UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JUL 2·1 20~ 

OFFICE OF 

ENFORCEMENT AND 

COMPLIANCE ASSURANCE 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

Issuance of Clean Water Act National Pollutant Discharge Elimination System 

Compliance M~· tori.ng ~trategyl _ 

Lisa 

Director

C. Lund 

, Offi · of Compliance 

~~ 

Regional Enforcement Division Directors 

Regional Water Division Directors 

The attached Compliance Monitoring Strategy (CMS) provides revised compliance monitoring 

goals for the National Pollutant Discharge Elimination System (NPDES) program. This revised 

strategy provides increased flexibility to EPA and state agencies when conducting compliance 

monitoring ;activities through an expanded set of tools for determining compliance and to address 

local water )pollution and compliance concems. The goals in this revised strategy address both 

the frequency and type of compliance monitoring activities that are appropriate for various 

categories ofNPDES regulated facilities. The strategy also provides additional flexibility to 

address the most important water quality problems, an expanding universe of regulated entities, 

and resource ljmitations. 

Compliance monitoring is a comerstone of EPA's program to protect and restore water quality. 

The primary goal of the combined EPA and state compliance monitoring efforts, such as on-site 

inspections .and evaluation of self-reported Discharge Monitoring Report (DMR) data; is to 

ensure and document whether entities regulated under the NPDES and pretreatment programs are 

complying with their CW A obligations. EPA and state compliance monitoring programs should 

accurately identify and document noncompliance, support the enforcement process, monitor 

compliance with enforcement orders and decrees, establish presence in the regulated communjty, 

deter noncompliance, support the permitting process and further the broad watershed protection 

and restoratiton goals of the NPDES program. 

Last year OECA engaged EPA regions and states in a national dialogue about the existing 

flexibility int the NPDES CMS and how the definition of what constitutes compliance monitoring 

can be furth1er expanded while maintaining program integrity. The attached revisions to the 2007 

Internet Address (URL) • http://www.epa.gov 

RE•cycled/Recyclable • Prinled with Vegetable Oil Based Inks on 100% Post~onsumer, Process Chlorine free Recycled Paper 
CMS are the result of our discussions with the EPA regional and state agencies implementing 

NPDES compliance and enforcement programs. Collectively, we recognize that our compliance 

monitoring programs need to evolve and incorporate new technologies and innovative 

compliance monitoring approaches. These revisions more fully encompass the suite of 

compliance monitoring tools that are available to EPA and states today and reflect the key 

concepts ofNext Generation Compliance, taking into account opportunities created by increased 

electronic reporting, increased transparency, and advanced monitoring technologies. 

In addition to the CMS revisions to account for an expanded defmition of compliance 

monitoring, the revised NPDES CMS includes, as necessary, other changes to keep the strategy 

current and to incorporate feedback received since issuance of the 2007 strategy. The key 

revisions include: 

• Mor1e specific guidance on alternative CMS plans; 

• Additional compliance monitoring tools beyond traditional on-sjte compliance 

insp(::ctions~ 

• Updates to several compliance monitoring goals to improve clarity and simplify 

implementation of the CMS; and 

• AddJresses compliance monitoring for vessels and pesticide operators. 

I want to thank the individuals in the states, the state associations, EPA regions, and 

Headquarters who worked with us in revising the 2007 NPDES CMS. We, in close coordination 

with EPA re:gions and states, will continue to regularly monitor and evaluate implementation of 

the revised strategy and modify it as appropriate. 

Please share this CMS with your counterpart at all affected state agencies and departments in 

your region. If you have any questions or concerns regarding the revised NPDES CMS, please 

contact Martha Segall (202-564-0723) or Rebecca Roose (202-566-1387). Thank you in advance 

for your cooperation as we implement the revised CMS. 

Attachment 

cc: Cynthia Giles, Assistant Administrator, Office of Enforcement and Compliance 

Assu1rance 

Nancy Stoner, Acting Assistant Administrator, Office of Water 

Susan Shinkman, Director, Office of Civi.l Enforcement 

AndTew Sawyers, Director, Office of Wastewater Management 

Edw.ard J. Messina, Director, Monitoring, Assistance-and Media Programs Division 

Mark Pollins, Director, Water Enforcement Division 

Deborah Nagle, Director, Water Permits Division 

Rick Duffy, Deputy Director, Monitoring, Assistance and Media Programs Division 

Regional Enforcement Coordinators 

Julia Anastasio, Executive Director; Association of Clean Water Administrators 

Sean Rolland, Deputy Director, Association of Clean Water Administrators 
 

 

 

Clean Water Act
	

National Pollutant Discharge Elimination System
	

Compliance Monitoring Strategy 

2014
	

U.S. Environmental Protection Agency
	

Office of Enforcement and Compliance Assurance 

Office of Compliance
	
 

 

 

 

 

 

 

 

DISCLAIMER
 

The discussion in this document is intended solely as guidance. This document is not a regulation. 

It does not impose legally binding requirements on the United States Environmental Protection 

Agency (EPA), States, or the regulated community. This policy does not confer legal rights or 

impose legal obligations upon any member of the public. The general description provided here 

may not apply to a particular situation based on the circumstances. Interested parties are free to 

raise questions and objections about the substance of this policy and the appropriateness of the 

application of this policy to a particular situation. EPA retains the discretion to adopt approaches 

on a case-by-case basis that differ from those described in this policy where appropriate. This 

document may be revised periodically without public notice. EPA welcomes public input on this 

document at any time. 

Any questions concerning this policy may be directed to Martha Segall (Segall.martha@epa.gov) 

or Rebecca Roose (roose.rebecca@epa.gov). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table of Contents 

Introduction ................................................................................................................................................... i
 

Summary of FY2013 CMS Evaluation........................................................................................................ ii
 

Summary of FY2013 National Dialogue on Expansion of Compliance Monitoring.................................. iii
 

Part 1: Implementation of the Revised NPDES Compliance Monitoring Strategy........................................ 1
 

Planning Process ....................................................................................................................................... 1
 

Alternative CMS Plans............................................................................................................................... 2
 

Oversight, Reporting and Measurement .................................................................................................. 4
 

Part 2: Compliance Monitoring Frequency Goals for NPDES Sources .......................................................... 6
 

1.A. Major Permittees .......................................................................................................................... 6
 

1.B. Traditional Non-Major Permittees .................................................................................................... 7
 

1.C. Pretreatment Program.................................................................................................................. 9
 

1.C.1. PretreatmentAudits..................................................................................................................9
 

1.C.2. Pretreatment Compliance Inspections....................................................................................10
 

1.C.3. Significant Industrial User Inspections.....................................................................................10
 

1.D. Sludge/Biosolids..........................................................................................................................11
 

1.E. Oversight Inspections..................................................................................................................11
 

2.A. Combined Sewer Systems (CSSs)....................................................................................................12
 

2.B. Sanitary Sewer Systems (SSSs) ....................................................................................................13
 

2.C. Stormwater .................................................................................................................................13
 

2.C.1. Municipal Separate Storm Sewer Systems (MS4s) ..................................................................13
 

2.C.2. Industrial Stormwater..............................................................................................................15
 

2.C.3. Construction Stormwater Sites...............................................................................................15
 

2.D. Concentrated Animal Feeding Operations ..................................................................................16
 

2.D.1. Large and Medium CAFOs with NPDES Permits.......................................................................16
 

2.D.2. Large CAFOs without NPDES Permits ......................................................................................16
 

2.D.3. Medium AFOs without NPDES Permits....................................................................................17
 

2.D.4. Small AFOs...............................................................................................................................17
 

3.A Pesticides ....................................................................................................................................18
 

3.B Vessels.........................................................................................................................................18
 

Part 3: Activity Type Descriptions ...............................................................................................................19
 

Part 4: ICIS-NPDES Data Entry.....................................................................................................................25
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Introduction 

This Compliance Monitoring Strategy (CMS) provides compliance monitoring goals for 

the Clean Water Act (CWA) National Pollutant Discharge Elimination System (NPDES) 

program. The revised goals and flexibilities described in this CMS will be fully effective in the 

federal FY2015 planning and reporting cycle. 

Regulations found at 40 CFR 123.26 set forth requirements for compliance evaluation 

programs for states with NPDES program authorization.1 Analogous regulations for the 

pretreatment program are set forth in 40 CFR 403.10(f)(2). This CMS provides recommended 

minimum frequencies for compliance monitoring activities that, from a national perspective, the 

EPA believes constitute a strong and balanced compliance monitoring program that should be 

reflected in all approved state NPDES and pretreatment programs, as well as in all EPA’s direct 

implementation activities. 

Compliance monitoring is a cornerstone of the EPA’s program to achieve clean water. 

The primary goal of the combined EPA and state compliance monitoring efforts, such as on-site 

inspections and evaluation of self-reported Discharge Monitoring Report (DMR) data, is to 

ensure and document whether entities regulated under the NPDES and pretreatment programs are 

complying with their CWA obligations. EPA and state compliance monitoring programs should 

accurately identify and document noncompliance, support the enforcement process, monitor 

compliance with enforcement orders and decrees, establish presence in the regulated community, 

deter noncompliance, support the permitting process, and further the broad watershed protection 

and restoration goals of the NPDES program. 

Achieving these goals will continue to require EPA and state collaboration, innovative 

approaches to compliance monitoring and efficient and effective allocation of resources. 

Compliance monitoring programs are challenged by tightened budgets at all levels of 

government and the growing concern about environmental and public health effects of wet 

weather dischargers. The 2007 NPDES CMS made changes to earlier inspection frequency goals 

1 These regulations include, in part, the requirement that a state maintain: 

(1) A program which is capable of making comprehensive surveys of all facilities and activities subject to the 

State Director’s authority to identify persons subject to regulation who have failed to comply with permit 

application or other program requirements. Any compilation, index or inventory of such facilities and 

activities shall be made available to the Regional Administrator upon request. 

(2) A program for periodic inspections of the facilities and activities subject to regulation.		These inspections 

shall be conducted in a manner designed to: 

a.		 Determine compliance or non-compliance with issued permit conditions and other permit 

requirements 

b.		 Verify the accuracy of information submitted by permittees and other regulated persons in 

reporting forms and other forms supplying monitoring data; and 

c.		 Verify the accuracy of sampling, monitoring and other methods used by permittees and other 

regulated persons to develop that information; 

(3) A program for investigating information obtained regarding violations of applicable program and
	

permit requirements; and
	

(4) Procedures for receiving and ensuring proper consideration of information submitted by the public 

about violations.
	

i 
 

 

 

 

 

 

 

 

 

 

 

 

in order to promote an effective balance across the NPDES compliance monitoring program. 

Implementation of the 2007 NPDES CMS has provided deterrence to noncompliance in the most 

significant environmental areas by allowing increased effort in NPDES program areas that 

impact water quality in priority watersheds and water segments. 

The EPA Office of Enforcement and Compliance Assurance (OECA) is revising the 2007 

NPDES CMS as a result of an FY2013 internal, informal evaluation of the 2007 policy and the 

FY2013 national dialogue on expansion of compliance monitoring that OECA conducted with 

regions and states. The revised CMS draws on these recent activities to better reflect the range of 

important compliance monitoring activities that are an integral part of our program today and 

better encompass the planning process needed to ensure consistent national implementation in 

accordance with EPA goals and priorities. Furthermore, the revised CMS reflects the key 

concepts of Next Generation Compliance, including electronic reporting, increased transparency 

and technological advances, and offers additional flexibilities to states in determining the most 

effective use of limited compliance monitoring resources. For example, we expect 

implementation of this revised policy to facilitate increased use of next generation targeting 

tools, such as the Pollutant Loading Tool (available through “Enforcement and Compliance 

History Online” (ECHO)) and EPA’s GeoPlatform, and further program transparency by 

utilizing the ECHO state dashboards and e-reporting to better manage NPDES compliance 

monitoring activities across the country. 

