Outflow Effluent Questions Raised by Planning Commissioners

As unprecedented environmental damage caused by a failed pipeline in the Gulf of Mexico continues to dominate world headlines, Clarke County’s own pipeline project is coming under scrutiny. On Friday, Clarke County Planning Commissioners and a local environmental consultant raised questions about potential ground water pollution caused by future leaks from the new sewage treatment outfall pipeline currently being installed between Berryville’s Parshall Road sewage treatment plant and the Shenandoah River. Town and county staff offered assurances that the outflow line poses little threat to county groundwater but did not guarantee that future leaks were impossible. In the meantime, at least one landowner in the pipeline’s path is holding out for more money before voluntarily agreeing to an easement for the project.

Over the past several weeks commuters in Clarke County have observed construction crews burying lilac-colored pipes along Route 7 east of Berryville. According to David Tyrrell, Director of Utilities for the Town of  Berryville, the pipes will carry water that has been treated and filtered at the Town’s new waste water treatment facility. “The color of the pipe was selected intentionally to signify recycled water rather than drinking water,” Tyrrell said.

Sewage outfall trench to Shenandoah River, Clarke County, Virginia - Photo Edward Leonard

The new outfall pipeline will carry approximately 300,000 gallons of recycled water each day from the Parshall Road facility to a discharge point at the Shenandoah River next to the Route 7 bridge crossing. Tyrrell said that although the discharge will be above the waterline of the Shenandoah River, the actually pipe will be covered by broken stone covering in a receded area of the river bank. “A person passing the area will see nothing more that some wet rocks,” Tyrell said.

Friday’s debate about the wisdom of spanning Clarke County’s karst topology with a pipeline carrying treated wastewater was spurred by a mandatory Planning Commission review of the pipeline’s impact on property owned by Mark and Philip Shenk. According to County officials, the Shenk’s are the only property owners who have failed to voluntarily agree to a compensation offer in exchange for allowing the pipeline to cross their property. After review, the Planning Commission determined that pipeline will have no impact on the continued use of the Shenk property of agricultural purposes and forwarded the finding to the Board of Supervisors for further action.

Given that new outfall line was first proposed by the Town of Berryville in 2008 and is already under construction, the Planning Commission debate over safety concerns was primarily academic.

Several commissioners voiced concerns about the possibility of raw sewage leaking into groundwater from the pipeline. Clarke County’s karst topography, landscape formed by layers of water soluble limestone bedrock, is particularly susceptible to groundwater pollution. If raw sewage were introduced into the County’s karst geology it could quickly contaminate large areas of groundwater.

Sewage outfall line construction materials in Clarke County, Virginia - Photo Edward Leonard

“There is no possible way for raw sewage to enter into the outfall line,” Tyrrell reassured the Commission. “Any water entering the outflow line has to first pass through a .1 micron filter. The water coming out of the outflow line is cleaner than any creek or river in the county. I’d drink it before I would drink any surface water source.”

Chuck Johnston,  Clarke County Planning Administrator, went a step further in his assurance. “I personally guarantee that the outfall line will not carry any sewage.”

Despite staff assurances, several Planning Commissioners remained concerned about potential problems.

Supervisor Pete Dunning (White Post) challenged Tyrrell’s claim. “I’d love to see you or Chuck drink that stuff. That’s just idle talk and you know it.”

Commissioner Bev McKay said, “If the water were that clean it would be put back into the drinking system. Do you have a way to monitor if there is a leak into the groundwater?” Tyrrell confirmed that the pressure gauges at both ends of the pipe will allow treatment plant operators to monitor the 30-35 p.s.i. flow. A drop in pressure would indicate a leak.

Bob Marshall, a private environmental consultant in Berryville, questioned the outflow line’s path to the river during the public comment period. “Groundwater is a county resource,” Marshall told the Commissioners. “I’m concerned that a line carrying wastewater to the Shenandoah River was sited so close to a rock quarry where blasting occurs.”

