Coal, Emissions

AES gets new filtration system for its Granite Ridge plant’s cooling tower

STURBRIDGE, Mass., March 4, 2002 — AES is getting a new filtration system for the cooling tower at its Granite Ridge electricity generating plant, in Londonderry, N.H.

USFilter is providing AES Granite Ridge’s 720-megawatt natural gas-fired power station in Londonderry, N.H., with cooling tower, boiler feedwater, and demineralization systems. USFilter’s ACTIFLOC® system, a clarification and filtration water treatment system, will be used to pre-treat makeup water for the power station’s state-of-the-art plume-abated cooling tower.

To minimize the demand on local drinking water supplies, treated effluent from the city of Manchester’s wastewater treatment facility (WWTF) is piped to the power station. Using USFilter’s ACTIFLOC system for the removal of suspended solids and turbidity, AES is recycling 4 million gallons of water per day (mgd) from the Manchester WWTF for cooling purposes.

At the AES facility, the water receives further treatment, including filtration and clarification. The water is then pumped to the cooling tower where 75 percent (approximately 3-mgd) of the water evaporates and is emitted as water vapor. The remaining 1-mgd is returned to the Manchester WWTF through a 3-mile sewer line, where it mixes with other water, is treated and is then released into the Merrimack River.

USFilter’s pre-engineered ACTIFLOC system incorporates USFilter’s proven microsand enhanced clarification process and multi-media filtration. This compact package plant is economical to install and operate, and ensures high finished water quality. Self-contained and easy-to-install, the ACTIFLOC system will capably address the power station’s need for quick startup and space restrictions.

AES’s contractor for the Granite Ridge Station project is Dick Corp. of Pittsburgh, Penn. According to Hal Miller, project manager of Dick Corp., USFilter was selected because of its cutting-edge technology, competitive price, and the promised speed of installation.

Says Miller, “The ACTIFLOC system’s versatility in dealing with changing concentrations of suspended solids set USFilter apart from the competition.”

USFilter’s water treatment installation is expected to be up and running in March 2002. Services include systems startup, operator training, and performance guarantee. The AES Granite Ridge Station will be fully operational this summer.

AES is a global power company with competitive generation, distribution, and retail supply businesses in more than 19 countries.

USFilter, a Vivendi Environnement company, provides comprehensive water and wastewater systems and services to commercial, industrial, municipal and residential customers. Vivendi Environnement (NYSE:VE), comprised of Vivendi Water (worldwide water products and services), Onyx (solid waste and industrial services), Dalkia (energy management), and Connex (transportation and logistics), is the largest environmental services company in the world with more than 215,000 employees about 100 countries and annual revenues of nearly $25 billion. Visit the company’s web sites at www.usfilter.com or www.vivendienvironnement-finance.com.