In Virginia, Loudoun Water (formerly the Loudoun County Sanitation Authority) approves all specifications and plans for community-based systems in new developments. The developers then deed the systems to Loudoun Water to own and operate. The agency relies heavily on natural wastewater treatment, such as septic tanks, drip irrigation, and recirculating sand filters, which are shown here. Photos: Loudoun Water
The wastewater treatment building at a subdivision in Aldie, Va., is served by a community wastewater system that disperses effluent in a low-pressure distribution system. About half of the effluent is lost to evapo-transpiration from both the grass and the soil. The other half recharges the groundwater approximately half a mile from the closest well. The wastewater treatment system consists of dual-train extended aeration package plants within a building, followed by a deep bed denitrification filter and a low-pressure distribution in aerobic drainfields.
“When package plants came out in the 1980s, people didn't know how to operate them, and they got a bad rap,” Danielson says. It didn't matter to most communities, because the EPA was offering grant money to help fund the expansion of centralized wastewater systems. Now that that funding is no longer available, and suburban sprawl is at a crossroads, “people are starting to look at lower-cost alternatives.”FINANCIAL ASSURANCES ARE KEY
In 1998, after a land transfer with the state, the town of Newtown in Connecticut spent $100,000 to install a community-based system servicing six houses.
Public Works Director Fred Hurley thinks it was a smart move. “The septic systems were failing, but it just wasn't commercially feasible to bring those houses onto the centralized system,” he says. Homeowners pay a quarterly assessment to the town's Water and Sewer Authority to offset the costs of operations and maintenance.
That system, along with a $200,000 system consisting of two duplex grinder pumps that feed into the centralized system from a 60-unit trailer park, are operated by United Water/Suez, which also operates and maintains the town's main wastewater treatment plant.
Hurley acknowledges that the town learned from the legal battle in nearby Brookfield. In Newtown developers must provide financial assurance in the event of a system failure, a sort of escrow account that guarantees funding for repairs.
The Water and Sewer Authority also oversees a maintenance fund supported by condominium association fees at a privately maintained community system for a 60-unit condominium development that was installed privately in the late 1990s. The fund is tapped whenever maintenance is required.
“The town conducted a full engineering analysis of the soils, examined the design of the system, and ensured there would be adequate funding reserves deposited annually to maintain it and provide for replacement of the system,” Hurley explains. “It lowered the town's exposure to virtually zero.”
Requiring financial assurance from developers is still largely new territory, says Grose, who explains that the goal is to have the benefitting property owners pay for the upgrade to a community-based decentralized system, “or the city brings in sewers and levees benefit assessments like it would with any sewer user.”
To convince the public and elected officials that a decentralized system should be part of the overall waste-water-treatment mix, Danielson advocates what he calls “triple bottom line accounting.”
“Look at the numbers, but also look at the impact on the environment and the impact on society,” he explains. “Put a dollar value on how you're affecting the environment and society. For example, what's going to be the cost on the neighborhood of ripping up the streets to put in a new sewer line? With major infrastructure improvements, you're working on a 20-year cycle, you're carrying all that additional cost to operate and maintain these idle facilities in some manner until you build them out.”
Decentralized systems should be evaluated alongside other treatment options, says Jeff Moeller, senior program director for the Water Environment Research Foundation.
“Decentralized systems are no longer a stopgap for outlying areas,” he says. “And centralized systems are no longer a one-size-fits-all solution.”