The state has proposed a plan to investigate contamination of water supplies caused by a toxic chemical used to treat utility poles.
State officials say there are about 600,000 utilities poles in Vermont, nearly all of which have been treated with a wood preservative called pentachlorophenol, or PCP. Officials say exposure to this chemical is linked to short- and long-term health effects.
In recent years, the state has responded to four cases where this toxic chemical leached from utility poles. In three instances drinking water supplies were contaminated. The health department says no landowners have experienced any negative health effects.
The state on Thursday asked the Vermont Public Service Board to approve the formation of a working group that would develop best management practices to prevent future contamination. The 12-member group would be composed of four utility representatives, four state officials, and four members of the public appointed by the board.
George Desch, the Agency of Natural Resource’s point person on the issue, said the state wants to prevent future PCP contamination. Reported incidents of contamination are rare, he said.
“We need to basically get some data that actually informs how big of a problem this is,” he said.
Kerrick Johnson, the vice president for the state’s transmission utility, said the Vermont Electric Power Co. located eight drinking water supplies located within 100 feet of its poles.
Exposure to PCPs can cause short-term health effects – including skin and respiratory irritations, liver and kidney damage – and long-term risks such as damage to the central nervous system and cancer, according to the Vermont Department of Health.
Lori Cragin, the state epidemiologist for environmental health, said the chemical can be absorbed through inhalation and physical contact. Residents should not drink or use water that is considered to be contaminated, she said.
When the chemical is detectable by smell, the risk to exposure is already 900 times the limit considered safe by the federal environmental regulators, Cragin said.
The health department offers a $75 kit used to test for PCP. The results take less than one week to process, Cragin said.
The Environmental Protection Agency began to regulate the use of the chemical in 1987. PCPs have been used to treat utility poles since the 1940s, state officials say.
The first case of water contamination occurred in 2009 when new utility poles were placed in Clarendon and Bennington, according to state officials.
The state believes PCPs infiltrated nearby water supplies for homes located approximately 50 feet away. The properties had shallow wells and the owners reported the smell. The utilities later replaced the poles with cedar poles and in one case paid for a new well and in the other installed a new filtration system.
Last April, a Monkton resident’s shallow drinking well was contaminated with PCP from runoff caused by routine maintenance in the state utility corridor. VELCO says it notified the landowner before it replaced the utility pole that it was monitoring the drinking water. The company later replaced the well and notified the state about the incident.
The state’s call for an investigation came shortly after natural gas pipeline opponents warned that construction of Vermont Gas’ 41-mile pipeline extension through Addison County could release the toxic chemical into nearby resident’s water supplies.
In response to recommendations from state officials, the Public Service Board ordered Vermont Gas on July 25 to halt construction in the utility corridor. There are 153 poles located within 50 feet of the entire proposed pipeline’s footprint that could disturb contaminated soils, Vermont Gas estimates.
On Aug. 4 regulators lifted the restriction in the Redmond Road area of the corridor. Vermont Gas says there is no contamination risk for this section of the project because there are no utility poles. The Agency of Natural Resources supports Vermont Gas’ proposal to lift the restriction in this area.
Vermont Gas developed a soil management plan it says will ensure toxins are not released into drinking water supplies. State regulators still need to approve the plan.
The purpose of the plan is to identify contaminated areas and to develop procedures to prevent contamination during construction.
The state has asked Vermont Gas to test about 10 percent of areas of high risk before digging near contaminated areas. If the company trenches the pipeline in contaminated areas, it would be required to coordinate with utilities owning the poles to properly dispose of high and low level hazardous waste.
