Energy Resource Recovery Facility
The I-95 Energy Resource Recovery Facility in Fairfax County is privately owned and operated by Covanta Fairfax, Inc., a subsidiary of Covanta Energy. Under contract to Fairfax County, the facility is located adjacent to the I-95 Landfill Complex. The Energy Resource Recovery Facility is one of the largest waste-to-energy facilities in the country. The facility has been in operation since 1990.
Municipal solid waste serves as the fuel for the facility. Steam is produced that turns turbines that can generate over 80MW of electricity. The facility can process not only municipal solid waste, but also such waste items as confidential documents, infested nursery plant materials, old currency and other items that need assured destruction.
The facility is heavily regulated, subject to continuous emissions monitoring, and required to report any exceedance of emission limits to the issuing authority or Virginia Department of Environmental Quality. The Solid Waste Management Program oversees operation of the I-95 Energy Resource Recovery Facility and is responsible for providing a minimum of 930,750 tons of waste to the facility annually (a commitment referred to as the Guaranteed Annual Tonnage). The initial term of this agreement ended in 2011, with a 5-year extension until 2016.
Renewable Electricity Production:
By producing electricity using solid waste, the facility avoids both the cost and emissions of using a fossil fuel to produce the electricity. Since 1990, energy production by the plant has replaced the equivalent of approximately two million barrels of crude oil per year.
How Waste Is Processed:
The following is a diagram of the energy recovery process, highlighting the emissions control system.
- Combustion controls reduce carbon monoxide (CO), dioxins and hydrocarbons.
- Ammonia is injected to control nitrogen oxides (NOx).
- Semi-dry scrubbers inject lime to control acid gases.
- Carbon is introduced to control mercury.
- Fabric filter baghouses control particulate matter and metals.
- Continuous emissions monitoring system continually checks emissions and alerts if there are exceedances.
Solid waste enters the facility from collection vehicles that dump their waste on the tip floor. The waste is picked up by cranes and deposited in the four chutes and onto reciprocating grates that move the waste into the combustors. The waste is tumbled and burned as fuel, heating the boilers where steam is produced. The steam travels through pipes to the turbines that generate the electricity.
Ash, gas and other products of burning continue through the facility, where reagents such as lime, ammonia and carbon are introduced to condition the ash by-product and clean the exhaust gases. The gases pass through the baghouses (a collection of large fabric filters), where particulate matter is filtered. The cleaned gases are emitted through the stack. The ash is cooled then deposited onto conveyors and transported to the ash building to await further processing that removes ferrous and nonferrous metals.
Ash from the Fairfax facility is nonhazardous and is disposed in the ash monofill of the I-95 Landfill Complex.
Key stack emissions are continuously monitored for permit compliance. Exhaust gas from the facility is also tested annually to ensure that emissions do not exceed permit limits. Similarly, ash produced during the combustion process is tested periodically for metals content, pH and other factors. Finally, recovered water from the steam generating process is recycled many times before it is treated and discharged into the sewer system.
As indicated by the demanding set of permit limits and testing protocols imposed by federal and state law, the plant is subject to rigorous scrutiny by environmental protection agencies. As a result, Covanta commits significant resources to reducing its impact on the environment
Overall Emissions Reductions from Energy Resource Recovery Facility resulting from the Clean Air Act retrofit in 2000:
98.3 percent removal of sulfur dioxide
95.5 percent removal of hydrochloric acid
98.6 percent removal of mercury
- 45 percent reduction in nitrogen oxides
Solid Waste Management Plan Strategies:
Through the development of the county's Solid Waste Management Plan, a 20-year plan for how the county will effectively manage the waste it generates, the Board of Supervisors approved the strategy of continuing to use the E/RRF beyond the end of the current service agreement.
Incineration Is Cool For The Climate:
The Intergovernmental Panel of Climate Change (IPCC), EPA, and the Commonwealth of Virginia all recognize that waste incineration with energy recovery is a key mitigation technology that reduces greenhouse gases caused by processing of municipal solid waste.
The E/RRF makes some significant and specific contributions to Fairfax County's efforts to remain a "cool county:"
- Manages Fairfax County trash right here in our community, reducing the need for fossil fuels to transport our waste to downstate landfills.
- Handles Fairfax County waste disposal now, rather than creating a new waste management legacy for the next generation.
- Eliminates methane gas and other greenhouse gases on a ton for ton basis.
- Generates approximately 670 kilowatts of electricity for every ton of trash burned, using a renewable fuel source.
- Recycles enough metal annually to build over 20,000 automobiles.
Facts and Statistics:
Occupies 23 acres at the I-95 Landfill Complex.
Includes four industrial boilers that can burn over 3,000 tons per day of municipal solid waste (about 1.1 million tons per year) depending on the moisture content of the waste.
Uses a controlled combustion process that burns waste at a temperature of 1,800 degrees Fahrenheit.
Reduces waste by up to 90 percent in volume, leaving an ash poduct that is landfilled.
Reduces waste by 75 percent in weight during processing.
Produces enough electricity to power 75,000 homes.
Avoids the equivalent of approximately one million tons of greenhouse gas emissions each year, through avoided landfill emissions and by generating renewable energy.
The facility uses some of the energy it generates (approximately eight Megawatts) for its operation. The remainder is sold to Dominion Virginia Power.
The facility recovers the energy from municipal solid waste originating in Fairfax County, the District of Columbia, and other local jurisdictions.
Ferrous and nonferrous metals in the waste stream are also recovered as part of the resource recovery process.