David Tyrrell, Berryville’s Director of Utilities, says that he has always loved chemistry and that fondness is reflected in his eyes when Tyrell starts talking about the processes going on deep within the Town’s sewage treatment plant tanks. What sets Tyrell apart from many other technical experts is that he understands the ins-and-outs of things like “anaerobic versus aerobic” and “polymer de-waterfication” so well that even non-techies can understand his explanations.
Given his love for science, especially the chemical magic behind extracting clean water from raw sewage sludge, it probably felt like Christmas morning and getting the biggest chemistry set in the world when Tyrell took over the construction and management of Berryville’s $28M sewage treatment plant two years ago.
During a tour on Wednesday Tyrell demonstrated his encyclopedic knowledge of how the new plant will convert 300K gallons of daily raw sewage to almost-drinkable water in just 24 hours rather that the current plant’s 45-day process.
“The new plant uses activated sludge that concentrates the bacterial process” Tyrell explained to Berryville mayor Wilson Kirby, council member David Tollett (Ward Four) and town manager Keith Dalton who travelled to the sewage plant construction site to see how things were progressing. “Not only is the new process faster than the existing process, the final output includes less solids, nutrients and has a lower oxygen demand.”
Tyrell said that part of the magic can be found in the high-tech fiber filtration that provides the final step in separating water from potentially dangerous pathogens. Tyrell said that the filters contain thousands of miles of hollow membrane tubing that prevents anything larger than one micron from passing through. Because the membranes are the last step in the filtration process there is no physical way for untreated water to reach the outfall line.
Each of the four membrane filtration panels used in the plant costs $125K and is expected to last ten to twelve years.
Tyrell says that the four-stage sewage treatment process produces not only clean water that will improve the quality of the Shenandoah River and the Chesapeake Bay, but also Class “B” bio-solids, a safe agricultural fertilizer source because there are no industrial heavy metal sources in Berryville.
While construction of the new treatment plant is expensive – $10.5M of the cost was covered by a grant from the Virginia Department of Environmental Quality with the remainder paid by Berryville taxpayers – the upgrade is long overdue.
Tyrell said that the existing waste water outfall line, replaced by a new line late last year, is 110 years old and that the lab facility for the existing treatment plant was built in 1958. The new facility’s state-of-the-art technology and processing capability can handle as much as 4.5M gallons of sewage a day if necessary.
Construction work on the plant is being managed by Caldwell and Santmyer Inc. of Berryville, Virginia.
Even though the end result of the new sewage treatment plan will be cleaner water and a healthier Chesapeake Bay, the price tag for the project is significant for a small town like Berryville.
“This is the most expensive project that the Town of Berryville has ever done and the benefits will last for a long time” said Mayor Kirby. “It’s amazing how effective the technical process is. Even so, there’s a lot of other things that we’d rather be spending the tax dollars on. I guess this is a necessary evil.”
Tyrell says that he expects the new plant to begin processing sewage later this summer.
Take a tour of Berryville’s new sewage treatment plant here: