VA Department of Environmental Quality-Clean Water Financing and Assistance Program (WQIF)
Water Quality Improvement Fund (WQIF) Match- City of Richmond Wastewater Treatment Plant Nutrient Removal Upgrade
Project Description as Proposed:
The City of Richmond owns and operates a Wastewater Treatment Plant (WWTP) with an existing dry weather flow (DWF) design capacity of 45 million gallons per day (MGD). The City also operates a Combined Sewer System (CSS) consisting of sewers that carry sanitary sewage and storm water runoff in a single pipe. The City’s individual VPDES permit requires the WWTP to treat wet weather flows of at least 75 MGD until all CSS storage facilities are emptied. The existing WWTP liquid processes includes preliminary treatment, primary clarification, biological activated sludge process, secondary clarification, deep bed/gravity effluent filtration, disinfection and dechlorination prior to discharge to the James River. Solids handling processes include separate thickening of primary and waste activated solids, digestion, and dewatering prior to land application.
The City’s preliminary engineering report identifies improvements, which will be implemented in five construction contracts. The improvements, respective to each contract, are described as follows.
Total Phosphorus Control: Chemical storage and new feed pumps will be installed to dose ferric chloride in the primary and secondary sedimentation tanks.
Methanol Feed and Storage: The existing filters will be upgraded to denitrification filters, which includes methanol storage tanks, chemical metering pumps, and controls.
Filter Upgrades: The existing filters will be upgraded to reliably remove particulate phosphorus and nitrogen to meet the new permit limitations of the general permit.
UV Disinfection: The existing chlorination facilities will be replaced with UV disinfection.
Main Plant Incoming 13.2 kV Switchgear: The existing switchgear and portions of the electrical distribution system will be replaced. Based on present concerns for electrical safety, the new switchgear will be installed within a building instead of an outdoor walk-in enclosure.
Scum Control Upgrades: The existing primary sedimentation tanks will be upgraded with new troughs and electrically actuated gates to improve control of scum in the activated sludge process. Scum will be conveyed to a new scum concentrator building.
Aeration Upgrades: The aeration tanks will be upgraded and improved to operate as a Step Feed process. Improvements to the aeration tanks include new internal mixed liquor recycle pumps and baffles, as well as an upgrade of gates and the fine bubble diffuser system.
Return Activated Sludge (RAS) Capacity Upgrades: RAS pumping will be increased from an existing capacity of 45 MGD to about 60 MGD; thereby, reducing the solids carryover to the effluent filters during wet-weather flows.
Bioaugmentation Upgrades: The existing sludge holding tanks will be upgraded to accommodate the bioaugmentation process and facilitate restarting the activated sludge system and shorten the period to recover nitrification.
Final Sedimentation Tanks: Two new sedimentation tanks (nominal capacity of 90 MGD) are proposed to improve the solid capture efficiency and reduce the solids loading to the effluent filters.
Fermentation: One existing digester will be converted to a fermentation reactor to produce volatile fatty acids (VFA) from primary sludge. The VFA will be returned to the anoxic zone to improve the efficiency of the denitrification in the aeration tanks and lessen the dependency on methanol. The upgrades include odor control, transfer pumps, and electrical/instrumentation
No Federal Funding; Match Only: $894,051
Walter Gills; 804.698.4133, firstname.lastname@example.org
10/1/2012 - 9/30/2013; Project Open
Final Product Received:
Project Summary Provided by Grantee:
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