July 16, 2009

TJ Finseth

ERG

14555 Avion Parkway, Suite 200

Chantilly, VA 20151

Reference : Covanta Fairfax, Inc.

EPA/ERG Tour on 7/21/2009

Dear Mr. Finseth,

I am the Environmental Compliance Specialist for Covanta Fairfax, Inc and will be assisting you in 

providing information about the facility as it relates to wastewater discharge. I have included a description on 

the following pages of the facility operation and will be available to answer any questions that you have prior 

to your visit next Tuesday. Due to the recent installation of the Reverse Osmosis (RO), some of the current

water information may need clarification with our Chief Engineer, Michael Blackwelder.

Plant Description

Covanta Fairfax is located on an approximately 23-acre site within the boundaries of the I-95 Landfill. The 

area is approximately 1.75 miles from US Highway 1 on Furnace Road in the vicinity of Lorton, Virginia 

and approximately 25 miles southwest of Washington D.C. Covanta Fairfax owns and operates the I-95 

Energy/Resource Recovery Facility (I-95 E/RRF) under an agreement with Fairfax County, Virginia. The I95 E/RRF is a nominal 3000-ton per day refuse-fired electric generating facility. The I-95 E/RRF has 

operated continuously since it began commercial operation in June 1990. The facility consists of four 

nominal 750 TPD refuse-fired boilers and two 63.8-megawatt turbine generators, along with ancillary 

equipment. The facility processes 3000 TPD of municipal solid waste for a population of more than 900,000 

in the Washington, D.C. suburbs of Fairfax County. Air pollution control equipment consists of spray dryer 

absorbers for acid gas reduction, fabric filter baghouses for particulate removal, a carbon injection system for 

mercury control and a selective non-catalytic reduction system for reduction of nitrogen oxides. The heat 

energy produced during the combustion of municipal solid waste is converted into electricity that is sold to 

Virginia Dominion Power Company.

Waste is delivered to the facility via refuse trucks. The refuse trucks enter the facility through a controlled 

access gate and proceed to a weigh station. The weigh station determines the total tonnage of waste 

delivered and, when applicable, the total amount of unacceptable waste rejected. Once through the weigh 

station, the trucks proceed to the tipping bays located within the enclosed tipping hall to deposit the waste in 

the refuse pit, or temporarily onto the tipping floor. Several loads a day are dumped onto the tipping floor, in 

order to allow the loads to be inspected for unacceptable waste. Unacceptable waste is deposited into a large 

drop box inside the tipping hall. The rejected waste is subsequently transported to an appropriate disposal 

site. All acceptable waste is pushed into the refuse pit using a front-end loader. Waste from the refuse pit is 

mixed, stockpiled and deposited into the furnace feed hoppers by overhead cranes. The refuse pit and tipping 

hall are maintained at a slightly negative pressure by the combustion air fans (forced draft fans) that draw air 

from the building. This design feature provides effective odor control. Waste accepted at the facility is 

primarily municipal solid waste, which includes household, commercial and institutional waste.

Waste is continuously fed into the combustion units from the feed hoppers through refractory-lined feed 

chutes. The combustion units are integrated reciprocating grate stokers and top supported, single pass, 

membrane waterwall boilers equipped with superheaters and economizers. A sophisticated combustion 

controls package maintains optimal combustion efficiency minimizing the formation of combustion-
dependent pollutants. Design (nominal) steaming rate for each combustor is 205,625 lbs/hr. Natural gas, 

used as auxiliary fuel in the boilers during start-up and shutdown, is received by pipeline.

The combustion air is divided into underfire and overfire air. The underfire air is heated in a steam coil then 

evenly distributed below the stoker grate before entering the combustion zone. Underfire air cools the grates, 

aids in the suspension of the waste for combustion, and provides combustion air. Overfire air, which is added 

above the stoker grate at the front and rear walls of the combustor, assures complete combustion of volatile 

off-gases.

The combined high-pressure superheated steam generated by the four combustion units is piped to either of 

two turbine generators. Total energy generation capacity at rated combustion rates is 80 MW. Plant load is 

approximately 10 MW. The balance of the electricity generated is sold to Virginia Dominion Power 

Company.

The combined bottom ash and fly ash is conveyed away from the waste combustors and fabric filters 

(baghouses) by a series of different conveyors. All conveyors are either located within buildings or are 

otherwise enclosed. The ash is combined in the proprietary Martin Ash Discharger and is conditioned with 

water as both a cooling agent and as a dust suppression agent. The combination of these two design/work 

practices effectively limits fugitive dust generation. Dewatering of the ash is accomplished by gravity, by the 

squeezing action of an ash extractor ram and by a vibrating pan. Oversize material (>10 inches) is removed 

from the ash stream by a grizzly scalper in a separate outbuilding. The remaining ash is sent through a series 

of sizing screens in the residual ash building. Appropriately sized ash is further processed through a nonferrous metal processing unit (the non-ferrous system, which was not operational for a period, is currently 

being brought back into service) to remove valuable non-ferrous metals for recycling. Ferrous metal is 

separated from the ash stream, as well. Recovered ferrous and non-ferrous material is/will be removed from 

the site by truck. Ash residue is loaded into covered trucks for removal to the I-95 Landfill operated by 

Fairfax County.

