BNA

A “zero-discharge” standard for sanitary sewer overflows is impossible to achieve, and any Environmental Protection Agency rule addressing such overflows should shield utilities from enforcement or lawsuits for overflows that are beyond their reasonable control, a municipal wastewater treatment official said July 13.

Chris Hornbeck, senior director of regulatory affairs for the National Association of Clean Water Agencies, was one of several municipal, industry, and environmental group representatives speaking at an EPA “listening session” on National Pollutant Discharge Elimination System permit requirements for sanitary sewer systems.Sanitary sewer systems are designed to carry sewage only, while combined sewer systems carry both sewage and stormwater. EPA issued a combined sewer overflow policy in 1994, but has not issued a final policy on sanitary sewer overflows.

EPA announced May 27 it plans to develop a proposed rule to better protect the environment from discharges of untreated sewage from municipal sanitary sewer systems (102 DEN A-7, 5/28/10).

Under current NPDES permits, there are no requirements to notify the public of sanitary sewer overflows; municipal satellites generally are not covered; and regulations are unclear about reporting and recordkeeping requirements for certain types of overflows. Satellite systems are sewage collection systems that feed into a municipal treatment plant but are located elsewhere and are not owned by the municipality.

NPDES regulations do not provide a framework for enforcement discretion or defense for unavoidable sanitary sewer overflows by regulated facilities, according to EPA.

Sanitary sewer overflows are often caused by blockages or breaks in sewer lines. They can release untreated sewage, which contains pathogens such as viruses, bacteria, and protozoa, into basements or out of manholes and onto city streets and into streams.

EPA said it is seeking comments on sanitary sewer collection systems, satellite collection systems, sanitary sewer overflows (SSOs), and peak wet weather discharges.

Connie Bosma, branch chief in the EPA Water Office Water Permits Division, told BNA that speakers at this and previous listening sessions support EPA's efforts to deal with wet weather flows both at the treatment plant and in collection systems. But how to accomplish this remains a question. Listening sessions were held in June in Seattle, Atlanta, and Kansas City.

Rule or Policy in Question
Bosma said EPA has not determined whether it plans to propose a rule or a policy on the issue.
Hornbeck said any final EPA regulation should take a “comprehensive, holistic approach” to the regulation of sanitary sewer collection systems, including uniform national requirements for permitting of satellite sewer collection systems, peak excess flow treatment facilities, and wet weather flow management practices at municipal wastewater treatment facilities.

Management, operation, and maintenance requirements should be carefully crafted to ensure that they do not prescribe specific requirements or standards for collection system management, Hornbeck said. In addition, satellite collection systems must be brought into the Clean Water Act program. Their owner/operators should be required to establish management, operation, maintenance, and capacity assurance programs, he said.

NACWA recommended that permits be issued directly to the satellite system owner or operator, but it also recommended studying existing regional collaborations and agreements to determine other possible approaches.

A potential rule also must recognize the important contribution of private sewers to the problem, Hornbeck said.
Hornbeck said NACWA feels strongly that the management of peak flows at the treatment plant must be addressed as a component of a sanitary sewer system rulemaking.

Now that EPA has expressed an interest in addressing the broader issue of sanitary sewer system management, he said, pursuing requirements considered in its 2005 proposed peak flows policy separately would not be appropriate.

Any final regulation must include provisions authorizing peak flow treatment scenarios at publicly owned treatment works under certain circumstances and address the permitting of peak excess flow facilities located in the treatment system, Hornbeck stressed.

Bosma said some people want EPA to finalize the 2005 proposed policy, while others think it should be addressed through a comprehensive rule addressing all wet weather flows. At this point, she said, EPA has not made a decision and is still seeking input.

The policy, which was never made final, was an attempt by EPA to clarify that the existing “bypass” provision of the NPDES regulations applies to peak wet weather diversions at publicly owned treatment works.
At issue is whether and under what circumstances treatment plants can allow wastewater to bypass the normal secondary stage of treatment, which typically uses biological methods, including bacteria, to treat the wastewater after it has gone through primary treatment.

According to EPA, older and improperly maintained sewer systems are more susceptible to infiltration and inflow. Wet weather can cause overflows in the sewer system. Increased influent at the treatment plant can exceed the capacity of secondary treatment units and lead to diversions, or bypasses, around treatment units to prevent upset of biological process.

Under existing rules, sewer overflows from publicly owned treatment works are generally prohibited without a National Pollutant Discharge Elimination System permit.

Gary Cohen, an attorney with the Washington, D.C., law firm Hall & Associates, said EPA needs to define the term SSO.

“Clean Water Act jurisdiction only applies to discharges to the waters of the United States. It does not appropriately address basement backups or other overflows from a sewer that do not reach receiving waters,” he said. “EPA's existing interpretations, and any new regulations, should recognize such limitation.”

Cohen said he represents a coalition of several hundred municipalities and municipal groups across the country, including those in New Jersey, New Hampshire, Massachusetts, Minnesota, Iowa, North Carolina, and Pennsylvania.

Basement Backups
Fred Andes, an attorney with Barnes & Thornburgh, which represents several municipal treatment agencies, also said the issue of “basement backups” is surfacing more frequently. “We don't think by itself this is a permit violation but it could be an example of improper operation and maintenance,” he said.

There should be some kind of “de minimis” provision in reporting requirements so they are not focused on very small discharges, he said. A capacity, management, and operation and maintenance program for sanitary sewers should recognize the flexible needs of communities, he said.

Satellite collection systems, owned by other parties, pose significant legal issues, Andes cautioned. He said he does not think EPA has put forward a clear and coherent position on how these systems can be made co-permittees.

It also is important that EPA consider developing a broader wet weather policy that includes combined sewer overflows, sanitary sewer overflows, green infrastructure, and other areas to help cities dealing with limited funding, Andes said. All these should be considered in a comprehensive plan, he added.

Burton Curry, with the Chesapeake Water Environment Association, said the association is seeking “real water quality improvement” based on scientific principles that considers the costs to the disadvantaged. “EPA must move cautiously in requiring NPDES permitting,” and must consider local jurisdictions, he said.