Rivanna Water & Sewer Authority is upgrading its Moores Creek Wastewater Treatment Plant (WWTP), which serves the City of Charlottesville, the urban areas of Albemarle County, and Crozet. This upgrade will be the most comprehensive revisions to the WWTP since the early 1980s. Rivanna Water & Sewer is upgrading this facility for several different, yet equally important, reasons:
Reduction of Nutrients
RWSA is required by the Virginia Department of Environmental Quality (DEQ) to meet new wasteload allocations for total nitrogen and phosphorus by 2011. Under the law RWSA has the choice to meet these allocations either by upgrading the Moores Creek WWTP, or by purchasing nutrient credits from wastewater facilities that treat beyond their allocation. RWSA has chosen to be a regional leader in environmentally responsible nutrient removal technology through a capital upgrade that will meet the allocation in 2011 yet go beyond our regulated allocation when the project is completed in 2012. Treated wastewater contains several nutrients, among them phosphorous and nitrogen, which, in large amounts, can disrupt the natural balance of the bodies of water into which they are released. When combined with other nutrient sources, it can disrupt the natural balance locally (Moores Creek), in downstream areas (the Rivanna and James Rivers), and in its final destination, the Chesapeake Bay. Upgrading the nutrient removal process at the Moores Creek facility will decrease the amount of nutrients being released into Virginia's waterways from this facility.
In upgrading the existing facilities at Moores Creek WWTP, not only will RWSA become a better steward of its environment, but it will be able to benefit other treatment plants throughout the Commonwealth through the nutrient exchange program. Upon completion of the upgrade, RWSA will go beyond its nutrient allocation quota, for which nutrient credits can be received. RWSA is an active member of the Virginia Nutrient Credit Exchange Association, which allows it to "sell" its surplus of nutrient credits to other facilities in Virginia that may not have the funds to upgrade their facilities.
State of the Art Odor Control
One of the naturally occurring characteristics of the treatment of human organic wastes is the odor emanating from it. A large quantity of the odor occurs at the septage receiving facility where septic tank cleaning contractors deliver their tank contents to the Moores Creek facility. A new fully-enclosed septage receiving facility will be constructed, thereby eliminating a majority of the offensive odors currently present at the entrance of the facility, and both the Pump Station and gravity thickeners will also be enclosed. Albemarle County is providing funding for the new septage receiving facility, which will be equipped with an "odor scrubber," a device that creates a vacuum which cleans the odor from the air. Lastly, RWSA will be installing water cannons on the large overflow basins that are already in use, which will facilitate rapid wash-down after wet weather events, further reducing the potential for offensive odors.
Renovating and Refurbishing Equipment
Most of the equipment now in use at the Moores Creek Wastewater Plant is over or nearing thirty years in age. By renovating and refurbishing the existing equipment, and in some areas purchasing new equipment to replace that which has reached its life-span, the Moores Creek facility will become more efficient and reliable in its service to the City and County.
Creation of Renewable Energy
Just as exciting as the reduction of nutrients being released into area waterways is the ability to produce renewable energy, which will enable the Moores Creek facility to partially power itself from the use of methane gas to create electricity. This feature will save the Authority in operating costs, and most importantly, will reduce our carbon footprint.
The digestion of biosolids naturally produces methane gas, which is currently harnessed and used to power compressed air for the aerobic treatment process. In reconfiguring the current methane piping system, the methane will directly power the anaerobic processes instead, which will boost its efficiency and reliability enormously. As an added bonus, any unused methane will be used to generate electricity that will be placed on the plant's power grid, enabling the plant to use less energy from outside sources, which will reduce costs and impacts on our environment even further.
This upgrade is projected to receive an estimated $21.5 million in grants from Virginia's Water Quality Improvement Fund, which will help defray the total construction cost of approximately $40.3 million.
