Virginia Department of Environmental Quality - Chesapeake Bay Program
Water Quality Improvement Fund Match (Town of Cape Charles Wastewater Treatment Plant Nutrient Removal Upgrade)
Project Description as Proposed:
The existing Cape Charles Wastewater Treatment Plant (WWTP) has a permitted design flow of 0.25 million gallons per day (MGD) and achieves secondary treatment using a contact stabilization package plant followed by an effluent polishing pond and ultraviolet disinfection.
Under Water Quality Improvement Fund (WQIF) Agreement #440-S-09-15 the Town is installing nutrient reduction technology (NRT) for nitrogen and phosphorus removal in a new 0.25 MGD facility. The upgraded facility will reduce the nitrogen load by about 6,000 lbs/yr and the phosphorus load by about 900 lbs/yr at full design flow. This retrofit will be a significant contributor to the overall nutrient reduction efforts in Virginia’s Chesapeake Bay watershed under the recently adopted EPA Total Maximum Daily Load for the Bay. More information about DEQ’s WQIF grant program is accessible at: http://www.deq.virginia.gov/bay/wqif.html.
Four nutrient removal options were evaluated for the project, and based on the factors of reliability, constructability, operational impact, and capital and annual cost comparisons, the selected alternative for the new 0.25 MGD WWTP is a membrane bioreactor (MBR) system operated as a 4-stage Bardenpho process. Processes being installed, and their WQIF grant eligibility as NRT, are described as follows.
Preliminary Treatment (not grant eligible): Headworks, Emergency Overflow Tank and Pumping.
Biological Treatment (grant eligible) and Solids Separation Processes (partially grant eligible):
· Fine Screens.
· Two Bioreactors, with zones dedicated to pre-anoxic, aerobic, and post-anoxic treatment. Integral mixed liquor and nitrate recycles are also provided.
· Two Membrane Tanks with support equipment housed in a Process Building; each train containing three membrane cassettes for a total of six cassettes. Each tank is provided with permeate pumps that draw a vacuum across the membranes, with reverse operation providing back-pulse cleaning. The membranes eliminate the need for secondary clarifiers and effluent filters.
Chemical Addition (grant eligible):
· Supplemental Carbon Feed System for denitrification; designed to accommodate multiple non-hazardous supplemental carbon sources (e.g., sugar water, glycerin, etc.).
· Alum Feed System for phosphorus removal.
Post Treatment (not grant eligible): UV Disinfection, Post-Aeration, Effluent Flowmeter, and Outfall Extension.
Solids Processing (partially grant eligible): Building and Waste Sludge Holding Tanks.
Miscellaneous: (partially grant eligible)
· Operations Building.
· Plant Water System.
· Plant Recycle System.
· Yard Piping, General Site Work and Electrical Costs.
Match to Virginia CZM Program grant from NOAA Only - $898,443
John Kennedy, 804.698.4312; John.Kennedy@deq.virginia.gov
10/1/2011 - 9/30/2012
Final Product Received:
Final Project Summary serves as Final Product.
Project Summary Provided by Grantee:
This project (WQIF Agreement #440-S-09-15; $7,960,630 grant) involves the replacement of the Town of Cape Charles’ existing 0.25 MGD wastewater treatment plant. The new facility includes enhanced nutrient reduction technology (NRT). The selected NRT used in the new facility is a membrane bioreactor (MBR) system operated as a 4-stage Bardenpho process. $967,099.15 of this WQIF grant was used as state match for Virginia’s Coastal Zone Management Program in Grant Year 2011.
The Cape Charles WWTP is located in the Eastern Shore Basin. As a “significant discharger”, this plant must comply with total nitrogen and total phosphorus waste load allocations as required in two State Regulations: (1) Water Quality Management Planning Regulation (9 VAC 25-720); (2) Chesapeake Bay Watershed General Permit Regulation (9 VAC 25-820). The construction of the new Cape Charles’ wastewater treatment plant with enhanced nutrient removal technology began in October, 2010. A Certificate to Operate was issued on February 29, 2012. DEQ reviewed the discharge performance of the facility from March through September 2012 The results of this review for Cape Charles WWTP are shown below:
· Average total phosphorus (TP) concentration = 0.37 mg/l (the value associated with their waste load allocation is 0.30 mg/l)
· Average total nitrogen (TN) concentration = 3.51 mg/l (the value associated with their waste load allocation is 4.0 mg/l)
It is anticipated that the facility will consistently meet the permit requirements now that it has gone through the challenges normally associated with start up of a new facility with new technology.
To-date, $7,403,663 of the $7,960,630 Water Quality Improvement Fund (WQIF) grant has been paid to the Town. In the period covering Oct. 1, 2011 - Sep. 30, 2012, nine WQIF grant reimbursements totaling $967,099 were made to the City for this project, which exceeds the $901,578 in State General Funds needed to provide a match for the Coastal Zone Management Program.
Additional information regarding this project can be found on our website:
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