensitive is also reasonable and appropriate. However, other method 

performance factors must also be considered.

On page 35715 of the Federal Register notice, EPA states:

"It is critical, therefore, that applicants provide data that have been measured with 

precision and accuracy so that they will be meaningful to the decision making process."

And:

"As discussed earlier, it is critical that the Director make permitting decisions based on 

accurate data and, thus, sound science. The use of imprecise analytical methods could 

lead the Director to make assumptions regarding the presence or absence of a pollutant in 

an applicant's discharge." In the same paragraph the notice goes on to state: "Moreover, 

if the Director were to include imprecise analytical methods for compliance monitoring 

puposes, the use of such methods could result in undetected exceedances of permit 

limits."

We agree that these considerations are critical to sound regulatory decision making and 

are appropriate analytical methodology. However, the proposed regulation changes 

outlined in the Federal Register notice fail to adequately implement these criteria.

(p. 1-2 of comments)

See Response 

3

011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AB Comment #2.

The first problem with the proposed regulations is that they fail to establish a common 

scientifically sound basis for comparing performances of different methods. The 

proposal would require that the Minimum Level be used as the basis for comparison and 

evaluation of suitability for a given purpose. However, in footnotes 4, 5, and 6 EPA goes 

on to indicate that Minimum Level can be established in a multitude of different ways. 

This effectively renders the term Minimum Level meaningless. Comparing a method 

with a Minimum Level based on the lowest calibration point to a method with a 

Minimum Level based on a multiple of the method detection limit (MDL) is meaningless. 

Adoption or acceptance of multiple definitions of the Minimum Level is not a suitable 

See Response 

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means for establishing which method is sufficiently sensitive because there is not a 

common basis for comparison.

We recommend that as a starting point EPA establish a single, well defined, and 

technically sound definition and determination procedure for the Minimum Level. In 

2005 EPA convened the Federal Advisory Committee for Detection and Quantitation's 

approaches and their use in the Clean Water Act Program (FACDQ) to provide consensus 

input on, among other issues, an appropriate definition and means of determining a 

quantification level. We recommend that EPA implement the recommendations of that 

committee and use them as the basis for establishing a common, defensible means of 

comparing the sensitivities of different analytical protocols (see Report of the Federal 

Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water 

Act Programs (December 2007)). (p. 2 of comments)

011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AC Comment #3. The second major problem with the proposed regulations and the multiple 

definitions of the Minimum Levels is that most, if not all, of those definitions fail to 

address accuracy or precision, which EPA has stated is a critical component of regulatory 

decision making. Multiplying an MDL by a factor (e.g., 2.18, 5, or 10) does not assure 

achievement of any particular degree of accuracy or precision. Thus, comparing methods 

with Minimum Levels defined in different ways or in the ways EPA has identified does 

not allow meaningful consideration of accuracy and precision in evaluating which 

methods are "sufficiently sensitive." Again, we recommend that the EPA adopt and 

implement the recommendations of the FACDQ prior to implementing the proposed 

regulations regarding determination of sufficient sensitivity. (p. 2-3 of comments)

See Response 

3

011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AD Comment #4. It is generally recognized that analytical method performance begins to 

decline at the extreme lower range of applicability and eventually gets to a point where 

data may not be of suitable quality to support decision making. In the most general 

sense, it is this understanding that supports the utility of the term quantitation limit. 

Thus, evaluations of the suitability of a method is sufficiently sensitive must involve 

consideration of the lowest concentration at which the required accuracy and precision 

can be achieved. This is a clear example of the importance of EPA following its own 

guidelines and establishing Measurement Quality Objectives (MQOs; see EPA Guidance 

for the Data Quality Objectives Process (EPA QA/G-4) at pages D-2(EPA/600/R-96/055 

August 2000) that must be met for Clean Water Act regulatory compliance testing. 

Established MQOs and the method for determining quantitation levels recommended by 

the FACDQ would form a sound and meaningful basis for comparing methods that would 

account for accuracy, precision, and sensitivity and thus sufficiency for permitting 

purposes. (p 3 of comments)

See Response 

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011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AE Comment #5. Another major shortcoming of the proposed changes to the regulations is 

that they fail to consider the actual performance of methods on real world samples and 

that matrix effects may limit sensitivity in ways not accounted for when a Minimum 

Level is established. Almost all MDLs are determined on reagent water, and any of the 

proposed definitions for the Minimum Level that involve use of the MDL as a starting 

point are therefore also based on reagent water. Minimum Levels defined as the lowest 

calibration point even go so far as to exclude performance of isolation, concentration, and 

/or cleanup steps in the procedures, and certainly do no consider matrix effects. For 

example, while on paper Method 608 may appear to be the most sensitive method for 

many of the analytes named in it, when applied to a real world matrix it is highly prone to 

false positives and/or high biases because it lacks selectivity. If EPA plans to proceed 

with regulations requiring use of "a [sufficiently] sensitive" method, it must include 

provisions for addressing method performance in real world samples. To do otherwise 

risks developing critical regulatory decisions on potentially faulty or unreliable data. (p. 3 

of comments)

See Response 

3

011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AF Comment #6. The proposed "sufficiently sensitive" regulations also address situations 

where EPA has not promulgated methods for an analyte. Section 122.44(i) (1) (iv) as 

currently written requires that if there is no approved Part 136 method, monitoring must 

be conducted according to a test procedure "specified in the permit" [40 CFR 122.44(i) 

(1) (iv) (2009), 122.21(j) (4) (viii)]. The only stipulation EPA provides is documentation 

of the Minimum Level [at 122.21(j) (4) (viii) (D)]. The requirement to use a suitably 

sensitive method as defined in the Notice is problematic for the reason stated above (i.e., 

it does not consider accuracy, precision, selectivity), does not define or characterize the 

appropriate degree of validation the method should be subjected to, and creates the 

burden of developing a "sufficiently sensitive" method on either the state or the 

permittee. It is quite possible that it may not be technically feasible to develop methods 

with "sufficient sensitivity" using current technology for analytes with extremely low 

water quality standards creating the problem where compliance with a legally enforceable 

provision is not possible. (p. 3-4 of comments)

See Response

3

011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AG Comment #7. EPA's established Alternate Test Procedure (ATP) provides a framework 

for method validation that would and should be applicable to situations where there are 

no sufficiently sensitive and approved methods. EPA should establish the MQOs 

required for the proposed testing, then use the levels of validation required of ATP 

petitioners to validate that those criteria are met (e.g., multi-laboratory testing for a 

specific matrix for statewide application, and multi-laboratory, multi-matrix testing for 

nationwide application). (p. 4 of comments)

See Response 

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011 National Council for Air 

and Stream Improvement, 

INC.

West Coast Regional Center

Larry LaFleur

NCASI Fellow

AH Comment #8.

EPA should not mandate use of a "sufficiently sensitive" method where a promulgated 

method does not exist, but should instead require use of the most sensitive method 

available that has undergone the required validation (and meets the required accuracy, 

precision, and selectivity and performs adequately on the subject matrix). Ideally, this 

would be a method that is "sufficiently sensitive" but in situations where technology may 

limit the ability to achieve the required sensitivity this would still allow permits to be 

issued. (p. 4 of comments)

See Response 

18

0012 American Water

Matthew J. Corson, P.E.

Manager Environmental 

Compliance and Stewardship

AI Comment #1.

American Waterworks supports EPA's position "that NPDES applicants and permittees 

must use sufficiently sensitive analytical methods when quantifying the presence of 

pollutants in a discharge" (page 35713). This includes using a method with a low enough 

minimum detection limit to allow a permittee to meet a discharge limit or an applicant to 

meet data request from the regulator. (p. 1 of comments)

EPA 

acknowledges 

the comment. 

0012 American Water

Matthew J. Corson, P.E.

Manager Environmental 

Compliance and Stewardship

AJ Comment #2.

However, American Water is concerned with the increased focus on reducing nutrient 

levels from an individual point source when there are often other sources in the watershed 

contributing much higher levels. Reducing wastewater treatment plant discharge limits to 

the nanogram per liter level does very little to protect a watershed when non-point source 

contributions result in receiving stream levels being measured in micrograms per liter or 

even milligrams per liter. 

According to EPA's Handbook for Developing Watershed Plans to Restore and Protect 

Our Waters:

"A watershed management plan defines and addresses existing or future water quality 

problems from both point sources and nonpoint sources of pollutants. Experience over 

the past decade has shown that effective watershed management includes active 

participation from stakeholders, analysis and quantification of the water quality goals, 

and implementation of specific actions needed to solve those problems."

American Water supports this approach and suggests that in many cases resources would 

be better spent implementing a watershed management plan than installing additional 

treatment to reduce nutrient discharges to levels that can be one or more orders of 

magnitude below the levels in the receiving stream. (p. 1-2 of comments)

See Response 

8

0013 Hampton Roads Sanitation 

District

Technical Services Division

AK Comment #1. It seems inappropriate to use the ML as a regulatory decision point given 

the current ML definition (3.18 x MDL) and MLs used in 40 CFR Part 136 methods are 

recognized to be flawed by all stakeholders including the states and EPA. Further, the 

Federal Advisory Committee (FAC) on Detection and Quantitation has made 

See Response 

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James J. Pletl, Ph.D.

Chief

recommendations to EPA on how to address the ML definition but EPA has yet to 

address those recommendations in a rulemaking. EPA states that it is critical that it make 

permitting decisions based on sound science, but the use of the current ML definition has 

already failed that standard. (p. 1 of comments)

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AL Comment #2. The proposed rule also fails the standard of sound science because it offers 

three different but possible approaches for defining the ML: 1) 3.18 x MDL, 2) whatever 

is published for a method, and 3) the lowest acceptable calibration point. Method 1631E 

complicates the issue more by taking 3.18 x MDL and then “rounding to the number 

nearest to (1, 2, or 5) x 10n, where n is an integer.” The level of confusion regarding the 

ML can have different MLs than the respective methods. As stated above, this rule 

should not be made final until a new , single definition of ML is promulgated based on 

the work of the Detection and Quantitation FAC. (p. 1 of comments)

See Response 

3

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AM Comment #3. The driver for this proposed change is to provide data of sufficient 

precision and accuracy, but EPA has not defined the data quality objectives for precision 

and accuracy to be applied to NPDES-related data. Therefore, no one can establish 

whether the ML meets this proposed need, even EPA. EPA goes on to say that is should 

not use imprecise analytical methods in permits, but EPA has not defined what this 

means. EPA states it needs to make permitting decisions based on accurate data, but EPA 

has not defined the level of accuracy required for use of the data. (p. 1 of comments)

See Response 

3

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AN Comment #4. The FR notice itself is trying to defend the need for the use of sufficiently 

sensitive methods, and then goes on to explain this need in terms of accuracy and 

precision. Based on EPA's own guidance regarding data quality indicators (DQIs) EPA 

should recognize that sensitivity is different than accuracy and precision, and although we 

agree that accurate and precise data should be used to meet NPDES requirements the 

desire to have more sensitivity will likely conflict with the need for accuracy and 

precision. Simply stated, values reported at lower concentrations do not inherently have 

greater accuracy or precision than higher concentrations. Quite the contrary, one often 

compromises accuracy and precision as sensitivity increases. This is a serious flaw in 

EPA's approach to the problem at hand. However, it should be emphasized that a need 

for greater sensitivity should not abandon or compromise needs for accuracy and 

precision. (p. 1-2 of comments)

See Response 

3

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AO Comment #5. EPA states that the ML should be less than the applicable water quality 

criteria. However, when following EPA’s guidance in the Technical Support Document 

for Water Quality-based Toxics Control, the decision point for the reasonable potential 

process is the wasteload allocation (WLA) rather than the criteria. The language needs to 

be adjusted accordingly. (p. 2 of comments)

See Response 

14
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0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AP Comment #6. The ML is used by labs as an internal gauge of performance. However, 

independent reviews of performance (DMR QA studies, for example) generally do not 

monitor the actual performance of labs at concentrations approximating the ML. It is 

important that if the ML were to be used by EPA as suggested that stakeholders using 

laboratories to meet NPDES requirements have some assurance that test labs can actually 

meet the required quality objectives at or near the concentration of the ML. This will 

require a significant shift in how third parties (permittees, EPA, states) evaluate 

laboratories and this shift must occur before further weight is placed on the ML. (p. 2 of 

comments)

See Response 

3

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AQ Comment #7. The “Scope and Rationale of the Proposed Rule” states that where 

insufficient sensitivity among 40 CFR Part 136 methods is concluded the permitting 

agency would have the authority to require a non-promulgated method in a NPDES 

permit based on the proposed language of the rule. This is problematic given the 

uncertainty associated with such methods and the fact that the public is not provided an 

opportunity to comment on the reliability and use of the methods other than through a 

permit negotiations or a challenge. This issue becomes even more important with 

NPDES permit applications where the permittee has no opportunity for a formal 

comment process. This text is also problematic because it conflicts with the language of 

the actual proposed language where “an NPDES applicant may use any suitable 

sufficiently sensitive method”. The latter language indicates that selection of the method 

is made by the permittee rather than the permitting authority. The decision should be 

made by the permittee, but any method required by a regulatory authority must first be 

interlaboratory validated and shown to meet the regulatory authorities’ data quality 

objectives for the NPDES program. (p. 2 of comments)

See Response 

3

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D., Chief

AR Comment #8. States only have a maximum of 2 years to implement this rule once 

finalized. It is not clear how this rule will impact NPDES permits which will not be 

renewed for up to 5 year after the rule has been adopted. Does the CWA modification 

trump the permit? (p. 2 of comments)

See Response 

11 and 

Response 12

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AS Comment #9. The FR notice states that published methods “give only an upper, not a 

lower, bound on the lab’s MDL and minimum level”. This is not universally true because 

the ML of the published method may not be based on a representative sample of lab 

performance. For example, some MLs are based on the performance of research and 

federal labs but do not include the performance of industrial or municipal labs. This is 

one reason why it is important to test all methods intended for regulatory use in labs 

representing all stakeholders that will use or be held to use those methods. (p. 2-3 of 

comments)

See Response 

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0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AT Comment #10. EPA states that it will provide regular updates on water quality criteria to 

ensure that the states use sufficiently sensitive methods. This is irrelevant for states that 

have adopted their own water quality criteria. Once state criteria are EPA-approved, only 

the state criteria can be used. Later-developed EPA criteria do not replace the properly 

adopted state criteria. Rather, the states are under an obligation to update their criteria 

periodically, but pending the states’ updates the adopted state criteria still control for 

NPDES purposes. The language should be removed because it infers to the contrary. (p. 

3 of comments)

See Response 

13

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AU Comment #11. Upon promulgation of this rule, laboratories/permittees should be given 

sufficient time to change methodologies. The time period to do this should not start until 

the rule is incorporated by each regulatory authority and should be at least 18 months in 

length to allow for review and selection of labs or purchase of equipment and training. (p. 

3 of comments)

See Response 

12

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AV Comment #12. EPA requires that data be collected within 4.5 years prior to the NPDES 

permit renewal application and cover different periods of the year to address discharge 

quality variability. If the rule is finalized in December of 2010 and a permit renewal is 

due in 2012 sampling/analyses by the permittee have already begun and may not meet the 

requirement of the CWA modification. EPA and States should grandfather permit 

renewal data up to and including a date well after the rule is finalized to allow use of data 

already generated, to avoid loss of resources, and to avoid situations where permittees 

may be found in noncompliance because the data they provide does not complete the 

permit application. (p. 3 of comments)

See Response 

11

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AW Comment #13. The proposed rule specifically refers to “the method ML”. There are 

very few methods with a ML; therefore the proposed language does not address the vast 

majority of 40 CFR Part 136 methods. A footnote in the proposed rule states that the ML 

can also be “the lowest calibration point in a method”. Methods in 40 CFR Part 136 do 

not define the lowest calibration point to be used; this is decided by the respective 

laboratory. It would seem to be more appropriate to refer to “the lowest calibration point 

used by a laboratory”. (p. 3 of comments)

See Response 

3

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AX Comment #14. The proposed rule equates “ML”, “QL” and “RL”, however these terms 

do not always apply to methods and the rule specifically applies to methods. For 

example, the QL and/or the RL for a lab may be one value equal to or less than the 

method ML, but they are not necessarily equivalent with the ML. Using the ML 

definition of 3.18 x MDL, it would be nearly impossible for a lab to use 3.18 x MDL as 

the lowest calibration standard. This is particularly true for methods that measure dozens 

of analytes. It is much more practical for labs to adopt MLs that are similar in 

concentration across analytes and that are less than the respective WLAs than to calculate 

See Response 

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a MDL for each analyte, multiply each of those MDLs by 3.18, and then create dozens of 

dilutions equaling that product for dozens of analytes. Therefore, the QL/RL may be 5 

ppb for numerous analytes in EPA method 625 but the MDL x 3.18 for each analyte does 

not equal 5 ppb. (p. 3 of comments)

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AY Comment #15. The FR notice suggests that it will apply to NPDES pollution prevention 

programs for dischargers to wastewater treatment facilities. Given the sample matrix 

issues of such samples permittees may not be able to meet these requirements because 

matrix effects often require dilution of samples which increases the ML. Some of these 

samples may even damage components of the more sensitive instruments due to their 

high concentrations. (p. 3-4 of comments)

See Response 

9

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

AZ Comment #16. EPA concludes in the proposal that it “is expected to result in little or no 

new or increased burden to applicants or permittees”. This conclusion is based on a cost 

review of analytical methods conducted by EPA. This review included very few 

analytical procedures compared to those available in 40 CFR Part 136, equated single 

parameter methods with multi-parameter methods, and artificially biased the conclusions 

by grouping all method costs over $400 together. These issues, along with others, 

significantly increase the probability that the conclusions reached by EPA are not 

defensible. Therefore, the question of costs to permittees due to this rule has not been 

adequately answered. (p. 4 of comments)

See Response 

1

0013 Hampton Roads Sanitation 

District

Technical Services Division

James J. Pletl, Ph.D.

