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Background Information on EPA's Permit for the Massachusetts Water Resources Authority (MWRA) Outfall

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Water Quality: Discharge Permit for MWRA Outfall- Protection of Massachusetts and Cape Cod Bays, May 1999

Massachusetts and Cape Cod Bays are key environmental resources, and the discharge permit for the MWRA outfall takes an aggressive approach to their protection. The permit represents a three-part strategy: first, the most comprehensive requirements ever imposed in this type of permit; second, extensive monitoring to ensure that those requirements are met; and third, prompt response to problems if they occur.

Stringent Requirements

  • The discharge must not cause or contribute to exceedances of water quality standards for 158 pollutants.
  • The discharge must meet "secondary treatment" standards set by EPA.
  • The discharge must not interfere with fish or other aquatic life.
  • The discharge must not contribute to eutrophication (e.g. algae growth or a change in species due to excessive nutrients).
  • MWRA must implement the most stringent pollution prevention measures, best management practices, and water conservation requirements ever imposed in this type of permit.

Extensive Monitoring

  • The discharge will be monitored three times daily for bacteria and chlorine; once per day for solids concentration, oxygen-demanding material, and pH; and once per month for numerous other potential pollutants.
  • The permit includes an unprecedented ambient monitoring program to detect any impact on Massachusetts and Cape Cod Bays--43 monitoring stations, collecting data on a wide range of environmental indicators.
  • Data will be reviewed by a panel of independent scientists reporting to EPA and DEP-all monitoring results will be made available to the public, and key data will be available on the Internet.

Prompt Response

  • Extensive environmental reviews have predicted that the discharge of effluent which has received secondary treatment will not have adverse impacts on Massachusetts and Cape Cod Bays. However, to ensure prompt response to any unexpected problems, the permit requires implementation of a "contingency plan," the first such plan required by an EPA permit in New England.
  • The contingency plan establishes "caution" and "warning" levels for 25 environmental indicators.
  • The permit requires prompt action if a warning level is reached--unless it is demonstrated that the discharge is not contributing to an environmental problem.
  • Both regulatory agencies and citizens have the right to sue to enforce permit conditions.

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Response Summary: MWRA Permit - Response to Public Comments, May, 1999

The Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection (DEP) received extensive public comments on the Massachusetts Water Resource Authority's (MWRA) draft discharge permit. Many environmental groups praised the comprehensive and stringent requirements in the draft permit:

"We would first like to commend the EPA for the thoroughness of this permit. We recognize that it is the most stringent NPDES permit issued to date." - Coastal Advocacy Network

"Massachusetts Audubon wishes to compliment the Environmental Protection Agency and the Massachusetts Department of Environmental Protection (MADEP) for drafting the most stringent and environmentally protective permit of which we are aware."
- Massachusetts Audubon Society

"MBP finds the permit to be comprehensive and detailed in the issues that are covered, and this permit sets a new high standard for future NPDES permits." - Massachusetts Bays Program

Many commenters, while supportive of the overall approach, also proposed changes to strengthen specific elements of the permit. EPA and DEP have revised the permit in response to these comments. Some of the most significant improvements to the permit are:

Electronic dissemination of data: To make information more accessible to the public, the final permit requires that key monitoring data and other information be posted on the MWRA's website. In addition, EPA will distribute key data-including any exceedances of contingency plan caution or warning levels-by email to interested members of the public.

To subscribe to EPA's email list, send the following message: "subscribe mwrapermit [your first name] [your last name]" to Do not include quotation marks in your message. If your name is Jane Smith, the message should read: subscribe mwrapermit jane smith.

Infiltration/Inflow: The final permit includes a requirement that the MWRA develop and implement a comprehensive plan to identify and remediate infiltration/inflow and sanitary sewer overflow problems.

Science advisory panel: The final permit includes language which highlights the role of the Outfall Monitoring Science Advisory Panel (OMSAP), a panel of independent scientists appointed by EPA and DEP, in evaluating monitoring data; advising EPA and DEP as to whether the MWRA's discharge contributes to any exceedances of caution or warning levels; and proposing and evaluating potential modifications to the monitoring and contingency plans.

