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Prince William County Service Authority

Prince William County Service Authority

H.L. Mooney AWWTP Information

CUSTOMER SERVICE Home Start New Service Login to Pay Bill Customer Service FAQ Understanding Your Bill Automatic Bill Payment Sign up to Pay Bill Online Service Problems Past Due Account Discontinue Service Change of Address User Rates Availability, Inspection and Other Fees Consumer Confidence Reports For Engineers ABOUT US About Us News and Media The Pipeline video newsletter Community Outreach Programs Board of Directors Officials Board Meeting Schedule Careers Customer Responsibilites Get to Know Your Water Comprehensive Annual Financial Report Planning, Business and Development Hydrant Meter Program Procurement Sitemap MORE LINKS Our Environment RFP and IFB Announcements Privacy		H.L. Mooney AWWTP Information The H. L. Mooney Water Reclamation Facility Construction of the Facility was completed in 1979 under the United States Environmental Protection Agency’s (USEPA) Clean Water Act Grant Program with a hydraulic capacity of 12.0 million gallons per day (MGD). The facility was named for Mr. H. L. Mooney, the former Administrator of the Occoquan-Woodbridge-Dumfries-Triangle Sanitary District (OWDTSD). The Facility was expanded in 1987 to a treatment capacity of 18 MGD. Influent and Treatment Influent to the H. L. Mooney Water Reclamation Facility (WRF) comes from the eastern half of Prince William County, serving more than 35,000 residences and businesses. The H. L. Mooney WRF is operated 24-hours a day, 365 days a year and utilizes a conventional activated sludge process in conjunction with advanced (tertiary) treatment, including chemical addition and filtration. Prior to discharging effluent into the Neabsco Creek, the water is irradiated with ultra violet light for disinfection and then oxygenated. The waste byproducts of the process—settled and digested biosolids—are dewatered using high-speed centrifuges and then incinerated within a fluidized bed incinerator. The inert ash from this process is disposed of at the County Landfill. The facility produces a high quality effluent consistently averaging biochemical oxygen demand (BOD) and suspended solids discharges of under 3 mg/l. This represents a 99 percent reduction of pollutants in wastewater received by the Facility. Annually, the Mooney facility removes approximately 140 tons per year of phosphorous and 730 tons per year of nitrogen from the water before it is discharged into Neabsco Creek, a Potomac River tributary. Activated Sludge Conventional activated sludge is a highly stable and reliable microbiological process. In the activated sludge process, concentrated micro-organisms suspended within the oxygenated wastewater break down the proteins, carbohydrates, oils and fats contained in the sewage. Ferric chloride and polymers are added to the system to remove phosphorus and enhance the settling process. Excess biosolids are removed from the process and dewatered in high-speed centrifuges and then incinerated, resulting in a fine powdered ash. Nitrification Presently, the H. L. Mooney WRF staff operates the activated sludge process in a nitrification/denitrification (BNR) mode. The BNR mode is a fairly new advancement to activated sludge wherein the ammonia that is naturally inherent in wastewater is broken down into nitrates and nitrites. In denitrification, the nitrates and nitrites are stripped of their oxygen content by bacteria operating in a very low-oxygen (anoxic) environment. Nitrogen gas is released into the atmosphere. This reduction of ammonia and nitrogen helps to minimize algae growth by eliminating a key nutrient: nitrogen. Lime is added for pH control. Phosphorous The H. L. Mooney WRF consistently reduces the level of phosphorous in its effluent from an average of 7.5 mg/l to 0.1 mg/l. Removal of phosphorous further reduces the likelihood of algal growth in Neabsco Creek and the Potomac River. Why is algae growth a concern? Nitrogen and phosphorous are nutrients that encourage the growth of aquatic algae. Although some algae are desirable, a problem is encountered when algae grow out of proportion to the normal balance of the aquatic ecosystem. Algae are a natural and critical part of the Potomac River and Chesapeake Bay ecosystems. Algae, like land plants, capture the sun’s energy and support the food web that benefits fish and shellfish. They occur in sizes ranging from tiny microscopic cells floating in the water column (phytoplankton) to large mats of visible macroalgae that grow on bottom sediments. Algae may become harmful if they occur in unnaturally-high abundance or if they produce a toxin. A high abundance of algae can block sunlight to underwater grasses. They may also consume too much oxygen in the water, leading to fish kills, surface scum and odors that interfere with the feeding of shellfish and other organisms which filter water to obtain their food. Some algal species can also produce chemicals that are toxic to humans and aquatic life. Fortunately, of the more than 700 species of algae in the Chesapeake Bay, less than two percent of them are believed to have the ability to produce toxic substances. Preparing for the Future, Protecting our Environment The Service Authority completed a $42 million first phase of an upgrade to the H. L. Mooney WRF in efforts to help safeguard the Chesapeake Bay. The second phase, estimated at $150 million, is scheduled to begin in the spring 2007. It will expand the Facility’s capacity to 24 MGD to accommodate growth in the County as well as a higher level of nitrogen removal. Construction is scheduled for completion in 2010, and is expected to contribute significantly to the health of the Chesapeake Bay. Visit the Facility Tours of the Mooney facility are available for professionals, other adults and youth groups. The H. L. Mooney WRF is located at 1851 Rippon Boulevard, Woodbridge, Virginia 22191. To arrange an age-appropriate tour, please call Keenan Howell, Communications Director, at (703) 335-8937 or email HYPERLINK "mailto:khowell@pwcsa.org" khowell@pwcsa.org.		ENVIRONMENTAL STEWARDSHIP Drinking Water and Water Reclamation Consumer Confidence Reports Going Green Chesapeake Bay Watershed Conservation Tips Only Tap Water Delivers For Kids and Teachers Decrease the Grease! Conservation House Before You Put it Down the Drain Leak Detection Espanol RELATED LINKS Environmental Protection Agency (EPA) American Water Works Association (AWWA) Water Environment Federation (WEF) Miss Utility Metropolitan Washington Council of Goverments Global Water Sanitations and Health International Water and Sanitation Centre Thames Water–World Water (This site contains links to web sites owned by third parties. These links are provided solely as a convenience to you and are not an endorsement by PWCSA of the contents on those other sites. PWCSA is not responsible for the content of any linked sites and makes no representations regarding the content or accuracy of materials on such sites. If you decide to visit any third-party sites using links from this site, you do so at your own risk.)