Chief

BA Comment #17. The proposed rule is problematic for many reasons and should not be 

pursued without first completely addressing the ML issues raised by EPA’s FACA on 

Detection and Quantitation. Given the EPA has not yet addressed these issues the 

process to complete this rulemaking should be suspended and the schedule for the 

rulemaking retracted. (p. 4 of comments)

See Response 

3
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0014 Environmental Laboratory 

Advisory Board Federal 

Advisory Commission

David N. Speis

Chair

BB Comment #1. The Environmental Laboratory Advisory Board (ELAB), the Federal 

Advisory Committee to EPA on issues related to laboratory measurement and 

accreditation, would like to comment on EPA's proposed rule for the Use of Sufficiently 

Sensitive Test Methods for Permit Applications and Reporting, 75 Fed. Reg. 35, 712-20, 

June 23, 2010. The proposed rule would require that, for NPDES permit purposes, 

analytical methods from 40 CFR Part 136 be used that have method minimum levels 

(ML) low enough to measure the amount of pollutant in a facility's discharge, the effluent 

limit in the permit, or the water quality criterion, or lacking such a method, the Part 136 

method with the lowest ML for the pollutant. Where there are no approved methods in 

Part 136 for a pollutant, the rule would suggest monitoring by unapproved methods, at 

the discretion of the director. 

Stakeholders have indicated to ELAB that while there are benefits to the concepts 

outlined in the rule, there is also the potential for unintended negative consequences. 

ELAB would like to meet with appropriate regulatory officials to further discuss the 

details prior to final promulgation of the rule. ELAB would like the opportunity to 

suggest improvements in the language to address stakeholder concerns so that the desired 

goals can be achieved without compromising the ultimate data quality objectives and 

resulting decisions. (p. 1 of comments)

EPA 

acknowledges 

the comment. 
41

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0015 The Inter Industry 

Analytical Group

BC Comment #1. Analytical methods need to be adequately characterized. Instead of 

the proposal, which is designed to force permit writers to assign sufficient methods even 

if none exist, EPA would be better served by adopting a uniform definition of detection 

limit and quantitation level and developing a consistent, non-iterative, non-arbitrary 

method for determining them – a method that does not merely multiply the detection limit 

by some constant to estimate the quantitation limit. And the definitions should start with 

measurement quality objectives (MQOs) that specify the level of performance that an 

analytical method should achieve. Uniform definitions and a consistent method for 

determining DLs and QLs would provide a “level playing field” and avoid having 

different DLs and QLs for the same method from jurisdiction to jurisdiction or even from 

lab to lab. 

It is essential that the precision, bias, and quantitation limits of analytical methods be 

known if they are to be used to measure compliance with legal requirements (NPDES 

permit limits). In § 304(h) of the Clean Water Act, Congress directed EPA to 

“promulgate guidelines establishing test procedures for the analysis of pollutants.” 33 

U.S.C. § 1314(h). Even without the statute, it is a bedrock principle of Due Process that a 

person cannot be held liable for violating a law if he was not given notice of what 

behavior would violate it. In addition, an agency lacks the power to find a “violation” 

when the measured departure from a standard is within the boundaries of probable 

measurement error. Amoco Oil Co. v. EPA, 501 F.2d 722, 743 (D.C. Cir 1974).

Industry experts in analytical methods have insisted for decades, both in dialogue with 

EPA [footnote omitted] and in the court cases summarized below, that EPA should 

determine and publish the characteristics of analytical methods that are to be used for 

compliance monitoring. Members of the IIAG have gone to court several times to defend 

this principle.

When EPA published the Part 136 regulations on October 26, 1984, 49 Fed. Reg. 43,234 

(corrected at 50 Fed. Reg. 690-97 (Jan. 4, 1985)), one IIAG member sought review in the 

Fourth Circuit Court of Appeals. Virginia Electric & Power Co. v. EPA, Doc. No. 84-

2227 (4th Cir., petition for review filed Nov. 9, 1984). UWAG asserted that the Part 136 

rules did not adequately take into account the precision and bias of the analytical 

methods. The case was settled in 1985.

EPA published its final direct current plasma (DCP) method and other methods in 1990. 

55 Fed. Reg. 24,532 (June 15, 1990). On October 1, 1990, several companies filed 

See Response 

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petitions for review in the Fourth Circuit Court of Appeals, primarily because EPA 

claimed it was not legally required to validate test methods based on interlaboratory data 

or publish performance data for tests it was adding to Part 136. To address this issue, 

EPA published a technical correction to the DCP rule that incorporated the DCP protocol, 

including an appendix with method performance data. 56 Fed. Reg. 43,702 (September 4, 

1991). Upon a motion by UWAG, the Fourth Circuit case was dismissed as unripe 

December 4, 1991. UWAG preserved its right to raise issues of analytical variability in 

future Part 136 rulemakings.

Members of the IIAG also challenged EPA’s Method 1631B for mercury. They 

petitioned the D.C. Circuit to review the rule, challenging the procedures EPA used to 

establish the MDL and ML. On October 19, 2000, EPA and the industry petitioners 

agreed to a settlement by which EPA would propose revised methods for determining 

detection and quantification limits. See 68 Fed. Reg. 11,773 (March 12, 2003).

EPA’s proposal, published March 12, 2003, was unsatisfactory. In 2003, 36 companies 

and organizations, representing a broad cross-section of municipalities, industries, and 

laboratories, wrote the Assistant Administrator for EPA’s Office of Water about the 

shortcomings in EPA’s MDL and ML procedures. Letter to G. Tracy Mehan, III, RIN 

2040-A053, August 15, 2003 (re 69 Fed. Reg. 11,770 (March 12, 2003)). The 36 signers

of the letter agreed on six “Consensus Principles on Detection and Quantitation Levels.” 

Among the consensus principles was agreement that the Office of Water’s proposed 

MDL and ML procedures “do not provide a scientifically acceptable basis for 

establishing detection and quantitation levels, nor do they provide a sound basis for 

ascertaining compliance with NPDES permit limits set below levels of quantitation.”

The widespread dissatisfaction with EPA’s MDL and ML led EPA to convene a Federal 

Advisory Committee (the FACDQ), which provided its recommendations in December 

2007.Report of the Federal Advisory Committee on Detection and Quantitation 

Approaches and Uses in Clean Water Act Programs 46 (December 2007) (hereinafter 

“FACDQ Report”). The FACDQ was composed of representative stakeholders from state 

regulatory agencies, municipalities, environmental laboratories, environmental groups, 

industry, and the EPA Office of Water. Four members from IIAG companies sat on the 

FACDQ. Among other things, the FACDQ agreed unanimously that the current MDL 

procedure has deficiencies that “can and should be corrected.” FACDQ Report 62.
43

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In short, industry has for over 26 years pressed the position, well supported by the science 

of analytical chemistry and by considerations of due process and fundamental fairness, 

that analytical measurements used to determine compliance with legal requirements 

should be well characterized and their variability made known to the public and the 

regulated community. After 26 years, these issues remain unresolved, and we regret that 

with the proposed Sufficiently Sensitive rule, EPA has not only failed to make progress 

on these issues but has taken several steps backward. (p. 2-4 of comments). 

0015 The Inter Industry 

Analytical Group

BD Comment #2. The proposed rule summarizes the flaws in the system but makes no 

effort to correct them.

This proposed rule is, frankly, a retreat from good science. In it EPA abandons the 

bedrock principle that regulatory decisions should be based on established measurement 

techniques whose characteristics (precision, bias, detection limit, and quantitation level) 

have been determined, and indeed determined by data from multiple laboratories to 

reflect real-world conditions.

Part of the proposed rule, to be sure, seems reasonable on its face as far as it goes: 

NPDES permittees should use analytical methods that are capable of measuring down to 

the permit limits and water quality criteria that have to be achieved. About that there can 

be no disagreement in principle, if there are such methods that produce reliable, 

consistent results.

See Response 

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But that is not the kind of guidance NPDES permittees and State permit agencies need. 

The problem that has vexed the regulated community, laboratories, and permit writers for 

years is what to do when there is not a well-characterized method that will reliably 

quantify analytes at appropriately low levels. EPA’s proposed rule fails to resolve this 

fundamental problem.

Footnotes 4, 5, and 7 in the Federal Register notice at 75 Fed. Reg. 35,714-15 provide a 

glimpse into the present regulatory system, with all its flaws:

(4) The term “minimum level” refers to either the lowest calibration point in a method or 

a multiple of the method detection limit (MDL), whichever is higher. Minimum levels 

may be obtained in several ways: They may be published in a method; they may be the 

lowest acceptable calibration point used by a laboratory; or they may be calculated by 

multiplying the MDL in a method, or the MDL determined by a lab, by a factor. 

[Citations omitted].

(5) For the purposes of this rulemaking, EPA is considering the following terms to be 

synonymous: “quantitation limit,” “reporting limit,” and “minimum level.”

7 To address this situation some State permitting authorities have developed a list of 

monitored parameters and prescribed a required minimum level that must be achieved for 

each parameter as a part of their State regulations or policy.

75 Fed. Reg. 35,714-15.

This reflects the shortcomings of the present system, but EPA’s proposal serves only to 

accept and perpetuate those shortcomings. Instead of defining the “minimum level” in 

footnote 4, EPA notes that the ML has several meanings, making it largely meaningless 

for practical purposes. A permit writer, a permittee, and an environmental group may 

each interpret the term “minimum level” differently as presented. Comparing different 

analytical methods by using a term with no established definition is senseless, because 

different methods may be characterized with respect to “quantitation” in completely 

different and noncomparable ways.

In particular, the ML depends on the sample matrix. As EPA notes in footnote 6, the 

MDL is determined from analysis of a sample in a given matrix. But the ML used by a 

regulatory agency might be based on an entirely different matrix from the permittee’s 
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wastewater discharge. Disagreements between regulators and permittees are certain to 

result.

Suppose, for example, that a permittee, using its actual wastewater, finds that the ML in 

its matrix (not the published one) is below the water quality criterion or permit limit and 

thus “sufficiently sensitive”? The regulatory agency, using lower MLs from reagent 

water, might demand a different analytical method with an ML that could not consistently 

be attained in practice, causing the permittee to appear to be in noncompliance.

Part 2 of the proposed three-part definition makes a method “sufficiently sensitive” if 

“[t]he method minimum level is above the applicable water quality criterion or permit 

limitation, but the amount of the pollutant or pollutant parameter in a facility’s discharge 

is high enough that the method detects and quantifies the level of the pollutant or 

pollutant parameter in the discharge.” However, this definition fails to specify what it 

means for a method to “detect” and “quantify.” By “detect” EPA may mean “register a 

signal higher than the MDL.” But the MDL is widely recognized as being highly variable 

and unanchored. Again, a definition for “quantify” is conspicuously absent from EPA’s 

proposal.

To make matters worse, footnote 5 at 75 Fed. Reg. 35,715 col. 1 says that EPA considers 

“quantitation limit,” “reporting limit,” and “minimum level” to be synonymous. Thus 

EPA accepts not only multiple “MLs” as though they were all the same but multiple 

“MLs,” “quantitation limits,” and “reporting limits” as though they were all the same. 

This sort of framework does nothing to ensure that the most sensitive method is used. The 

attached report by API, Analytical Detection and Quantification Limits: Survey of State 

and Federal Approaches (Pub. No. 4721) (June 2002), illustrates this very point. It 

demonstrates how many different procedures are being used to set benchmarks for 

quantification and how variable – and arbitrary – these various procedures are.

To further complicate matters, some published methods do not specify an ML at all. For 

such methods EPA’s proposal leaves permittees and regulators in the dark. If there is no 

published ML, what is the permittee to do? Use the method MDL multiplied by a 

constant? Use the lowest calibration standard listed in the published method? Use an 

individual laboratory’s MDL multiplied by a constant? Use the individual laboratory’s 

lowest calibration standard?

On page 35,716 EPA backs away from the need to establish predictable detection and 

quantitation limits:EPA acknowledges that a laboratory might achieve MDLs and 
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minimum levels lower than those published when the promulgated method was 

developed. Thus, the Director should not rely solely on MDLs or minimum levels in 

published methods because they give only an upper, not a lower, bound on the lab’s MDL 

and minimum level. (Footnote omitted.) This may imply that states can set a testing 

requirement based on the performance of a single laboratory. It would promote widely 

varying detection and quantitation limits from state to state and even from laboratory to 

laboratory.Much of the effort of members of the FACDQ was directed to avoiding such a 

result by seeking a uniform, national QL national to discourage the practice of relying on 

the performance of a single laboratory. Out of twenty FACDQ members, only one 

(EPA’s Office of Water) opposed specific recommendations about how EPA should set 

target Measurement Quality Objectives for setting National Quantitation Limits, and even 

EPA agreed that it should promulgate how a National Quantitation Limit is derived. 

FACDQ Report 37.Moreover, in defining “sufficiently sensitive” EPA creates more 

confusion than clarity. In EPA’s proposed formulation, a “sufficiently sensitive” method 

is, among other things, a method whose ML is lower than the “applicable” water quality 

criterion. What this means in practice is ambiguous. A better definition would be a 

quantitation level below a water quality criterion for the measured pollutant or pollutant 

parameter “that is contained in water quality standards that have been adopted for the 

water receiving the effluent.”

Another problem is that the proposal fails to distinguish between water quality standards 

and permit limits that are derived from water quality standards. In determining 

“reasonable potential,” the permitting authority, referring to EPA’s proposed rule, will 

demand an analytical method with an ML below the in-stream water quality criterion. But 

if the resulting permit limit is higher than the in-stream criterion, the permitting agency 

should allow any method with a quantitation level below the permit limit, even if it is 

above the water quality criterion. EPA’s proposed rule makes it unlikely a regulatory 

agency will recognize this distinction. Another problem with the proposed rule is that it 

might be read to require a “sufficiently sensitive” method even when the method by its 

own terms should not be used. Method 1631 for mercury, for example, is very sensitive. 

But because it is so sensitive, contamination is a problem, and “clean” sampling methods 

(as described in a different publication, EPA Method 1669) are called for. But Method 

1669 itself (§ 1.4) says that “[t]his method is not intended for determination of metals at 

concentrations normally found in treated and untreated discharges from industrial 

facilities.” It is virtually impossible, in an industrial setting, to avoid contamination by 

suiting up, as 1669 requires, in suits, gloves, and masks.
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Moreover, Method 1631 suggests soaking laboratory air intake filters in gold chloride 

solution so that mercury in incoming air will amalgamize with the filter’s gold. Are labs 

required to go to such lengths to be “sufficiently sensitive”? If not, how is a laboratory to 

know which precautions to take?

Still another problem with the proposed rule is how it is to be interpreted for technologybased limitations of “zero” or “no discharge” (where the Subchapter N or O regulations 

do not specify the method to be used for compliance monitoring). Since such limits can 

only be based on the administrative record at the time they were promulgated, they 

should not be interpreted as concentrations that can be detected by analytical methods 

that were not in use at the time. A “zero” or “no discharge” or “nondetect” limit should 

be understood to mean no lower than the detection limit of the analytical method that 

EPA used to determine that zero discharge was achievable and to establish the limit, not 

some newer method capable of detecting even lower levels of the pollutant.

Some of the above problems could be ameliorated if EPA would expressly allow 

permittees to use a less sensitive method where it serves the regulator’s purpose. For 

example, suppose an NPDES permit requires sampling an internal wastestream where the 

pollutant concentration is higher than it is at the ultimate outfall to waters of the United 

States. In such a case the permittee should be allowed to use any approved method 

sensitive enough to measure the levels at the internal point, even if the method’s 

minimum level is higher than the ultimate effluent limit at the outfall. In short, the 

proposed rule should say that the most sensitive method need not be required in 

circumstances in which the permitting agency determines that the most sensitive method 

is not necessary. (p. 5-10 of comments)

0015 The Inter Industry 

Analytical Group

BE Comment #3. The Federal Register notice establishes the need for measurement

quality objectives but does nothing about it. The preamble to the proposed rule makes 

a good case for establishing measurement quality objectives (MQOs) [footnote omitted] 

for analytical methods. For example, on page 35,715 EPA says that precision and 

accuracy are important, indeed “critical”:

“It is critical, therefore, that applicants provide data that have been measured with 

precision and accuracy so that they will be meaningful to the decision making process.”

Similarly: “As discussed earlier, it is critical that the Director make permitting decisions 

based on accurate data and, thus, sound science. The use of imprecise analytical methods 

See Response 

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could lead the Director to make assumptions regarding the presence or absence of a 

pollutant in an applicant’s discharge.”

And in the same paragraph EPA explains why imprecise methods could be harmful: 

Moreover, if the Director were to include imprecise analytical methods in permits for 

compliance monitoring purposes, the use of such methods could result in undetected 

exceedances of permit limits.

These passages reinforce the fundamental point that the IIAG has been advocating for 

years: analytical methods used for regulatory purposes should meet measurement quality 

objectives. These MQOs should be set on the basis of data from multiple laboratories so 

that the characteristics of a method, as used by different permittees, different regulatory 

agencies and different laboratories, are known.

EPA has already spent considerable effort toward setting data quality objectives. See, 

e.g., EPA QA-4, Guidance for the Data Quality Objectives Process (EPA/600/R-96/055 

August 2000). Moreover, the Federal Advisory Committee would have recommended 

that EPA establish data quality objectives where detection and quantitation limits are 

used in decision making, except that the EPA Office of Water representative on the 

Committee disagreed. FACDQ Report 7. Even so, the FACDQ did recommend a ≤ 1% 

false positive rate objective for detection and an initial objective of ≤ 5% false negatives 

for promulgated methods. FACDQ Report 9. Only the EPA Office of Water disagreed 

with the recommendation that target measurement quality objectives be established for 

quantitation limits in Part 136. Id. 10. Yet the proposed rule ignores the need for quality 

objectives and indeed takes a step back from them.

