WTC site damage assessment map, Sept 21, 2001

NYC 9/11 Public Portal Document

Environmental Impacts

Based on per capita usage, water demands for the proposed re-development would generally be consistent with the pre-disaster conditions at the WTC disaster area. Implementation of any of the proposed action alternatives is not expected to increase overall water demand at the WTC. New water lines would be designed to provide water in adequate quantities to provide service to existing populations. No significant impacts to area water supplies are anticipated. The energy required to operate the proposed water supply projects would be provided by the repaired ConEdison network and would not result in a significant demand in the study area.

3.6.3.3 Sanitary Sewer

The New York City’s Department of Environmental Protection (NYCDEP) operates 14 wastewater treatment plants (WWTPs) also known as water pollution control plants in New York City. Throughout most of the City, the sewers are combined, which means that while sanitary sewage normally flows to WWTPs through the combined pipes, during rain events, when stormwater enters the system, the volume is too great to be handled by the plants. The combined sanitary sewage and runoff are discharged to nearby surface waters. However, the DEP limits the volume and the rate of runoff that can be discharged into the combined city sewers and the NYCDEP’s regular maintenance and upgrades to the sewer system combined with decreased stormwater overflow have helped to bring New York’s waters into compliance with the state and federal standards. The CSO system is a potential source of surface water pollution. Sewage from Manhattan is processed at the North River and Newtown Creek Water Pollution Control Plants.

Environmental Impacts

The New York City Administrative Code 15 RCNY 19, Use of Public Sewers, Sections 19-01 through 19-04, establish industrial discharge limits for several toxic substances. These limits are based on federal regulations governing the Industrial Pretreatment Program (IPP), which is locally administered by the NYCDEP. As necessary, during construction and operation, pre-treatment systems would be designed and specified to meet industrial discharge limits as administered by the NYCDEP. Meeting IPP limits would ensure that discharges to the sewer system would not result in an adverse impact on water quality.

Based on NYCDEP limits, the discharge of stormwater from the project is not expected to have an adverse impact on Newtown Creek. In addition, sanitary sewer demands for the proposed re-development would generally be consistent with the pre-disaster conditions at the WTC disaster area. Implementation of any of the proposed action alternatives is not expected to increase sanitary sewer demand in the vicinity of the WTC. New sanitary sewer lines would be designed to provide sanitary wastewater services in the area of damage and line replacement. No significant impacts to area sewage systems are anticipated after construction. The energy required to operate the proposed

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