Much of the air pollution control equipment is located adjacent to the boiler building to the south. This 

equipment includes the four spray dryer absorbers, four baghouses, associated screw conveyers which 

convey collected fly ash back into the boiler building to the ash discharges, a carbon storage silo, two pebble 

lime storage silos, lime slurry tanks, quench reactors and associated equipment. The continuous emissions

monitoring system (CEMS) shelter is also located in this area. The dolomitic lime silo that stores lime for ash 

conditioning is also located in this area. Activities in this area include deliveries of pebble lime, carbon and 

dolomitic lime to the storage silos, and maintenance of the carbon system, lime system, baghouses and fly 

ash screw conveyors.

Pebble lime, carbon and dolomitic lime are pneumatically conveyed from delivery trucks to the appropriate 

storage silos. Conveying air is vented through a fabric filter (baghouse) mounted on the top each storage 

silo. Collected dust discharges back into the storage silo. Pebble lime is typically delivered eighteen times 

per month. Carbon is delivered one to two times per month. Dolomitic lime deliveries are received four times 

a week.

The 19% aqueous ammonia storage tank (used to store ammonia for the NOX control system) is located to 

the west of the boiler building inside secondary containment. Ammonia is delivered five times a week.

Note: Covanta Fairfax has recently installed a Reverse Osmosis System that eliminates much of the 

following information in this paragraph referencing a demineralizer. We are presenting this information 

to illustrate the ongoing improvements in internal water management at the facility. Covanta Fairfax has a 

demineralizer treatment system for boiler feed water. The demineralizer system and the sulfuric acid and 

sodium hydroxide (caustic) storage tanks associated with its use are located inside the demineralizer building 

on the first floor along the west wall. The tanks are located inside concrete containment areas. From the 

secondary containment any spilled material would be pumped into the neutralization tank. Treated effluent 

from the neutralization tank is regulated pursuant to SIU Wastewater Discharge Permit #A51109 and is 
discharged to the Norman M. Cole POTW. The fill ports for the acid and caustic tanks are located outside 

along the west wall of the demineralizer building within secondary containment.

Exhaust steam from the turbine is condensed to water. The water used to condense the steam is pumped to 

the facility’s cooling towers, which are located along the south roadway opposite the APC area. The chlorine 

generator used to treat the cooling water is located inside the chlorine generator building, which is adjacent 

to the cooling towers to the east. The tanks for sulfuric acid and biocide used to treat the cooling water are 

located inside the demineralizer building.

Excess water and ash from cleaning and maintenance activities drains into floor trenches located in the boiler 

building and in the APC area. These floor trenches drain into sumps and subsequently to the two settling 

basins located in the APC area. Solids settle to the bottom of the settling basins. Water is pumped from the 

settling basins to the ash discharges to provide quench water for the ash residue. Ash and sediment from the 

trenches and the settling basin is disposed of either with the combined ash residue or with the refuse in the 

main storage pit.

Process wastewater from the facility consists of boiler blowdown, cooling tower blowdown, neutralization 

tank batch discharges and sanitary sewage from facility buildings. These wastewaters, along with effluent 

from the Fairfax County Landfill, are pumped from a lift station located to the east of the administration 

building to the POTW.

Water Permits

• SIU Waste Water Discharge (Norman M. Cole POTW - Fairfax County).

• VPDES Direct Discharge Non-Contact Cooling Tower Water (Inactive as project is on hold).

• VPDES General Industrial Storm Water Management (Includes required SWPPP).

Other Environmental Permits

• PSD / Air

• Title V / Air

• Solid Waste

Please contact Scott Drew if you have any questions. Looking forward to meeting you on Tuesday.

Regards,

Joseph Herrmann

Environmental Compliance Specialist
Facility Aerial View
Facility Site Plan
Water Source and Use

Average quantity of water received and wastewater discharged daily:

Basic System

(Prior to RO installation)

Parshall flume.

1800 ft3/13500 gal

Pump vault.

4320 ft3/32,400 gal

Lift Station Pumps. 

3’” solids sewage pump. 

480V,25A,3P,60hz,20hp

450GPM at 75’head

Manholes

Neut Tank

Basket

Turb 

bldg 

sump.

Sanitary

Fairfax County

Landfill 

POTW

Piping vault

720 ft3/5400 gal

Cooling Tower

Blowdown