Like the 2007 NPDES CMS, this revised CMS addresses inspections for NPDES 

major and traditional non-major permittees, pretreatment, oversight, biosolids, and wet 

weather sources (Combined Sewer Systems, Sanitary Sewer Systems, MS4s, Industrial and 

Construction Stormwater, and Concentrated Animal Feeding Operations). In addition, this 

revised CMS addresses compliance monitoring of pesticide operators and vessels that are 

regulated under the NPDES program. 

Summary of FY2013 CMS Evaluation 

During FY2013, the Office of Compliance (OC) conducted an informal evaluation of the 

implementation of the 2007 NPDES CMS. As stated in the October 2007 cover memo, EPA and 

state NPDES inspection programs must address competing challenges of water quality 

degradation and limited resources through innovative and efficient targeting of resources on the 

most important noncompliance and environmental problems, particularly those that had not been 

adequately addressed by earlier NPDES compliance monitoring goals. 

OC’s informal evaluation focused on input gathered from each EPA region and CMS 

implementation data from Federal Fiscal Years 2011-2012, including commitments from CMS 

plans and inspection activities derived from end-of-year reports and ICIS-NPDES (Integrated 

Compliance Information System). Key findings included: 

 Most regions find the CMS to be an important tool for management of the inspection 

program. They typically engage in routine, detailed discussions with their states about 

how best to allocate inspection resources based on state circumstances and the 

national CMS goals. 

ii 
 

 

 

 

 

	 Implementation of the 2007 CMS varies greatly across regions and states. This 

includes the level of regional involvement in the planning process and the way the 

flexibilities in the CMS are utilized by states. 

o	 In many cases deviations from the national goals are not explained or justified 

in the CMS plan. 

o	 Several regions have not been receiving end-of-year reports from their states. 

o	 There are notable differences between implementation by authorized states 

and implementation by EPA regions in direct implementation areas. This can 

largely be attributed to the 2007 CMS’s emphasis on state inspection 

planning. 

 Many states are not meeting their annual commitments. 

 According to data entered into ICIS-NPDES by EPA and states, actual inspection 

activities for majors and traditional non-majors fall short of national goals. 

Summary of FY2013 National Dialogue on Expansion of Compliance Monitoring 

OECA recognizes that although historically we have focused on comprehensive on-site 

inspections to track compliance monitoring activities nationwide, there are additional compliance 

monitoring activities that can play a vital role in helping EPA and states achieve our broader 

compliance monitoring goals. OECA held a national dialogue on the flexibility existing in the 

compliance monitoring strategies for each of the statutory compliance and enforcement 

programs, including the NPDES CMS. The stated purpose of this dialogue was as follows: 

	 Achieve compliance monitoring goals through a broader spectrum of activities that allow 

for a compliance determination at a facility or sub-facility level. The primary goals of 

compliance monitoring include: 

- Assess and document compliance with permits and regulations; 

- Support the enforcement process through evidence collection and case 

development; 

- Monitor compliance with enforcement orders and decrees; 

- Deter noncompliance; 

- Provide feedback on development of regulations and permits, as well as 

implementation challenges to permit and rule writers; and 

- Ensure program integrity. 

	 As the universe of regulated sources expands and EPA/state/local/tribal resources 

continue to be constrained, consider how to achieve the goals of environmental 

compliance and enforcement programs through a broader set of effective and efficient 

compliance monitoring activities. 

	 Establish a framework to revise the statutory compliance monitoring strategies to provide 

EPA/state/local/tribal agencies with increased flexibility to develop alternative 

approaches using a broader range of compliance monitoring activities to evaluate 

compliance, in addition and complementary to traditional on-site inspections. 

As a result of the dialogue, this revised NPDES CMS provides circumstances where EPA 

iii 
 

 

 

 

 

regions and states may utilize “focused compliance inspections” and “off-site desk audits” in 

addition and complementary to traditional comprehensive inspections. This change expands 

upon the flexibilities in the 2007 NPDES CMS, which did not provide for off-site desk audits or 

focused inspections to count toward any of the national goals. Part 1 of this revised CMS 

articulates certain conditions that must be met in order for these expanded compliance 

monitoring activities to count toward CMS coverage, including, for example, that the off-site 

desk audit or focused inspection must be conducted for the purpose of making a compliance 

determination. Part 2 of this CMS includes several metrics under which off-site desk audits or 

focused inspections count toward the national goals when included in a traditional CMS plan. 

For all other CMS metrics articulated in this policy, the region or state may propose to conduct 

focused inspections or off-site desk audits as part of an alternative plan, according to the 

conditions and process set forth in Part 1 below. 

Under this CMS, an off-site desk audit encompasses a range of valuable off-site 

compliance monitoring activities, including, but not limited to, review of facility reports and 

records, review of agency-gathered testing, sampling and ambient monitoring data, evaluation of 

responses to CWA section 308 information requests, review of compliance deliverables 

submitted pursuant to permits or enforcement actions, and analysis of aerial or satellite images. 

An off-site desk audit conducted pursuant to a CMS plan will include the appropriate 

combination of the aforementioned activities to allow the region or state to make a facility-level 

or program-level (for pretreatment and MS4s) compliance determination. Also, in order for an 

off-site desk audit or focused inspection to count toward CMS implementation, the region or 

state must report the activity into ICIS-NPDES (either through direct entry or via the CDX 

National Environmental Information Exchange Network). See Part 3 for more detailed 

descriptions of the off-site desk audit and focused inspection. 

OECA has made these changes to allow agencies greater flexibility to focus and 

efficiently deploy their resources on their most significant environmental concerns and pollution 

problems through an alternative CMS plan. After issuance of this revised CMS, OECA will 

assess with regions and states the need for additional tools and guidance, such as forms or 

checklists, about what constitutes a focused inspection and an off-site desk audit. 

iv 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Part 1: Implementation of the Revised NPDES Compliance 

Monitoring Strategy 

Planning Process 

We expect that there will be a dialogue between regions and individual states about 

annual program commitments and potential resource trade-offs. The national goals in this 

policy, many of which have built-in flexibilities, are a starting point for negotiations. States and 

regions may utilize the flexibilities set forth in the policy to tailor inspection frequency goals to 

target compliance monitoring resources on facilities that pose the greatest threat to water 

quality. Trade-offs should be considered in the context of supporting overall NPDES program 

integrity. 

The purpose of this CMS is to better focus inspection resources overall; it is not 

intended to reallocate resources away from other NPDES program areas. The suggested 

planning process to implement the compliance monitoring goals articulated in this CMS strikes 

an appropriate balance of coverage across NPDES programs by considering factors such as 

noncompliance trends, water quality considerations within individual states, and state and EPA 

resources. These compliance monitoring planning expectations are intended to promote joint 

planning where such processes do not exist or need to be strengthened. The planning process, 

guided by the criteria and goals articulated in this policy, is also intended to provide an 

opportunity to identify state-specific circumstances and encourage dialogue on the approaches 

the state expects to implement, which will then be documented in the CMS plan. 

EPA regional NPDES programs should work closely with each of their states and 

internally to plan compliance monitoring activities for all NPDES sources covered by this policy 

and to ensure an effective inspection presence in each direct implementation program area. To 

provide for consistent implementation of the national CMS goals, each EPA region and state 

should develop an annual written CMS plan.2 For regions, the plan should cover all direct 

implementation program areas, including non-authorized states, Indian country and nonauthorized program areas (e.g., pretreatment and biosolids) in states with NPDES program 

authorization. 

CMS plans should be developed by regions and states on an annual basis and include 

universe estimates and annual commitments for every applicable metric (i.e., NPDES subprogram) covered by this national CMS policy.3 Where a state does not have any sources 

covered by a particular metric (e.g., a state with no Combined Sewer Systems), no commitment 

is needed. The majority of national recommended minimum inspection frequencies in this CMS 

are multi-year goals, e.g., inspect all traditional non-majors at least once every five years. This 

means that while CMS plans look at one year, EPA and states will be looking across multiple 

2 While annual CMS planning is recommended, EPA may approve biennial CMS plans on a case-by-case basis. 3 For purposes of setting inspection commitments to meet the goals in this policy, CMS plans should reflect the 

number of facilities to be inspected, e.g., if a state plans to inspect the same facility twice in a year, that facility 

would only be counted one time toward the state’s inspection commitment for that metric. 

1
 
 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

years to evaluate whether the commitments for a given year indicate that the region/state is on 

track to meet the national goals. 

Where a region or state relies on the flexibilities provided by this policy to make 

commitments for inspection frequencies and compliance monitoring activities, the annual CMS 

plan should clearly reflect those decisions by including an explanation of why and how the 

flexibility was applied. Any such explanation must be detailed enough to explain the basis for 

the flexibility applied in the plan, including any implications on CMS planning in future years. 

Depending on the circumstances of the agreed upon commitment, the written explanation could 

be brief (i.e., one or two sentences) or a full paragraph. 

EPA and state compliance monitoring planning will rely on compliance data obtained 

from ICIS-NPDES, compliance monitoring activities in at least the most recent prior year, field 

reconnaissance, institutional knowledge, and citizen tips and complaints. To support attainment 

of water quality goals, the compliance monitoring planning process should increasingly be 

influenced by information on water quality impairments to which facilities may be contributing 

(pursuant to listings under section 303(d) of the CWA) and other relevant water quality data. As 

discussed further in Part 2, OECA encourages regions and states to use the Inspection Targeting 

Model (ITM), including the ITM sorting tool, and/or the DMR Pollutant Loading Tool for 

preliminary screening, identification of inspection targets, and compliance monitoring plan 

development. Regions are expected to actively engage with states in development of CMS 

commitments and take into account end-of-year reports on actual activities. 

Alternative CMS Plans 

An alternative NPDES CMS plan is a plan that includes one or more compliance 

monitoring commitments that deviate from the national goals and flexibilities set forth in Part 2 

of this policy. As compared to the national goals, an alternative plan could include modified 

frequency of comprehensive inspections, modified compliance monitoring activities (e.g., offsite desk audit), or a combination of the two. 

Scope of review: EPA Regions and OECA will evaluate the appropriateness of any 

proposed alternative plan to ensure overall program integrity and to facilitate national 

consistency to the extent appropriate. EPA review will consider source information such as 

compliance history, facility location, and potential environmental impacts and state program 

information such as significant program deficiencies identified through prior oversight activities. 

The proposed alternative plan should include adequate detail for EPA to understand (1) the 

overall approach proposed, including the rationale for any deviations and tradeoffs; (2) a 

description of the affected regulated universe(s); and (3) an explanation of how the region or 

state has determined that the resulting reduced/modified attention at certain facilities will not 

have negative public health or environmental impacts. In addition, the alternative plan should 

include the details always expected in a CMS plan (e.g., universe of facilities subject to each 

CMS metric and number of compliance monitoring activities planned for the year). 

