Virginia Coastal Program: 2003 Coastal Grant Project Description and Final Summary
Project Task:
FY2003 Task 6
Grantee:
Virginia Department of Environmental Quality - Chesapeake Bay Program
Project Title:
Water Quality Improvement Fund - Match; Project - Prince William County
Project Description as Proposed:
In 1995, the treatment
scheme was upgraded from lagoon to incorporate a new anoxic/oxic
reactor; thus creating a multi-celled activated sludge reactor basin.
The jet aeration system was also replaced w/ floating aerators.
Under the scope of work needed to further expand the existing 4.0
MGD plant (described above) to a 5.4 MGD year round nutrient reduction
(NRT) facility, additional treatment volume is needed for the WWTP
process. Under the proposal submitted for NRT cost-share, the WWTP
will be expanded from 4.0 MGD to 5.4 MGD and will include the additional
volume needed for denitrification (total nitrogen reduction). The
proposed installation includes an additional, earthen reactor basin
with surface aeration, secondary clarification, and new IRS &
RAS pumping facilities. Since the WQIF grant was signed, other treatment
options to improve water quality have been considered, such as the
Biolac Process or pumping this sewage to the County’s other
WWTP at Massaponax. Whichever option is selected and under design
flows, the project should result in an annual reduction of 131,575
pounds of total nitrogen being discharged to the watershed.
Other items to be installed but not eligible for the BNR cost-share
include: new headworks, effluent filtration and disinfection, prior
to its final discharge to the Rappahannock River.
Federal Funding:
$1,122,839 in MATCH FUNDING
Project Contact:
Robert Ehrhart, 804.698.4466, rwehrhart@deq.virginia.gov
Project Status:
Grant Closed
Final Product Received:
Project Summary Provided by Grantee:
The purpose of this project was to upgrade the existing 18 MGD activated sludge process to meet the revised Potomac Embayment Policy effluent limits and to retrofit the system with BNR (using both influent BOD and methanol addition as carbon source). The project included BNR pilot plant to confirm design criteria and performance, effluent filters (50% for denitrification), methanol facilities, aeration basin modifications, modification to the RAS & WAS pumping structure, an additional secondary clarifier, and modifications to grit facilities.
Phase I - Aeration Basins, Methanol Facility, Final Filters, Operations Support Facility, Equalization Basin #3:
The project is complete.
Phase II Preaeration/Odor Facility: The project is complete.
Phase III Aeration Basin, Clarifier and Sludge Pumping Station: The project is complete.
Prior to constructing the project, in 1999 the total nitrogen discharged to tidal waters from the project was about 540,700 pounds. Subsequent to completing the project in 2005, the total nitrogen discharged to tidal waters from the project was 210,900 pounds, which demonstrates a drastic reduction in nutrients and positive benefit to water quality.
Disclaimer: This project summary provides the federal dollars initially awarded to the grantee. Due to underexpenditure or reprogramming of grant funds, this figure may change. For more information on the allocation of coastal grant funds, please contact Laura McKay, Virginia Coastal Program Manager, at 804.698.4323 or email: Laura.McKay@deq.virginia.gov
A more detailed Scope of Work for this project is available. Please direct your request for a copy to Virginia.Witmer@deq.virginia.gov