Avoiding a commitment to set data quality objectives is not consistent with other EPA 

programs. Under EPA’s RCRA program, the Office of Solid Waste (OSW) uses precise 

statistics (80% coefficient of the confidence interval) to demonstrate whether a waste is 

hazardous. Also, the OSW has rejected the MDL.

The FACDQ, with only EPA disagreeing, determined that EPA should establish Data 

Quality Objectives (with indicators and Measurement Quality Objectives) for Clean 

Water Act programs where Detection/Quantitation Limits are used in decision making 

(FACDQ Report 7). There was unanimous agreement that, in order to maintain 

consistency, EPA programs that reference the MDL procedure should consider adopting 

whatever procedure replaces it (id. 59). Again, only the EPA representative disagreed that 
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EPA should evaluate and modify the uses of data in Clean Water Act programs (id. 60).

(p. 10-12 of comments)

0015 The Inter Industry 

Analytical Group

BF Comment #4.Fourth, many 40 CFR Part 136 methods have no ML defined in the method 

at all. Therefore the ML would have to be defined using one of the arbitrary techniques 

EPA throws out in footnote 4 (that is, a multiple of the MDL or the lowest calibration 

point). What is not clear is whether the MDL in such cases would be based on the 

method-defined MDL (MDL method) and calibration range or the performance of an 

individual lab. If it is defined by the individual lab, will it be based on a lab wide MDL 

(MDL lab) or calibration range or on the basis of a single instrument within the 

laboratory? Will the MDL be determined using reagent water, or in the matrix being 

tested? Footnote 6 leaves these questions unanswered:The MDL is determined using the 

procedure at 40 CFR 136, appendix B. It is defined as the minimum concentration of a 

substance that can be measured and reported with 99 percent confidence that the analyte 

concentration is greater than zero and is determined from analysis of a sample in a given 

matrix containing the analyte.Finally, most of EPA’s calibration criteria are so wide as to 

be almost meaningless. In some cases they have been shown to lead to significant bias.

(p. 12-13 of comments)

See Response 

3

0015 The Inter Industry 

Analytical Group

BG Comment #5. The rule for when there is no approved Part 136 method will weaken 

40 CFR Part 136 and EPA’s ATP program.

A serious problem with the proposal is that it largely abandons the drive for reliable new 

methods. Instead it sacrifices quality and predictability in order to force permitting 

agencies to focus on methods that will purportedly measure as low as legal standards 

require – regardless of the quality of the data.

Section 122.44(i)(iv) as presently written requires that, if there is no approved Part 136 

method, monitoring must be conducted according to a test procedure “specified in the 

permit.” 40 CFR §§ 122.44(i)(iv), 122.21(j)(4)(viii) (2009). The proposed change would 

require a “sufficiently sensitive” method specified in the permit:

[When there is no Part 136 method] monitoring shall be conducted according to a 

sufficiently sensitive test method ....

Proposed 40 CFR § 122.44(i)(1)(B), 75 Fed. Reg. 35,720 col. 2. Thus, when EPA for any 

reason has failed to develop and approve a method suitable for Part 136, states and 

regions would be required to find a method that would register a signal at the level of the 

See Response 

3 and 

Response 18
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legal standards, with the only condition being that they describe the method and 

“document” an “ML” of some kind.

This proposal would create a shortcut around the provisions (however inadequate) that 

EPA has created over the years to try to ensure the integrity of environmental data. It is 

unwise for several reasons.

First, the requirement to use any method with a “documented” ML forces permitting 

agencies to use unapproved methods outside the framework of EPA’s Alternate Test 

Procedure (ATP) Program. See http://www.epa.gov/waterscience/methods/atpl. Sections 

136.4 and .5 of 40 CFR establish the ATP program, and they contain procedural 

safeguards. Unfortunately, the proposed “any sufficiently sensitive method” rule contains 

none. In effect, it may make 136.4 and .5 irrelevant. It would require permit writers to 

specify “alternative” methods without meeting any of the requirements of the ATP 

program. Henceforth, the only requirement for an alternative method would be that it was 

capable of measuring down to legal standards. If there is no method in Part 136, any 

sufficiently “sensitive” method would do, no matter how variable the results or how 

robust the method.That is not to say the existing ATP program is perfect either. EPA 

should adopt measurement quality objectives for the ATP program. Then, for the 

different levels of demonstration (a method to be used only for a single discharger, a 

method to be approved statewide, or a method to be approved for the entire country), 

approval of non-part 136 methods in quest of better sensitivity should follow the structure 

of the ATP program (distinguishing, for example, among methods to be made by a single 

lab, by several labs using a single matrix, or by several labs using multiple 

matrices).Second, although footnote 8 is correct that there is similar language in § 

122.21(g)(7), the new proposed language expands this language into something new 

entirely. Subsection (g)(7) refers to “effluent characteristics” as characterized in the 

permit application for the purpose of determining “reasonable potential” to contribute to a 

water quality criterion exceedance. The new proposal, on the other hand, applies to all 

compliance monitoring. The data quality requirements for determining reasonable 

potential and for compliance monitoring may be, and in some cases should be, different, 

with compliance determinations demanding a higher level of quality.

More important, the current language of § 122.21(g)(7) requires a “suitable” method, 

which surely means suitable in terms of data quality, not just the ability to detect a signal 

at low levels. The new “sufficiently sensitive” language lacks any reference to 

“suitability” at all. The only requirement (other than measuring to a low-enough level) is 
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to have a “documented” ML.

Third, the entire measure of quality under the proposal is the ML. Thus the proposed rule 

incorporates the shortcomings of the ML described above. An ML could be based on a 

single laboratory’s performance or calibration range and could be determined in different 

ways by different labs or by the same lab using different instruments.

Fourth, the requirement that the ML be “documented” is exceptionally vague. 

Conceivably this may require nothing more than something in writing. The rule contains 

no requirements to ensure that the ML is replicable from laboratory to laboratory. A 

laboratory could run a calibration to a lower-than-usual range and provide no 

documentation of or information on method performance. EPA should insist on a higher 

standard of documentation of method performance for non-Part 136 methods than “the 

applicant shall provide a description of the method, including documentation of the 

minimum level.” EPA has established tiers of method validation in its ATP program, and 

there is no reason why a similar set of requirements should not be a part of this proposed 

regulation.

Fifth and finally, requiring the use of any “sufficiently sensitive” method when there is no 

Part 136 method removes the incentive to develop better analytical methods in the future. 

If the proposed rule is adopted, no regulatory agency need take responsibility for 

improving analytical methods. An agency may simply require each permittee to find a 

“sufficiently sensitive” method (even if none exists), require it in a permit, and be done. 

Part 136 of 40 CFR would become largely superfluous, with no provision for updating it 

or need to update it as far as the regulatory agency is concerned. This is not what 

Congress intended when it directed EPA in § 304(h) to “promulgate test procedures for 

the analysis of pollutants.”

The FACDQ unanimously agreed that EPA should continue to act as the national lead for 

Clean Water Act programs in developing analytical methods and setting the performance 

standards for those methods (FACDQ Report 60). The proposed rule is contrary to that 

recommendation. (p. 13-16 of comments)
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0015 The Inter Industry 

Analytical Group

BH Comment #6. EPA’s analysis of “impacts” is inadequate. At pages 35,717-18 of the 

Federal Register notice, EPA analyzes the “impacts” of the proposed rule. The discussion 

contains no dollar numbers, but EPA’s conclusion is that “the proposed rule is expected 

to result in little or no new or increased burden to applicants or permittees.”This finding 

is not credible. Anyone who uses laboratory methods knows that a rule designed to force 

permittees to use newer and more sensitive analytical methods, including methods so new 

they have not been included in 40 CFR Part 136, will increase costs significantly. EPA’s 

contrary conclusion, based on cost ranges provided in NEMI and assumptions used in 

past ICRs, is arbitrary. (p. 16-17 of comments)

See Response 

1

0015 The Inter Industry 

Analytical Group

BI Comment #7. Conclusion. In concept, part of the proposed rule is sound. That is, 

clarifying that analytical methods should be able to measure down to the level of legal 

requirements would be useful if done correctly. Also, the idea that it is not necessary to 

use a more sensitive method if the analyte is present within the range of acceptable 

performance of a less sensitive method is reasonable and appropriate, and would save 

money without compromising data quality.

However, the license to use any “sufficiently sensitive” method so long as it is described 

and its ML documented is unacceptable, in that it will result in poor-quality data and 

allow poor-quality data to be used to impose penalties and to brand permittees as 

“violators.”

Instead of this flawed rule, EPA should establish measurement quality objectives, a single 

meaningful definition of detection and quantification, and appropriate procedures for 

determining detection limits and quantitation levels of methods. A consistent framework 

along these lines would help permitting agencies make meaningful decisions about the 

relative sensitivities of different methods. (p. 17 of comments)

See Response 

3

0016 Metro Wastewater 

Reclamation District

Theresa Pfeifer

Regulatory Compliance 

Officer

BJ Comment #1. The rule needs to define “minimum level” and what it is based on.(p. 1 of 

comments)

See Response 

3

0016 Metro Wastewater 

Reclamation District

Theresa Pfeifer

Regulatory Compliance 

Officer

BK Comment #2. There is no discussion of the need to validate methods and/or the accuracy 

requirements of the method. The rule should require methods to be scientifically 

acceptable and have to meet EPA’s Alternate Test Method criteria. (p. 1 of comments)

See Response 

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0016 Metro Wastewater 

Reclamation District

Theresa Pfeifer, Reg. Comp. 

Ofcr.

BL Comment #3. How do the concepts in EPA’s performance-based guidance apply to this 

situation? (p. 1 of comments)

See Response 

3

0016 Metro Wastewater

Reclamation District

Theresa Pfeifer

Regulatory Compliance 

Officer

BM Comment #4. What if the Permittee is unable to locate a lab achieving a method 

minimum level low enough to determine compliance? Will EPA or States provide 

guidance in those situations or have a list of labs capable of achieving required minimum 

levels? Or what if costs to run the analyses are exorbitant compared to other methods? 

Any variances for such issues? (p. 1 of comments)

See Response 

3

0016 Metro Wastewater 

Reclamation District

Theresa Pfeifer

Regulatory Compliance 

Officer

BN Comment #5. The proposed rules states, “When no analytical method is approved under 

40 CFR 136, required under subchapter N or O, or otherwise required by the Director, an 

NPDES applicant may use any suitable sufficiently sensitive method; however, the 

applicant shall provide a description of the method, including documentation of the 

minimum level.” The rule also goes on to state, “the Director must specify a sufficiently 

sensitive analytical method as a condition of the NPDES permit.” What if the NPDES 

permit does not specify a sufficiently sensitive method; are you required to comply with 

40 CFR 136 until the permit requires sufficiently sensitive methods? What if there are no 

water quality standards for a pollutant; can you use any method?(p. 1 of comments)

See Response 

10 and 

Response 18

0016 Metro Wastewater 

Reclamation District

Theresa Pfeifer

Regulatory Compliance 

Officer

BO Comment #6. The State of Colorado (which is a delegated NPDES state) requires under 

the Pretreatment Section of its CDPS permits, “If based upon information available to the 

Permittee, there is reason to suspect the presence of any toxic or hazardous pollutant 

listed in Table V, or any other pollutant in a quantity or concentration known or 

suspected to adversely affect DWTW operation, receiving water quality, or solids 

disposal procedures, analysis for those pollutants shall be performed at least (required 

frequency) on both the influent and the effluent.” And “Where analytical techniques are 

not specified or approved under 40 CFR Part 136, the Permittee shall use its best 

professional judgment and guidance from the State and the Approval Authority regarding 

analytical procedures.” Will the Director address all of the pollutants identified in Table 

V and the required minimum detection limit or will this section now be site-specific 

detailing what pollutants from Table V must be monitored by the Permittee and, for those 

with no method approved by 40 CFR 136, detail the method(s) that must be used? (p. 1-2 

of comments)

See Response 

9

0017 New Jersey Department of 

Environmental Protection

Bureau of Surface Water 

Permitting

BP Comment #1. The term minimum level is defined under footnote 4 at the bottom of page 

35714 of the Federal Register and continuing onto the top of page 35715 as “either the 

lowest calibration point in a method or a multiple of the method detection limit (MDL), 

whichever is higher”. However, we could not locate a definition of this term in the actual 

See Response 

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Pilar Patterson

Chief

rule language. Please provide a definition in the rule text or location where the definition 

may be found.(p. 1 of comments)

0017 New Jersey Department of 

Environmental Protection

Bureau of Surface Water 

Permitting

Pilar Patterson

Chief

BQ Comment #2. The amendments at 40 CFR 122.21(e)(3)(i) state that a method approved 

under 40 CFR part 136 is “sufficiently sensitive” when the “method minimum level (ML) 

is at or below the level of the applicable water quality criterion for the measured pollutant 

or pollutant parameter” or “the method ML is above the applicable water quality 

criterion, but the amount of the pollutant or pollutant parameter in a facility’s discharge is 

high enough that the method detects and quantifies the level of the pollutant or pollutant 

parameter in the discharge.” Each of these “sufficiently sensitive” method criteria cite the 

applicable water quality criterion as the reference level for the analytical method.

As cited at 40 CFR 122.44(d)(1)(ii) the applicable water quality criterion plays a critical 

role in determining the need for water quality based effluent limitations (WQBELs) for a 

pollutant. However, other factors play important roles as well; including, where 

appropriate, the dilution of the effluent in the receiving water. When dilution is available 

for a facility’s discharge, the maximum allowable effluent value is greater than the 

applicable water quality criterion. Please clarify the intent of the rule when addressing the 

site-specific factors identified at 40 CFR 122.44(d)(1)(ii). (p. 1 of comments)

See Response 

14

0017 New Jersey Department of 

Environmental Protection

Bureau of Surface Water 

Permitting

Pilar Patterson

Chief

BR Comment #3. According to the proposed rule, it seems clear that only data that are at or 

above the minimum level (ie. Quantitation limit and not detection limit) are acceptable 

for NPDES purposes. Many laboratories typically report data that is below their 

quantitation limits but still detectable. This data is typically qualified or flagged with a 

“J” to designate an estimated concentration value. Please confirm that laboratory data 

results below the quantitation or minimum level and qualified as estimated are 

unacceptable for NPDES purposes. (p. 1-2 of comments)

See Response 

7 and 

Response 11

0017 New Jersey Department of 

Environmental Protection

Bureau of Surface Water 

Permitting

Pilar Patterson

Chief

BS Comment #4. In footnote 12 of the proposed rule, one example of an acceptable 

modification is provided. It states that “Examples of such modifications may include 

changes in the sample preparation digestion procedures such as the use of reagents 

similar in properties to ones used in the approved method”. It was our understanding that 

a change in reagents was not an allowable modification, as it would result in a change in 

chemistry. This because “similar in properties” is not well defined. 40 CFR Part 136.6 

Section a.6.b.1 states “an analyst may modify an approved test procedure (analytical 

method) provided that the chemistry of the method or the determinative technique is not 

changed”. Section a.2 of that rule defines chemistry of the method as “the reagents and 

reactions used in a test procedure that allow determination of the analyte(s) of interest in 

an environmental sample”. Please comment further on the acceptability of allowing for 

See Response 

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changes to reagents with similar properties and, specifically, how this rule will allow 

changes in reagents when previous versions did not. (p. 2 of comments)

0018 American Petroleum 

Institute

BT Submitted report titled: “Analytical Detection and Quantification Limits: Survey of State 

and Federal Approaches”

EPA 

acknowledges 

the comment. 

0019 Ford Motor Company

Ford Environmental Quality 

Office

John H. Phillips

BU Comment #1. EPA characterizes this proposal as a minor amendment of the CWA to 

codify that under the NPDES program only “Sufficiently Sensitive” analytical test 

methods may be used when completing NPDES permit applications and when performing 

sampling and analysis to monitor compliance with the permit. While this may be a 

“minor” wording change it is far from a minor revision to the CWA, because of its far 

reaching ramifications. This specific wording change has large implications related to 

compliance assessment and enforcement. The impact of pending EPA Office of Water 

actions, such as the promulgation of Method 1668 (PCB Congener Analysis by 

HRGC/HRMS) and a new MDL procedure would be much greater should this proposal 

be accepted as written. The EPA needs to complete the long awaited revised MDL/ML 

rule making, which will consistently define detection (MDL) and quantification (ML), 

based on sound scientific principles before it can proceed with this proposal.

The two commendable objectives of this proposal are; 1) the desire to be able to 

accurately measure the pollutant of concern in the matrix of concern at the permit 

(WQBEL) limit when ever possible and 2) the use of only “quantitative” data (results 

above the method Quantitation Limit) when assessing compliance. Unfortunately this 

proposal fails miserably to achieve either of these objectives.

See Response 

3

0019 Ford Motor Company

Ford Environmental Quality 

Office

John H. Phillips

BV Comment #2. Under footnote #4 it explains that the Minimum Level (ML) can be 

derived a number of different ways. This is true because the USEPA has not been 

consistent or uniform in the way it defines and derives the ML. It can be the lowest point 

on a calibration curve or it can be some multiple of the MDL with some being undefined 

(0.5x, 1x, 5x, 10x, 100x, ?x). The lowest acceptable calibration point does not ensure the 

ability to quantify or even detect an analyte in wastewater matrix at that concentration. 

Not only is the MDL an unanchored and highly variable parameter (very lab, instrument, 

technique and matrix dependent), but the multiplier used to derive the ML has not even 

been defined. Per recommendations of the FACDQ and the EPA Office of Quality 

guidance (EPA QA/G-4) the quantitation (ML) must be defined based on method 

precision and bias (not arbitrarily) and the detection (MDL) must be based on both false 

positive and false negative error rates. Footnote #5 equates the ML as the “quantitation 

See Response 

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limit” and footnote #6 defines the MDL as only addressing false positive error rates. The 

definition of the ML is nebulous and has not been clarified in any way in this proposal.