Process for review: If a state wishes to develop an alternative CMS plan, regions will 

2
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014	 NPDES Compliance Monitoring Strategy 

seek OECA consultation and review before finalizing the state’s alternative plan. Regions should 

also submit any alternative CMS plans for direct implementation activities to OECA for 

consultation and review. Regions should submit draft regional or state alternative plans to OECA 

for consultation and review as early in the planning process as possible, but no later than August 

15 each year. If a Region is unable to meet this timeline, the Region should contact the 

appropriate staff in the Water Branch of OC’s Monitoring, Assistance and Media Programs 

Division (MAMPD) to discuss a modified schedule. Our goal is to work efficiently and 

effectively across EPA and the states to provide for CMS plans to be in place at or near the 

beginning of the year covered by each plan (e.g., the first day of the federal fiscal year, October 

1). OECA understands that many Regions utilize the section 106 grant process as a means of 

documenting a state’s annual CMS plan. We will make every effort to integrate the alternative 

plan review process into existing Regional timetables and processes for approving state CMS 

plans, grant workplans and performance partnership agreements. OECA may periodically assess 

alternative plan implementation, as appropriate, including through the State Review Framework 

process. 

Any alternative CMS commitments that include focused inspections and/or off-site desk 

audits must meet the following conditions, at a minimum, in order to be approved as part of an 

alternative plan: 

1.		 The activity must by conducted for the purpose of making a compliance determination4

; 

2.		 The activity must be conducted by appropriate personnel, as specified in the definitions 

of each alternative activity (see Part 3); 

3.		 The approved alternative CMS plan must document the region/state’s evaluation of the 

five facility-specific questions below; and 

4.		 The activity must be reported to ICIS-NPDES (including through the CDX National 

Environmental Information Exchange Network) to ensure transparency, accountability 

and appropriate follow-up. Reporting includes entry of facility-specific information, 

compliance actions, and results of the activity (e.g., any noted violations, SNC, etc.). 

When developing an alternative CMS plan, regions and states should consider the 

following facility-specific questions before proposing a focused compliance inspection and/or 

off-site desk audit: 

1.		 Is the facility currently subject to an enforcement action or a compliance schedule 

resulting from an enforcement action?
	

2.		 Has the facility been reported in Significant Noncompliance (SNC) within the previous 

four quarters? 

3.		 Does the facility have any unresolved single-event violation(s) identified in prior 

inspection(s)?
	

4.		 Does the facility discharge listed pollutants to impaired waters? 

5.		 Does the facility have any known potential to impact drinking water supplies? 

If the answer to any of the above questions is “yes”, the region or state should further 

scrutinize whether a focused inspection or off-site desk audit of the facility would be adequate to 

assess compliance and protect water quality. Each year that an alternative plan is proposed that 

includes focused inspections and/or off-site desk audits, planners and EPA reviewers should 

4 When conducting a focused inspection pursuant to the provisions of this policy, the region or state may make a 

compliance determination at the sub-facility level relative to the scope of the focused inspection. 

3
 
 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

revisit these questions on a facility-specific basis to address changing circumstances (e.g., 

impaired waters listings and compliance status). For any facility that is a viable candidate for a 

focused inspection or off-site desk audit, review of the alternative plan proposal will include 

consideration of how long it has been since the last comprehensive inspection in order to ensure 

that all facilities are subject to periodic comprehensive inspections.5 

Following are several example alternative CMS plan scenarios. This is not an exhaustive 

list of alternative plan provisions that could be approved. Rather, it is a sample of some of the 

likely scenarios that states may encounter when implementing this policy. All proposed 

alternative plans will be approved by EPA regions on a case-by-case basis. 

A. For major facilities that have been evaluated under the five alternative CMS 

considerations set forth above, a region or state could propose the following alternative 

approach: every five years conduct at least one comprehensive on-site inspection, one 

focused compliance inspection, and one off-site desk audit. Regions and states are 

encouraged to utilize the ITM or comparable method to evaluate facilities against the five 

alternative CMS considerations. 

B. A region or state may have a situation where their MS4s are not performing well in their 

role of overseeing active construction sites and industrial stormwater dischargers. In 

exchange for reduced comprehensive inspection coverage in industrial and construction 

stormwater sectors, the region or state could increase the number of comprehensive 

inspections for their MS4s to ensure that the MS4s are conducting critical local oversight 

of construction and industrial stormwater discharges. Under this scenario, a state could 

commit to conducting inspections at 5% of industrial stormwater facilities and off-site 

desk audits at an additional 5% of the universe, for example. In this scenario, the 

compliance improvement benefit would presumably accrue through higher compliance in 

the future at the facilities under the MS4’s jurisdiction, versus increased compliance at 

just a few individually inspected facilities. 

C. A region or state may propose fewer inspections in a particular area, such as industrial 

stormwater, for a limited time (up to two years, for example) in order to utilize those 

resources to explore or ground-truth innovative compliance monitoring 

approaches/techniques. Such a trade-off in an alternative CMS plan would require 

accompanying justification for the innovative approach, including a description of the 

expected results (i.e., how and when expected results will be documented and how the 

results could enhance the state, regional and/or national program). 

Oversight, Reporting and Measurement 

OECA and the EPA regions will use existing procedures, such as mid-year and end-ofyear reviews, both for associated grant workplans and Annual Commitment System (ACS) 

commitments, and periodic State Review Framework and Pretreatment Program evaluations to 

assess regional and state performance. In addition, OECA may periodically compare regional 

5 Throughout this document, when used without qualification, “comprehensive inspection” includes any of the 

following types of inspections: compliance evaluation inspection, compliance sampling inspection, performance 

audit inspection, compliance biomonitoring inspection, diagnostic inspection, toxics sampling inspection (XSI) and 

pretreatment program audit. 

4
 
 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

and state commitments to actual compliance monitoring activities recorded in ICIS-NPDES 

and/or end-of-year CMS reports. The goals of any performance assessment are to identify 

strengths and address weaknesses of EPA and state compliance monitoring programs, develop 

mutual commitments to achieve ongoing program improvement, increase program transparency, 

and promote national consistency. 

The current ACS measure applicable to the NPDES CMS (ACS measure CWA07) 

requires that each region submit to OECA by the end of the calendar year a CMS plan for each 

authorized state and for direct implementation. The ACS measure also requires the regions to 

provide OECA with an end-of-year report corresponding to each plan that was developed for that 

year. End-of-year reports are due to OECA by the end of the calendar year following completion 

of the plan year (e.g., end-of-year report for an FY2014 plan will be due December 31, 2014). 

OECA’s expectation is that EPA regions will work with each state to develop an annual EOY 

report summarizing implementation of the prior year’s plan, regardless of whether it was a 

traditional or alternative plan. 

The CMS plans and end-of-year reports should include appropriate data to enable OECA 

to compare actual compliance monitoring activities against the annual commitments. States are 

encouraged to enter all of their actual compliance monitoring activities into ICIS-NPDES so that 

the end-of-year reports can be generated through standard ICIS-NPDES reports that correspond 

to the CMS metrics. See Part 4 of this CMS for ICIS-NPDES data entry quick reference tool. 

There are several data entry activities that are relevant to implementation of this revised 

CMS. First, regions or states may choose to enter annual compliance monitoring commitments 

into ICIS-NPDES by using the “planned inspection indicator” to tag facilities the region or state 

plans to inspect that year. OECA will aggregate commitment information available in ICISNPDES and use it on the Enforcement and Compliance History Online (ECHO) dashboards to 

display state performance in relation to CMS commitments. Facility-specific information about a 

state’s inspection plans would not be made publicly available. Second, state and regional 

compliance monitoring activities conducted pursuant to this CMS must be reported into ICISNPDES (including through the CDX National Environmental Information Exchange Network) in 

accordance with all applicable data entry requirements, including any future regulations that 

establish data requirements and reporting timeframes. Third, EPA expects regions and states to 

update ICIS-NPDES with data about focused inspections or off-site desk audits conducted 

pursuant to an alternative plan in accordance with expectations set forth in this CMS. For 

example, before EPA approves an alternative plan that includes focused inspections or off-site 

desk audits, the state must commit to entering the completed activities into ICIS-NPDES 

(including through CDX). 

5
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Part 2: Compliance Monitoring Frequency Goals for NPDES 

Sources
 

Part 2 describes the national recommended minimum frequency and activity type for 

NPDES sources. The national recommended minimum frequencies and activity types differ 

across the metrics to account for the differences among the various NPDES programs including: 

numbers of regulated entities, complexities in compliance monitoring, regulatory requirements, 

and the history and status of compliance. Under certain circumstances more frequent compliance 

monitoring is warranted. For example, sources that are located near sensitive areas (i.e., drinking 

water intakes) and/or designated high quality waters may need to be monitored more frequently 

than the recommended minimum goals set forth in the metrics below. A CMS plan that is 

consistent with the minimum goals and flexibilities set forth in each of the metrics below is 

considered to be a traditional CMS plan, not an alternative CMS plan. 

All compliance monitoring and evaluation activities should be undertaken in such a 

manner that will lead to timely, appropriate and effective follow-up response to identified 

noncompliance (e.g., informal action or formal enforcement action consistent with the applicable 

enforcement response policies). On-site inspections should be conducted by an authorized 

inspector. Inspectors conducting evaluations for state/local/tribal agencies should be compliant 

with the inspection policies and processes of the respective agency. EPA employees and 

state/local/tribal individuals authorized to conduct evaluations on behalf of EPA using EPA 

federal inspector credentials should be conducting evaluations consistent with appropriate federal 

training requirements.6 An authorized inspector may include an approved third party.7 

Please refer to Part 4 of this document for a guide to the acceptable ICIS-NPDES 

compliance monitoring types and their corresponding codes to be used for data entry of activities 

conducted pursuant to the national recommended frequency goals set forth below. 

1.A. Major Permittees 

Major NPDES permits cover discharges from Publicly Owned Treatment Works 

(POTW) facilities with designed discharge flows of greater than 1 million gallons per day and 

active major industrial facilities scoring more than 80 for the six factors on the “NPDES Permit 

Rating Work Sheet”(available at http://www.epa.gov/npdes/pubs/owm0116.pdf). As of July 

2014, there are 6,579 active major NPDES permits (4,397 active major POTW permits, 2,105 

active major industrial permits, and 77 active Federal permits) according to ICIS-NPDES. 

6 See most current version of EPA Order 3500.1, Training Requirements for EPA Personnel Who Are Authorized to 

Conduct Civil Compliance Inspections/Field Investigations and EPA Inspector Supervisors, and EPA Order 3510, 

EPA Federal Credentials for Inspections and Enforcement of Federal Environmental Statutes and Other 

Compliance Responsibilities. 7 See Guidance for Issuing Federal EPA Inspector Credentials to Employees of Contractors to Conduct Inspections 

on Behalf of EPA (May 31, 2013) and Guidance for Issuing Federal EPA Inspector Credentials to Senior 

Environmental Employment Program Enrollees to Conduct Inspections on Behalf of EPA (September 30, 2013). 

6
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

OECA’s goal for state and regional inspection of major permittees is a minimum 

frequency of at least one comprehensive inspection every two years. Inspections of major 

POTWs may be conducted in conjunction with inspections of the Sanitary Sewer Systems 

(SSSs) and their satellites and Combined Sewer Systems (CSSs) that are connected to the 

POTW. At the end of each federal fiscal year, data will be taken from ICIS-NPDES to report on 

both a regional and state basis the percentage of majors that have received a comprehensive 

inspection within the most recent two completed federal fiscal years. Currently, this information 

is publicly displayed on the ECHO State Performance Dashboards, available at 

http://echo.epa.gov/node/19?media=water&state=National&view=activity. 