Red tide: EPA and DEP will ask the OMSAP to investigate the need for additional red tide monitoring stations in Massachusetts and Cape Cod Bays. If the OMSAP recommends that additional monitoring is necessary, the MWRA is required to prepare a scope of work for such monitoring within ninety days.

Nutrients: The final permit adds language, drawn from state water quality standards, specifying that "nutrients in the effluent shall not cause accelerated or cultural eutrophication."

Contingency plan: Where a contingency plan "warning level" is exceeded, the final permit establishes a 30-day deadline for the MWRA to develop a plan and schedule to address any environmental impacts resulting from its discharge. The final permit also clarifies that the OMSAP will play a key advisory role in such cases.

Receiving water: Although the actual discharge location is in Massachusetts Bay, the final permit recognizes the fact that diluted effluent from the MWRA outfall is expected to reach Cape Cod Bay (as is the case with the current discharge at the mouth of Boston Harbor). The permit authorizes a discharge to "receiving waters located in Massachusetts Bay, which is adjacent to Cape Cod Bay, and a part of the Gulf of Maine."

Endangered species: The final permit has been modified to prohibit any adverse effect on critical habitat for endangered species.

Diversion of discharge: The final permit requires that the MWRA produce a plan for preserving the physical integrity and capacity of the existing Deer Island outfalls. The MWRA is required to maintain these facilities in good working order. The final permit also requires that alternative discharge scenarios-including discharge through the existing Deer Island outfalls-must be considered as an option under the MWRA's contingency plan. The "bypass" provision of the permit has been clarified to allow the use of the Deer Island outfalls if required by EPA and DEP.

Flow limit: The final permit clarifies that the prohibition on the addition of new communities to the MWRA's wastewater service area applies even to communities that are already within the MWRA service area for drinking water.

Polymers: The final permit allows the National Marine Fisheries Service to disapprove the use of polymers (which may improve the removal of solids from wastewater under certain high-flow conditions) at concentrations greater than two parts per million. EPA and DEP must also agree before this concentration may be exceeded. Before any use of polymer, including concentrations below two parts per million, the MWRA is required to perform toxicity tests in order to determine the level of polymer which would cause toxicity; this level may not be exceeded under any circumstances.

Stellwagen Bank: The final permit adds a requirement that the MWRA submit an annual report to the Stellwagen Bank National Marine Sanctuary, that includes all monitoring data related to the Sanctuary and documents any effects of the MWRA discharge on Sanctuary resources and qualities over the previous year.

Maintenance: The final permit requires that the MWRA produce annual maintenance updates and status sheets, including key indicators of maintenance activities and detailed information on equipment replacement.

Notice of new or changed discharges: The final permit requires notice to the public of any significant change in the volume or character of pollutants introduced into the MWRA system by any source, where that change may cause the MWRA's discharge to cause or contribute to an exceedance of water quality standards.

Increased flexibility: Some commenters (including both the MWRA and environmental groups) suggested that the draft permit's approach in two areas--pollution prevention and water conservation--did not allow the MWRA enough operational flexibility to optimize the effectiveness of these programs.

EPA and DEP have revised the pollution prevention section of the permit to allow the MWRA greater flexibility in developing a program to achieve the stringent requirements of the permit. The draft permit required that the MWRA's pollution prevention program include a number of specified elements, unless the MWRA obtained the agreement of EPA and DEP that the purpose of each specific element could be achieved through another means. The final permit continues to require that the MWRA obtain EPA and DEP's approval for the plan as a whole, but does not require approval for changes to each specific element-this change is intended to allow greater flexibility in designing an effective program.

The water conservation section of the permit has been revised to replace a set of individual requirements (percentage reduction in unaccounted-for water; meter calibration; etc.) with a more global performance requirement-continued reductions in wastewater volume per capita over the life of the permit. While the final plan must be approved by EPA and DEP, the MWRA is free to choose whatever operational methods it believes will be most effective in achieving this requirement. (The permit does include a list of potential methods which the MWRA must consider as it develops a comprehensive water conservation plan.)

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