Linden Combined Cycle Plant Reclaimed Water Reuse System, NJ, USA

In August 2002 PSEG Power, the energy producing subsidiary of Public Service Enterprise Group (PSEG) awarded USFilter a US$1.2 million contract for a system to filter reclaimed water for reuse in the cooling towers at its Linden Combined Cycle Plant in New Jersey.

LOCATION

Linden's central location in New Jersey puts it within close proximity to the entire Tri-State area, including Manhattan, Brooklyn, Queens, Staten Island, Monsey, Lakewood and Teaneck.

Linden lies two miles from the Goethals Bridge, providing easy and quick links to Staten Island and Brooklyn from New Jersey.

REUSE OF RECLAIMED WATER

The reclaimed water, which is treated effluent from local municipal wastewater treatment plants, will be reused at the Linden Combined Cycle Plant instead of being discharged into local receiving streams.

USFilter is supplying Hydro-Clear pulsed bed sand filters to treat an average flow of 4,200 gallons per minute of reclaimed water from the Linden-Roselle Sewerage Authority wastewater treatment plant. The filtration system, supplied by USFilter's Zimpro Products, Rothschild, Wisconsin, will consist of seven cells in concrete tanks and will be located on the sewerage authority property.

After filtration, the reclaimed water will be pumped approximately one mile to the Linden power station. It will be treated further to prevent scaling and foaming and then made available for two ten-cell mechanical draft-cooling towers.

The beneficial reuse of reclaimed water reduces the power station's dependence on potable water while assuring a reliable, continuous source.

The factors that are driving the need to reuse reclaimed water include the cost of potable water, closeness of the source and the New Jersey Department of Environmental Protection guidelines for beneficial reuse of reclaimed water.

Those guidelines explain that the importance of Reclaimed Water for Beneficial Reuse (RWBR) programmes came to light during the drought of 1999, when the New Jersey state experienced firsthand the importance of protecting and conserving potable water supplies.

RWBR programmes involve taking what was once considered waste, giving it a high degree of treatment and using the resulting high-quality reclaimed water for new beneficial uses.

PSEG POWER

PSEG Power uses reclaimed water for cooling and other power station needs. The company has been using Hydro-Clear filters for more than six years for a similar application at its Bergen power station.

PSEG Power is one of the USA's largest independent power producers with approximately 16,000MW of electric generating capacity in operation or construction.

HYDRO-CLEAR FILTER

The Hydro-Clear filter features an under drain system and a shallow bed (10in deep) of single-media, fine-grained sand. Designed for filtration of solids from wastewater treatment plant effluent, the Hydro-Clear sand filter is a gravity filter that incorporates a shallow bed design and the ability to periodically 'pulse' the bed during the filter cycle, in order to increase the overall length of the filter runs.