This revised policy includes the pre-approved alternative approach for inspections of 

major NPDES permittees that was introduced in the 2007 NPDES CMS and made possible with 

the July 2008 release of the Inspection Targeting Model (ITM) (which can be accessed after 

logging into ECHO at http://echo.epa.gov/). The purpose of the ITM is to distinguish between 

facilities that have strong records of compliance and those who have records indicating 

compliance problems, particularly effluent violations for pollutants that may be contributing to 

water quality impairments reflected in section 303(d) listings. Under this available alternative, 

regions and states can use the ITM, or a comparable targeting methodology, to adjust the 

inspection frequency to one comprehensive inspection every three years for NPDES major 

facilities that are in compliance, not subject to any credible citizen tips or complaints, and are 

not contributing to section 303(d) impaired waters listings based on the most current data 

available when developing the CMS plan. Regions and states should implement this flexible 

approach in accordance with any future guidance about how to use the ITM and/or revisions to 

the ITM methodology. Facilities that do not meet these criteria will remain subject to a 

minimum comprehensive inspection frequency of once every two years. A CMS plan that 

utilizes this approach for decreasing inspection frequency of some majors is still considered a 

traditional CMS plan. 

1.B. Traditional Non-Major Permittees 

Traditional non-major NPDES permits cover POTW facilities with designed discharge 

flows of less than 1 million gallons per day (1 MGD) or serving populations of less than 10,000 

persons and active non-major industrial facilities (i.e., facilities scoring less than 80 for the six 

factors on the NPDES Permit Rating Work Sheet, available at 

http://www.epa.gov/npdes/pubs/owm0116.pdf) that have not been designated as a discretionary 

major by the EPA region. As of July 2014, there are approximately 87,000 active non-major 

NPDES permittees that are covered by this metric. POTW permits account for approximately 

41,700. Out of the total number of non-major permittees subject to this metric, approximately 

45,400 have individual permits and 41,600 are covered by general permits (including general 

permits for various industrial categories, POTWs and other water treatment facilities).8 The 

minimum inspection frequency goals recommended in 1.B.1 and 1.B.2 below are intended to 

apply to traditional non-majors covered by both individual and general permits. Compliance 

monitoring goals for non-majors in the wet weather program areas are articulated under 

8 Data sources are the Permit Management Oversight System (PMOS), available at 

http://cfpub.epa.gov/npdes/permitissuance/genpermits.cfm, and ICIS-NPDES. 

7
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014	 NPDES Compliance Monitoring Strategy 

separate metrics in this CMS. 

OECA’s minimum compliance monitoring goals for each traditional non-major facility 

are set forth below. Inspections of traditional non-major POTW’s may be conducted in 

conjunction with inspections of the SSSs (and their satellites) and CSSs that are connected to 

the POTW. The screening process for selecting non-major facilities to be inspected should be 

attentive to facilities that do not appear, based on available data, to have been inspected in more 

than five years or facilities that have histories of noncompliance, are the subject of citizen tips or 

complaints, and/or may be contributing to violation(s) of water quality standards. 

OECA encourages regions and states to utilize the ITM sorting tool (which can be 

accessed after logging into ECHO at http://echo.epa.gov/). for preliminary screening and 

identification of inspection targets for traditional non-majors under this metric. Users can access 

the sorting tool by selecting "Values Only" in the ITM output options. The sorting tool does not 

utilize weightings due to concerns particularly about the current completeness of data for 

traditional non-majors and how that might affect the results obtained from a weighted model. 

Use of the sorting tool is optional. Regions and states choosing to use this functionality will 

likely want to analyze the data in a spreadsheet and include additional state data (beyond what 

is available in ICIS-NPDES) that would increase the rigor of the analysis. The sorting tool 

allows regions and states to sort facilities based on factors that include: water quality 

impairments; associated pollutants that may be discharged by the permittee; SNC within the 

most recent two years; unresolved Single Event Violations; days since last comprehensive 

inspection; days since last inspection (all types); and current enforcement actions. In the future, 

EPA regional offices may determine on a state-by-state basis that ICIS data on non-majors is 

adequate to allow utilization of the weighting functionality in the ITM for this metric; however, 

the compliance monitoring goals for traditional non-majors provided below will still apply. 

Regions and states may also elect to utilize the Discharge Monitoring Report (DMR) Pollutant 

Loading Tool (available at http://cfpub.epa.gov/dmr/) to look at pollutant loadings that exceed 

permit limits to help focus on the biggest polluters. 

1.	 Traditional non-major permittees that are not contributing to CWA section 303(d) 

listed impairments. The minimum inspection frequency goal is to inspect each 

traditional non-major facility that is not contributing to section 303(d) impairments at 

least once every five years. In addition to the comprehensive inspection types (see 

footnote 5), the following inspection types will count toward metric 1.B.1: focused, 

reconnaissance, enforcement follow-up, oversight, and sludge/biosolids. The 

aforementioned non-comprehensive inspections will be counted under this metric 

because these facilities are not discharging pollutants that contribute to listed 

impairments. 

2.	 Traditional non-majors that discharge one or more pollutants that are relevant to 

an impairment on the CWA section 303(d) list. Traditional non-major facilities that 

are permitted to discharge pollutants of concern corresponding to the 303(d) listing 

parameter should be inspected at least once every five years with a comprehensive 

inspection. Of the traditional non-major permittees that discharge to section 303(d) 

listed waters, OECA expects there are some that, due to the nature of their discharges, 

8
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

are not in fact contributing to the water quality conditions that have resulted in the listed 

impairment. Such facilities on impaired waters that are not contributing to the 

impairment may be inspected with a less comprehensive inspection (e.g., a 

reconnaissance inspection) under metric 1.B.1 above. 

During the annual planning process, when determining which traditional non-major 

facilities should be inspected using a comprehensive inspection, regions and states should inform 

that decision by carefully reviewing available information on the permittees, such as 

noncompliance information and information that is indicative of the completeness and currency 

of ambient monitoring information for the receiving waters to which the permittees discharge. 

Where information indicates patterns of noncompliance or uncertainty about the status of 

receiving waters, strong consideration should be given to utilizing a comprehensive inspection. 

In order to ensure a minimum level playing field, states and regions are encouraged to conduct a 

comprehensive inspection of at least 5% of all traditional non-majors each year even if more 

facilities qualify for non-comprehensive inspection under metric 1.B.1 above. 

1.C. Pretreatment Program 

Routine compliance monitoring activities for the pretreatment program include audits and 

inspections of POTWs with approved pretreatment programs, review of all POTW pretreatment 

program annual reports, inspections of industrial users and oversight of state pretreatment 

programs that are implemented pursuant to 40 CFR 403.10(e) (i.e., states where the state agency 

functions as the control authority in lieu of approved local pretreatment programs). In addition to 

the specific pretreatment program compliance monitoring activities outlined under the metrics 

below, the approval authority (i.e., the state agency or EPA Region that is responsible for 

approving local pretreatment programs) should track the submission of POTW annual reports 

made pursuant to 40 CFR 403.12(i) and review 100% of all submissions to determine if the 

POTW is properly implementing its approved pretreatment program, including, as appropriate, 

oversight and enforcement of Significant Industrial Users (SIUs). 

1.C.1. Pretreatment Audits 

Pretreatment approval authorities should conduct at least one audit every five years of 

each POTW with an approved pretreatment program, generally corresponding to an annual 

audit rate of 20% of active approved programs. 

A pretreatment audit includes oversight inspections of at least two Industrial Users (IU) 

discharging to the POTW. For additional information on selecting the appropriate IUs for 

oversight inspections, see Guidance for Conducting a Pretreatment Compliance Inspection 

(September 1991), available at http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=50000629.txt. 

IU oversight inspections are included as part of a pretreatment audit in order for the auditor to: 

1) verify that the IU permit/control mechanism correctly reflects the physical and operational 

conditions of the facility; 2) validate whether the POTW has correctly evaluated compliance 

(including appropriate sampling methods); and 3) assess the POTW’s IU inspection procedures. 

In the course of conducting audits of POTWs with approved pretreatment programs, the 

9
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

approval authority should ensure that the POTW is following its Enforcement Response Plan 

when the POTW identifies IU noncompliance. For additional information on conducting

pretreatment audits, see Control Authority Pretreatment Audit Checklist and Instructions 

(February 2010), available at 

http://www.epa.gov/npdes/pubs/final_pca_checklist_and_instructions_%20feb2010.pdf. 

1.C.2. Pretreatment Compliance Inspections 

Pretreatment approval authorities should conduct at least two Pretreatment Compliance 

Inspections of each POTW with an active approved pretreatment program every five years. 

These inspections are in addition to the audit that should be conducted every five years, as 

described under metric 1.C.1 above. 

In the course of conducting inspections of POTWs with approved pretreatment programs, 

the approval authority should ensure that the POTW is following its Enforcement Response Plan 

when the POTW identifies IU noncompliance. For additional information on conducing

pretreatment compliance inspections see Guidance for Conducting a Pretreatment Compliance 

Inspection (September 1991), available at 

http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=50000629.txt. 

1.C.3. Significant Industrial User Inspections 

For SIUs discharging to POTWs without approved pretreatment programs, the control 

authority (i.e., either the EPA Region or state agency) should track and review SIU semi-annual 

reports submitted pursuant to 40 CFR 403.12(e) and (h). For more information on EPA and state 

responsibilities associated with overseeing SIUs that discharge into POTWs without an 

approved pretreatment program, see the EPA memorandum, Oversight of SIUs Discharging to 

POTWs without Approved Pretreatment Programs (May 18, 2007), available at 

http://www.epa.gov/npdes/pubs/ciumemo05182007signed.pdf. 

The General Pretreatment Regulations at 40 CFR part 403 include a requirement for 

approved publicly owned treatment works (POTWs) and states that implement the POTW 

pretreatment program under 40 CFR 403.10(e) to “inspect and sample the effluent from each 

significant industrial user at least once a year.” 40 CFR 403.8(f)(2). In accordance with these 

regulations, for the industrial pretreatment program, 100% of SIUs permitted by approved 

POTWs or state approval authorities must be inspected and sampled annually. The approved 

POTW or state approval authority may conduct additional inspections as necessary, for example, 

when required semi-annual self-monitoring reports from SIUs show noncompliance, or based on 

reconnaissance, or tips or complaints received by the EPA, the state, or approved POTW. If the 

appropriate state legal authorities are in place, the annual inspection and sampling requirement 

may be reduced to once every two years for SIUs designated with a reduction in monitoring and 

inspection frequency in accordance with provisions under 40 CFR 403.12(e)(3) and 40 CFR 

403.8(f)(v)(c).9 Given the regulatory requirement for annual sampling inspections of all SIUs, a 

state’s alternative plan cannot include an off-site desk audit in lieu of an annual SIU sampling 

9 For more information, see the 2005 Pretreatment Program Streamlining Rule, available at 

http://water.epa.gov/polwaste/npdes/pretreatment/upload/streamlining_fr_notice.pdf. 

10
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

inspection. 

1.D. Sludge/Biosolids 

The objective of a sewage sludge/biosolids inspection is to assess facilities engaged in 

a regulated sludge or biosolids activity to evaluate compliance with applicable regulatory 

provisions, including sludge monitoring, recordkeeping and reporting, treatment operations, 

sampling and laboratory quality assurance and use or disposal practices. Sludge/biosolids 

inspections may be conducted in conjunction with compliance inspections at major and nonmajor POTWs. Inspections may also be conducted to respond to citizen tips or complaints. 

For states with biosolids program authorization, the recommended inspection frequency 

goal is at least one sludge/biosolids inspection of each major POTW every five years. Biosolids 

use and disposal operations, including incineration and surface application, should receive at 

least one sludge/biosolids inspection every five years. However, under this revised CMS, states 

may substitute an off-site desk audit for sludge/biosolids generation, use, and disposal sites that 

meet the following criteria: (1) are not currently subject to enforcement actions or compliance 

schedules that are the result of concluded enforcement actions; (2) have not been reported in 

Significant Noncompliance (SNC) within the previous four quarters; (3) have no unresolved 

single event violation(s) identified in prior inspection(s); (4) do not discharge to CWA section 

303(d) listed waters for pollutant(s) contributing to the listing; and (5) have no known potential 

to impact drinking water supplies. A CMS plan that utilizes this approach for conducting offsite desk audits in lieu of sludge/biosolids inspections is still considered a traditional CMS plan. 