The H. L. Mooney Water Reclamation Facility

Construction of the Facility was completed in 1979 under the United States Environmental Protection Agency’s (USEPA) Clean Water Act Grant Program with a hydraulic capacity of 12.0 million gallons per day (MGD). The facility was named for Mr. H. L. Mooney, the former Administrator of the Occoquan-Woodbridge-Dumfries-Triangle Sanitary District (OWDTSD). The Facility was expanded in 1987 to a treatment capacity of 18 MGD.

Influent and Treatment
Influent to the H. L. Mooney Water Reclamation Facility (WRF) comes from the eastern half of Prince William County, serving more than 35,000 residences and businesses.

The H. L. Mooney WRF is operated 24-hours a day, 365 days a year and utilizes a conventional activated sludge process in conjunction with advanced (tertiary) treatment, including chemical addition and filtration. Prior to discharging effluent into the Neabsco Creek, the water is irradiated with ultra violet light for disinfection and then oxygenated. The waste byproducts of the process—settled and digested biosolids—are dewatered using high-speed centrifuges and then incinerated within a fluidized bed incinerator. The inert ash from this process is disposed of at the County Landfill. The facility produces a high quality effluent consistently averaging biochemical oxygen demand (BOD) and suspended solids discharges of under 3 mg/l. This represents a 99 percent reduction of pollutants in wastewater received by the Facility. Annually, the Mooney facility removes approximately 140 tons per year of phosphorous and 730 tons per year of nitrogen from the water before it is discharged into Neabsco Creek, a Potomac River tributary.

