Water Pollution Control Plant Upgrade
Q1. What is the Water Pollution Control Plant (WPCP)?
A1. The WPCP is a facility that treats 30 million gallons of wastewater daily from Arlington County residences and businesses. Approximately 20 percent of our flow comes from neighboring communities including, Alexandria, Fairfax, and Falls Church. It is the mission of the WPCP to safely and economically process wastewater and hazardous waste materials for a healthy environment for all to live.
Q2. Why is there construction happening at the Water WPCP?
A2. A number of significant improvements are being made to the WPCP as part of the Master Plan 2001 Update, which was developed to outline the continuation of the capital improvement plan.
Improvements being made to the plant and the wastewater treatment process include:
- Modernization of an aging infrastructure,
- Expansion to better manage capacity issues,
- Additional odor control facilities, and
- Compliance with new regulations in the liquid treatment areas.
Q3. How does this renovation benefit Arlington County in the long run? How will it benefit residents?
A3. The County’s renovated facility will provide better treatment that will:
- Treat 40 million gallons per day and accommodate high flows during wet weather,
- Discharge cleaner water to Four Mile Run, the Potomac River, and the Chesapeake Bay,
- Generate fewer odors, and
- Bring the County into compliance with new regulatory requirements.
Q4. Why is construction taking place now?
A4. The WPCP had been treating volumes that exceed 95 percent of its rated capacity for many years. Virginia Department of Environmental Quality (VA DEQ) requires treatment facilities to either consistently operate below 95 percent of capacity or construct more facilities.
Additionally, stricter nitrogen limits have been added to the regulatory requirements for facilities that discharge into the Chesapeake Bay and other Virginia tributaries. The new waste load allocations require treatment plants to meet a total nitrogen limit of 3 mg/l. Arlington has been operating near 8 mg/l.
Arlington County must also meet the requirements of a consent order issued by VA DEQ to minimize partially treated external bypasses.
Q5. How long will construction last? When will the project be completed?
A5. The project is slated for completion in 2013/14.
Q6. What is causing the noise during construction?
A6. While a variety of equipment and construction work now underway is generating noise, the diesel pile driving is causing the largest magnitude of intermittent noise. The two main sources of noise from diesel pile driving are the impact of the hammer on the pile and vibrations from the pile into the air when it is struck.
Efforts being made to abate noise include:
- Use of impact cushion (A hairpin is being fabricated to improve probability of success).
- Installation of noise absorbing blankets in the aeration tank excavation to reduce the noise that is reflected to the community. Additional blankets are anticipated to be installed by the end of June 2007.
- Testing of dampening devices on the piles to reduce pile vibration noise generation.
- Placement of shrouds/blankets on the pile driving rigs.
- Successful tests on individual pile driving rigs will result in application to the remaining pile driving rigs.
Q7. What is causing the odor during construction?
A7. The plant’s permit nitrogen limits require the treatment facility to keep solids longer than normal in its biological treatment process which creates foam on the surface. If the sludge foam gets too thick or old, odors are generated. Also, during construction shut downs of various facilities are required to allow for the contractors to make tie-ins, work on various lines and install equipment. Shut downs tend to upset the biomass and generate significantly more foam. The facility does not currently have the necessary equipment to allow for the removal of surface foam from the aeration tanks and three of the secondary clarifiers.
Q8. What times of day is construction allowed?
A8. Construction is restricted to the hours of 7:00 am to 7:00 pm, Monday-Friday, with the exception of County holidays. Additional working hours are approved when necessary to allow for construction activity such as jack and bore, concrete pours, and other low-noise work. Pile driving has not been approved for any hours outside of the base construction hours (7:00 am to 7:00 pm Monday-Friday).
Q9. When did the Arlington County Board approve the project?
A9. A Master Plan team was formed in 2001 to evaluate the impact of upcoming regulations and to develop a plan for major capital improvements at the plant. The proposed improvements were approved by the Board in January 2003 to meet current and future capacity demands in the most environmentally appropriate manner. The construction projects were approved by the County Board on July 8, 2006.
Q10. How much will the improvements to the WPCP cost?
A10. Projected total cost estimate is $568 million.
The long-term financing strategy for the Master Plan 2001 Update is to fund it via the Virginia Department of Environmental Quality wastewater revolving loan fund (RLF). The RLF offers the lowest possible interest rate and debt issuance costs. Interest rates vary from a no-interest loan (considered where financial conditions warrant and where at least 75 percent of the project cost is applicable to resolving mandated water quality problems) to the ceiling rate of 1 percent below the current market for the Commonwealth of Virginia’s twenty year double-A rated revenue bond at the time of closing. The project also received a grant from the Department of Environmental Quality Water Quality Improvement Fund for the construction of Enhanced Nutrient Reduction facilities in the amount of $96 million.
The loan will be repaid over the next 20 years from increases in the water/sewer rate. Rate increases are projected to range from 10%-15% per year for several years for funding all County Utilities Fund projects and operating expenses. Rates are expected to remain lower than the average sewer rate in the DC metro region.
Q11. Who do I contact with concerns or questions about this project?
A11. Contact Scheryl Price at (703) 599-1549.