In states where EPA is the permitting authority for biosolids, compliance monitoring 

activities for biosolids facilities will be conducted in accordance with plans and protocols 

established by the EPA Biosolids Center for Excellence. 

1.E. Oversight Inspections 

OECA does not contemplate any changes to its oversight processes as a result of 

issuance of the revised CMS. Oversight inspections are described in the memorandum Revised 

Policy Framework for State/EPA Enforcement Agreements (August 1986) and an Office of 

Water memorandum 1987 National Guidance for Oversight of NPDES Programs (April 1986). 

These memoranda establish that oversight inspections should: (1) assess how well the 

state inspectors are determining compliance; (2) be tailored to fit state performance; and (3) 

provide incentives to strong state performance by reducing the number, level and/or frequency of 

some reporting requirements consistent with regulations or reducing the frequency of oversight 

inspections. In states where criteria for good performance are not met, EPA may suggest 

changes in procedures and the state use of resources or training, provide technical assistance, 

and/or increase the number of oversight inspections. 

Regions will develop a state-by-state oversight proposal for each year, which should 

include at least some oversight activity in each state. As provided under the Clean Water Act 

11
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Action Plan Interim Guidance on Strengthening EPA and State Performance and Oversight 

(available at http://www2.epa.gov/sites/production/files/documents/interim-guid-npdes062210.pdf), regions should focus oversight resources to the most pressing performance 

problems in states. The State Review Framework (SRF) is the major enforcement program 

oversight activity for the NPDES compliance monitoring program, and the oversight inspections 

performed in the year prior to the review should inform the SRF review. OECA will work with 

regions that are interested in developing an approach for oversight of the pretreatment 

compliance monitoring program. Annual data metrics analyses also can inform an oversight 

schedule. These oversight activities may include inspections, both joint state/EPA inspections 

where the state has the lead role in the inspection and independent inspections of facilities by the 

EPA, or other activities. 

Additional factors that the EPA may consider when scheduling oversight inspections 

include: (1) significant changes in state program structures or personnel are taking place; (2) a 

new state regulatory structure is being implemented; (3) the state is reporting low violation 

identification rates; (4) the state is reporting low inspection coverage rates; or (5) patterns in 

tips/complaints from citizens. 

2.A. Combined Sewer Systems (CSSs) 

Inspections of CSSs are comprehensive inspections that evaluate compliance with the 

Clean Water Act and CSO Control Policy (available at 

http://www.epa.gov/npdes/pubs/owm0111.pdf) requirements as written in the NPDES permit, 

an enforcement order, a consent decree, or another enforceable document. The inspector 

should verify whether the permittee is preventing CSOs during dry weather, implementing the 

nine minimum controls, adhering to a schedule for development, submission, and 

implementation of a long-term CSO control plan, eliminating or relocating overflows to 

sensitive areas, adhering to effluent limitations, and implementing a post-construction 

compliance monitoring program. 

As of 2014, nationally there are 859 CSO communities that need to develop and 

implement a long-term CSO control plan. The minimum inspection frequency goal is for all 

major and non-major CSSs to receive at least one comprehensive inspection every five years. 

These inspections may be conducted in conjunction with compliance inspections at major and 

non-major POTWs. More frequent inspections, including CSO inspections, may be necessary 

for some systems in order to promptly evaluate known or suspected recurring overflows. An 

inspector conducts a CSO inspection in response to information received regarding a known or 

suspected overflow event to evaluate compliance with CSO provisions present in the NPDES 

permit, an enforcement order, a consent decree, or another enforceable document. In many 

cases, CSO inspections will be scheduled based on information about overflow occurrences 

received directly by EPA, or from other governmental organizations, citizens groups, or nongovernmental organizations. 

If regions and states are not able to meet this goal, proposals for modified frequency 

goals as part of an alternative CMS plan may be considered for particular systems based on 

12
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

the alternative CMS considerations described in Part 1 above and additional information 

such as: overall history of good compliance based on information from prior CSO 

inspections (e.g., permit conditions, nine minimum controls), no dry weather overflows 

(identified through inspections, record reviews or complaints/community reports), declining 

CSO activation rates, and status of receiving waters. 

2.B. Sanitary Sewer Systems (SSSs) 

Inspections of sanitary sewer collection systems are comprehensive inspections that 

evaluate compliance with NPDES permit terms and conditions for system design, operation 

and maintenance, permit reporting requirements, an enforcement order, a consent decree, or 

another enforceable document. The inspector collects information to verify that the permittee 

is complying with the NPDES permit conditions (duty to mitigate and proper operation and 

maintenance) and the required notification procedures. The inspector also determines whether 

there have been any unpermitted discharges, or discharges from a location other than the 

discharge point specified in the permit, to waters of the United States. When preparing for an 

inspection of an SSS, the inspector should consider OECA’s Guide for Evaluating Capacity, 

Management, Operation, and Maintenance (CMOM) Programs at Sanitary Sewer Collection 

Systems (2005) (available at 

http://www.epa.gov/npdes/pubs/cmom_guide_for_collection_systems.pdf). 

The minimum inspection coverage goal for SSSs is for regions and states to conduct 

comprehensive inspections of at least 5% of SSSs each year. The universe subject to this 

coverage goal is the number of POTW permits in the state that include one or more sanitary 

sewer collection systems. Where a permit covers satellite collection systems, in order to allow 

the inspector to evaluate overall collection system compliance, the SSS inspection should 

include review of satellite systems that together comprise a substantial percentage of the total 

flow to the treatment plant. Inspection priority should be given to SSSs with chronic overflows 

and/or pump stations. 

More frequent inspections, including SSO inspections, may be necessary for some 

systems in order to promptly evaluate known or suspected recurring overflows. An inspector 

conducts an SSO inspection in response to information received regarding a known or 

suspected overflow event. In many cases, SSO inspections will be scheduled based on 

information about overflow occurrences received directly by EPA, or from other governmental 

organizations, citizens groups, or non-governmental organizations. SSO inspections, as well as 

broader inspections of SSSs and their satellites, may be conducted in conjunction with 

compliance inspections at major and non-major POTWs. 

2.C. Stormwater 

2.C.1. Municipal Separate Storm Sewer Systems (MS4s) 

As of 2014 there are approximately 250 Phase I MS4 permits that cover approximately 

855 permittees (the difference being that many MS4 permits include two or more co13
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

permittees). As of 2014, there are approximately 6,700 Phase II MS4s covered by 150 permits 

nationally. 

There is a strong need for permitting authorities to assess the quality of these MS4 

stormwater management programs. On-site MS4 audits (evaluating all aspects of the MS4 

stormwater management program), on-site inspections, and off-site desk audits are valuable 

tools for evaluating whether the MS4s are in compliance with permit requirements. All 

compliance monitoring of MS4 programs should include review of the stormwater 

management plan elements to provide a representative picture of overall MS4 performance. 

The minimum compliance monitoring goal for MS4s is for regions and states to 

determine compliance of each MS4 permittee and co-permittee at least once every five years 

by conducting one or more of the following compliance monitoring activities: on-site audit, 

MS4 inspection, or off-site desk audit. Off-site desk audits should not be conducted for any 

MS4 permittee that has not previously been subject to an on-site inspection or audit that has 

documented a compliance baseline for the MS4. As part of this goal, each MS4 permittee and 

co-permittee should receive an on-site audit or inspection at least once every seven years. 

Regions and states have the flexibility to extend the seven-year goal for on-site 

inspections/audits to every 10 years for a co-permittee that contributes a minimal volume of 

the total flow to the MS4. More frequent on-site audits, inspections or off-site desk audits may 

be necessary for certain MS4s based on factors such as noncompliance (including 

noncompliance at underlying construction sites and industrial stormwater facilities), failure to 

implement a stormwater management plan, citizen tips or complaints, referrals from other 

governmental organizations, and follow-up on activities mandated by an enforcement order. 

This goal provides flexibility to regions and states to determine the most appropriate 

approach to assess compliance within the MS4 universe without having to develop an 

alternative CMS pursuant to Part 1 of this policy. Priority should be given to auditing or 

inspecting MS4s located in priority watersheds that contribute to CWA section 303(d) listings 

and those located near waters that the state has designated for higher levels of protection. 

Furthermore, the scope of any inspection should be determined based on the highest priority 

minimum measures for that MS4, as determined by a review of the MS4’s compliance history, 

water quality concerns, permit revisions, noncompliance at construction sites and industrial 

facilities within its jurisdiction, and other local factors. 

Monitoring activities on the construction oversight programs of MS4s should be closely 

coordinated with monitoring activities at individual construction sites (see metric 2.C.3 below). 

Likewise, monitoring activities on industrial oversight elements of Phase I MS4s, and where 

they exist as part of Phase II MS4s (e.g., Illicit Discharge Detection and Elimination programs), 

should be closely coordinated with monitoring activities at individual industrial stormwater 

dischargers (see metric 2.C.2 below). 

Please note that while many Phase I MS4s may technically qualify as “major permittees” 

per the “NPDES Permit Rating Sheet,” the inspection frequency goal for major permittees under 

metric 1.A does not apply to Phase I MS4s. 

14
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

2.C.2. Industrial Stormwater 

Industrial stormwater inspections are designed to ensure that regulated facilities have an 

NPDES permit for stormwater discharge and a Stormwater Pollution Prevention Plan 

(SWPPP), and that the facility is in compliance with the permit and is implementing the 

SWPPP to ensure that the permittee is meeting technology and water quality based 

requirements. During the inspection the inspector reviews the permit and the SWPPP, reviews 

self-inspection reports and other records to verify that the facility is complying with its permit 

and is implementing the SWPPP, and walks the site to verify that the SWPPP is accurate and 

BMPs are in place and functioning properly. 

Current estimates indicate that there are approximately 90,000 industrial stormwater 

permittees nationwide, contained within 29 industrial categories. The inspection goal for 

industrial stormwater permittees is to inspect at least 10% of the universe each year. Regions and 

states should also conduct compliance monitoring activities to locate industrial facilities that 

have failed to obtain permit coverage or file a “no exposure certification” under 40 CFR 

122.26(g). Inspections of unpermitted industrial stormwater facilities, including those with “no 

exposure certification,” will count toward the annual industrial stormwater coverage goal of 

10%. 

Priority should be given to inspecting permittees of environmental concern and 

those located in priority watersheds that may discharge a pollutant(s) that contributes to 

CWA section 303(d) listings, and permittees located near high quality waters that the state 

has designated for higher levels of protection to prevent degradation. 

To conserve resources, regions and states are encouraged to consider opportunities to 

conduct a facility’s industrial stormwater inspection in conjunction with the NPDES compliance

inspection for permitted major and non-major industrial facilities. Consideration should also be 

given to coordinating industrial stormwater inspections with oversight of MS4 industrial 

stormwater programs in Phase I MS4s and where such elements exist as part of Phase II MS4s. 

2.C.3. Construction Stormwater Sites 

Stormwater inspections are designed to ensure that regulated facilities have an NPDES 

permit for stormwater discharge and a Stormwater Pollution Prevention Plan (SWPPP) and are 

following the specifications in each. During the inspection, the inspector reviews the permit 

and the SWPPP and determines whether the SWPPP meets the requirements set forth in the 

permit. The inspector also reviews records, such as self-inspection reports, to verify that the 

facility is complying with its permit and the SWPPP and walks the site to verify that the 

SWPPP is accurate and BMPs are in place and functioning properly. 