0019 Ford Motor Company

Ford Environmental Quality 

Office

John H. Phillips

BW Comment #3. At the end of the second paragraph it states, "Moreover, if the Director 

were to include imprecise analytical methods in permits for compliance monitoring 

purposes, the use of such methods could result in undetected exceedances of permit 

limits". By definition an "undetected exceedance" is a false negative, which is not 

controlled for or evaluated for by either the MDL or the ML. The third paragraph states 

that the Director must accept data that is generated only by sufficiently sensitive 

analytical methods. While this is good, the proposal fails to scientifically define what 

sufficiently sensitive means. The proposal uses a three part definition to describe when a 

method is "sufficiently sensitive".

At the end of the second paragraph it states, "Moreover, if the Director were to include 

imprecise analytical methods in permits for compliance monitoring purposes, the use of 

such methods could result in undetected exceedances of permit limits". By definition an 

"undetected exceedance" is a false negative, which is not controlled for or evaluated for 

by either the MDL or the ML. The third paragraph states that the Director must accept 

data that is generated only by sufficiently sensitive analytical methods. While this is 

good, the proposal fails to scientifically define what sufficiently sensitive means. The 

proposal uses a three part definition to describe when a method is "sufficiently sensitive".

1. The method minimum level (ML) is "at or below the level of the applicable water 

quality criterion or permit limitation."

2. The ML is above the applicable criterion or permit limit, "but the amount of the 

pollutant or pollutant parameter in a facility's discharge is high enough that the method 

detects and quantifies the level of the pollutant or pollutant parameter in the discharge."

3. The method has the lowest ML of the methods approved by EPA under 40 CFR 136.

This definition has several problems. First most Part 136 methods do not have MLs and 

when they do there is little consistency from one method to the next as to how the ML 

was derived. Second the ML or "quantitation limit" is rarely if ever established based on 

the ability to quantify at a known level of precision and bias. Third an ML derived in 

reagent water is not representative of how well a method can quantify an analyte in a real 

world matrix. Next the proposal allows the any lab to define what "sufficiently sensitive" 

means. As long as the lab can detect (which is not defined) and quantify (which is not 

See Response 

3 and 

Response 12
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defined) the level of the pollutant parameter in the discharge. The agency makes no 

attempt to define what it means to detect or quantify, so it becomes a completely arbitrary 

limit. How can we have a national standard or a national environmental database with 

comparable data when their are no absolutes. Not only will MDLs and MLs vary from lab 

to lab, but so will data quality.

The proposed rule further loosens data quality standards when it goes on to propose;

"When no analytical method is approved under 40 CFR 136, required under subchapter N 

or O, or otherwise required by the Director, an NPDES applicant may use any suitable 

sufficiently sensitive method; however, the applicant shall provide a description of the 

method, including documentation of the minimum level."

The responsibility is now moved away from the USEPA having to generate and 

promulgate sufficiently sensitive test methods to enforce its regulations and placed 

squarely on the permitting agency or the permittee. No criteria are provided, such as 

currently used by the EPA through the Alternative Test Procedure (ATP) approval 

process. This also eliminates public review of test methods and allows for the use of test 

methods which have not been validated or vetted for use in the CWA program. The only 

criteria given that a method is sufficiently sensitive is the ML. Unfortunately method 

sensitivity is not the only characteristic that allows one to accurately measure the 

concentration of an analyte at the required level. Method selectivity may be just as 

important or even more important than sensitivity when it comes to measuring pollutant 

concentrations in wastewater, surface water or groundwater. These matrices can be 

complex and present positive and negative interferences, which confound precision, 

accuracy and sensitivity. A highly sensitive method may be unable to quantify or detect 

the pollutant of interest until orders of magnitude over the method ML, in which case a 

more selective and less sensitive method may be a better choice, reducing the chance of 

false positives and false negatives and improving the precision and accuracy of the result.

The proposal goes on to say that individual States will need to amend their statutes or 

regulations if they do not require the use of sufficiently sensitive test methods. This will 

require significant time to accomplish as there will be many conflicts that arise between 

current state regulations and the new nebulous definition of "sufficiently sensitive" test 

methods. Some states such as Texas are already going down a different more 

scientifically defendable path regarding method sensitivity. If the states' programs are 

already more protective of the environment, because they use methods that are more 
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selective or use a more scientifically sound approach than "sufficiently sensitive" to set 

permit limits will those programs and rules be allowed to remain unchanged?

0019 Ford Motor Company

Ford Environmental Quality 

Office

John H. Phillips

BX Comment #4 This rule change will impact all NPDES permit holders directly 

(municipalities and industries with direct discharges of either wastewater or storm water) 

into a public waterway, but will impact many, many more parties who are indirect 

discharges to municipal systems with discharge permits. All laboratories currently 

providing analytical test results in support of NPDES programs will also be impacted, 

due to the requirement to provide method performance data (MDLs, RLs, QLs or MLs 

and calibration data). If there is no 40 CFR Part 136 method approved for a parameter of 

interest then the lab will need to develop or implement a new method, which is 

"sufficiently sensitive" to meet the permit conditions. These method development costs 

will likely be borne by the permit holder.

The cost to switch to a "sufficiently sensitive" method will almost always be higher, due 

to the higher method analytical costs. In some cases this cost can be an order of 

magnitude or more. The method costs derived from the NEMI database presented in the 

docket are clearly an insufficient cost analysis and misleading. Consider the following;

- There are hundreds of methods approved for use in 40 CFR Part 136, only 33 are 

evaluated for cost.

- Method costs are listed in broad price ranges only <$50, $51-$200, $201-$400 and 

>$400.

- No consideration is taken regarding the cost of a method that is able to analyze multiple 

parameters at a time verses single parameter methods (cost/parameter).

- No consideration is taken on how many additional methods may need to be used to 

achieve sufficient sensitivity for all parameters of interest.

- No consideration is taken for highly sensitive and very costly methods which have been 

proposed, but not yet promulgated, such as method 1668B.

- No consideration is taken for the need to develop additional methods for parameters, 

which do not currently have an applicable 40 CFR Part 136 method.

-Total compliance monitoring costs must include, sampling costs, test frequency, number 

of parameters, number of methods, specific methods, sample matrix, method QC, 

required detection and quantitation limits.

See Response 

1 and 

Response 9
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0019 Ford Motor Company

Ford Environmental Quality 

Office

John H. Phillips

BY Comment #5. Ford believes that this proposed rule is based on shifting and week 

foundations (the ML and MDL) at best and offers no improvement over the current 

regulatory status. This rule would clearly complicate the implementation of regulatory 

compliance programs. To the extent that EPA decides to proceed with a rule, that should 

not happen unless and until the Agency proceeds with, and completes, the rulemaking 

recommended by the FACDQ to clearly define key regulatory terms, including 

Quantitation Limit (ML) and Detection Limit (MDL). To assist EPA to that end we 

recommend the following changes if the rule is to be promulgated:

- Set target national measurement quality objectives for setting Quantitation Limits to 

replace the ambiguous MLs.

- Specify that in determining which method should be used, the permitting agency must 

consider, in addition to sensitivity, the important issues of accuracy and precision.

- Provide that test methods should not be used unless they have been validated. In 

addition, methods should have to meet the criteria set forth in the EPA "Alternate Test 

Procedure" program before they can be used.

- Include a provision specifying that in cases where there are matrix interference concerns 

with a specific effluent, alternate methods that are less sensitive, but have less of an 

interference problem, may be used.

(p. 1-3 of comments)

- Allow the permitting agency to determine, for site-specific reasons, that use of the 

sensitive method is not necessary (for example, if testing with a less sensitive method at 

an internal monitoring point can allow the permittee to calculate whether it is complying 

at the final effluent point)

See Response 

3

0020 Albuquerque Bernalillo 

County

Water Utility Authority

John M. Stomp III, P.E.

Chief Operating Officer

BZ Comment #1. Different laboratories report different minimum levels (MLs) for the same 

analytical method and some laboratories may have multiple MLs. EPA should clarify that 

if a laboratory is using the method listed in 40 CFR 136 with the lowest specified ML, 

then the permittee may choose a laboratory based on the analytical “method” not the 

laboratory specific ML. Considerations for contracting lab work from competing 

laboratories is dependent on many factors including ML and cost. (p. 1 of comments)

See Response 

3

0020 Albuquerque Bernalillo 

County

Water Utility Authority

John M. Stomp III, P.E.

Chief Operating Officer

CA Comment #2. 

EPA needs to define "suitable".

(p. 1 of comments)

See Response 

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0020 Albuquerque Bernalillo 

County

Water Utility Authority

John M. Stomp III, P.E.

Chief Operating Officer

CB Comment #3. Regarding "EPA acknowledges that a laboratory might achieve MDLs 

and minimum levels lower than those published when the promulgated method was 

developed..." (p. 35716 - bottom of column one, top of column two).

If a laboratory is able to achieve a lower MDL and ML than specified in a promulgated 

method:

-Does the laboratory need to go through a demonstration pursuant to 40 CFR 136.6 

before that method can be used for NPDES application or permit compliance purposes?

-Does EPA need to approve the demonstration? (p. 1-2 of comments)

See Response 

3 and 

Response 6

0020 Albuquerque Bernalillo 

County

Water Utility Authority

John M. Stomp III, P.E.

Chief Operating Officer

CC Comment #4. Some methods specified in 40 CFR 136 do not include MLs. Please 

explain how this rulewould apply to those methods. (p. 2 of comments)

See Response 

3

0020 Albuquerque Bernalillo 

County

Water Utility Authority

John M. Stomp III, P.E.

Chief Operating Officer

CD Comment #5. Please further explain what is meant by "method is otherwise required by 

the Director". EPA needs to ensure that any "required" methods are scientifically 

acceptable. EPA should list the criteria that will be used to determine the appropriate 

method. (p. 2 of comments)

See Response 

15

0020 Albuquerque Bernalillo 

County

Water Utility Authority

John M. Stomp III, P.E.

Chief Operating Officer

CE Comment #6. It is difficult to forecast an impact on applicants because future changes to 

Water Quality Standards and, therefore, requirements for using analytical methods with 

lower MDLs are not understood at this time. (p. 2 of comments)

See Response 

1

0020 Albuquerque Bernalillo 

County

Water Utility Authority

John M. Stomp III, P.E., COO

CF Comment #7. EPA should build in flexibility for the Director to determine, for sitespecific reasons, that the use of an extremely sensitive method is not necessary (e.g., 

testing at an internal monitoring point with a less-sensitive method to determine if 

treatment processes are performing correctly). (p. 2 of comments)

See Response 

3

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CG Comment #1. ODEQ has previously submitted comments on a proposal by EPA Region 

6 to lower MQLs. These comments explained the practical and financial difficulties 

faced by the permittees and the Oklahoma accredited laboratories for the implementation 

of the proposed MQLs. Many of our previous comments also apply to EPA's proposed 

methods contained in this notice of modifications of 40 CFR Parts 122 and 136. These 

financial concerns have been magnified by the current recession this country is 

See Response 

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experiencing. The financial burdens are even more of a concern and more still for small 

municipalities and businesses. (p. 1 of comments)

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CH Comment #2. 

EPA Region 6 has stated that these MLs are based on routinely achievable levels, but 

does not indicate that these levels were achieved in a typical wastewater effluent matrix. 

EPA Region 6 goes on to say that a Federal Advisory Committee (FAC) has been formed 

to publish Minimum Levels (MLs) reflecting matrix effects. EPA should not publish this 

rule requiring the use of these methods without the appropriate MLs to address matrix 

effects. EPA should present this proposal to an organization such as the EPA FACA or 

the Environmental Lab Advisory Board for discussion before proposing to modify 40 

CFR.

(p. 1 of comments)

See Response 

3

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CI Comment #3. EPA has not determined what the best method is to determine MDLs and 

proposes to simply implement the most sensitive method. ODEQ believes this proposal 

is premature. (p. 1 of comments)

See Response 

3

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CJ Comment #4. EPA has stated that although some labs may have to purchase new 

equipment, the cost of monitoring to the regulated community should be reduced. Not 

only will labs have to purchase new equipment, they will have to dedicate space for clean 

sample preparation and retrofit clean room appurtenances into dedicated space for clean 

sample preparation and retrofit clean room appurtenances into dedicated space or build 

new clean rooms. EPA should consider the clean room requirements in its economic 

analysis. (p. 1 of comments)

See Response 

1

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CK Comment #5. Permittees will have to pay for clean sampling events which require more 

personnel and clean suits that need to be thrown away after each sample aliquot. For one 

six hour composite sample taken in Oklahoma, over $2,000 worth of disposables were 

used twice the staff were required for this sample. EPA should consider the increased 

cost of taking a sample to meet the quality requirements for the this level of analysis. 

ODEQ would like to review exactly how EPA determined the cost of implementing these 

MLs.(p. 2 of comments)

See Response 

1

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CL Comment #6. EPA has stated that compliance with water quality standards will 

improve. Using these MLs will not improve compliance with water quality standards. 

This proposal will cause more facilities to be out of compliance with permits. EPA 

should consider the increase in non-compliance to modify requirements on enforcement 

authorities or the associated costs and personnel effort by these enforcement authorities.

(p. 2 of comments)

See Response 

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0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CM Comment #7. EPA Region 6 has stated that other states have already implemented 

MQLs using these MLs as a sufficiently sensitive method. The ODEQ would like to 

know which states have implemented these MLs so that their labs and regulated 

communities could be surveyed to determine issues, costs, and effects of this change. (p. 

2 of comments)

See Response 

2

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CN Comment #8. The compliance date for adoption of this rule change to 40 CFR parts 122 

and 136 is two years if statutory changes are required. Two years may not be enough 

time due to Oklahoma's rule making process. (p. 2 of comments)

See Response 

12

0021 Oklahoma Department of 

Environmental QualityJ

immy D. Givens

Deputy Executive Director

CO Comment #9. EPA should restrict definition iii of sufficiently sensitive analytical test 

methods to only apply to the proposed pollutants in the Region 6 Minimum 

Quantification Level Guidance. This broad definition would require the most sensitive 

analysis of all 38 pollutants with criteria lower than current MQLs, with no increase in 

sensitivity obtained by analyzing for application purposes for almost one quarter of them

(the nine pollutants that were apparently not routinely analyzed to the current MQL, 

much less the even lower ML). (p. 2 of comments)

See Response 

2

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CP Comment #10. Out of the 38 pollutants examined by EPA Region 6, nine pollutants 

were apparently not routinely analyzed to the current MQL. Those MQLs and associated 

MLs should be raised. (p. 2 of comments)

See Response 

2

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CQ Comment #11. This notice states EPA welcomes comments on potential impacts of the 

proposed rule on small entities. For one six hour composite sample taken in Oklahoma, 

over $2,000 worth of disposables were used and twice the staff were required for this 

sample. EPA should consider the increased cost of taking a sample to meet the quality 

requirements for this level of analysis. Small entities will have a higher percentage of 

their operating budget dedicated to meet the sampling requirements and analysis of this 

proposed rule change. Small entity analysis should include costs of clean sampling 

requirements and the added overhead to store all the newly required sampling equipment. 

EPA should consider the current recession that this country is in and its drastic affect on 

small business budgets. (p. 3 of comments)

See Response 

1

0021 Oklahoma Department of 

Environmental Quality

Jimmy D. Givens

Deputy Executive Director

CR Comment #12. If a more sensitive method is implemented and you have to dilute the 

sample, then you've raised the detection limit. This negates the increase in the 

"sufficiently sensitive method." (p. 3 of comments)

See Response 

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0022 West Virginia Municipal 

Water Quality Association

David C. Sago

President

CS Comment #1. EPA's proposed amended regulation would require that, for NPDES 

permit applications and for permit compliance reporting, an approved Part 136 method be 

used that is at or below the level of the applicable water quality criterion, or is at or below 

the level of the applicable water quality criterion, or if the concentration of the pollutant 

parameter is high enough, a method that properly quantifies the concentration. The 

MWQA generally supports EPA's proposal. However additional flexibility should be 

included in the regulation for those cases where there is a wasteload allocation ("WLA") 

or a permit limit above the water quality criterion.

We agree that an appropriate Part 136 analytical method should in all cases be used 

which allows a correct quantification of the pollutant parameter. In many cases the 

quantification level will be the water quality criterion. However, there are also many 

cases where dilution is available, and where there is a properly calculated WLA or similar 

value that is protective of the instream criterion, at a value than the criterion. In those 

instances the regulation should provide for the use of a method that provides a 

quantification level at or below the WLA or other appropriate value. In such cases there 

is no benefit to the use of a more sensitive method, and the more sensitive methods may 

have additional costs or other disadvantages.

We further note that, although the preamble to the proposal refers to the use of an 

analytical method with a QL at or below the water quality criterion or permit limit, the 

proposal itself does not appear designed to address permit limits at levels higher than the 

respective criteria.

Accordingly, we recommend that the regulation be changed before promulgation to 

address these important issues. We ask the EPA consider the following possible text to 

accomplish this.

40 C.F.R. 122.21 (e)(3).

(i) For purposes of this requirement, a method approved under 40 CFR Part 136 is 

"sufficiently sensitive" when:

(A) The method minimum level (ML) is at or below the level of the applicable water 

quality criterion, wasteload allocation or other critical regulatory value for the measured 

parameter;

(B) The method ML is above the applicable water quality criterion, wasteload allocation, 

permit limit or other critical regulatory value, but the amount of pollutant or pollutant 

See Response 

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parameter in a facility's discharge is high enough that the method detects quantifies the 

level of the pollutant or pollutant parameter in the discharge....

