Hydro International Supplying Reg-U-Flo Vortex Valves to Wastewater Utility in Racine, Wisconsin

Valves Being Installed as Part of Project Designed to Alleviate Basement Flooding

The utility is in the process of installing the valves, along with a new sewer bypass, on the northwest side of the city. The bypass diverts flow from the Virginia Street interceptor sewer to the Ohio Street storage interceptor sewer during periods of heavy rain. Prime contractor Reesman's Excavating & Grading, Inc. began construction in late 2008. The project is expected to be completed in the second half of 2009.

The two Reg-U-Flo Vortex Valves - one 11.3 inches in diameter, the other 5.9 inches - were recommended by engineering firm AECOM's Milwaukee, Wis., office, which had deployed Hydro International's valves in several other area communities.

Racine has reported several basement flooding incidents over the years, occurring during significant rainfall events, in the sewer area resulting from infiltration and inflow into the city's sewers. When the flow requirements exceed the available capacity, the sewer can surcharge, leading to flooded basements in low-lying areas.  The additional complication with the Virginia Street interceptor sewer is that there is no local sewer within this block so the sanitary laterals are directly connected to the interceptor sewer, meaning that any surcharging of the interceptor sewer provides an immediate basement backup response.

The wastewater utility plans to use the Reg-U-Flo Vortex Valves to restrict the flows that enter the Virginia Street interceptor sewer and provide a relief to the Ohio Street storage interceptor sewer. The flows are recombined downstream of Virginia Street, within Lockwood Park, where surcharging is acceptable.

Two valves are included in this project, one on the upstream end to restrict excessive flows from entering the Virginia Street interceptor sewer and the other on the downstream end of the Ohio Street storage interceptor sewer to restrict flow to the interceptor sewer and thereby provide storage.

The valves accomplish this through simple fluid hydraulics that requires no power to operate and have no moving parts. Designed with a snail or conical shape, high flows initiate a vortex within the valve that restricts the flow of water that can pass through the device while maintaining large clear openings compared to conventional flow control methods. When head pressure builds, water circulates in a vortex pattern, allowing an air core to form within the device to prevent surging of water to the conveyance system. The unique head / discharge relationship for the devices also result in a greater level of protection from flooding for any given storm over other more conventional methods of flow control. The entire system functions via gravity flow with minimal moving parts, thereby reducing operation and maintenance concerns.

"The valves were put to the test on April 26, 2009, when we received 3.1 inches of rain in a short amount of time," said Keith Haas, General Manager for the Racine Wastewater Utility. "Residents on Virginia Street received no backups while other historic locations in the City were hit again. I am sold on the technology and its proven performance."

"The Hydro Reg-U-Flo Vortex Valve has proved itself over time as an efficient, cost-effective solution for flow control needs, with more than 17,000 installations worldwide," said Neil Raymond who heads up Hydro's CSO/WetWeather team. "We are happy to be participating in this forward-looking project to benefit the citizens of Racine, Wisconsin."

About Hydro International

Hydro International plc is a global supplier of environmentally sustainable products and innovative solutions that control and treat stormwater, wastewater and combined sewer overflows, utilizing award-winning advanced vortex and complementary technologies. Hydro International's US Wastewater operation, based in Hillsboro, Oregon, is the leading provider of municipal grit removal solutions and CSO/wet weather management products to control flows within collection systems and wastewater treatment plants. Hydro International also has US Stormwater operations based in Portland, Maine and has international offices in Dublin, Ireland, and Clevedon and Ely in the U.K.  The company is a public company listed on the London Stock Exchange (AIM market ticker: HYD).

About AECOM

AECOM (NYSE: ACM) is a global provider of professional technical and management support services to a broad range of markets, including transportation, facilities, environmental and energy. With 43,000 employees around the world, AECOM is a leader in all of the key markets that it serves. AECOM provides a blend of global reach, local knowledge, innovation, and technical excellence in delivering solutions that enhance and sustain the world's built, natural and social environments. AECOM serves clients in more than 100 countries and had revenue of $5.6 billion during the 12-month period ended December 31, 2008. More information on AECOM and its services can be found at http://www.aecom.com.

About Reesman's Excavating & Grading, Inc.

A family-orientated company, Reesman Excavating and Grading, Inc. takes pride in its long-standing traditions. Its history of solid service and quality-driven results is driven by employees that are the pride of the industry. Experience allows Reesman's to get the job done to specification, in an efficient manner, while making sure that safety is the number one priority. Continual investment toward the future, for example with GPS technology, helps Reesman's remain one of the leaders of the pack when compared to the competition.