The Rappahannock County Water and Sewer Authority (RCSWA), based in Sperryville, is looking for engineering expertise to help analyze and correct a frequent problem — infiltration of groundwater into the sewer system. Water from outside the system seeps into the pipes and is carried into the regular treatment system.
“It’s a fairly common problem,” said RCWSA chair Alex Sharp in a phone call Wednesday, “that can stress a system during a large rain event.”
Although the Sperryville plant’s capacity is 55,000 gallons per day (gpd), the normal flow is about 20,000 gpd, said Sharp. But with a large rain event, the flow rate can exceed 100,000 gpd.
“This has been an issue since the treatment plant was built in the 1980s,” said Sharp. In the late 1990s a 30,000 gallon equalization tank was installed to help with flow surges. But the real solution is to find out where the infiltration is coming from and stopping the leakage.
The RCSWA pumps wastewater from septic systems in the Sperryville system and treats it at the plant off Route 522. The most likely source of the leakage, said Sharp, is in the pipes that run from residences or businesses into the individual septic tanks. Roots can grow into the pipes, creating cracks and allowing water to seep in.
“That’s what we suspect is happening,” he said, “but we won’t know until we have an engineering firm do an evaluation.”
The authority hopes to qualify for funding under a U.S. Department of Agriculture Special Evaluation Assistance for Rural Communities and Households (SEARCH) grant.
“The program helps small, financially distressed rural communities with feasibility studies, design and technical assistance on proposed water and wastewater disposal projects,” according to the program webpage.
“The application itself is basically complete,” said Sharp. “But we need to select an engineering firm before we can apply.” The authority hopes to make a selection at its next meeting on April 12.
Sharp stresses that the system is sound and that the infiltration problem is not posing a health or other risk to the public. Finding and mitigating the problem “will make it easier to treat waste properly,” he said, “and make the system better.”