A comparable change should also be made to the proposed language at subsection 

122.44. (p. 1-2 of comments)

0023 Alaska Oil and Gas 

Association

Marilyn Crockett

Executive Director

CT Comment #1. The proposed rule would cause untenable and costly compliance problems 

in isolated areas in Alaska. The number of available in-state laboratories that can 

perform sufficiently sensitive test methods is extremely limited. If this ruling is 

implemented as stated, shipments to laboratories outside of Alaska would be required. In 

addition, logistics from offshore platforms and remote sites typically require helicopter 

transport to land to airplane to land transport. This would add to the challenge of meeting 

sample holding times and other preservation restrictions especially in light of delays 

caused by coordination between offshore facilities, air transport, laboratory schedules, 

and Transportation Safety Administration restrictions. Furthermore, shipments of 

samples can be especially challenging and subject to delays in Alaska due to adverse 

weather conditions, volcanic eruptions, and earthquakes which can ground air 

transportation. (p. 1 of comments)

See Response 

3

0023 Alaska Oil and Gas 

Association

Marilyn Crockett

Executive Director

CU Comment #2. The rule should include allowances for isolated areas for holding times, 

and sampling and monitoring delays due to problems transporting samples and limitation 

on laboratory capability. (p. 1 of comments)

See Response 

3

0023 Alaska Oil and Gas 

Association

Marilyn Crockett

Executive Director

CV Comment #3. To be consistent with the "sufficiently sensitive" definition described in 

the preamble, the amended language in Part 122.21 (e)(3)(i) should clearly state that a 

method is "sufficiently sensitive" when either (A) or (B) or (C) applies. Amended 

language in Part 122.44 (i)(1)(iv)(A) should likewise state that a method is sufficiently 

sensitive when any of (1) or (2) or (3) apply.

(p. 1 of comments)

See Response 

4

0023 Alaska Oil and Gas 

Association

Marilyn Crockett

Executive Director

CW Comment #4. The analysis of sufficiently sensitive test methods must be practical for 

site-specific logistics. Conditions under 122.21 (e)(3) and 122.44 (i)(1)(iv) are needed

-122.21 (e)(3)(iii) the method ML under (i) or (ii) above must account for holding times 

necessary for logistical constraints in Alaska.

-and similarly under 122.44 (i)(1)(iv)(C) the method ML under (A) or (B) above must 

account for holding times necessary for logistical constraints in Alaska. (p. 2 of 

comments)

See Response 

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0023 Alaska Oil and Gas 

Association

Marilyn Crockett

Executive Director

CX Comment #5. The preamble provides additional explanation for the third criterion for 

sufficiently sensitive, however, the specific language in the proposed rule does not. 

Section III of the Scope and Rationale of the Proposed Rule EPA (page 35716) states that 

for the third criterion “...the applicants or permittees should use “the most sensitive” of 

the approved methods for the pollutant” [emphasis added]. This qualification is missing 

in 122.21 (3)(i)(C) and 122.44 (1)(iv)(A)(3) and both should be revised to state:

-The method has the lowest ML of the analytical methods approved under 40 CFR 136 

for the measured pollutant or pollutant parameter. (p. 2 of comments)

See Response 

5

0024 Virginia Association of 

Municipal Wastewater 

Agencies, Inc.

CY Comment #1. EPA’s proposed amended regulation would require that, for NPDES 

permit applications and for permit compliance reporting, an approved Part 136 method be 

used that is at or below the level of the applicable water quality criterion, or if the 

concentration of the pollutant parameter is high enough, a method that properly quantifies 

the concentration. VAMWA generally supports EPA’s proposal; however, additional 

flexibility should be included in the regulation for those cases where there is a wasteload 

allocation (“WLA”) or a permit limit above the water quality criterion.

We agree that an appropriate Part 136 analytical method should be used which allows a 

correct quantification of the pollutant parameter. In many cases, the quantification level 

will be the water quality criterion. However, there are also many cases where dilution is 

available, and where there is a properly calculated WLA or similar values that is 

protective of the instream criterion, at a value higher than the criterion. In those instances 

the regulation should provide for the use of a method that provides a quantification level 

at or below the WLA or other appropriate values. In such cases there is no benefit to the 

use of a more sensitive method, and the more sensitive methods may have additional 

costs or other disadvantages.

We further note that, although the preamble to the proposal refers to the use of an 

analytical method with a QL at or below the water quality criterion or permit limit, the 

proposal itself does not appear designed to address permit limits at levels higher than the 

respective criteria.

Accordingly, we recommend that the regulation be changed before promulgation to 

address these important issues. We ask that EPA incorporate the following revisions to 

address the foregoing issues: 

40 C.F.R. 122.21 (e)(3).

See Response 

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(i) For purposes of this requirement, a method approved under 40 CFR Part 136 is 

“sufficiently sensitive” when:

(A)The method minimum level (ML) is at or below the level of the applicable water 

quality criterion, wasteload allocation or other critical regulatory value for the measured 

parameters;

(B) The method ML is above the applicable water quality criterion, wasteload allocation, 

permit limit or other critical regulatory value, but the amount of pollutant or pollutant 

parameter in a facility’s discharge is high enough that the method detects and quantifies 

the level of the pollutant or pollutant parameter in the discharge...

A comparable change should also be made to the proposed language subsection 122.44.

(p. 1-2 of comments)

0025 The Dow Chemical 

Company

Global Regulations Affairs

Tracey Maloney, P.E.

CZ Comment #1. EPA’s proposal is a “significant regulatory action” under Executive 

Order 12866.

Executive Order 12866, “Regulatory Planning and Review,” was intended to provide 

oversight and ensure careful consideration before promulgating any “significant 

regulatory action.” According to section 3(f) of that Executive Order, a regulatory action 

is “significant” if (among other things):

- It may raise novel legal or policy issues, or 

- It may have an annual effect on the economy of $100 million or more, or

- It may adversely affect competition or jobs.

EPA’s proposal meets all three of the tests above. To explain this, we must provide some 

background information about the proposal.

-EPA’s rationale for the entire proposal is unsound. EPA’s explicit rationale for this 

action, is that the Agency is borrowing from its recent experience with analysis for 

mercury and applying the same approach to all pollutants. That approach is unsound. 

Pollutants are not all the same. An analytical approach that works for mercury (a metal) 

may not work for volatile or semi-volatile organic compounds. To cite the most obvious 

flaw, EPA actually has sensitive analytical methods for mercury. In contrast, EPA admits 

that there may not be any “sufficiently sensitive” test methods for some other 

compounds. Thus, it is literally impossible to “extend” the approach for mercury.

- EPA’s drive for greater sensitivity will increase the risk of “false positives” and thereby 

impair the validity of analytical data. EPA’s proposal is all about sensitivity of analytical 

methods. Sensitivity is important, but it is not the only thing that is important. Greater 

sensitivity often comes at the cost of lest specificity. In other words, a method that can 

See Response 

1 and 

Response 3
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detect a compound at a lower concentration may risk “false positives” by inaccurately 

identifying other substances as the target compound. This, of course, would defeat 

EPA’s purposes. The Agency has specifically stated that “it is critical that the Director 

make permitting decisions based on accurate data and thus, sound science.” If the use of 

a more sensitive method results in inaccurate identification of compounds, the Director’s 

decisions would be based on inaccurate data. Unfortunately, the Agency does not appear 

to have considered this in the proposal.

-The proposal would greatly increase the nation-wide economic burden of chemical 

analyses required for NPDES permits and for permit applications. EPA does not appear 

to have recognized that the proposal would have any economic impact at all. In reality, 

the proposal will impose substantial additional costs on permittees across the entire 

country. The potential magnitude of these additional costs makes the proposal a 

“significant regulatory action.” For example: 

-The proposal would have the effect of requiring permitted facilities to develop their own 

analytical methods, at their own expense. In cases where EPA does not have any 

approved methods for a particular compound, the proposal still requires monitoring to be 

conducted using “a sufficiently sensitive test procedure specified in the permit.” In some 

cases there may be an existing analytical method (although not EPA-approved). That 

would be the best case. However, there will also be situations where no analytical 

method – at all- exists that can detect and quantify a particular substance at the 

concentrations desired by the EPA. In that situation , EPA’s current proposal would 

appear to require the permitted facility to develop and validate an analytical method that 

is “sufficiently sensitive.” The cost of developing even one method could be millions of 

dollars. Worse yet, any one facility may have to develop methods for multiple 

substances. And, if numerous facilities across the country – perhaps in different EPA 

regions – each discharge the same substance, they may each have to develop methods 

independently, thereby incurring massive costs in the most inefficient manner. This is 

because there is no obvious way for those permittees to know of each other. As a further 

concern, not only would money be wasted, but numerous divergent inconsistent methods 

would be developed for the same substance. This aspect alone could make the proposal a 

“significant regulatory action.” 

- Requiring more sensitive methods will increase the cost “per analysis.” In general, the 

cost “per analysis” is higher for analytical methods that are more sensitive. The amount 

of incremental cost per analysis can vary from one method to another. However, more 

sensitive methods usually require more stringent laboratory procedures, and sometimes 

more costly laboratory equipment. Thus, the cost of analysis tends to increase. Nothing 
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in EPA’s proposal even mentions this. Considering that analyses under permits must be 

run repeatedly (for example, quarterly, monthly, weekly or even daily), and that the 

NPDES program applies to a very large number of facilities nationwide, this factor alone 

could make the proposal a “significant regulatory action.” 

- EPA’s proposal will require more analyses to be run. For example, it is currently 

common to run a single scan by a single method, and thereby receive analytical data for a 

large number of compounds. This keeps the cost down but may not achieve, for some 

compounds, the detection and quantifications level that EPA now desires. This means the 

permittee would now have to run the broad scan and a number of additional, singlecompound analyses. This will obviously increase the cost of analysis under NPDES 

permits and to support permit applications, but EPA does not even mention this, 

anywhere in the proposal. 

- EPA’s proposal will necessitate confirmatory analyses to address “false positives.” As 

mentioned above, greater analytical sensitivity often increases the risk of “false 

positives.” This means the methods may register a non-target compound and mistakenly

identify it as the target substance. Sometimes it is possible to dispel this “mistaken 

identify” by using a different analytical method. However, doing so requires additional 

expenditures. EPA’s proposal does not acknowledge this.

Based on the rationale above, EPA’s proposal meets at least three test, any one of which 

would trigger applicability of Executive Order 12866.

1. The proposal raises novel legal or policy issues. For example:

- There is a question whether the Clean Water Act grants EPA the authority to require 

permittees to develop and validate analytical methods, at their own expense, whenever 

EPA has failed to do so.

- There is an additional novel policy question whether EPA should be allowed to 

implement a proposal that would have the effect of requiring multiple different permittees 

to independently develop duplicative and inconsistent, non-EPA-approved, “in-house”

analytical methods for the same pollutant. – EPA has asserted that this proposal imposes 

no new information collection burdens, and that OMB’s approval of the burdens of the 

existing regulations automatically covers the amended regulations. There is a legal 

question whether EPA may disregard the new burden of additional analyses, more costly 

analyses and especially the cost of developing in-house analytical methods, and thereby 

rely on OMB’s review of the burdens of the pre-amendment regulations.

2. The proposal may have an annual effect on the economy of $100 million or more. The 

cost of developing in-house analytical methods, the cost of more expensive analyses, the 
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cost of more numerous analyses, and the cost of more confirmatory analyses to rule out 

“false positives” will be extensive and nation wide.

3. The proposal may adversely affect competition and jobs in a meaningful way. The 

additional costs that this proposal will cause are truly substantial. In today’s economy, 

any substantial increase in costs has the potential to make American businesses less 

competitive in the global market, and thereby jeopardize jobs.For all these reasons, 

EPA’s proposal is a “significant regulatory action” subject to Executive Order 12866. (p. 

1-4 of comments)

0025 The Dow Chemical 

Company

Global Regulations Affairs

Tracey Maloney, P.E.

DA Comment #2. EPA’s proposal imposes new burdens that may not have been 

approved under the Paperwork Reduction Act. 

EPA asserts that this proposal “does not impose any new information collection burden.” 

However, as has been demonstrated above, the proposal will actually require enormous 

additional expenditures to develop analytical methods and conduct additional analyses. It 

is unclear on what basis EPA asserts that OMB has already approved those burdens. 

Unless OMB agrees that those burdens were foreseen and approved previously, the 

proposal should be submitted to OMB for review under the Paperwork Reduction Act. (p. 

4 of comments)

See Response 

1

0025 The Dow Chemical 

Company

Global Regulations Affairs

Tracey Maloney, P.E.

DB Comment #3. EPA’s proposal requires further review under the Regulatory 

Flexibility Act. EPA has asserted that the proposal “will not have a significant 

economic impact on a substantial number of small entities.” However, EPA has utterly 

failed to consider the economic impacts described above, and thus has not evaluated the 

extent to which those economic impacts would affect small entities. Small entities would 

likely experience particular difficulty if, for example, they were required to develop 

sensitive analytical methods at their own expense. Due to the lack of consideration of 

these issues, EPA has not provided any valid basis to exclude this regulatory action from 

the Regulatory Flexibility Act. (p. 4 of comments)

See Response 

1

0025 The Dow Chemical 

Company

Global Regulations Affairs

Tracey Maloney, P.E.

DC Comment #4. EPA’s proposal requires further consideration of the Unfunded 

Mandates Reform Act. According to EPA’s Federal Register notice, the Unfunded 

Mandates Reform Act applies to a federal mandate that might result in (among other 

possibilities) expenditures of $100 million or more by “the private sector” in any one 

year. As has been shown above, EPA’s proposal may result in expenditures by the 

private sector in excess of $100 million annually. EPA also asserts that the proposal 

contains “no regulatory requirements that might significantly or uniquely affect small 

governments.” However, small governments often operate wastewater treatment 

See Response 

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facilities. Consequently, the increased costs that this proposal would create may heavily 

on small governments.For the reasons stated above, EPA’s rationale for excluding the 

Unfunded Mandates Reform Act is incorrect. (p. 4-5 of comments)

0025 The Dow Chemical 

Company

Global Regulations Affairs

Tracey Maloney, P.E.

DD Comment #5. EPA’s exclusion of Executive Order 13175 may be incorrect. EPA 

has stated that the proposal is not subject to Executive Order 13175 (Consultation and 

Coordination with the Indian Tribal Governments) because it “will not have substantial 

direct effects on Tribal governments, on the relationship between the Federal 

Government and Indian Tribes, or on the distribution of power and responsibilities 

between the Federal Government and Indian Tribes.” EPA’s assertion may be incorrect. 

If tribal governments implement permitting programs, this proposal may impose greater 

responsibilities on tribal governments to identify and recognize “sufficiently sensitive”

analytical methods. The proposal may also impose new responsibilities on tribal 

governments to require and oversee the development of new analytical methods where 

none exist. And if tribal governments operate wastewater treatment systems, the proposal 

may impose substantial new costs on those tribal governments. Consequently, it seems 

conceptually possible that the proposal may trigger Executive Order 13175. (p. 5 of 

comments)

See Response 

1

0025 The Dow Chemical 

Company

Global Regulations Affairs

Tracey Maloney, P.E.

DE Comment #6. For all reasons stated above, our primary recommendation is that EPA 

should withdraw this proposed rule for further deliberation. It seems very evident that 

EPA has not recognized, much less evaluated, a number of the impacts of the regulation. 

Therefore, it seems only fair that EPA should reconsider the proposal in light of those 

impacts. The reconsideration should include such things as whether EPA really intends 

and desires to impose those burdens (and if not, how to rephrase the rule). If EPA does 

intend to impose those burdens, then presumably the reconsideration should include a 

justification for those burdens, then presumably the reconsideration should include 

submittal of the proposal for review under appropriate executive orders and statutes as 

identified in the paragraphs above.

If EPA is unwilling to withdraw the proposal for reconsideration, then EPA must either 

submit the proposal for review under the executive orders and statues identified above, or 

develop a valid rationale for excluding the proposal for such review.

In either case, the proposal should not move forward as presently constituted, without the 

review that are required by law.

(p. 5 of comments)

See Response 

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0026 Wisconsin Department of 

Natural Resources

Tom Mugan

DF Comment #1. I agree with the general objective of the general objective of the proposed 

changes: to formally clarify that method sensitivity should play a primary role in method 

selection for use in testing pollutant concentrations with very low water quality criteria in 

NPDES outfalls. However, I have a few concerns with actual language used.

The changes to 122.21 require that permittees use methods that are “sufficiently 

sensitive” for application monitoring.

- In 122.21 (e)(3)(i), three options define what “sufficiently sensitive” means. It appears 

that there should be an “or” following the second option [122.21(e)(3)(i)(B)].

-In 122.21 (e)(3)(ii), the permittee may use an un-approved method for a substance that 

has no approved methods; but now 122.21 (e)(3)(i)(C) is no longer in play (an 

unapproved method cannot be the approved method with the lowest ML). If the pollutant 

in question has an extremely low water quality criterion, this provision could suggest a 

permittee must strive to meet an ML that is impossible with existing technology. This 

could be a problem if the Director fails to specify a method since the language limits the 

permittee choice of methods in that “...the applicant may use any suitable, sufficiently 

sensitive method...”.

- In Wisconsin, we would normally suggest a suitable method in the application 

instructions.

The changes to 122.44 require that permittees use methods that are “sufficiently 

sensitive” for permit required monitoring.

- In 122.44(i)(1)(iv)(A), three options define what “sufficiently sensitive” means. IT 

appears that there should be an “or following the second option [122.44(i)(1)(iv)(A)(2)].

- In 122.44(i)(1)(iv)(B), the permittee must use an un-approved method for a substance 

that has no approved methods; but now 122.44(i)(1)(iv)(A)(3) is no longer in play. If the 

pollutant in question has an extremely low water quality criterion, this provision could 

require the permittee to meet an ML that is impossible with existing technology. This 

could be a more significant problem since the language indicates that “...monitoring shall 

be conducted according to a sufficiently sensitive test procedure...” (emphasis added).

