On the International Space Station, wastewater is recycled and astronauts drink the clean fluid that emerges at the end of the process. It is a toilet-to-tap cycle.
In Virginia, "used" water is re-introduced to the drinking water system typically only after the water has flowed down a river for some distance, or infiltrated/injected into groundwater in an Aquifer Storage and Recharge (ASR) process.
Only indirect reuse is permitted for reclaimed wastewater in Virginia. Direct reuse, involving a pipeline providing a direct link between the outfall of a wastewater treatment plant and the intake pipe of a drinking water facility, has been implemented in Big Spring, Texas and other places where water resources are limited.1
The technology is readily available to recycle water in Virginia, just as in Texas and on the International Space Station, but no community has faced a water supply shortage that was serious enough to overcome the public's attitude (the "yuck" factor) regarding direct reuse.
Three types of water are candidates for reuse, as defined by the Virginia Department of Environmental Quality (DEQ):2
For years, wastewater was considered to be just a waste product, saturated with unhealthy microorganisms and other pollutants, rather than as a potential resource. Since 2008, however, Virginia has permitted re-use of wastewater for industrial processes, air conditioning systems, irrigation, and other uses that do not involve direct human contact. Wastewater utilities can recycle water, rather than discharge it directly to "receiving waters."
In some cases, reusing the water reduces pollutants that otherwise would flow into the Chesapeake Bay. In other cases, the heat energy in treated wastewater is used to reduce heating/cooling costs.
For an industrial user or golf course, re-use allows a company to purchase lower-cost water that still meets their requirements, rather than purchase more-expensive water treated to drinking water standards. For the wastewater utility, re-use allows expansion of a treatment plant to handle more volume from more customers - while still discharging less than the nitrogen/phosphorous limits in the facility's Virginia Pollution Discharge Elimination System (VPDES) permit. Drinking water utilities lose customers when potable water is replaced by reclaimed water, but that source increases reliability of adequate water supplies in the utility's long range planning.
In 1976-77, the Virginia Department of Transportation (VDOT) tested re-use of wastewater at a rest area on I-81 near Fairfield. Blue dye was added to the treated water, and it was then used to flush toilets. 95% of water used at the rest area was recyvcled, while potable water was still required for sinks and drinking fountains. Perhaps even more appropriately, Loudoun County's Broad Run Water Reclamation Facility recycles wastewater to flush the toilets, sending the water in a perpetual cycle through that facility.3
The first industrial water reuse project in Virginia was a pilot project by the Hampton Roads Sanitation District (HRSD), implemented in 2002 before the statewide regulations were changed. The HRSD York River Treatment Plant was located next to a oil refinery owned by Amoco near Yorktown. The wastewater treatment plant built a short pipeline underneath a creek and pumped 500,000 gallons a day of treated wastewater to the refinery for use in its operations.