This compliance monitoring metric applies to construction stormwater sites of equal to 

or greater than one acre of disturbed area (i.e., all regulated Phase I and Phase II construction 

sites). EPA’s 2014 estimate is that there are approximately 85,000 construction starts 

nationwide annually. The minimum recommended inspection frequency for this metric is a joint 

EPA and state goal to inspect at least 10% of the regulated construction sites annually. To 

determine the applicable universe at the inspection planning stage, the 10% goal should be 

15
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

applied to the estimated number of active regulated construction sites in the state in the coming 

year. As part of this goal, EPA and the states should follow-up on tips and complaints about 

potentially unpermitted construction sites. Inspections of unpermitted construction sites will 

count toward the annual construction stormwater coverage goal of 10%. 

Priority should be given to sites located near 303(d) listed waters that are impaired for 

construction-associated pollutants (e.g., sediment), and at sites located near high quality waters 

that the state has designated for higher levels of protection to prevent degradation. 

For estimating joint EPA and state progress relative to the joint annual goal, states 

include in their annual CMS report aggregate reporting of the total number of NPDES 

construction stormwater inspections that have been conducted by the state and EPA during the 

year. 

2.D. Concentrated Animal Feeding Operations 

The objective of concentrated animal feeding operation (CAFO) inspections is to verify 

that CAFOs are not illegally discharging to waters of the United States, as well as to verify that 

permitted CAFOs are in compliance with their NPDES permits. 

2.D.1. Large and Medium CAFOs with NPDES Permits 

EPA recommends that states and regions conduct a comprehensive inspection of NPDES 

permitted CAFOs at least once every five years to evaluate compliance with the permit, 

including terms of the nutrient management plan, reporting and recordkeeping. More frequent 

inspections may be appropriate for CAFOs that meet certain conditions, including the following: 

- Exceptionally large livestock and poultry operation 

- History of noncompliance 

- Significant site-specific environmental concerns, including operations located on 

impaired an waterbody and subject to Total Maximum Daily Load (TMDL) wasteload 

allocations 

- Permit includes a voluntary alternative performance standard pursuant to the CAFO 

Effluent Limitations Guideline in 40 CFR part 412 

- State requirements apply to specific areas of the operation 

2.D.2. Large CAFOs without NPDES Permits 

If not inspected to date, inspect all large CAFOs that are not covered by an NPDES 

permit within five years to determine whether the facility discharges. Thereafter, inspect as 

needed based on the possibility for an unauthorized discharge. Inspections of unpermitted 

CAFOs should evaluate all aspects of the CAFO, including practices associated with land 

application of manure, litter and process wastewater to determine whether all land application 

discharges are exempt agricultural stormwater. OECA encourages regions and states to utilize 

available desktop screening tools, such as aerial and satellite images and geographic information 

systems (GIS) software, in conjunction with known CAFO universe data, to both identify large 

16
 
 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

CAFOs that do not have NPDES permits and to select inspection targets. 

2.D.3. Medium AFOs without NPDES Permits 

Assess all medium-sized AFOs one-time initially to determine whether the facility is a 

medium CAFO, including whether the facility discharges. Assessments evaluate whether the 

facility meets the definition of a medium CAFO due to the number of animals confined and 

one of the two following criteria being met: (1) pollutants are discharged to a water of the 

United States through a manmade ditch, flushing system or other similar manmade device, or 

(2) pollutants are discharged directly into water of the United States that passes over, across or 

through the facility or otherwise comes into direct contact with the animals confined in the 

operation. See 40 CFR 122.23(b)(6). Prioritize on-site assessments based on priority 

watersheds, nutrient impairments, complaints, or other information. The region or state may be 

able to make a determination about certain facilities, such as those that are not near a water of 

the U.S., by conducting a thorough off-site assessment. An off-site assessment of a medium 

AFO would most likely involve review of maps and aerial images and any agency or public 

records about the operation. 

After the initial assessment, if the facility is not a medium CAFO, States and regions 

should conduct future on-site inspections as needed based on available information, such as 

citizen tips or complaints, and designate the AFO as a CAFO if the facility is a significant 

contributor of pollutants to a water of the United States. If the facility is a medium CAFO, a 

NPDES permit is required; therefore, the inspector should coordinate with the EPA or state 

permit writer and thereafter inspect the CAFO in accordance with section 2.D.1 of this policy. 

2.D.4. Small AFOs 

States and regions should conduct an on-site inspection of small AFOs as needed based 

on a citizen tip or complaint or other information to determine whether the AFO should be 

designated as a CAFO. In states with NPDES program authorization, CAFO designations may be 

made by the State Director. The Regional Administrator may also designate CAFOs in 

authorized states , but only where the Regional Administrator has determined that one or more 

pollutants in the AFO’s discharge contributes to an impairment in a downstream or adjacent state 

or Indian country water that is impaired for that pollutant. States or EPA shall consider the 

following factors in making a designation: (i) the size of the AFO and the amount of wastes 

reaching waters of the United States; (ii) the location of the AFO relative to waters of the Unites 

States; (iii) the means of conveyance of animal wastes and process wastewaters into waters of 

the United States; (iv) the slope, vegetation, rainfall and other factors affecting the likelihood or 

frequency of discharge of animal waste manure and process wastewaters into waters of the 

United States; and (v) other relevant factors. s No designation by either the State Director or 

Regional Administrator may be made unless pollutants are discharged into a water of the United 

States due to either (1) a manmade ditch, flushing system or other similar manmade device, or 

(2) a water of the United States that passes over, across or through the facility, or otherwise 

comes into direct contact with animals confined at the operation. See 40 CFR 122.23(c). 

17
 
 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

3.A Pesticides 

As a result of a U.S. Sixth Circuit Court of Appeals decision in National Cotton 

Council, et al. v. EPA, as of October 31, 2011, point source discharges of biological 

pesticides, and chemical pesticides that leave a residue, into waters of the U.S. are required to 

comply with NPDES requirements. The EPA finalized a rule on June 21, 2013, to remove the 

exemption for pesticide discharges from the NPDES regulations. EPA and the states 

currently regulate pesticide discharges to waters of the United States primarily through 

NPDES general permits. Visit www.epa.gov/npdes/pesticides for additional information. 

There is no set compliance monitoring frequency goal for pesticide operators subject 

to the NPDES program. Regions and states should conduct compliance monitoring activities 

in response to tips and complaints and other available information relevant to compliance. 

3.B Vessels 

EPA currently regulates discharges incidental to the normal operation of commercial 

vessels greater than 79 feet in length and operating as a means of transportation primarily 

through the Vessel General Permit (VGP). The first VGP was issued in 2008 and effective until 

December 19, 2013. On March 28, 2013, EPA re-issued the VGP for another five years. A brief 

overview of the 2013 VGB is available at 

http://www.epa.gov/npdes/pubs/vgp_overview2013.pdf. 

Recreational vessels as defined in section 502(25) of the Clean Water Act are not subject 

to the 2013 VGP. Likewise, except for ballast water discharges, NPDES permits are not required 

for any discharges incidental to normal operation of commercial fishing vessels and other nonrecreational vessels less than 79 feet. However, unless Congress takes additional action, the 

moratorium from the requirement to obtain permit coverage for incidental discharges from these 

vessels expires December 18, 2014. In anticipation of the end of the moratorium, EPA published 

a draft small Vessel General Permit (sVGP) in 2013 to provide for permit coverage for these 

incidental discharges and will finalize the sVGP during the summer of 2014. Visit 

http://www.epa.gov/npdes/vessels for updates. 

There is no set compliance monitoring frequency goal for vessels subject to the NPDES 

program. Regions and states should conduct compliance monitoring activities in response to tips 

and complaints and other available information relevant to compliance. EPA headquarters and 

regions will work jointly and cooperatively with the U.S. Coast Guard pursuant to the 2011 

Memorandum of Understanding between the two agencies, “For Collaboration on Compliance 

Assistance, Compliance Monitoring, and Enforcement of Vessel General Permit Requirements 

on Vessels,” available at http://www.uscg.mil/hq/cgcvc/cvc1/general/vgp/CG_EPA_MOU.pdf. 

18
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Part 3: Activity Type Descriptions 

This part provides detailed descriptions of each activity type discussed in the previous 

sections and performed by NPDES compliance personnel. Compliance personnel should choose 

the type of compliance monitoring activity to be conducted based on the compliance status and 

history of the facility, the information needed from the facility, the type of facility involved, data 

about the quality of receiving waters, etc. The type of inspection selected will inform what 

activities will be conducted onsite, such as what additional information the inspector will gather 

or verify during the inspection. Where feasible, compliance personnel should perform 

background and records reviews prior to going onsite to streamline onsite activities and to utilize 

resources more efficiently. Note that some types of NPDES inspections may encompass several 

elements from multiple inspection types (e.g., a stormwater inspection may encompass elements 

from both a Compliance Sampling Inspection and a Performance Audit Inspection). 

Combined Sewer Overflow Inspection 

During a CSO inspection, the inspector conducts an on-site inspection in response to 

information received regarding a known or suspected overflow event. A CSO inspection 

evaluates compliance with the CWA and CSO Policy requirements as written in the NPDES 

permit, an enforcement order, a consent decree, or another enforceable document. The inspector 

should verify whether the permittee is preventing CSOs during dry weather, implementing the 

nine minimum controls, adhering to a schedule for development, submission, and 

implementation of a long-term CSO control plan, eliminating or relocating overflows to 

sensitive areas, adhering to effluent limitations, and implementing a post-construction 

compliance monitoring program. 

Compliance Biomonitoring Inspection 

This on-site inspection of an NPDES direct discharger includes the same objectives and tasks as 

a Compliance Sampling Inspection. A Compliance Biomonitoring Inspection reviews a 

permittee's toxicity bioassay techniques and records maintenance to evaluate compliance with the 

bio- monitoring terms of the NPDES permit and to determine whether the permittee's effluent is 

toxic. The Compliance Biomonitoring Inspection also includes the collection of effluent samples 

by the inspector to conduct acute and chronic toxicity testing to evaluate the biological effect of a 

permittee's effluent discharge(s) on test organisms. Each state should have the ability to conduct 

bio-monitoring inspections, have a designated contractor conduct inspections, or have an 

equivalent program to independently verify a discharger’s compliance with Whole Effluent 

Toxicity permit requirements. 

Compliance Evaluation Inspection 

The Compliance Evaluation Inspection is an on-site nonsampling inspection of an NPDES 

direct discharger designed to verify permittee compliance with applicable permit selfmonitoring requirements, effluent limits, and compliance schedules. Inspectors must review 

records, make visual observations and evaluate treatment facilities, laboratories, effluents and 

receiving waters. During the Compliance Evaluation Inspection, the inspector must examine 

both chemical and biological self-monitoring, which form the basis for all other inspection 

types except the Reconnaissance Inspection. 

19
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Compliance Sampling Inspection 

The Compliance Sampling Inspection of an NPDES direct discharger includes the same 

objectives and tasks as a Compliance Evaluation Inspection. In addition, inspectors must take 

representative samples. Inspectors then verify the accuracy of the permittee's self-monitoring 

program and reports through chemical and bacteriological analysis; evaluate compliance with 

discharge limitations; determine the quantity and quality of effluents; and provide evidence for 

enforcement proceedings where appropriate. 