- In Wisconsin, before settling a requirement in a permit, we would work with the 

laboratory community and the permittee to be sure there is a valid method that will 

provide the information needed to assess the impact to water quality and compliance with 

limitations or other permit conditions. And we would normally specify that method in 

the permit. However, I have concerns that a future third party interpretation with legal 

precedent might interfere with our desire to set realistic requirements in a permit. (p. 1 of 

comments)

See Response 

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0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DG Comment #1. [National Association of Clean Water Agencies (NACWA)] overarching 

concern is that EPA’s proposed action seems premature given the Agency’s ongoing 

assessment of the [Federal Advisory Committee on Detection and Quantitation 

(FACDQ)] recommendations regarding the need for a new and consistent definition of 

minimum level. In addition, the proposed rule appears to require the use of methods that 

have not been approved by EPA through the 40 CFR Part 136 process and that may not 

have undergone validation of any other scientific review. Given the uncertainty 

associated with such methods and the fact that the public is not provided an opportunity 

to comment on the reliability and use of those methods, NACWA believes such an 

approach contravenes basic principles of valid science. (p. 1 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DH Comment #2. Issues with the Use of the Minimum Level as Proposed. It seems 

inappropriate to use the minimum level (ML) as a regulatory decision point given the 

current ML definition (3.18 x method detection level (MDL)) and MLs used in 40 CFR 

Part 136 methods are recognized to be flawed by all stakeholders including the states and 

EPA. The FACDQ has made recommendations to EPA on how to address the ML 

definitions but EPA has yet to address those recommendations in a rulemaking. EPA 

states that it is critical that it make permitting decisions based on sound science, but the 

use of the current ML definition has failed that standard. (p. 2 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DI Comment #3. Issues with the Use of the Minimum Level as Proposed. The proposed 

rule falls short of providing a sound, consistent approach because it offers three different 

options for defining the ML:a. 3.18 x MDL,b. Whatever is published for a method, or c. 

The lowest acceptable calibration point.

Mercury method 1631E confuses the issue more by taking 3.18 x MDL and then 

“rounding to the number nearest to (1, 2, or 5) x10n, where n is an integer.” The level of 

confusion regarding the ML to be used in the proposed rule is further complicated by the 

fact that labs can have different MLs than the respective methods. As stated above, this 

rule should not be finalized until a new, single definition of ML is promulgated based on 

the work of the FACDQ. (p. 2 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DJ Comment #4. Issues with the Use of the Minimum Level as Proposed. 

EPA states that the ML should be less than the applicable water quality criteria. 

However, when following EPA’s guidance in the Technical Support Document for Water 

Quality-based Toxics Control, the decision point for the reasonable potential process is 

the wasteload allocation (WLA) rather than the criteria. The language needs to be 

adjusted accordingly.

(p. 2 of comments)

See Response 

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0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DK Comment #5. Issues with the Use of the Minimum Level as Proposed. The ML is 

used by labs as an internal gauge of performance. However, independent reviews of 

performance (discharge monitoring report (DMR) quality assurance (QA) studies, for 

example) generally do not monitor the actual performance of labs at concentrations 

approximating the ML. It is important that if the ML were to be used by the EPA as 

suggested, stakeholders using laboratories to meet NPDES requirements must have some 

assurance that these labs can actually meet the required quality objectives at or near the 

concentration of the ML. This will require a significant shift in how third parties 

(permittees, EPA, states) evaluate laboratories and this shift must occur before further 

weight is placed on the ML. (p. 2 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DL Comment #6. Issues with the Use of the Minimum Level as Proposed. The notice 

states that published methods “give only an upper, not a lower, bound on the lab’s MDL 

and minimum level.” This is not universally true because the ML of the published 

methods may not be based on a representative sample of lab performance. For example, 

some MLs are based on the performance of research and federal labs but do not include 

the performance of industrial or municipal labs. This is one reason why it is important to 

test methods intended for regulatory use in labs representing all stakeholders that will use 

those methods. (p. 2 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DM Comment #7. Issues with the Use of the Minimum Level as Proposed. The proposed 

rule specifically refers to “the method ML.” There are very few methods with an ML. 

Therefore, the proposed language does not address the vast majority of 40 CFR Part 136 

methods. A footnote in the proposed rule states that the ML can also be “the lowest 

calibrations point in a method.” Methods in 40 CFR Part 136 do not define the lower 

calibration point to be used. This is decided by the respective laboratory. It would be 

more appropriate to refers to “the lowest calibration point used by a laboratory” in this 

instance.

(p. 3 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DN Comment #8. Issues with the Use of the Minimum Level as Proposed. The proposed 

rule equates “ML,” “quantitation level (QL)” and reporting limit (RL),” however these 

terms are not synonymous in all cases. For example, the QL and/or the RL for a lab may 

be one value equal to or less than the method ML, but they are not necessarily equivalent 

with the ML. Using the ML definition of 3.18 x MDL, it would be nearly impossible for 

a lab to use 3.18 x MDL as the lowest calibration standard. This is particularly true for 

methods that measure dozens of analytes. It is much more practical for labs to adopt MLs 

that are similar in concentration across analytes and that are less than the respective 

WLAs than to calculate a MDL for each analyte, multiply each of those MDLs by 3.18, 

and then create dozens of dilutions equaling that product for dozens of analytes. 

See Response 

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Therefore, the QL/RL may be 5 ppb for numerous analytes in EPA method 625 but the 

MDL x 3.18 for each analyte does not equal 5 ppb.

(p. 3 of comments)

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DO Comment #9. Use of Most Appropriate Method, Not Most Sensitive. The driver for 

this proposed change is to provide data of sufficient precision and accuracy, but EPA has 

not defined the data quality objectives for precision and accuracy to be applied to 

NPDES-related data. Therefore, no one including EPA can establish whether the ML 

meets this proposed need. EPA goes on to say that it should not use imprecise analytical 

methods in permits, but the EPA has not defined what this means. EPA states it needs to 

make permitting decisions based on accurate data, but EPA has not defined the level of 

accuracy required for use of the data. (p. 3 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DP Comment #10. Use of Most Appropriate Method, Not Most Sensitive. The notice 

defends the need for use of sufficiently sensitive methods, and explains this need in terms 

of accuracy and precision. Based on EPA’s own guidance regarding quality indicators 

(DQIs) EPA should recognize that sensitivity is different than accuracy and precision. 

Although NACWA agrees that accurate and precise data should be used to meet NPDES 

requirements the desire to have more sensitivity will likely conflict with the need for 

accuracy and precision. Simply stated, values reported at lower concentrations do not 

inherently have greater accuracy or precision than higher concentrations. Quite the 

contrary, one often compromises accuracy and precision as sensitivity increases. The 

need for greater sensitivity should not compromise the need for accuracy and precision.

(p. 3 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DQ Comment #11. Use of Most Appropriate Method, Not Most Sensitive. In many cases 

such as PCBs, pesticides, and other organics, GC/MS MDLs are not sufficiently sensitive 

to detect the level of the water quality standard. In the case of most organics, there is an 

approved gas chromatography (GC) method which provides a lower detection limit than 

the approved GC/MS method. In the case of many organic parameters, the ML rule could 

trigger a requirement to change from GC/MS to GC methods. This would be undesirable. 

GC/MS provides a much greater degree of confidence in the correct identification of the 

regulated parameter. Although use of dual columns in GC methods reduces uncertainty 

in the identification, GC/MS methods provide much greater confidence in the correct 

identification of organic parameters. The value of more sensitive quantitation is lost if 

See Response 

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one is not certain what is being quantified. There are numerous cases in which a GC 

method might be considered the most sensitive method. And its use required by the 

proposed rule. NACWA believes that the sufficiently sensitive method rule should 

recognize the superiority of GC/MS methods to GC methods and provide an exception to 

the sufficiently sensitive methods rule for the case of less sensitive GC/MS methods. (p. 3 

of comments)

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DR Comment #12. Implementation of the Proposed Requirements. The “Scope and 

Rationale of the Proposed Rule” states that where insufficient sensitivity among 40 CFR 

Part 136 methods is concluded, the permitting agency would have the authority to require 

a non-promulgated method in an NPDES permit based on the proposed language of the 

rule. This preamble text is problematic because it conflicts with the language of the 

actual proposed regulation where “an NPDES applicant may use any suitable sufficiently 

sensitive method.” The latter language indicates that selection of the method is made by 

the permittee rather than the permitting authority. NACWA believes that the decision 

should be made by the permittee. (p. 4 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback, Sr. Director

DS Comment #13. Implementation of the Proposed Requirements. States only have a 

maximum of 2 years to implement this rule once finalized. It is not clear how this rule 

will impact NPDES permits which will not be renewed for up to 5 years after the rule has 

been adopted. EPA should clarify how this rule change impacts reporting under current 

NPDES permits. (p. 4 of comments)

See Response 

11 and 

Response 12

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DT Comment #14. Implementation of the Proposed Requirements. EPA states that it 

will provide regular updates on water quality criteria to ensure that the states use 

sufficiently sensitive methods. This is irrelevant for states that have adopted their own 

water quality criteria. Once state criteria are EPA-approved, only the state criteria can be 

used. Later-developed EPA criteria do not replace the properly adopted state criteria. 

Rather, the states are under an obligation to update their criteria periodically, but pending 

the states’ updates the adopted state criteria still control for NPDES purposes. The 

language should be removed because it suggest the opposite. (p. 4 of comments)

See Response 

13

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DU Comment #15. Implementation of the Proposed Requirements. Upon promulgation 

of this rule, laboratories/permittees should be given sufficient time to change 

methodologies. The time period to do this should not start until the rule is incorporated 

by each regulatory authority and should be at least 18 months in length to allow for 

review and selection of labs or purchase of equipment and training. (p. 4 of comments)

See Response 

11 and 

Response 12

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

DV Comment #16. Implementation of the Proposed Requirements. EPA requires that 

data be collected within 4.5 years prior to the NPDES permit renewal application and 

cover different periods of the year to address discharge quality variability. If the rule is 

finalized in December of 2010 and a permit renewal is due in 2012, sampling/analyses by 

See Response 

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Chris Hornback

Senior Director

the permittee have already begun and may not meet the requirement of the CWA 

modification. EPA and States should grandfather permit renewal data up to and 

including a date well after the rule is finalized to allow use of data already generated, to 

avoid loss of resources, and to avoid situations where permittees may be found in 

noncompliance because the data they provide does not complete the permit application.

Also, if non-detectable or data below the ML is collected during the term of a permit, but 

the most sensitive method is not used, must that data be excluded from considerations for 

NPDES re-permitting if the water quality standard is below the ML of the method used? 

NACWA believes it is appropriate to allow the permit writer to use all the data collected 

during the term of the permit in addition to the data required to meet the minimum data 

requirements for the permit application, and requests that EPA clarify in the rule or 

preamble that this approach is allowed. (p. 4-5 of comments)

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DW Comment #17. Implementation of the Proposed Requirements. The notice is not 

clear whether the new requirements are intended to apply to indirect discharges to 

POTWs. The description in Table I-1, Entities Potentially Regulated by this Rule, does 

not refer to indirect dischargers, but the preamble refers to subchapter N which includes 

pretreatment standards for direct dischargers, but the preamble refers to subchapters N 

which includes pretreatment standards for direct and indirect discharge standards. The 

rule or preamble should be clear as to whether the rule applies to the pretreatment 

program monitoring conducted for compliance with Part 403. Because of the challenges 

associated with industrial discharge matrices, NACWA believes that the option to require 

the achievement of MLs below regulatory limits should be left to the discretion of the 

POTW. Industrial permittees may not be able to meet these requirements because matrix 

effects often require dilution of samples which increases the ML. Some of these samples 

may even damage components of the more sensitive instruments due to their high 

concentrations. (p. 5 of comments)

See Response 

9

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DX Comment #18. Implementation of the Proposed Requirements. Monitoring is 

sometimes required in an NPDES permit for parameters for which numeric water quality 

based effluent limits (WQBELs) are not specified in the permit. A condition may be 

included in the permit which states that the permittee may not cause a violation of 

instream standards. For some utilities, there are dozens of compounds for which 

quarterly monitoring is required and which have state water quality standards but for 

which no numeric WQBELs are included in the permit. In such a case, do the new 

requirements apply or do they apply only to those parameters which have specific 

numerical effluent limits and for which monitoring results are required to be reported on 

See Response 

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the DMR? NACWA believes that the ML requirement should only apply to parameters 

with explicit numerical limits which are reported on the DMR. (p. 5 of comments)

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DY Comment #19. Implementation of the Proposed Requirements. Not all approved 

methods are available commercially. NACWA recommends that the rule provides an 

exception for sensitive methods which are not commercially available to prevent creating 

an obligation for regulated entities to fund laboratories to provide those analytical 

services. (p. 5 of comments)

See Response 

3

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

DZ Comment #20. Implementation of the Proposed Requirements. Instructions for DMR 

reporting address the reporting of data below the MDL. The rule is silent on the 

communication of ML information on the DMR or NPDES application. NACWA 

requests that EPA clarify in the preamble to the final rule that there is no ML reporting 

obligation on the DMR or NPDES application. (p. 5 of comments)

See Response 

6

0027 National Association of 

Clean Water Agencies

Regulatory Affairs

Chris Hornback

Senior Director

EA Comment #21. Implementation of the Proposed Requirements. For multi-parameter 

approved methods which utilize similar technology with similar MDL/MLs (e.g. 624, 

1624, 6210B 18th), is an analyte-by-analyte comparison necessary to determine the

appropriate method? This would be a significant administrative difficulty and cost 

increase if POTWs would have to divide one analysis into two or three because 

parameters have slightly different MLs. (p. 5 of comments)

See Response 

3

0028 South Carolina Water 

Quality Association

F. Paul Calamita

General Counsel

EB Comment #1. EPA’s proposed amended regulation would require that, for NPDES 

permit applications and for permit compliance reporting, an approved Part 136 method be 

used that is at or below the level of the applicable water quality criterion, or if the 

concentration of the pollutant parameter is high enough, a method that properly quantifies 

the concentration. VAMWA generally supports EPA’s proposal; however, additional 

flexibility should be included in the regulation for those cases where there is a wasteload 

allocation (“WLA”) or a permit limit above the water quality criterion.

We agree that an appropriate Part 136 analytical method should be used which allows a 

correct quantification of the pollutant parameter. In many cases, the quantification level 

will be the water quality criterion. However, there are also many cases where dilution is 

available, and where there is a properly calculated WLA or similar values that is 

protective of the instream criterion, at a value higher than the criterion. In those instances 

See Response 

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the regulation should provide for the use of a method that provides a quantification level 

at or below the WLA or other appropriate values. In such cases there is no benefit to the 

use of a more sensitive method, and the more sensitive methods may have additional 

costs or other disadvantages.

We further note that, although the preamble to the proposal refers to the use of an 

analytical method with a QL at or below the water quality criterion or permit limit, the 

proposal itself does not appear designed to address permit limits at levels higher than the 

respective criteria.

Accordingly, we recommend that the regulation be changed before promulgation to 

address these important issues. We ask that EPA incorporate the following revisions to 

address the foregoing issues: 

40 C.F.R. 122.21 (e)(3).

(i) For purposes of this requirement, a method approved under 40 CFR Part 136 is 

“sufficiently sensitive” when:

(A)The method minimum level (ML) is at or below the level of the applicable water 

quality criterion, wasteload allocation or other critical regulatory value for the measured 

parameters;

(B) The method ML is above the applicable water quality criterion, wasteload allocation, 

permit limit or other critical regulatory value, but the amount of pollutant or pollutant 

parameter in a facility’s discharge is high enough that the method detects and quantifies 

the level of the pollutant or pollutant parameter in the discharge...

A comparable change should also be made to the proposed language subsection 122.44.

(p. 1-2 of comments)

0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EC Comment #1. The stated goal of the proposed rule is to ensure that NPDES permittees 

use analytical methods in permit applications and reports that are “sufficiently sensitive.”

We believe that is a worthwhile goal. However, the specific provisions in the proposed 

rule are not well-tailored to achieve that goal. Those provisions raise substantial scientific 

concerns, and are too vague and undefined to implement effectively. As a result, the 

proposal would have substantial financial and operational impacts on FWQC members, 

without a sufficient scientific basis or a significant practical benefit.

(p. 2 of comments)

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ED Comment #2. The FWQC believes that this proposed rule is not necessary. To the extent 

that EPA has a particular concern about States not using a new method, such as with 

mercury, EPA can address that problem directly. There is no need to make a substantial 

revision to the NPDES permitting regulations, particularly when that change would have 

the collateral impacts identified in these comments. To the extent that EPA decides to 

proceed with a rule, that should not happen unless and until the Agency proceeds with, 

and completes, the rulemaking recommended by the Federal Advisory Committee to 

define key regulatory terms as to quantitation and detection limits. (p. 2 of comments)

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0029 Federal Water Quality 

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Frediric P. Andes

Coordinator

EE Comment #3. Scientific Concerns (Reliance on ML). The proposed rule establishes a 

preference for use of certain analytical methods, based solely on one factor: whether that 

method has the lowest "minimum level" (ML) of the available methods. We believe that 

method sensitivity should not be the sole, or even the primary, factor in deciding which 

method should be used in the permit process. Other critical factors include accuracy, 

precision, selectivity, and whether the method has been validated. (As to accuracy, it is 

worth noting that in calculating ML, accuracy (i.e., percent recovery of analyte) is not 

considered; the MLs are calculated strictly based on standard deviation, or the ability of 

the lab to generate reproducible results. Thus, a lab can derive a very low ML (making 

method "sufficiently sensitive"), where the method is not acceptable from an accuracy 

perspective - in other words, is not "sufficiently accurate.")Even if having the lowest ML 

should be a key factor, EPA has ignored critical problems in applying that test. In some 

cases, a method with the lowest ML can be verified in the lab, but not in the field (for 

example, TRC). Often, different labs have different MLs for the same pollutant, and in 

some cases, an individual lab will have multiple MLs for the same pollutant, derived 

from different instruments. These lab MLs are frequently lower than the ML specified by 

EPA in the approved method. In addition, it is often the case that due to matrix 

interferences, the ML actually experienced when a method is run on effluents is 

significantly different than the ML result from a lab study (For example, it is common for 

a laboratory to experience "foaming" of a sample from the presence of detergents and 

surfactants during the purge and trap volatile organic compound analysis conducted by 

EPA Method 624. EPA Method 624 has MLs (as defined in the proposed rule, although 

no MLs are actually listed in the method) typically at 5 to 10 ug/L. To address samples 

that foam during analysis and therefore cause problems with the instrumentation, 

laboratories dilute the sample 5 to > 10 fold to minimize the sample matrix effects. As 

such, in the real sample matrix the sample-specific ML may be 25 to 100 ug/L or more, 

which is far greater than the normal ML.). Also, some methods list no ML at all (for 

example, EPA Methods 624 and 625, which are commonly used). For all of these 

reasons, specifying "the" ML for a given parameter is not a simple task.Further adding to 

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these complications is the fact that EPA itself does not have a single definition for the 

ML. Even in the EPA test method rules (40 CFR 136), there are multiple ways of 

defining the term “ML,” one of which is based on applying a multiplying factor (such as 

3 to 5 times) to the “method detection level” (MDL). Significant scientific flaws exist in 

the current EPA procedure to define MDL and, therefore, the ML. To address this issue, 

EPA convened a Federal Advisory Committee, which provided the Agency with specific 

recommendations. (The report can be found at 

http://www.epa.gov/waterscience/methods/det/faca /final-report-200712.pdf.) The 

Committee specifically recommended (at page iii of the report) that EPA promulgate a 

rule defining how quantitation limits will be derived. However, EPA has not yet 

proceeded with the recommended rulemaking, to define and clarify these critical 

regulatory terms. EPA needs to complete that task before requiring regulated dischargers 

to select test methods based – to any extent – on their MLs.