Activated Sludge
Conventional activated sludge is a highly stable and reliable microbiological process. In the activated sludge process, concentrated micro-organisms suspended within the oxygenated wastewater break down the proteins, carbohydrates, oils and fats contained in the sewage. Ferric chloride and polymers are added to the system to remove phosphorus and enhance the settling process. Excess biosolids are removed from the process and dewatered in high-speed centrifuges and then incinerated, resulting in a fine powdered ash.

Nitrification
Presently, the H. L. Mooney WRF staff operates the activated sludge process in a nitrification/denitrification (BNR) mode. The BNR mode is a fairly new advancement to activated sludge wherein the ammonia that is naturally inherent in wastewater is broken down into nitrates and nitrites. In denitrification, the nitrates and nitrites are stripped of their oxygen content by bacteria operating in a very low-oxygen (anoxic) environment. Nitrogen gas is released into the atmosphere. This reduction of ammonia and nitrogen helps to minimize algae growth by eliminating a key nutrient: nitrogen. Lime is added for pH control.

Phosphorous
The H. L. Mooney WRF consistently reduces the level of phosphorous in its effluent from an average of 7.5 mg/l to 0.1 mg/l. Removal of phosphorous further reduces the likelihood of algal growth in Neabsco Creek and the Potomac River.

Why is algae growth a concern?
Nitrogen and phosphorous are nutrients that encourage the growth of aquatic algae. Although some algae are desirable, a problem is encountered when algae grow out of proportion to the normal balance of the aquatic ecosystem. Algae are a natural and critical part of the Potomac River and Chesapeake Bay ecosystems. Algae, like land plants, capture the sun’s energy and support the food web that benefits fish and shellfish. They occur in sizes ranging from tiny microscopic cells floating in the water column (phytoplankton) to large mats of visible macroalgae that grow on bottom sediments. Algae may become harmful if they occur in unnaturally-high abundance or if they produce a toxin. A high abundance of algae can block sunlight to underwater grasses. They may also consume too much oxygen in the water, leading to fish kills, surface scum and odors that interfere with the feeding of shellfish and other organisms which filter water to obtain their food. Some algal species can also produce chemicals that are toxic to humans and aquatic life. Fortunately, of the more than 700 species of algae in the Chesapeake Bay, less than two percent of them are believed to have the ability to produce toxic substances.

Preparing for the Future, Protecting our Environment
The Service Authority completed a $42 million first phase of an upgrade to the H. L. Mooney WRF in efforts to help safeguard the Chesapeake Bay. The second phase, estimated at $150 million, is scheduled to begin in the spring 2007. It will expand the Facility’s capacity to 24 MGD to accommodate growth in the County as well as a higher level of nitrogen removal. Construction is scheduled for completion in 2010, and is expected to contribute significantly to the health of the Chesapeake Bay.

Visit the Facility

Tours of the Mooney facility are available for professionals, other adults and youth groups. The H. L. Mooney WRF is located at 1851 Rippon Boulevard, Woodbridge, Virginia 22191. To arrange an age-appropriate tour, please call Keenan Howell, Communications Director, at (703) 335-8937 or email HYPERLINK "mailto:khowell@pwcsa.org" khowell@pwcsa.org.

Metropolitan Washington Council of Goverments

Global Water Sanitations and Health

International Water and Sanitation Centre

Thames Water–World Water

(This site contains links to web sites owned by third parties. These links are provided solely as a convenience to you and are not an endorsement by PWCSA of the contents on those other sites. PWCSA is not responsible for the content of any linked sites and makes no representations regarding the content or accuracy of materials on such sites. If you decide to visit any third-party sites using links from this site, you do so at your own risk.)