Nine years after state officials found a dry cleaning solvent in two new drinking water wells at Aero Drive and South Meadow Street, the Town of Payson and the Arizona Department of Environmental Quality continue their efforts to clean up the problem.
At a meeting Tuesday night at the Expanded Groundwater Treatment System (EGTS) facility on Aero Drive, state officials said the system they built is working. They described the Water Quality Assurance Revolving Fund (WQARF) site as a model for the state and one of the most aggressive treatment systems in operation.
The state stepped in to help with the cleanup because the owner of the dry cleaning shop had died. The business, located at 904 S. Beeline Highway, had been in operation during the late 1970s and early 1980s. Groundwater testing in 1990 showed up to 25,000 parts per billion of PCE in the contaminated area.Drinking water standards allow 5 parts per billion.
"The total cost thus far is $7.5 million," said Michael Nesky, ADEQ's remedial project manager. "Four million of that is treatment and operations. The remainder is investigative."
The town covers the normal costs of getting water out of the ground and into its water system, and continues to monitor the treatment plant. The water department collects samples and sends them to an independent, state-certified laboratory twice a month. Samples taken in April from the layer of decomposed granite at the site of highest concentration showed 940 parts per billion of PCE.
ADEQ officials and contractors say they have no idea how long it will take to get the contaminant, tetrachloroethlylene (PCE), out of the plume that extends from Frontier Street to the north, Beeline Highway to the east, Aero Drive to the south and McLane Road to the west.
During a 7 1/2 month period in 1998, Emcon Consultants worked with ADEQ on the project, drilling at 14 locations and studying the geology under Payson.
"We built this system and did the investigation," said Bruce Travers, project manager with the company. "We were trying to investigate the geology of the system, the movement, and the nature of the contamination."
Travers said geologists on the drill rigs described the rocks and recorded the properties of the aquifer with an electronic tool.
With the data in hand, ADEQ came up with a system to clean the groundwater around the area that housed the former dry cleaning operation. They constructed an interim groundwater system in September 1997 to treat the water around the source, where the highest concentration of contamination was found.
Karen Probert, water specialist with the Payson Water Department, said the interim system can only treat up to 100 gallons of water per minute. The smaller system is designed to treat a low volume of water with a high amount of contamination.
The Expanded Groundwater Treatment System, which was built adjacent to the interim system on Aero Drive in October 1998, treats five times the amount of the smaller system, but works for lower concentrations of PCE.
"The EGTS can treat up to 500 gallons per minute in its present configuration, but it could be expanded to treat up to 800," Probert said.
Both systems now deliver 300,000 to 400,000 gallons a day to the town's water supply. Together, the two treatment systems have pumped about 75 million gallons of water from three wells into Payson's drinking water system.
But nine years after the initial discovery of contaminants in the water, there are still people in town who don't understand what's going on with the problem and its solution. That's why the Community Advisory Board (CAB) was created in the fall of 1998 to be a link between ADEQ and Payson residents.
"The biggest problem I've heard is mistrust of the government," said CAB member Susan Birchak. "That, more than anything else, is the thing to overcome."
Elaine Drorbaugh, another board member, said, "When we first started CAB, people didn't think we had a problem. Then, it went the opposite. People started being afraid to drink the water."
"You made a point that they thought it was really bad," said Lance Decker, a contractor with ADEQ. "You know what? It was."
Birchak, Drorbaugh and board members Jack Clayton, James Earhardt, Laurence Moore, Wayne Morgan, James Winter, Warren Disbrow Jr. and Georgia Salwitz spent the past year studying the problem and the systems that were created to solve the problem.
They said they gained a lot of information and tried to share what they learned, but they also told state officials that their job is not over.
At the meeting Tuesday, ADEQ officials had some new information and shared their findings with the group.
They said that the pumping and treating had removed about 600 pounds of the PCE from the groundwater. They also said they would continue to refine their concept of how the aquifer works after discovering that the water level had dropped five feet, more than had been anticipated.
"We think the aquifer is a little thinner than we thought earlier," said Paul Plato, a hydrogeologist with Emcon. "Since we turned the system on, some water has filled the void caused by the system and to some extent, it looks like we're capturing water from the west.
"What's next is, we pump and treat the groundwater, contain the existing plume and keep it from spreading. We'll continue to monitor and sample the wells and check on the progress of the cleaning."
Plato, Travers and others with the project said they want to assure the public that there is no significant risk to their health, even for the owners of private wells that have been contaminated. To be on the safe side, however, ADEQ continues to provide bottled water to five private well owners whose wells were contaminated.
"Today, Payson has a new water supply that was previously undrinkable thanks to the cooperative efforts of the Town of Payson Water Department, the Town Council, the ADEQ and Payson residents," Nesky said. "The estimate we had for the cost a long time ago was $10 million. Right now it's a guess, because we still have a lot more data to secure."
Probert said the town has seen some major improvement in the contaminant levels since this past spring, when the water department took samples.
"Since April, the contaminated water coming into the treatment site has been approximately 400 parts per billion," she said. "That's a significant difference. We've been getting excellent removal. We're not detecting any PCE in the finished water."
Travers said he is working to get a clearer and more accurate picture of how the system is working, how efficient it is and how long the clean-up operation will take. "It's going to be an ongoing process," he said. "We'll continually update the system. We just have to see what happens."
The members of CAB are planning a meeting within the next two months which will be open to the public. For information on the meeting or on the treatment systems, call Wayne Morgan, co-chair of CAB, at 474-3768.