EPA has also recognized that there are flaws in current instrument calibration methods, 

which influence how an ML is determined, and that improvements in these methods are 

needed. (http://epa.gov/fem/calibration.htm) These improvements should be made before 

EPA requires 

permittees to make decisions on use of test methods based on their MLs.

While the concerns laid out here apply to both applications and reports, they pose 

particular problems with regard to the application process. At the point when a discharger 

is applying for a permit, it may not know a great deal about pollutants for which it does 

not currently have limits or monitoring requirements. But this rule would require that 

discharger to make judgments about what levels of that pollutant are likely to be present 

in its discharge, in order to determine which method has to be used. (This situation raises 

other concerns later: if the laboratory or instrument that is initially used to demonstrate 

compliance with the permit limits changes or becomes unavailable, the discharger may no 

longer be able to demonstrate compliance with the permit.) For this reason and all of the 

others set forth above, EPA’s sole reliance on MLs to determine what methods must be 

used in the NPDES program is inappropriate and should be reconsidered. (p. 2-4 of 

comments)
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0029 Federal Water Quality 

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Frediric P. Andes

Coordinator

EF Comment #4. Scientific Concerns (Requiring Use of Unapproved Methods). In 

addition to improperly focusing on MLs as the sole test of whether a test method is the 

right one to use, the proposed rule has another serious scientific flaw: appears to require 

the use of methods that have not been approved by EPA through the 40 CFR 136 process, 

regardless of whether they have undergone validation or any other scientific review. That 

requirement contravenes basic principles of sound science.As the proposed rule 

acknowledges, it is essential that data provided in support of permit applications or 

discharge monitoring reports be valid and reliable. EPA states that "[i]is critical...that 

applicants provide data that have been measured with precision and accuracy so that they 

will be meaningful to the decision making process...The same holds true for monitoring 

and reporting relative to permit limits established for regulated parameters...[I]t is critical 

that the Director make permitting decisions based on accurate data and, thus, sound 

science." 75 Fed. Reg. at 35715.Given the acknowledged need for analytical methods that 

provide precise and accurate data, it would have been consistent with that need for EPA 

to limit the scope of the proposed rule to methods that have been approved under 40 CFR 

Part 136 or are required under 40 CFR chapter I, subchapter N or O (collectively, 

"approved methods"). At a minimum, EPA could have explained in the proposed rule 

how one could determine whether a method that is not an approved method is 

nevertheless valid and reliable. EPA did not do either. Instead, the proposed rule 

contemplates the use of unapproved methods, without any discussion of the need to 

establish that such methods are valid and reliable. EPA's only concern appears to be that 

an unapproved method have a low Minimum Level and be "suitable." 75 Fed. Reg. at 

35716. But "suitable" is not defined. In particular, EPA does not specify whether 

unapproved methods have to meet the same level of validation set forth in the Agency’s 

"Alternate Test Procedure" (ATP) program before they can be used.The implication that 

the "Director" can require use of an unapproved method is particularly troubling, as it 

appears to permit EPA to require the use of analytical methods that have not been 

validated in accordance with recognized scientific standards: EPA's Agency Policy 

Directive No. FEM-2005-001, Ensuring the Validity of Agency Methods -- Methods 

Validation and Peer Review Guidelines (2005) (hereinafter "Validation Policy") and 

FEM Document No. 2005-01, Validation and Peer Review of U.S. [EPA] Chemical 

Methods of Analysis (hereinafter "Validation Guidance"), neither of which are mentioned 

in the proposed rule. The Validation Policy states that "all methods of analysis should be 

validated prior to issuance as an agency method." Validation involves a demonstration 

that a method is "suitable for its intended purpose (i.e., yields acceptable accuracy for the 

analyte, matrix and concentration range of concern)." (Validation Policy, p.1). The 

Validation Guidance requires a showing that a method is "reproducible", meaning that the 

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method can be implemented consistently across labs. (Validation Guidance, p. 11). 

Absent validation, there is no way to know if an unapproved method will yield precise 

and accurate results.

In addition to requiring use of unapproved methods, the proposed rule could be read to 

require States or affected parties to actually develop new methods if there are no existing 

methods that are "sufficiently sensitive." That would be both impracticable and well 

beyond EPA’s authority under the Clean Water Act. Moreover, as discussed in Appendix 

B, EPA has made no effort to assess the potentially substantial economic impact of 

imposing such a requirement. EPA should make it clear, in any regulatory language that 

is issued, that it is not attempting to require any party to develop new analytical methods.

(p. 4-5 of comments)

0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EG Comment #4. Vague and Undefined Provisions. Labs often have MLs that are lower 

than the ML published by EPA. It is not clear under what circumstances that lower ML 

can be used in determining if the method is "sufficiently sensitive." Additionally, if the 

sample matrix or field conditions impact the sensitivity of the measurement, it is not clear 

which ML should be used in determining method sensitivity. (p. 5 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EH Comment #5. Vague and Undefined Provisions. Some unapproved methods involve 

use of high-volume samplers. The cost of sampling is very high ($5,000 to $20,000 per 

sample for high-volume samplers), and it is not feasible to apply those methods on a 

routine basis for NPDES reporting. EPA does not discuss whether those methods are 

required, simply because of their greater sensitivity. Most high-volume sample collection 

methods have not been validated and therefore are not acceptable for use in compliance 

monitoring. (Yves Tondeur and Jerry Hart, Ultratrace extraction of persistent organic 

pollutants, Trends in Analytical Chemistry, Volume 28, Issue 10, November 2009, Pages 

1137-1147). (p. 6 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EI Comment #6. Vague and Undefined Provisions. Some methods require use of 

specialized sampling techniques, which may not be practicable to implement at specific 

outfalls. EPA does not address whether permittees would still be required to attempt to 

apply those techniques, based solely on their having low MLs. (p. 6 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes, 

Coordinator

EJ Comment #7. Vague and Undefined Provisions. EPA refers to unapproved methods 

that are “otherwise required by the Director,” but does not explain what requirements it is 

intending to refer to. (p. 6 of comments)

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Frediric P. Andes

Coordinator

EK Comment #8. Vague and Undefined Provisions. As noted above, the proposed rule 

requires the use of "suitable" unapproved methods in some circumstances, but EPA 

nowhere explains what "suitable" means. Also, EPA does not address how those methods 

could be validated sufficiently to be used in the permitting process. (p. 6 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EL Comment #9. Vague and Undefined Provisions. The proposed rule sets forth three 

tests for determining when a method is "sufficiently sensitive." (40 CFR 122.21(e)(3)(i) 

and 40 CFR 122.44(i)(1)(iv)(A)). The preamble indicates that if a method meets any one 

of the three tests, it is "sufficiently sensitive." That makes sense. However, the regulatory 

language is not as clear. To be consistent with EPA’s intent, the Agency should put an 

"or" after each of the first two tests. Otherwise, the rule could be read to require the 

method with the lowest ML to be used, even if another method has an ML that is below 

the level of the water quality criterion. (p. 6 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EM Comment #10. Vague and Undefined Provisions. EPA mentions certain methods that 

are "required" by EPA regulations. EPA should add the words "or specified" after 

"required" in those provisions (40 CFR 122.21(e)(3)(ii) and 40 CFR 122.44(i)(1)(iv)(B)), 

to clarify that test methods that are specified in applicable effluent limitations guidelines, 

new source performance standards, or sludge standards to be used for compliance 

purposes are sufficient under this rule. (p. 6 of cmts) 

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EN Comment #11. Vague and Undefined Provisions. Many of the States with NPDES 

authority already have procedures that specify what methods are to be used, and how 

results are to be reported. Those procedures often differ from the requirements in the 

proposed rule. (For example, Texas has adopted specific provisions governing the 

circumstances under which one can use a less-sensitive method.) The proposed rule could 

be read to preempt those State procedures. EPA has not shown a need for such action, 

which would raise substantial legal concerns. EPA should make it clear that NPDES 

States can address these method-related issues in other ways, based on their judgments as 

to how best to ensure reliable and accurate reporting. (p. 7 of comments)

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Frediric P. Andes

Coordinator

EO Comment #12. Practical Impacts. There is a shortage of qualified labs that conduct the 

extremely sensitive methods that the proposed rule requires to be used. (This was evident, 

for example, in EPA’s Interlaboratory Validation Study for the "highly sensitive" Method 

1668 for PCBs. When this study was conducted in 2003-2004, 8 out of 14 labs utilizing 

this procedure could not meet the quality requirements, even though the method had been 

in use for 5 years. Further, much of the science and emerging technologies supporting 

these new methods is not well-understood by state accreditation body auditors, so many 

of the labs using these methods are doing so without any standardized third-party 

oversight and review. EPA must ensure that these sensitive methodologies are thoroughly 

validated, and can be applied consistently and reliably, before it references their use as a 

viable alternative to replace currently accepted and time-proven methodologies.) 

Requiring all permittees to use these methods -- even when that is not necessary -- will 

overwhelm the capacity of those labs, leading to substantial delays in obtaining timely 

results and major problems for permittees in scheduling analyses of their samples. It will 

also lead to significant increases in the cost of testing, due to increased method 

complexity, need to acquire new equipment, short supply and very large demand. (The 

proposed rule would cause particularly difficult and costly compliance problems in 

isolated areas like Alaska and Hawaii. The number of available in-state laboratories that 

can perform sufficiently sensitive test methods is even more limited than elsewhere. If 

this rule is implemented as proposed, shipments to laboratories in the contiguous US 

would be required. This would add to the challenge of meeting sample holding times and 

other preservation restrictions, especially in light of delays caused by coordination 

between offshore facilities, air transport, laboratory schedules, and Transportation Safety 

Administration restrictions. Furthermore, shipments of samples can be delayed due to 

adverse weather conditions, volcanic eruptions, earthquakes and even tsunamis, 

grounding air transportation.) (p. 7 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EP Comment #13. Practical Impacts (Problems with EPA's Cost Analysis). There are 

hundreds of methods approved for use in 40 CFR Part 136, but EPA evaluated costs for 

only 33. (p. 8 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EQ Comment #14. Practical Impacts (Problems with EPA's Cost Analysis). Method 

costs are listed by EPA in broad price ranges only - less than $50, $51-$200, $201-$400 

and more than $400. (p. 8 of comments)

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ER Comment #15. Practical Impacts (Problems with EPA's Cost Analysis). There is no 

consideration of the difference, in cost per parameter, of single-parameter methods that 

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EPA may require, versus costs for currently-used methods that are able to analyze 

multiple parameters at a time. (p. 8 of comments)

0029 Federal Water Quality 

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Frediric P. Andes, 

Coordinator

ES Comment #16. Practical Impacts (Problems with EPA's Cost Analysis). There is no 

analysis of how many additional methods may need to be used to achieve sufficient 

sensitivity for all parameters of interest. (p. 8 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

ET Comment #17. Practical Impacts (Problems with EPA's Cost Analysis). There is no 

discussion of the costs for highly sensitive and very costly methods that EPA has 

developed but not approved, such as method 1668B for PCBs. That method costs about 

$1,000 per sample to run, not including the costs of collecting the sample. In contrast, 

EPA’s approved methods for PCB analysis (EPA Methods 608 and 508) cost about $75-

$100 per sample to run. One FWQC member has calculated the costs of using Method 

1668B for their operations to exceed $125,000 per year. (p. 8 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EU Comment #18. Practical Impacts (Problems with EPA's Cost Analysis). There is no 

consideration of costs to develop additional methods for parameters that do not currently 

have an applicable 40 CFR Part 136 method. For example, recent method development 

costs ranging from $14,500 to $25,000 were obtained for the compound tolytriazole. 

These costs do not even include the costs of submitting the method to EPA and obtaining 

Agency approval. (p. 8 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EV Comment #19. Practical Impacts (Problems with EPA's Cost Analysis). Total 

compliance monitoring costs must include consideration of all of the following factors: 

sampling costs, test frequency, number of parameters, number of methods, specific 

methods, sample matrix, method QC, and required detection and quantitation limits. 

EPA’s analysis is too narrow, so it underestimates total monitoring costs. (p. 8 of 

comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EW Comment #20. Lack of Statutory/Executive Order Reviews. EPA’s summary of this 

proposed rule begins by describing the regulatory changes as “minor amendments (75 

Fed. Reg. 35712 column 3). In addition, EPA says the proposal does not constitute a 

"significant regulatory action" (See, e.g., 75 Fed. Reg. 35718 column 2) does not impose 

any new information collection burden (See, e.g., 75 Fed. Reg. 35718 column 2), will not 

have a significant economic impact on a substantial number of small entities (See, e.g., 

75 Fed. Reg. 35718 column 3), will not have substantial direct effects on Tribal 

governments (75 Fed. Reg. 35719 column 2), is exempt from Executive Order 13211 

"because it is not a significant regulatory action under Executive Order 12866," (75 Fed. 

Reg. 35719 column 2) and "does not involve technical standards" (75 Fed. Reg. 35719 

column 3). Individually and collectively, those assertions by EPA are unfounded. In 

reality, EPA’s proposed changes are very substantial, deserve considerable additional 

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thought by the Agency, and are subject to mandatory review under a variety of executive 

orders and regulatory review statutes. The reasons why review is required are discussed 

in more detail in Attachment B. (p. 9 of comments)

0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EX Comment #21. Recommendations. Specify that in determining which method should 

be used, the permitting agency must consider, in addition to sensitivity, the important 

issues of accuracy and precision. (p. 10 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

EY Comment #22. Recommendations. Provide that test methods should not be used unless 

they have been validated, in accordance with the principles set forth in EPA’s Validation 

Policy and Validation Guidance. Methods should have to meet the same level of 

validation set forth in the EPA “Alternate Test Procedure” program before they can be 

used. (p. 10 of comments)

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0029 Federal Water Quality 

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Frediric P. Andes

Coordinator

EZ Comment #23. Recommendations. Include a provision specifying that in cases where 

there are matrix interference concerns with a specific effluent, alternate methods that are 

less sensitive, but have less of an interference problem, may be used.

(p. 10 of comments)

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Frediric P. Andes

Coordinator

FA Comment #24. Recommendations. Allow NPDES States to specify their own 

procedures concerning use of sensitive methods in the permitting process, including 

options for use of less sensitive methods under appropriate circumstances. (p. 10 of 

comments)

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Frediric P. Andes

Coordinator

FB Comment #25. Recommendations. Allow flexibility in applying test method 

requirements to discharges in geographically isolated areas. (p. 10 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FC Comment #26. Recommendations. Allow the permitting agency to determine, for sitespecific reasons, that use of the sensitive method is not necessary (for example, if testing 

with a less sensitive method at an internal monitoring point can allow the permittee to 

calculate whether it is complying at the final effluent point). (p. 10 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FD Comment #27. Recommendations. Allow the permittee to request use of a less sensitive 

method if use of the more sensitive method is impractical due to safety concerns (for 

example, if the test method requires the sampling personnel to locate very close to the 

discharge (as with mercury Method 1631), and the discharge is a large-volume 

noncontact cooling water discharge into a lake). (p. 10 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FE Comment #28. Attachment A - Example of Lower Lab ML's. Due to EPA’s proposal 

to require the use of ‘‘sufficiently sensitive’’ analytical methods for mercury analysis, 

many in the regulated community will believe that they must abandon the traditional cold 

vapor atomic absorption spectroscopy (CVAAS) methods EPA 245.1 and 245.2 in favor 

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of the more expensive and problematic atomic fluorescence methods EPA 245.7 and 

1631. Unfortunately, EPA method 245.1 states that the method is applicable from 0.2 -10 

ug/L, despite the fact that new CVAAS technology, teamed with contamination control, 

can reduce the analytical method detection level (MDL) from 0.2 ppb to 1 ppt for lowlevel mercury analysis.

The City of Boise’s Water Quality Laboratory has obtained a 1 ng/L MDL for low-level 

mercury analysis by stringent contamination control: segregating labware and acid baths; 

using an automated closed system sample digester; enclosing the auto-sampler; and 

adding stannous chloride via a closed sample loop. The signal to noise ratio was 

increased by reducing water vapor interference by use of a gas/liquid separator and nafion 

dryer. Sensitivity was further enhanced through increasing the analyzed sample volume 

by varying the carrier gas flow and sample pump speed, using larger (22cm) sample and 

reference cells with twin solid state silicon detectors, and utilizing a thermally stabilized 

mercury lamp.