The refinery purchased reclaimed water at 50% of the cost of drinking water. The utility benefitted, because evaporation of the reclaimed water at the refinery into the atmosphere reduced the amount of nitrogen the utility discharged into the Chesapeake Bay. However, the refinery closed in 2010 after Giant Industries purchased it from Amoco, and HRSD lost its customer for reclaimed water. The utility spent $3 million, some borrowed in a 20-year loan from the Virginia Water Facilities Revolving Fund, to upgrade the York River Treatment Plant so the reclaimed water would meet industrial specifications - but then the refinery shut down only 9 years into the contract.4
green lines show pipes delivering treated wastewater to oil refinery north of the York River Waste Treatment Plant (WTP) and to outfall on York River
Source: Hampton Roads Sanitation District, Public GIS Viewer
Another plant in the Hampton Roads Sanitary District, the Virginia Initiative Plant (VIP) at Lamberts Point in Norfolk, has targeted potential re-use for irrigation at an adjacent 9-hole public golf course. Additional irrigation pipes were installed at the golf course, which was constructed on top of a closed municipal landfill, allowing use of treated wastewater for irrigation. The Keswick Club near Charlottesville uses wastewater from its own facilities for irrigating its golf course, providing a steady supplemental supply in case of drought. In Northern Virginia, the Laurel Hill Golf Course is irrigated with treated wastewater from the Noman Cole Wastewater Treatment Plant.5
The military has partnered with HRSD to take advantage of the steady temperature of wastewater discharged from the utility's Atlantic Treatment Plant in Virginia Beach. Since 2008, the Naval Air Station (NAS) Oceana - Dam Neck Naval Annex has run 14 million gallons/day of wastewater though a heat exchanger, reducing the annual heating/cooling costs at the military base. The wastewater was already passing through the base to its discharge point in the Atlantic Ocean. A private company funded and installed the new heat exchange system under a $33 million Energy Savings Performance Contract, and the military expects to reduce energy costs by more than that amount over the 17-year contract.6
In Fairfax County, the Norman Cole Wastewater Treatment Plant on Route 1 in Lorton partnered with the Covanta Fairfax Inc. Resource Recovery Plant waste-to-energy plant on Route 123. The arrangement allows the Noman Cole plant to increase the volume of wastewater it can process, without increasing the amount of nitrogen that it discharges into Pohick Creek.7
In Fauquier County, the Old Dominion Electric Cooperative uses wastewater from the Fauquier County Water and Sanitation Authority's Gordonsville Wastewater Treatment Plant to cool the Marsh Run gas-fired power plant. The wastewater evaporates, reducing the quantity of nitrogen and phosphorous for which the utility must obtain a permit to discharge into the Rappahannock River.
In Loudoun County, Green Energy Partners/Stonewall made a similar arangement for cooling the gas-fired 750-megawatt power plant near Leesburg. The town committed all of the town's wastewater for industrial reuse at that site:8
The power plant will build a new pipeline (the "Purple Line") to transport wastewater to the power plant, potentially eliminating all of the town's wastewater discharge (and all nutrients...) to the Potomac River. Leesburg faced an unusual problem - could it generate sufficient wastewater to meet the requirements for the power plant? The town normally produced 4 million gallons/day, though the wastewater treatment plant had sufficient capacity to process 7.5 million gallons/day. The power plant will build a 5 million gallon storage tank, as a reserve.
If needed, Leesburg could purchase potable water from Loudoun Water. Loudoun Water would prefer to sell wastewater from its Broad Run Water Reclamation Facility, but the Stonewall power plant location is too far away.9
purple pipes will distribute treated wastewater from Broad Run Water Reclamation Facility (BRWRF) in Loudoun County to customers north of Dulles airport
Source: Loudoun Water, Reclaimed Water System Map
The Broad Run Water Reclamation Facility in Loudoun County, which started operations in 2008, was designed to support a network of purple pipes that distribute reclaimed water for irrigation, chilling data centers, and other purposes permitted by the Virginia Department of Environmental Quality. That facility handles wastewater from a rapidly urbanizing area near Dulles airport.
When Dulles Airport was built in 1961, the Federal government installed a sewer line connecting the airport (and much of then-rural eastern Loudoun County) to the wastewater treatment plant at Blue Plains. By 2000, it was clear that rapidly-growing Loudoun County would need a new sewage treatment plant, because the county was close to exceeding the capacity allocated to it at the Blue Plains facility.
The Broad Run Water Reclamation Facility uses a different process for stripping waste out of wastewater, immersed membrane technology together with advanced biological nutrient removal, use of granular activated carbon and ultraviolet light disinfection. The end result is clean wastewater intended to be used as a resource, rather than treated as waste dumped into Broad Run.
The Loudoun County Sanitation Authority will distribute treated wastewater in four miles of brightly-colored purple pipes for reuse at the One Loudoun World Trade Center development, the National Rural Utilities Cooperative Finance Corporation building, and to other customers as the area develops - especially data centers needing water for cooling information technology equipment. Use of recycled water helps buildings earn status as "green," according to LEED (Leadership in Environmental and Energy Design) criteria.10