Bad news, Payson water users.
The state just stiffed you — again.
So the Payson Town Council last week picked up the tab — and set aside $167,000 to continue the decade-long effort to keep cancer-causing chemicals from seeping into the town’s drinking water.
The council’s action came after the Arizona Department of Environmental Quality notified the town that for the second year in a row it didn’t have the money to provide the $100,000 it had promised to help clean up the toxic chemicals dumped into the water table by a long-since-vanished dry cleaner on Aero Drive.
“This is an orphan site,” said Payson Mayor Kenny Evans. “The people who created this problem are long since gone.”
He said the state’s decision to quit funding the cleanup “after years of effort” could cause the underground plume of contaminated water to once more spread and contaminate the town’s drinking water supply.
“If we just shut it down, we’ll face recontamination,” he said.
The town stepped in to continue operating the network of six wells continuously pumping contaminated groundwater through a set of massive activated carbon filters to remove a witch’s brew of solvents. The chemicals include tetrachloroethene (PCE), trichloroethene (TCE) trans- and cis-1,2-dichloroethene (1,2-DCE) and methl tet butyl ether (MTBE).
Despite having abandoned the project, the state initially insisted the town use expensive, outside consultants rather than rely on town employees to test and filter the water. After some hard negotiating, the state reluctantly agreed to let the town use in-house experts — a concession that will save the town $37,000 annually.
For more than a decade, the state operated six wells to pump the already extensive plume of contaminated water out of the ground and filter out the chemicals. The pumps gradually drew the until-then spreading plume backward, preventing it from reaching additional wells.
However, if the town allows the pumps to fall silent, the water would again spread outward toward other wells.
Evans said that the town’s water supply will likely get additional protection from the contaminated plume in about two years when the town starts putting water from the Blue Ridge pipeline back into the water table. The Blue Ridge water will likely build an underground wall of water to keep the contaminated plume from spreading.
The town has been struggling since 1990 to clean up the contamination from solvents a dry cleaner dumped in the dirt for years before.
The chemicals used in the solvents have a bewildering variety of potential effects. The chemicals can cause cancer and nerve damage at high doses in laboratory animals and relatively clear-cut impacts on humans repeatedly exposed to high concentrations on the job. However, the precise effects of small amounts of the chemicals in drinking water remain the subject of debate.
For instance, TCE in high concentrations causes headache, dizziness, muscle spasms and heart arrhythmia and chronic exposure can cause damage to the liver and spontaneous abortions. Animal studies suggest the chemical might also increase the risk of liver cancer and leukemia.
Federal standards allow no more than 5 parts per billion in drinking water. Statistical studies estimate that if a million people drank two liters of water with 5 ppb of PCE every day for 70 years, five would develop cancer.
Studies suggest that TCE increases the risk of liver, kidney and other cancers, based on both animal studies and large-scale studies of exposure to the solvent in humans — mostly at the workplace. The chemical can also affect the nervous system and immune system. Alcohol and diabetes can increase the effects, which also impact children more strongly than adults.
The effects of small amounts of the chemical in drinking water have been much harder to measure. Some studies estimate that between 9 percent and 34 percent of U.S. drinking water supplies exceed the 5 parts per billion federal standard, although use of TCE has all but stopped in recent years.
In fact, Scottsdale suffered one of the nation’s worst contamination incidents, linked to a local computer chip manufacturing plant.
Town hydrologist Mike Ploughe said he’s hopeful the state will resume funding the cleanup effort when the bleak financial picture improves.
Evans estimated the state or the town will have to run the pumps for another 5 to 10 years to remove the last of the contaminated water.