Stringent technique and use of technology may allow CVAAS methods to meet all 

required measurement quality objectives and continue to be "sufficiently sensitive" for 

many NPDES applications. This example demonstrates how important it is for the 

regulators to maintain options rather than further limit the acceptable methods based on 

published MDLs and MLs in dated documents. Analytical options advance much faster 

than the method updates are released, so care is needed in rule-making to ensure that 

better science is an option to the regulated community. (p. 1 of comments)
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Coalition

Frediric P. Andes

Coordinator

FF Comment #29. Attachment B - Lack of Statutory and Executive Order Reviews.

EPA's analysis of the applicability of Executive Order 12866, the Paperwork Reduction 

Act, the Regulatory Flexibility Act, the Unfunded Mandates Reform Act, and Executive 

Order 13132 are superficial and conclusory at best. Executive Order 12866 is dismissed 

in one sentence: "This rule is not a 'significant regulatory action' . . . and therefore is not 

subject to review under the EO." 75 Fed. Reg. at 35718. The Paperwork Reduction Act 

and the Regulatory Flexibility Act take a little longer: four sentences. The Unfunded 

Mandates Reform Act merits five sentences, and the Regulatory Flexibility Act prompted 

a total of eight sentences.The principal basis for EPA's dismissal of each of these statutes 

and Executive Orders is the assertion that EPA is not imposing any new burdens, but 

simply "clarifying, based on existing legal requirements and authorities, that sufficiently 

sensitive analytical test methods must be used" to develop data for NPDES permit 

applications and discharge monitoring reports. 75 Fed. Reg. at 35718-719 (emphasis 

added). That simply is not true. Over the years, EPA has approved multiple analytical text 

methods for many pollutants (75 Fed. Reg. at 35714), and permit writers and regulated 

entities have freely chosen from those methods (see Id. at 35713 (the proposed rule would 

affect "entities that use or allow the use of any EPA-approved analytical methods")). Not 

until 2007 did EPA attempt to impose a requirement that regulated entities use a 

"sufficiently sensitive" method, and that effort was limited to mercury. See 75 Fed. Reg. 

at 35715. Even then, EPA only went so far as to "strongly recommend[]" that permitting 

authorities treat as incomplete permit applications that did not rely upon "sufficiently 

sensitive" methods. Thus, while EPA "has historically expected that applicants and 

permittees would select . . a . . . method . . . that is sufficiently sensitive" (Id.)(emphasis 

added), there is no evidence that EPA interpreted the existing rules as imposing a binding 

requirement to use "sufficiently sensitive" methods.The preamble to the proposed rule is 

replete with statements that demonstrate EPA;s intend to impose a new, legally binding 

obligation and burdens upon permit applicants and writers and permittees. For example:-

"[EPA] is proposing minor amendments to its [CWA] regulations to codify that only 

'sufficiently sensitive analytical test methods can be used . . ." 75 Fed. Reg. at 35712 

(emphasis added).- This proposal . . . would codify existing EPA guidance on . . . 

mercury and extend the approach outlined in that guidance to the NPDES program more 

generally." Id. (emphasis added).- "The purpose of today's proposal is to clarify that 

NPDES applicants must use sufficiently sensitive analytical methods . . . and the Director

[footnote omitted] must require and accept only such data." Id. at 35713 (emphasis 

added).- "[I]f the State currently requires a particular method or minimum level that is not 

"sufficiently sensitive" as defined in new EPA regulations . . . EPA would expect States 

to revise their statutes or regulations . . . States would need to revise any policy guidance 

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as well." Id. at 35716.- "EPA is simply clarifying . . . that sufficiently sensitive analytical 

test methods must be used." Id. at 35718 (emphasis added).

These and similar statements, combined with the fact that EPA has proposed amendments 

to the existing rules, instead of simply issuing a guidance document, contradict 

Administrator Jackson's certification that "this proposed action will not impose any new 

legally binding requirements or burden on EPA, States, or the regulated community, and 

specifically, and burden on any small entity." Id. EPA therefore needs to reassess whether 

it has met its obligations under the Executive Orders, the Paperwork Reduction Act, the 

Regulatory Flexibility Act, and the Unfunded Mandates Reform Act. We believe that it 

has not done so, for the reasons explained below. (p. 1-2 of comments)
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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FG Comment #30. Attachment B - Lack of Statutory and Executive Order Reviews. A. 

EPA’s proposal is a "significant regulatory action" under Executive Order 

12866.Executive Order 12866, "Regulatory Planning and Review," was intended to 

provide oversight and ensure careful consideration before promulgating any "significant 

regulatory action." According to section 3(f) of that Executive Order, a regulatory action 

is "significant" if (among other things):- It may raise novel legal or policy issues, or- It 

may have an annual effect on the economy of $100 million or more, or- It may adversely 

affect competition or jobs.- EPA’s proposal meets all three of the tests above. As an 

initial matter, we believe that the costs of compliance, and the resulting effect on the 

economy, will be substantial. As noted in the main body of the FWQC comments, EPA 

has seriously underestimated the costs that will result from implementing the new 

requirements. Those costs fall into the following basic areas:

- The proposal would have the effect of requiring permitted facilities to develop their own 

analytical methods, at their own expense. In cases where EPA does not have any 

approved method for a particular compound, the proposal still requires monitoring to be 

conducted using "a sufficiently sensitive test procedure specified in the permit." 

(Proposed text of 40 CFR 122.44(i)(1)(iv)(B)). In some cases there may be an existing 

analytical method (although not EPA-approved). That would be the best case. However, 

there will also be situations where no analytical method -- at all -- exists that can detect 

and quantify a particular substance at the concentrations desired by EPA. In that situation, 

EPA’s current proposal would appear to require the permitted facility to develop and 

validate an analytical method that is "sufficiently sensitive." The cost of developing even 

one method could be millions of dollars. Worse yet, any one facility may have to develop 

methods for multiple substances. And, if numerous facilities across the country -- perhaps 

in different EPA regions -- each discharge the same substance, they may have to develop 

methods independently, thereby incurring massive costs in the most inefficient manner. 

This is because there is no obvious way for those permittees to know of each other. As a 

further concern, this means not only would money be wasted, but numerous divergent, 

inconsistent methods would be developed for the same substance. This aspect alone could 

make the proposal a "significant regulatory action."

- Requiring more sensitive methods will increase the cost 'per analysis." In general, the 

cost "per analysis" is higher for analytical methods that are more sensitive. The amount of 

incremental cost per analysis can vary from one method to another. However, more 

sensitive methods usually require more stringent laboratory procedures, and sometimes 

more costly laboratory equipment. Thus, the cost on analysis tends to increase. Nothing 

See Response 

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in EPA’s proposal even mentions this. Considering that analyses under permits must be 

run repeatedly (for example, quarterly, monthly, weekly or even daily), and that the 

NPDES program applies to a very large number of facilities nationwide, this factor alone 

could make the proposal a "significant regulatory action."

- EPA’s proposal will require more analyses to be run. For example, it is currently

common to run a single scan by a single method, and thereby receive analytical data for a 

large number of compounds. This keeps the cost down but may not achieve, for some 

compounds, the detection and quantifications levels that EPA now desires. This means 

the permittee would now have to run the broad scan and a number of additional, singlecompound analyses. This will obviously increase the cost of analysis under NPDES 

permits and to support permit applications, but EPA does not even mention this, 

anywhere in the proposal.- EPA’s proposal will necessitate confirmatory analyses to 

address "false positives." As mentioned above, greater analytical sensitivity often 

increases the risk of "false positives." This means the methods may register a non-target 

compound and mistakenly identify it as the target substance. Sometimes it is possible to 

dispel this "mistaken identity" by using a different analytical method. However, doing so 

requires additional expenditures. EPA’s proposal does not acknowledge this.Based on the 

rationale above, EPA’s proposal meets at least three tests, any one of which would trigger 

applicability of Executive Order 12866.

1. The proposal raises novel legal or policy issues. For example:

- EPA here appears to claim legal authority, under the Clean Water Act, to require 

permittees to develop and validate analytical methods, at their own expense, whenever 

EPA has failed to do so.- EPA also appears to claim authority to require multiple 

different permittees to independently develop duplicative and inconsistent, non-EPAapproved, "in-house" analytical methods for the same pollutant.

- EPA has asserted that this proposal imposes no new information collection burdens (75 

Fed. Reg. 35718 column 2.), and that OMB’s approval of the burdens of the existing 

regulations automatically covers the amended regulations. We believe that EPA may not 

legally disregard the new burden of additional analyses, more costly analyses and 

especially the cost of developing in-house analytical methods, and thereby shield the 

proposal from OMB review.

2. The proposal could easily have an annual effect on the economy of $100 million or 

more. The cost of developing in-house analytical methods, the cost of more expensive 

analyses, the cost of more numerous analyses, and the cost of confirmatory analyses to 

rule out “false positives” will be extensive and nationwide.
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3. The proposal could adversely affect competition and jobs in a meaningful way. The 

additional costs that this proposal will case are truly substantial. In today’s economy, any 

substantial increase in costs has the potential to make American businesses less 

competitive in the global market, and thereby to jeopardize jobs.

For all these reasons, EPA’s proposal is a "significant regulatory action" subject to 

Executive Order 12866.

(p. 2-4 of comments)

0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FH Comment #31. Lack of Statutory and Executive Order Reviews. B. EPA’s proposal 

imposes new burdens that have not been approved under the Paperwork Reduction Act.

EPA asserts that this proposal "does not impose any new information collection burden." 

(75 Fed. Reg. 35718 column 2) However, as has been demonstrated above, the proposal 

will actually require enormous additional expenditures to develop analytical methods and 

conduct additional analyses. These burdens were not present in the existing regulations, 

and have not been approved by OMB. The proposal should be submitted to OMB for 

review under the Paperwork Reduction Act. (p. 4 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FI Comment #32. Lack of Statutory and Executive Order Reviews. C. EPA’s proposal 

requires further review under the Regulatory Flexibility Act.

EPA has asserted that the proposal "will not have a significant economic impact on a 

substantial number of small entities." (75 Fed. Reg. 35718 column 3) However, EPA has 

utterly failed to consider the economic impacts described above, and thus has not 

evaluated the extent to which those impacts would affect small entities. Small entities 

would likely experience particular difficulty if, for example, they were required to 

develop sensitive analytical methods at their own expense. Due to the lack of 

consideration of these issues, EPA has not provided any valid basis to exclude this 

regulatory action from the Regulatory Flexibility Act. (p. 4 of comments)

See Response 

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FJ Comment #33. Lack of Statutory and Executive Order Reviews. D. EPA’s proposal 

requires further consideration of the Unfunded Mandates Reform Act.According to 

EPA’s Federal Register notice, the Unfunded Mandates Reform Act applies to a federal 

mandate that might result in (among other possibilities) expenditures of $100 million or 

more by "the private sector" in any one year. As has been shown above, EPA’s proposal 

could easily result in expenditures by the private sector in excess of $100 million 

annually.EPA also asserts that that the proposal contains "no regulatory requirements that 

might significantly or uniquely affect small governments." (75 Fed. Reg. 35719 column 

1) However, small governments often operate wastewater treatment facilities. 

Consequently, the increased costs that this proposal would create, will fall heavily on 

small governments.For the reasons stated above, EPA’s rationale for excluding the 

Unfunded Mandates Reform Act is incorrect.

(p. 4 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FK Comment #34. Lack of Statutory and Executive Order Reviews. E. EPA’s needs to 

reassess whether Executive Order 13175 applies. EPA has stated that the proposal is not 

subject to Executive Order 13175 (Consultation and Coordination with Indian Tribal 

Governments) because it "will not have substantial direct effects on Tribal governments, 

on the relationship between the Federal Government and Indian Tribes, or on the 

distribution of power and responsibilities between the Federal Government and Indian 

Tribes." (75 Fed. Reg. 35719 column 2). EPA’s offers no analysis to support this 

assertion. If tribal governments implement permitting programs, this proposal may 

impose greater responsibilities on tribal governments to identify and recognize 

"sufficiently sensitive" analytical methods. The proposal may also impose new 

responsibilities on tribal governments to require and oversee the development of new 

analytical methods where none exist. And if tribal governments operate wastewater 

treatment systems, the proposal may impose substantial new costs on those tribal 

governments. Consequently, EPA needs to reassess whether Executive Order 13175, 

based on those possible impacts. (p. 4 of comments)

See Response 

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FL Comment #35. Lack of Statutory and Executive Order Reviews. F. EPA has 

incorrectly excluded this proposal from coverage under Executive Order 13211. EPA 

asserts that this proposal is not subject to Executive Order 13211 (Actions Concerning 

Regulations that Significantly Affect Energy Supply, Distribution, or Use). The Agency 

says this Executive Order does not apply "because [the proposal] is nota significant 

regulatory action under Executive Order 12866." (75 Fed. Reg. 35719 column 2). That 

rationale is incorrect. As has been demonstrated above, this proposal is a significant 

regulatory action under Executive Order 12866. Therefore, EPA has incorrectly excluded 

Executive Order 13045. (p. 5 of comments)

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0029 Federal Water Quality 

Coalition

Frediric P. Andes

Coordinator

FM Comment #36. Lack of Statutory and Executive Order Reviews. G. EPA should 

reconsider whether this proposal is subject to section 12(d) of the National Technology 

Transfer and Advancement Act. EPA has stated that this proposal is not subject to section 

12(d) of the National Technology Transfer and Advancement Act. The Agency’s stated 

rationale is that "This proposed rulemaking does not involve technical standards." EPA 

does not explain why that is the case. This rulemaking involves analytical methods, 

which conceptually would seem to fit a reasonable definition of "technical standards.' The 

rulemaking appears to have the effect of requiring development of new analytical 

methods where none exist. Therefore, EPA should reconsider whether the NTTAA is 

applicable. (p. 6 of comments)

See Response 

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0030 North Carolina Water 

Quality Association, Inc

F. Paul Calamita

General Counsel

FN Comment #1. EPA's proposed amended regulation would require that, for NPDES 

permit applications and for permit compliance reporting, an approved Part 136 method be 

used that is at or below the level of the applicable water quality criterion, or if the 

concentration of the pollutant parameter is high enough, a method that properly quantifies 

the concentration. VAMWA generally supports EPA's proposal; however, additional 

flexibility should be included in the regulation for those cases where there is a wasteload 

allocation ("WLA") or a permit limit above the water quality criterion.

We agree that an appropriate Part 136 analytical method should be used which allows a 

correct quantification of the pollutant parameter. In many cases, the quantification level 

will be the water quality criterion. However, there are also many cases where dilution is 

available, and where there is a properly calculated WLA or similar values that is 

protective of the instream criterion, at a value higher than the criterion. In those instances 

the regulation should provide for the use of a method that provides a quantification level 

at or below the WLA or other appropriate values. In such cases there is no benefit to the 

use of a more sensitive method, and the more sensitive methods may have additional 

costs or other disadvantages.

We further note that, although the preamble to the proposal refers to the use of an 

analytical method with a QL at or below the water quality criterion or permit limit, the 

proposal itself does not appear designed to address permit limits at levels higher than the 

respective criteria.

Accordingly, we recommend that the regulation be changed before promulgation to 

address these important issues. We ask that EPA incorporate the following revisions to 

address the foregoing issues: 

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40 C.F.R. 122.21 (e)(3).

(i) For purposes of this requirement, a method approved under 40 CFR Part 136 is 

"sufficiently sensitive" when:

(A)The method minimum level (ML) is at or below the level of the applicable water 

quality criterion, wasteload allocation or other critical regulatory value for the measured 

parameters;

(B) The method ML is above the applicable water quality criterion, wasteload allocation, 

permit limit or other critical regulatory value, but the amount of pollutant or pollutant 

parameter in a facility's discharge is high enough that the method detects and quantifies 

the level of the pollutant or pollutant parameter in the discharge...

A comparable change should also be made to the proposed language subsection 122.44.

(p. 1-2 of comments)

0031 Maryland Association of 

Municipal Wastewater 

Agencies, Inc

FO Comment #1. EPA's proposed amended regulation would require that, for NPDES 

permit applications and for permit compliance reporting, an approved Part 136 method be 

used that is at or below the level of the applicable water quality criterion, or if the 

concentration of the pollutant parameter is high enough, a method that properly quantifies 

the concentration. VAMWA generally supports EPA's proposal; however, additional 

flexibility should be included in the regulation for those cases where there is a wasteload 

allocation ("WLA") or a permit limit above the water quality criterion.

We agree that an appropriate Part 136 analytical method should be used which allows a

correct quantification of the pollutant parameter. In many cases, the quantification level 

will be the water quality criterion. However, there are also many cases where dilution is 

available, and where there is a properly calculated WLA or similar values that is 

protective of the instream criterion, at a value higher than the criterion. In those instances 

the regulation should provide for the use of a method that provides a quantification level 

at or below the WLA or other appropriate values. In such cases there is no benefit to the 

use of a more sensitive method, and the more sensitive methods may have additional 

costs or other disadvantages.

We further note that, although the preamble to the proposal refers to the use of an 

analytical method with a QL at or below the water quality criterion or permit limit, the 

proposal itself does not appear designed to address permit limits at levels higher than the 

respective criteria.

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Accordingly, we recommend that the regulation be changed before promulgation to 

address these important issues. We ask that EPA incorporate the following revisions to 

address the foregoing issues: 

40 C.F.R. 122.21 (e)(3).

(i) For purposes of this requirement, a method approved under 40 CFR Part 136 is 

"sufficiently sensitive" when:

(A)The method minimum level (ML) is at or below the level of the applicable water 

quality criterion, wasteload allocation or other critical regulatory value for the measured 

parameters;

(continued from above)

(B) The method ML is above the applicable water quality criterion, wasteload allocation, 

permit limit or other critical regulatory value, but the amount of pollutant or pollutant 

parameter in a facility's discharge is high enough that the method detects and quantifies 

the level of the pollutant or pollutant parameter in the discharge...

A comparable change should also be made to the proposed language subsection 122.44.

(p. 1-2 of comments)