Member Pipeline - Regulatory - Alert (RA 04-06)
To: Members & Affiliates,
Wet Weather Issues Committee, Pretreatment & Hazardous Waste
Committee, and Legal Affairs Committee
From: National Office
Date: March 17, 2004
Subject: EPA CSO NINE MINIMUM CONTROL AUDITS
Reference: RA 04-06
Printer friendly versionIt has come to the attention of the Association of Metropolitan Sewerage Agencies (AMSA) that numerous combined sewer overflow (CSO) communities around the nation are experiencing audits by the U.S. Environmental Protection Agency (EPA or the Agency), pertaining to their implementation of the CSO Control Policy of 1994 (59 Fed. Reg. 18688), particularly their ability to demonstrate implementation of the nine minimum controls (NMCs) set forth in the Policy. The NMCs are minimum technology-based controls that can be used to address CSO problems without extensive engineering studies or significant construction costs, prior to the development and implementation of long-term control plans (LTCP) as required by the Policy. Failure to implement these controls can result in a consent decree between EPA and the municipality that establishes a schedule for implementation of the CSO Control Policy, including the NMCs. The steps to implement the NMCs are set out in a May 31, 1995, EPA guidance document (http://www.epa.gov/npdes/pubs/owm0030.pdf).
AMSA Urges CSO Members to be Prepared for EPA Audits
The CSO Control Policy mandated that all permitted entities
implement, with appropriate documentation, the NMCs as soon as practicable, but
no later than January 1, 1997. While that deadline has long past, enforcement of
this requirement has not been forgotten. On September 16, 2003, Walker B. Smith,
Director of the Office of Regulatory Enforcement, in EPA’s Office of Enforcement
and Compliance Assurance, and Bruce S. Gelber, Chief of the Environmental
Enforcement Section of the Department of Justice’s (DOJ) Environment and Natural
Resources Division, sent a memorandum (http://www.amsa-cleanwater.org/private/legal/CSOcdguidefinal916pdf.pdf)
to various offices throughout EPA headquarters and regions to address a number
of important aspects of consent decrees for long term remedial measures to
address CSOs. The memorandum spelled out that the principal objective of all CSO
negotiations between the enforcement authority and a municipality or other
defendant is to reach agreement on a federal consent decree which requires the
(1) development and implementation of a LTCP necessary to achieve compliance
with the Clean Water Act, consistent with the CSO Control Policy, and the (2)
implementation of the NMCs set forth in the CSO Control Policy. As a result of
the September 2003 memorandum, several AMSA member agencies have been audited to
determine their compliance with the CSO Control Policy.
AMSA urges members in CSO communities to have on hand site-specific documentation regarding their implementation of the NMCs, which could be requested during an EPA audit, including the following: operation and maintenance (O&M) plans, revised sewer use ordinances for industrial users, sewer system inspection reports, infiltration/inflow studies, pollution prevention programs, public notification plans, and facility plans for maximizing the capacities of the existing collection, storage, and treatment systems, as well as contracts and schedules for minor construction programs for improving the existing system’s operation.
Nine Minimum Controls
Briefly described below are each of the NMCs. For more information refer to
EPA’s guidance at
http://www.epa.gov/npdes/pubs/owm0030.pdf.
1. Proper operation and regular maintenance programs for the sewer system and the CSOs.
This generally will consist of a program that clearly establishes O&M, and inspection procedures to ensure that a combined sewer system and treatment facility will function in a way to maximize treatment of combined sewage and meet applicable National Pollutant Discharge Elimination System (NPDES) permit provisions.
2. Maximize use of the collection system for storage.
This control entails making relatively simple modifications to the combined sewer system (CSS) to enable the system itself to store wet weather flows until downstream sewers and treatment facilities can handle them.
3. Review and modification of pretreatment requirements to assure CSO impacts are minimized.
The objective of this control is to minimize the impacts of discharges into CSSs from nondomestic sources during wet weather events, and to minimize CSO occurrences by modifying inspection, reporting, and oversight procedures with the approved pretreatment program. Some communities have found that annual pretreatment forms can be used for this.
4. Maximization of flow to the publicly owned treatment work (POTW) for treatment.
This control involves simple modifications to the CSS and treatment plant to enable as much wet weather flow as possible to reach the treatment plant, thereby controlling the magnitude, frequency, and duration of CSOs that flow untreated into receiving waters.
5. Prohibition of CSOs during dry weather.
This includes any measures taken to ensure that the CSS does not overflow during dry weather flow conditions. The requirement for DWO elimination is enforceable independent of any programs for the control of CSOs. DWO control measures include improved O&M, as well as physical changes to regulator and overflow devices (see Chapter 6 of EPA’s guidance).
6. Control of solid and floatable materials in CSOs.
The sixth minimum control is intended to reduce, if not eliminate, visible floatables and solids using relatively simple measures, including baffles, screens, and racks. Such devices are used to remove coarse solids and floatables from combined sewage. Devices such as booms and skimmers can help remove floatables from the surface of receiving waters. Pollution prevention measures (discussed below) can prevent extraneous solids and floatables from entering the CSS.
7. Pollution prevention.
The objective of this minimum control is to reduce to the greatest extent possible the amount of contaminants that enter the CSS. Most of the suggested measures involve behavioral changes rather than construction of storage or treatment devices.
8. Public notification to ensure that the public receives adequate notification of CSO occurrences and CSO impacts.
The intent of this minimum control is to inform the public of the location of CSO outfalls, the actual occurrences of CSOs, the possible health and environmental effects of CSOs, and the recreational or commercial activities curtailed as a result of CSOs. The most appropriate mechanism for public notification will probably vary with local circumstances, such as the character and size of the use area and means of public access.
9. Monitoring to effectively characterize CSO impacts and the efficacy of CSO controls.
This control involves visual inspections and other simple methods to determine the occurrence and apparent impacts of CSOs. This entails an initial characterization of overflow occurrences and known water quality problems and incidents that reflect use impairments caused by CSOs.
Conclusion
As noted above, the September 2003 memorandum from EPA and DOJ spelled out that
consent decrees entered in CSO negotiations require defendants, in this case
municipalities, to not only implement these nine minimum controls, but develop
and implement an LTCP as well. Generally, these consent decrees give a deadline
for submitting the LTCP of no more than two years from the date of lodging of
the consent decree. It should be of interest to AMSA members that have already
implemented an LTCP, or are in the processing of doing so, that when the LTCP’s
programs go above and beyond the level of control achieved by any or all of the
nine minimum controls, the obligation to perform those nine minimum controls
ceases.
AMSA urges its members to review the requirements of both the nine minimum controls and the long-term control plans found in the CSO Control Policy (http://cfpub.epa.gov/npdes/cso/cpolicy.cfm), and implement such programs to be prepared for the EPA audit process and to avoid potential enforcement actions.
For more information, please contact Will Pettit, AMSA’s Regulatory Analyst at 202/833-3280 or wpettit@amsa-cleanwater.org.