Severn Trent Services Selected to Provide Tertiary Nitrification to U.K. Utility


FORT WASHINGTON, Pa. - March 20, 2007 - Severn Trent Services have been awarded three separate contracts to provide TETRAT Nitrifying Submerged Aerated Filter (NSAF) technology to Thames Water Utilities, the United Kingdom's largest water and wastewater treatment company, which is based in Reading, England.

The NSAF systems will be installed at existing facilities at Waddesdon, Culworth and Byfield and will provide "add on" tertiary nitrification to enable Thames Water Utilities to consistently meet ammonia standards.

These are the first TETRA NSAF units to be installed within Thames Water and all are due to be installed and in operation by the spring of 2007. The units are of a modular design and have been designed to handle peak flows ranging from 345 to 2,784m3/day.

The TETRA NSAF is an up-flow, fixed film, biological reactor and can be supplied in GRP, steel or concrete variants. The NSAF has proven to be robust and is simple to control, maintain and operate. Its effectiveness in ammonia removal has been demonstrated at numerous installations throughout the United Kingdom over the past 10 years.

About Severn Trent Services
Severn Trent Services (www.severntrentservices.com), based in Fort Washington, Pa., is a leading supplier of water and wastewater treatment solutions. The company's broad range of products and services is concentrated around disinfection, instrumentation and filtration technologies, contract operating services and state-of-the-art residential metering products and services. Our analytical services group is the United Kingdom's leading environmental testing organization, and our international management services business provides support in all aspects of water and wastewater utility operational development and business transformation. Severn Trent Services is a member of the Severn Trent Plc (London: SVT.L) group of companies. Severn Trent is a FTSE 100 company.

Contact:
Lori Doppelt
215-997-3727
ldoppelt@severntrentservices.com

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