Concentrated Animal Feeding Operation Inspection 

The objective of this inspection is to evaluate a CAFO’s compliance with permit 

requirements, permit conditions, applicable regulations, and other requirements. To evaluate 

compliance with requirements and regulations, a CAFO inspection involves review of facility 

documents and records, such as the facility’s permit, nutrient management plan, animal 

inventory, and all associated records. The on-site inspection also includes assessing the 

structural integrity, maintenance condition, and storage availability of the facility. For CAFOs 

that land-apply manure, litter, or process wastewater, the CAFO inspection will include 

review of in-field and edge-of-field conservation practices, land application protocols and all 

other factors relevant to determining whether the CAFO has non-agricultural stormwater 

discharges from land application areas. Where appropriate, CAFO inspections may include 

sampling of manure, litter, wastewater and/or soil. A CAFO inspection may also require 

collection of information necessary to establish whether the receiving water of any CAFO 

discharge is a water of the United States. 

Diagnostic Inspection 

The Diagnostic Inspection is an on-site activity that primarily focuses on Publicly Owned 

Treatment Works (POTWs) that have not achieved permit compliance. POTWs that are having 

difficulty diagnosing their problems are targeted. The purposes of the Diagnostic Inspection are 

to identify the causes of noncompliance, suggest immediate remedies that will help the POTW 

achieve compliance, and support current or future enforcement action. Once the cause of 

noncompliance is defined, an administrative order is usually issued that requires the permittee 

to conduct a detailed analysis and develop a composite correction plan. 

Focused Compliance Inspection 

In order for a Focused Compliance Inspection (also referred to in the CMS as a Focused 

Inspection) to count toward implementation of an approved alternative CMS plan, all applicable 

conditions outlined in Part 1 must be met. A Focused Inspection is an on-site inspection that 

evaluates compliance for one or more specific portions of a facility (e.g., specific operation or 

process stream), permit or program (e.g., a pretreatment control authority’s oversight of 

industrial users) in order to make a compliance determination. A fact-driven analysis determines 

whether a comprehensive inspection (see footnote 5) or a Focused Inspection is appropriate for 

the particular facility. Some industries that typically require full process-based inspections may 

not qualify for a Focused Inspection. The scope of a Focused Inspection should be informed by 

the facility’s compliance history, information about recent changes in the facility’s operation, 

and other data that indicates a portion of the program or facility that is more likely to have 

associated compliance issues. A Focused Inspection is more detailed than a Reconnaissance 

Inspection, but not as comprehensive as a Compliance Evaluation Inspection, Compliance 

Sampling Inspection, Diagnostic Inspection, or Pretreatment Compliance Inspection. Although 

20
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

the scope of a Focused Inspection is narrower than a Compliance Evaluation Inspection, the level 

of detail required for the portion of the facility, permit or program aspect reviewed should be 

comparable to the level of detail required for a Compliance Evaluation Inspection. A 

Reconnaissance Inspection, which only requires a preliminary overview of a permittee's 

compliance program and brief inspection of the facility, does not qualify as a Focused Inspection. 

Follow-up Inspection 

The Follow-up Inspection is a resource intensive on-site inspection conducted when a 

compliance problem is identified as a result of a routine inspection or a complaint. For a 

Follow-up Inspection, the appropriate resources are assembled to deal effectively with a 

specific enforcement problem. 

Municipal Separate Storm Sewer System Audit 

An MS4 Audit is used to evaluate overall MS4 stormwater management program 

implementation, and identify problems the local government may have in implementing the 

program. MS4 Audits involve an on-site visit and comprehensive review of the local 

government's MS4 stormwater management program including, where applicable: (1) structural 

and source control measures; (2) detection and removal of illicit discharges and improper 

disposal into storm sewers; (3) monitoring and controlling pollutants in stormwater discharges; 

(4) implementing and maintaining structural and nonstructural best management practices 

(BMPs); (5) implementation schedules and assignment of appropriate individuals; (6) the 

inspection and enforcement program for covered industrial facilities and construction sites; and 

(7) the dry weather screening program. The auditor should make a determination of whether 

controls are in place and in good working order, and whether facilities have schedules for 

construction of structural control measures. 

Municipal Separate Storm Sewer System Inspection 

An MS4 Inspection is an on-site inspection that involves reviewing some, but not all, elements of 

the MS4 stormwater management program to evaluate whether the MS4 is implementing an 

adequate program in the selected program elements. The program elements would be selected by 

the region or a state after review of the MS4 permit and other relevant information. See MS4 

Audit definition for program elements. 

Off-site Desk Audit 

In order for an Off-site Desk Audit to count toward implementation of an approved alternative 

CMS plan, all applicable conditions outlined in Part 1 must be met. An Off-site Desk Audit is a 

comprehensive off-site compliance evaluation of information, data, records, and facility reports 

in order to make a facility-level or program-level (for pretreatment and MS4s) compliance 

determination. Routine off-site compliance monitoring activities, such as reviewing selfmonitoring reports or records of phone calls with the facility, are not enough to be considered an 

off-site desk audit. An Off-site Desk Audit may include review of agency-gathered testing, 

sampling and ambient monitoring data, responses to CWA section 308 requests, compliance 

deliverables submitted pursuant to permits or enforcement orders, remote sensing, aerial or 

satellite images, DMRs, annual reports, conversations with facilities, and tips and complaints. In 

conducting an Off-site Desk Audit, regions and states may utilize video conferencing with 

facility personnel to gather additional information as they conduct their evaluation. For example, 

21
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

video conferencing could enable the auditor to join facility personnel on a virtual walking tour of 

all or part of the facility. The Off-site Desk Audit must be performed by an authorized inspector 

(consistent with appropriate federal, state, or tribal authority) or other credible regulator (i.e., an 

individual designated by the EPA or state/local/tribal agency with sufficient knowledge, training, 

or experience to assess compliance). This individual should select the candidate for the Off-site 

Desk Audit based on personal knowledge of the facility, in conjunction with information from 

DMRs, other reports, and prior on-site inspections, and have adequate information about the 

facility’s activities to make a compliance determination. 

Performance Audit Inspection 

The inspector conducts an on-site performance audit inspection (PAI) of an NPDES direct 

discharger to evaluate the permittee's self-monitoring program. As with a Compliance Evaluation 

Inspection, the PAI verifies the permittee's reported data and compliance through a records 

check. However, the PAI provides a more resource-intensive review of the permittee's selfmonitoring program and evaluates the permittee's procedures for sample collection, flow 

measurement, chain-of-custody, laboratory analyses, data compilation, reporting, and other areas 

related to the self-monitoring program. In a Compliance Evaluation Inspection, the inspector 

makes a cursory visual observation of the treatment facility, laboratory, effluents, and receiving 

waters. In a PAI, the inspector observes the permittee performing the self-monitoring process 

from sample collection and flow measurement through laboratory analyses, data workup, and 

reporting. The PAI does not include the collection of samples by the inspector. However, the 

inspector may require the permittee to analyze performance samples for laboratory evaluation 

purposes. 

Pretreatment Audit 

A Pretreatment Audit involves an on-site visit and a comprehensive evaluation all aspects of the 

local POTW control authority’s program. The primary goals of the audit are to assess the local 

program’s compliance with the regulatory requirements under the NPDES direct discharge 

permit, note areas of the control authority’s program that need to be modified to bring the 

program into compliance with the regulations, and to identify circumstances that might warrant 

enforcement actions against the control authority. In the course of conducting a Pretreatment 

Audit, the region or state should ensure that the POTW is following its Enforcement Response 

Plan when the POTW identifies industrial user noncompliance. Ultimately, the Pretreatment 

Audit will help the approval authority (i.e., region or state) identify areas for improvement and 

make recommendations to increase the effectiveness of the control authority’s program. A 

Pretreatment Audit includes oversight inspections of at least two industrial users that discharge 

to the POTW and may include sampling. 

The Pretreatment Audit is further defined and discussed in the Control Authority Pretreatment 

Audit Checklist and Instructions, which includes sections for evaluating environmental 

indicators and investigating the control authority’s use of pollution prevention techniques 

(February 2010), available at 

http://www.epa.gov/npdes/pubs/final_pca_checklist_and_instructions_%20feb2010.pdf. 

22
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Pretreatment Compliance Inspection 

The on-site Pretreatment Compliance Inspection (PCI) is a tool for the approval authority (i.e., 

region or state) to determine the control authority’s compliance with and enforcement of its 

approved pretreatment program during the years between audits. The PCI evaluates the POTW's 

implementation of its approved pretreatment program. It includes a review of the POTW's 

records on monitoring, inspections, and enforcement activities for its industrial users (IUs). In 

the course of conducting a PCI, the region or state should ensure that the POTW is following 

its Enforcement Response Plan when the POTW identifies IU noncompliance. The PCI should 

include an appropriate number of IU inspections or site visits to evaluate the control authority 

oversight procedures and to assess accurate application of categorical pretreatment standards. 

The PCI can include IU sampling, depending on the reason for the inspection. For example, 

samples may be collected and analyzed to verify the industrial user’s self-monitoring program. 

Inspectors may prefer to conduct the PCI concurrently with an NPDES inspection of the 

POTW. For additional information on the steps involved in conducting a PCI, see EPA’s 

Guidance for Conducting a Pretreatment Compliance Inspection (September 1991), available 

at http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=50000629.txt. 

Reconnaissance Inspection 

The Reconnaissance Inspection is an on-site inspection that can be conducted with or without 

sampling (RWS and ROS in ICIS-NPDES, respectively) and is used to obtain a preliminary 

overview of a permittee's compliance program. The inspector performs a brief visual 

inspection of the permittee's treatment facility, effluents, and receiving waters. The 

Reconnaissance Inspection uses the inspector's experience and judgment to quickly summarize 

any potential compliance problems. One objective of the Reconnaissance Inspection is to 

expand inspection coverage without increasing inspection resources. The Reconnaissance 

Inspection is the briefest and least resource intensive of all CWA inspections. 

Sanitary Sewer Overflow Inspection 

During an SSO Inspection, the inspector conducts an on-site inspection in response to 

information received regarding a known or suspected overflow event. An SSO Inspection 

evaluates compliance with NPDES permit terms and conditions for system design, operation 

and maintenance, permit reporting requirements, an enforcement order, a consent decree, or 

another enforceable document. The inspector collects information to verify that the permittee is 

complying with the NPDES standard permit conditions (duty to mitigate and proper operation 

and maintenance) and the required notification procedures. The inspector also determines 

whether there have been any additional unpermitted discharges, or discharges from a location 

other than the discharge point specified in the permit, to waters of the United States. When 

preparing for an SSO Inspection, the inspector should consider OECA’s Guide for Evaluating 

Capacity, Management, Operation, and Maintenance (CMOM) Programs at Sanitary Sewer 

Collection Systems (2005), available at 

http://www.epa.gov/npdes/pubs/cmom_guide_for_collection_systems.pdf. 

Sewage Sludge/Biosolids Inspection 

The objective of a Sewage Sludge/Biosolids Inspection is to assess facilities engaged in a 

regulated sludge or biosolids activity (see 40 CFR part 503) to evaluate compliance with 

applicable regulatory provisions, including sludge monitoring, recordkeeping and reporting, 

23
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

treatment operations, sampling and laboratory quality assurance and use or disposal practices. 

Sewage Sludge/Biosolids Inspection are on-site activities that may be conducted in conjunction 

with compliance inspections at major and non-major POTWs. The Pretreatment Compliance 

Inspection, Compliance Evaluation Inspection, and Performance Audit Inspection are the most 

likely vehicles for evaluating compliance with sludge/biosolids requirements. 

