BRISTOL, Va. — If the city of Bristol, Virginia had responded to reports of elevated benzene levels in landfill wastewater dating back to 2018, it might have been able to avoid or lessen its current landfill crisis, the CEO of BVU Authority said Friday.
Since 2018, the city has received 32 notices of violation for benzene levels above what is allowed in its landfill operating permit. BVU and wastewater treatment plant operator Inframark monitor pretreated sewage of a number of businesses and industries, but the city landfill is currently the only one in violation, according to BVU President and CEO Don Bowman.
“BVUA’s industrial permit monitoring program, managed by a third party, may have been like a canary in the coal mine at the city’s landfill,” Bowman said. “BVUA’s notice of violations benzene reports to the city began in 2018, well before widespread community odor complaints. The NOV’s may have been an early indication that something was going wrong with the city’s landfill, a couple of years before the avalanche of odor reports started.
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Benzene is a colorless liquid derived from petroleum and a known carcinogen commonly found in gasoline, lubricants, pesticides and cigarette smoke.
“I don’t know if the city staff lacked the initiative, technical expertise or adequate consultants to address the benzene NOVs,” Bowman said. “At that time, BVUA was only reporting the NOV’s directly to Mark Campbell, the city’s former environmental health and safety officer who worked at the landfill as was our then standard procedure.”
BVUA now submits the notice letters directly to the city manager/attorney as well as copies to the Virginia Department of Environmental Quality and a founder of HOPE for Bristol, a citizens group, Bowman said.
“One theory is that the benzene may be a by-product of a suspected sub-surface reaction occurring deep within the landfill. An opposing theory offered by the city in the past is that the benzene is migrating into the landfill from off site. At this point, I don’t know that the city has taken a firm position,” Bowman said.
City officials didn’t immediately respond to a request for comment.
New agreement
On Friday, BVU and the city announced an agreement and proposed timeline for removing benzene from the landfill wastewater.
The agreement calls for the pre-treatment system to be installed by December 2022, but included an opportunity to extend that deadline by six months.
“Currently, the city has not identified the source of the benzene. Until reduced or eliminated, the city must pretreat their wastewater to reduce benzene,” Bowman said in a written statement. “The parties agree there are commercially available technologies the city could pursue. Benzene is a carbon-based derivative with a weak chemical attraction to water that evaporates quickly into the air quickly.
“One common industrial treatment method is ‘air stripping,’ although it is ultimately the responsibility of the city to collaborate with their engineers to identify the right methods and pretreatment processes to return the landfill to compliance with their benzene discharge permit requirements,” Bowman said.
The city also violated its permit by failing to submit a semi-annual self-monitoring report for the period of Jan. 1 to June 1, 2021, according to the agreement. In it, the city agrees to respond to any notice of violation in a “timely fashion,” to conduct its own testing and acknowledge BVU will conduct bi-weekly monitoring of all wastewater effluent.
The agreement requires the city to take comprehensive corrective actions to address deficiencies, implement controls and risk management practices on benzene levels. The agreement also limits wastewater volumes and flow rates through an equalization flow tank. The priority is removal of the benzene as soon as possible.
Until the storage tank is constructed, the city agrees that maximum wastewater flow from the landfill will be 800 gallons per minute for no more than nine out of every 24 hours. Once the tank is operational, the city agrees to a peak discharge flow rate of 300 gallons per minute and maximum volume of 14 million gallons per month, according to the agreement.
Last month, the City Council approved funds for hiring a contractor to perform work on the landfill wet well, where the benzene is believed to be entering the sewer system. City leaders previously outlined plans to acquire and install a wastewater storage tank and the technology needed to remove the benzene.
The agreement also includes a series of fines should the city fail to comply with the terms of the agreement.
Benzene history
Last week, the city received another notice of violation, including the highest reading to date — 4.09 milligrams per liter, or 58 times the Occupational Safety and Health Administration-approved “maximum instantaneous limit” 0.07 — recorded on Oct. 28, according to the notice.
A subsequent sample collected Nov. 10 had a reading of 0.55.
Of 32 samples collected since 2018, the average reading was 1.321 milligrams per liter. In 2021, the average reading was 1.76 across the 19 samples that have been collected and analyzed.
BVUA has increased the frequency of its monitoring — from every few months to twice monthly — because benzene from the landfill has appeared each time a sample was collected, Bowman said.
“I’m optimistic, if the city can figure out a solution for the landfill subsurface reaction, the benzene levels should fall in the wastewater,” Bowman said.
Because no other state agency fills the role, as the wastewater operator, BVUA is responsible for issuing the violation notices to the city.
Work to begin
The agreement was completed days before the city’s initial step in responding to the benzene issue, which is to begin this week.
It involves contractor Charles R. Underwood of Sanford, North Carolina, coming to replace and repair pumps that service the landfill’s deep wells, which reach the bottom of the landfill floor.
“The plan is to start Tuesday,” said Ernie Hoch, manager of solid waste and environmental services for Draper Aden Associates and the city’s primary landfill consultant. “With a little luck, we’ll have the two largest pumps back and replaced before Christmas.”
One of three pumps is currently running so if it fails the city would be unable to pump out any of the water, Hoch said.
That was the emergency action the City Council took Nov. 22, hiring the contractor to perform the pump and related work, after the Virginia Department of Environmental Quality sent a warning email early last month directing the city to address this issue immediately.
Once the pumps are replaced, a team of trained divers will be brought in to determine what happens next, Hoch said.
“We are going to send a rescue dive team down into the well to do some exploration and some repairs then replace the last pump early in January. Potentially, we could have that done by the end of January,” Hoch said.
The divers will enter through a metal door on the surface and go down the 320-foot shaft to the bottom. They are specially trained in this type of work and will have specific duties once they reach the bottom, Hoch said.
“We’re looking to see if there is any deterioration of the wet well down there, check the pipes, check the pumps, the amount of sediment at the bottom. There are some smaller pumps down there we will probably replace. We don’t know what we’ll find until we get down there,” Hoch said. “There are two wet wells. One is leachate and one is groundwater.”
Landfill leachate begins as rainwater that flows into and percolates through the degrading trash and typically emerges contaminated with high concentrations of pollutants. Groundwater is present below the earth’s surface and typically doesn’t contain pollutants.
“The two types of water are mixing together right now and we don’t know where or why it’s mixing together so we’re trying to determine that,” Hoch said. “The bigger plan is to put in a benzene stripping device to take the benzene out of the water, but in order to do that we need to understand the volumes — whether they’re part of the gradient or part of the leachate and right now we don’t know. It appeared the benzene was more in the gradient water than the leachate but what we’re trying to determine is how we treat it. Do we have to treat 200,000 gallons a day or can we treat it separately with different concentration levels?”
City Manager Randy Eads previously said the planned benzene treatment will involve another phase of work.
“Benzene pretreatment is expected to be an 18-month project expected to begin in January or February,” Eads said. “That will consist of building a 1-million-gallon storage tank, reroute our current leachate and gradient water into the storage tank, where we will install air strippers that will agitate the water, which will evaporate the benzene out of the water. We will capture that [benzene] through a charcoal filter then dispose of it appropriately.”