Tyrrell said that although he is very confident about the outflow line’s construction there is no way to guarantee that a leak will not occur sometime in the future. “Twenty years out there’s no guarantee of anything,” Tyrrell told the Commission. “We have a resident inspector on-site at all times. The integrity of the line is guaranteed.”

Sewage outfall line construction materials in Clarke County, Virginia - Photo Edward Leonard

Commissioner Bob Wade (Millwood) said, “So it sounds like at least we’re better prepared than BP.”

“I wish that we could guarantee that it will never leak,” said Commissioner Thomas McMillen, “but we can’t say that.”

Does the new wastewater outflow line pose a risk to Clarke County’s groundwater? Clarke Daily News met with David Tyrrell, Director of Utilities for the Town of  Berryville, to get the answers.

CDN: You have said that the new outfall line will never carry raw sewage. How can you be sure?

Tyrrell: All water transported through the outfall line must first pass through a .1 micron filter. The water is drawn through a four foot by five foot filter, which looks like thousands of hollow, four-foot long spaghetti strands, by creating a pressure differential.

CDN: It sounds similar to the portable water filtering systems that people take along on camping trips.

Tyrrell: There are similarities between the two approaches.

CDN: What are the chances that a leak will occur?

Tyrrell: There are no guarantees about anything. However, we’re using a type of pipe called  C-909. It’s a very sturdy, plastic pipe and should last for at least 100 years.

CDN: You mentioned that treatment plant operators will be able to detect leaks by monitoring the pressure in the outflow line. If a leak does occur how will you find its location?

Tyrrell: Our first approach will be to do a visual inspection of the pipeline easement. If the leak is not visually obvious there is technology that enables us to “listen” to the pipe in order to hear where it is leaking.

CDN: Residential building site septic fields require resistivity testing prior to approval. Was resistivity testing performed for the outfall line?

Tyrrell: Resistivity tests the geologic make-up of the area planned for a septic system. This isn’t required for an outflow line. However, soil testing was done and a geologic engineer did review the entire easement path. No sinkholes or problems were identified during the testing.

CDN: You’ve said that you’d drink the discharge from the outflow line before you’d drink from a stream or river. What did you mean?

Tyrrell: The water in the outflow line has been filtered using a process that removes nitrogen, particulates and bacteria. Streams and rivers running through farmland are full of bacteria and other materials. Because of Clarke County’s karst geology streams and rivers are depositing bacteria in the ground water all of the time. Farmer John’s cows already have a bigger impact on our groundwater than a leaky outflow line ever will.

CDN: Is that why water from the old outflow line is being offered as an irrigation source to farmers?

Tyrrell: Yes.

CDN: Can you explain how it will work?

Tyrrell: Any farm that the outflow line crosses has the option to tap the line for irrigation purposes. The landowner will have to pay for the tap and irrigation equipment but there is enough pressure in the line to push the water out into the fields.

CDN: Are there any health concerns or restrictions when using the water for irrigation?

Tyrrell: The water cannot be used on food directly consumed by humans. But, for example, it could be used to water hay that is consumed by cows which then are consumed by humans.

CDN: If the outflow water is safe why are there any restrictions at all?

Tyrrell: The direct human consumption restriction is probably there to protect against water produced by older technology systems around the state. Our new plant will have four separate filter trains and we’ll be able to monitor water quality at all times. When it’s completed we’ll have the most up-to-date water processing system in the area. The water that we produce will be wet but raindrops will contain more nutrients than our outflow water.

CDN: The outfall line enters the Shenandoah River directly across the public boat launch. Will the area need to be posted?

Tyrrell: There is no requirement for signage.

CDN: Who’s doing the construction work for the pipeline?

Tyrrell: R. L. Rider, Inc. or Warrenton.

CDN: When will the project be completed?

Tyrrell: In about one year.

CDN: Thanks for your time!

Comments

  1. I want to see Mr. Tyrrell and Mr. Johnston swimming in the river where this “recycled” water pours in. Why did they not construct a pond nearby instead of spending (I don’t even know how much, if anyone could answer that I’d appreciate it) all of this money?