Significant Industrial User Inspection 

For purposes of this CMS, the SIU Inspection of an indirect discharger is performed where 

agencies are acting as the pretreatment control authority pursuant to 40 CFR 403.10 in the 

absence of a local POTW with an approved pretreatment program, or where EPA or the state is 

otherwise performing oversight. The SIU Inspection is an on-site activity that includes a close 

review of the indirect discharge permit and the SIU’s compliance, recordkeeping and reporting 

since the last inspection. The pretreatment regulations provide that state and local control 

authorities must conduct sampling inspections of all SIUs at least annually to evaluate 

compliance with applicable pretreatment standards independent of the IU’s self-monitoring 

reports. See 40 CFR 403.8(f). 

Stormwater Inspection 

Stormwater Inspections at industrial facilities and construction sites are designed to evaluate 

compliance with NPDES permits for stormwater discharge. A Stormwater Inspection may also 

evaluate whether an industrial facility or construction site has obtained NPDES permit coverage 

if required. A Stormwater Pollution Prevention Plan (SWPPP) documents how the facility intends 

to comply with the terms and conditions of the permit, including effluent limitations. During the 

on-site inspection, the inspector reviews the permit and the measures described in the SWPPP to 

evaluate whether the facility is following its plan for complying with the permit. The inspector 

also reviews records, such as self-inspection reports, to verify that the facility is complying with 

its permit and following the SWPPP, and walks the site to verify that the SWPPP is accurate and 

BMPs are in place and functioning properly. 

Toxics Sampling Inspection 

The Toxic Sampling Inspection of an NPDES direct discharger is an on-site inspection that has 

the same objectives as a conventional Compliance Sampling Inspection. However, it places 

increased emphasis on toxic substances regulated by the NPDES permit. The Toxic Sampling 

Inspection covers priority pollutants other than heavy metals, phenols, and cyanide, which are 

typically included in a Compliance Sampling Inspection (if regulated by the NPDES permit). A 

Toxic Sampling Inspection uses more resources than a Compliance Sampling Inspection 

because sophisticated techniques are required to sample and analyze toxic pollutants. A Toxic 

Sampling Inspection may also evaluate raw materials, process operations, and treatment 

facilities to identify toxic substances requiring controls. 

24
 
 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Part 4: ICIS-NPDES Data Entry 

OECA is providing this table as a reference tool for EPA and state personnel who enter compliance monitoring activity data into 

ICIS-NPDES. All of the information in the table corresponds to the goals and flexibilities set forth in Part 2 of this policy and 

implemented under a traditional CMS plan. For alternative CMS plans, the table below is the starting point for ICIS-NPDES data 

entry and can be tailored for any metrics in the alternative plan where the compliance monitoring commitments deviate from the 

national CMS goals summarized in the table. Please contact the Office of Compliance, Monitoring, Assistance and Media Programs 

Division, Water Branch if you have questions about ICIS-NPDES data entry for activities conducted pursuant to an alternative CMS 

plan. 

Source/Metric CMS Goal –

National Recommended 

Minimum Frequency 

Acceptable ICIS-NPDES 

Compliance Monitoring Type 

for Traditional CMS Plan 

Corresponding ICISNPDES Compliance 

Monitoring Type Code 

Notes 

1.A: Major 

Facilities –

National Standard 

At least one 

comprehensive inspection 

every other year 

Evaluation, Sampling, Audit, 

Diagnostic, Biomonitoring, 

Toxics 

CEI, SA1, AU1, DIA, CBI, 

TX1 

1.A: Major At least one Evaluation, Sampling, Audit, CEI, SA1, AU1, DIA, CBI, See Part 2, Section 1.A for 

Facilities – comprehensive inspection Diagnostic, Biomonitoring, TX1 further discussion of the ITM. 

Pre-approved every three years for Toxics 

Alternative facilities designated for 

modified inspection 

frequency by Inspection 

Targeting Model (ITM) or 

comparable modeling tool 

1.B.1: Traditional One inspection every five Evaluation, Sampling, Audit, CEI, SA1, AU1, DIA, CBI, Inspection type flexibility 

non-major – non- years (comprehensive Diagnostic, Biomonitoring, TX1, RWS, ROS, FLP, allowed because facility is not 

impaired waters inspections for at least %5 

of universe per year) 

Toxics, Reconnaissance with 

Sampling, Reconnaissance 

without Sampling, Follow-up, 

Oversight, Focused, Operation 

and Maintenance 

OVS, FOC, OPM contributing to impaired waters. 

25
 
 

 

July 2014 NPDES Compliance Monitoring Strategy 

Source/Metric CMS Goal –

National Recommended 

Minimum Frequency 

Acceptable ICIS-NPDES 

Compliance Monitoring Type 

for Traditional CMS Plan 

Corresponding ICISNPDES Compliance 

Monitoring Type Code 

Notes 

1.B.2: Traditional 

non-major –

impaired waters 

Comprehensive inspection 

once every five years 

Evaluation, Sampling, Audit, 

Diagnostic, Biomonitoring, 

Toxics 

CEI, SA1, AU1, DIA, CBI, 

TX1 

1.C.1: 

Pretreatment 

program audits 

At least one audit every 

five years, including 

oversight inspection of 

two Industrial Users (UIs) 

Audit 

For SIU inspections: Oversight, 

Audit (IU), Evaluation (IU), 

Non-sampling (IU), Sampling 

(IU), Toxics (IU) 

AU1 

For SIU inspections: 

OVS, AU2, CE2, PIU, 

PSI, TX2 

Include program code 

CWAPRTRT. 

1.C.2: 

Pretreatment 

program 

inspections 

At least two Pretreatment 

Compliance Inspections 

every five years 

Evaluation, Follow-up, 

Oversight 

CEI, FLP, OVS Include program code 

CWAPRTRT. 

1.C.3: 

Pretreatment -

SIUs 

Annual sampling 

inspection of all SIUs 

discharging to POTWs 

without an approved 

pretreatment program 

Oversight, Audit (IU), 

Evaluation (IU), Sampling (IU), 

Toxics (IU) 

OVS, AU2, CE2, PSI, TX2 This is a regulatory requirement. 

See 40 CFR 403.8(f). 

1.D: Sewage 

Sludge/Biosolids 

At least one 

comprehensive inspection 

or off-site desk audit every 

five years for major 

POTWs and all regulated 

use and disposal facilities 

Evaluation, Sampling, Desk 

Audit 

CEI, SA1 or DSA Include CWAS program code. 

May be conducted in 

conjunction with compliance 

inspections at major and nonmajor POTWs. 

See Part 2, Section 1.D for offsite desk audit criteria 

applicable to authorized state 

programs. 

26
 
 

 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Source/Metric CMS Goal –

National Recommended 

Minimum Frequency 

Acceptable ICIS-NPDES 

Compliance Monitoring Type 

for Traditional CMS Plan 

Corresponding ICISNPDES Compliance 

Monitoring Type Code 

Notes 

1.E: Oversight Regional discretion; should 

include some activity in 

each state each year 

Oversight OVS Include program code (e.g., 

CWAPRTRT), if applicable. 

2.A: Combined 

sewer systems 

(CSS)- Major and 

non-major 

At least one CSO 

inspection every five years 

Evaluation, Sampling CEI, SA1 Include program code CWACSO. 

When entering EPA inspections, 

select the OECA National 

Priority “WW – CSOs < 50K serv. 

pop’n.” or “WW – CSOs >= 50K 

serv. pop’n.,” where applicable.

2.B: Sanitary 

Sewer Systems 

5% of universe of 

permitted POTWs with SSS 

annually 

Evaluation, Sampling CEI, SA1 Include program code CWASSO. 

When entering EPA inspections, 

select the OECA National 

Priority “WW – SSOs >= 10 mg/d 

and < 100 mg/d,” where 

applicable. 

2.C.1: MS4 – Phase 

I and Phase II 

Audit, MS4 inspection, or 

off-site desk audit of entire 

universe every five years. 

At least one on-site audit 

or inspection every seven 

years. 

Audit, Sampling, Evaluation, 

Desk Audit 

AU1, SA1, CEI, and DSA Include program code 

CWASTMM. 

When entering EPA audits and 

inspections, select the OECA 

National Priority “WW – MS4s –

Phase I” or “WW – MS4s –

Phase II,” where applicable.

2.C.2: Industrial 

stormwater 

10% of universe annually 

Inspections of unpermitted 

sites, including those with 

“no exposure”

Evaluation, Sampling CEI, SA1 Include program code 

CWASTMN. 

27
 
 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Source/Metric CMS Goal –

National Recommended 

Minimum Frequency 

Acceptable ICIS-NPDES 

Compliance Monitoring Type 

for Traditional CMS Plan 

Corresponding ICISNPDES Compliance 

Monitoring Type Code 

Notes 

certification, count toward 

the 10% goal. 

2.C.3: Construction 

stormwater sites 

10% of permitted universe 

annually 

Inspections of unpermitted 

sites count toward the 

10% goal. 

Evaluation, Sampling CEI, SA1 Include program code 

CWASTMC. 

2.D.1: Large and 

medium permitted 

CAFOs 

Minimum of one 

comprehensive inspection 

every five years; more 

frequent recommended if 

certain criteria are met 

Evaluation, Sampling CEI, SA1 Include program code 

CWACAFO. 

When entering EPA CAFO 

inspections, select the OECA 

National Priority “WW – CAFO”

or “WW – CAFO Regional 

Initiative !rea,” where 

applicable. 

2.D.2: Large 

unpermitted 

CAFOs 

Assess entire universe to 

determine whether the 

CAFO discharges; inspect 

thereafter as needed. 

Evaluation, Sampling CEI, SA1 Include program code 

CWACAFO. 

When entering EPA CAFO 

inspections, select the OECA 

National Priority “WW – C!FO”

or “WW – CAFO Regional 

Initiative !rea,” where 

applicable. 

2.D.3: Medium 

AFOs 

Onetime assessment of 

whether AFO is a CAFO, 

then inspect as needed 

Evaluation, Sampling, AFO 

Designated, AFO Defined, Desk 

Audit 

CEI, SA1, AFN, AFD, 

DSA 

Include program code 

CWACAFO. 

28
 
 

 

 

 

July 2014 NPDES Compliance Monitoring Strategy 

Source/Metric CMS Goal –

National Recommended 

Minimum Frequency 

Acceptable ICIS-NPDES 

Compliance Monitoring Type 

for Traditional CMS Plan 

Corresponding ICISNPDES Compliance 

Monitoring Type Code 

Notes 

When entering EPA CAFO 

inspections, select the OECA 

National Priority “WW – C!FO”

or “WW – CAFO Regional 

Initiative !rea,” where 

applicable. 

On-site inspection is required in 

order to designate. 

2.D.4: Small AFOs As needed Evaluation, Sampling, AFO 

Designated 

CEI, SA1, AFN Include program code 

CWACAFO. 

On-site inspection is required in 

order to designate. 

3.A: Pesticides As needed Evaluation, Sampling, Audit, 

Diagnostic, Biomonitoring, 

Toxics, Reconnaissance with 

Sampling, Reconnaissance 

without Sampling, Follow-up, 

Oversight, Focused, Operation 

and Maintenance 

CEI, SA1, AU1, DIA, CBI, 

TX1, RWS, ROS, FLP, 

OVS, FOC, OPM 

3.B: Vessels As needed Evaluation, Sampling, Audit, 

Diagnostic, Biomonitoring, 

Toxics, Reconnaissance with 

Sampling, Reconnaissance 

without Sampling, Follow-up, 

Oversight, Focused, Operation 

and Maintenance 

CEI, SA1, AU1, DIA, CBI, 

TX1, RWS, ROS, FLP, 

OVS, FOC, OPM 

29