Vol. 5 No. 1 Summer 1997
A Newsletter About New Jersey's Water Quality Programs

Graphic created from a photo by Stanley V. Cach, Jr.

Combined Sewer Overflow Program Update

Combined sewer overflow (CSO) discharges have long been recognized as a significant source of water pollution. While much has been accomplished over the past 20 years in the area of wastewater treatment, CSOs continue to be a major environmental concern in several areas of the state. With a permitting strategy in place and the help of funding programs, the Division of Water Quality hopes to make significant environmental gains by upgrading or reducing the current number of CSOs.

Why Are CSOs A Problem?

Combined sewers are designed to carry sanitary sewage at all times and stormwater collected from streets and other sources, thus serving a combined purpose. However, when it rains, combined sewer systems may not have the capacity to carry all of the stormwater and sanitary sewage, causing an overflow into the nearest water body. These untreated overflows, which contain pathogens (disease causing organisms), floatable debris, toxic metals, settleable solids, toxic organic chemicals, nutrients, and organic contaminants, degrade water quality and adversely impact aquatic animals, plants, and human health in certain situations. In the New Jersey/New York Harbor Estuary complex alone, CSOs contribute 89% of the pathogenic indicator organisms.

There are approximately 280 individual CSO discharge points in 24 communities located in 8 counties. These discharge points are in older, urban areas along tidal portions of the Delaware River in Camden, Gloucester, and Mercer counties, along the tidal portion of the Raritan River in the City of New Brunswick, and throughout the New Jersey/New York harbor complex. The discharges impact 25 waterbodies in 10 watersheds (see tables below).

Watersheds Impacted by CSOs
Hudson River	Rahway River
Passaic River	Delaware River
Second River	Arthur Kill
Hackensack River	Raritan River
Elizabeth River	Elizabeth Channel

Waterbodies Impacted by CSOs
Newark Bay
Upper New York Bay
Raritan Bay
Atlantic Coastal Waters
Delaware Bay

There are a number of mandates in place to help New Jersey address CSOs, including:

• New Jersey Sewage Infrastructure Improvement Act of 1988 (SIIA) This law identified CSOs as a major source of ocean and other surface water pollution contributing to the degradation of the coastal waters of the state. It directed municipalities operating combined sewer systems to institute abatement measures required by the state. It also authorized the DEP to create a grant fund for the planning and design of municipal CSO abatement facilities.
• National CSO Control Policy of 1994 This policy was issued by the Environmental Protection Agency to coordinate the planning, selection, design, and implementation of CSO management practices and controls to meet the requirements of the Clean Water Act. The policy has three objectives:
  1. To ensure if CSOs occur, they are only as a result of wet weather;
  2. To bring all wet weather CSO discharge points into compliance with the technology and water quality-based requirements of the Clean Water Act; and
  3. To minimize water quality, aquatic biota, and human health impacts from CSOs.

In 1990, the EPA approved the DEP's CSO permitting strategy. To date, all CSO points have been permitted either through an individual permit (7 issued to 10 permittees and 36 CSO Points) or a general permit (19 individual authorizations issued for 244 CSO Points).

All permits contain a performance based limitation for the control of the discharge of solid/floatable materials. A half inch spaced bar rack standard was established to substantially reduce the materials discharged into waterways and to assure capture of needles or other dangerous medical wastes prior to discharge. Permits also require the implementation of other technology-based limits to minimize the impact of CSOs. These limitations are based on the National CSO Control Policy's Nine Minimum Control Measures which are:

• Proper operation and regular maintenance programs for sewer systems and CSO Points,
• Maximum use of collection systems for storage,
• Review and modification of pretreatment requirements to assure CSO impacts are minimized,
• Maximization of flow conveyed to treatment plants,
• Prohibition of dry weather flows,
• Control of solids and floatable materials in CSOs;
• Pollution Prevention;
• Public notification to ensure that the public receives adequate notification of CSO occurrences and CSO impacts; and
• Monitoring to effectively characterize CSO Impacts and the efficacy of CSO controls.

The Governors of New York and New Jersey recently approved a plan for the NY/NJ Harbor Estuary and New York Bight which will protect the water quality, living resources, and habitat of the harbor and bight area. Known as the Comprehensive Conservation and Management Plan (CCMP), the plan was developed through a partnership comprising various government agencies and a diverse coalition of hundreds of citizen volunteers.

At present, planning studies for the control of Solids/Floatables in CSOs and the elimination of Dry Weather Overflows have been completed or are being prepared for 90% of the CSO Points in New Jersey, while design studies have either been completed or are being prepared for only 10% of the CSO Points.

• Long-Term Control Plans need to be developed and implemented. These plans require the monitoring and modeling of Combined Sewer Systems to characterize the frequency, duration and nature of CSO discharges. Affected receiving waterbodies must also be monitored and modeled to characterize the influences of the CSOs, and other sources of pollution, during wet weather. An assessment will then be made to determine what actions, if any, are necessary to bring the receiving waterbodies into compliance with State Water Quality Standards.
• The DEP needs to provide the water quality monitoring and modeling expertise needed to help develop and implement inter-jurisdictional agreements between municipalities for Long-Term Control Planning.
• SIIA funding initiatives should continue so as to complete all outstanding CSO planning and design projects.
• State financial assistance should continue to be applied to CSO projects needed to control Solid/Floatable discharges and to eliminate Dry Weather Overflows.

While there is still much to be accomplished, the Division is hopeful a continued CSO improvement effort will lead to substantial advances in water quality in those areas of the state impacted by these facilities. If you have any questions about the CSO program, please contact Stanley V. Cach, P.E., P.P., of the Bureau of Engineering and Construction Permitting - North at (609) 292-6894 or Gautam R. Patel, Acting Chief, Bureau of Engineering and Construction Permitting - South, at (609) 984-6840