The Clean Air Council, on behalf of several conservation and environmental groups, has submitted a letter to state Department of Environmental Protection Secretary Chris Abruzzo questioning DEP’s air quality monitoring report regarding the Chevron well explosion in Dunkard Township.
DEP issued its study last month that concluded air monitoring conducted following the Feb. 11 well explosion indicated no pollutants at concentration levels that would be harmful to local residents or emergency responders.
DEP took samples at several sites, upwind and downwind of the well pad, from Feb. 12, the day following the explosion, to Feb. 20, the day the wells were capped.
“PA DEP’s sampling protocol suffered from numerous inadequacies that could have prevented the investigation from detecting harmful levels of pollution,” the council said.
DEP’s report said no concentration levels of pollutants were detected that would indicate a potential acute or short-term health concern for ‘typical local residents,’” the letter states. However, DEP should have evaluated impacts based on the most vulnerable individuals, including the elderly, children and those with existing medical conditions, it said.
The council also maintains 24-hour averages used by DEP underestimate exposure to potential peak concentrations, including any plumes of high concentration levels of pollutants, and should not be used to evaluate acute exposure to pollutants.
DEP completed insufficient air samples to support its conclusion the fire did not produce “pollution spikes” harmful to human health, the council said.
DEP used air sampling canisters to collect both instantaneous samples, referred to as grab samples, and 24-hour continuous samples.
Two grab samples were collected near residences downwind of the well site each day. For a benchmark, a single daily upwind grab sample was also taken. In addition, a 24-hour continuous sample was taken at one of the two downwind sample sites.
However, using only one 24-hour continuous monitor downwind, DEP failed to take into account changes in wind direction during the day that could have moved any plume of pollutants outside the range of the monitors, the council said.
In addition, grab samples taken only twice a day could possibly have missed any high volume of pollutants emitted for a short time. If any brief, high volume of pollutants were detected by the 24-hour monitor, it would go unrecorded because it would be averaged with all emissions during the day, the council said.
The council also notes DEP failed to conduct sampling the first day of the fire. “It is possible that many of the most harmful air toxics were emitted on the first day of the fire,” it said.
On the day of the explosion, Chevron barred DEP personnel and the agency’s emergency response vehicle from access to the site. DEP subsequently cited Chevron for failing to allow its personnel access to the property.
“This conforms to a troubling pattern in which PA DEP fails to enforce environmental laws and abdicates its legal obligation to protect the people’s right to breathe clean air,” the council said.
DEP spokeswoman Morgan Wagner, in an email, said the agency is preparing an official response to the council’s letter.
She noted, however, DEP personnel were on-site almost immediately following the explosion and remained on-site 24 hours a day until the emergency ended.
Chevron initially denied access to the well pad based on safety concerns, however, DEP emergency responders were able to set up the monitoring equipment they felt was necessary, she said. DEP cited the company to make it clear “an operator does not have the authority to restrict DEP’s access.”
Wagner also said the agency disagrees with the council’s assertions regarding DEP’s sampling methodology.
“We began our independent sampling a day after the fire was reported,” she said. “Our staff is highly trained in this area and we stand by our sampling protocol.” Chevron also was monitoring the air at the same time, she said.
DEP monitored for 57 toxic air pollutants. “Again, as the report says, the ground-level concentrations of those toxic air pollutants were not detected at levels in excess of concentrations that would indicate a potential acute or short-term health concern for emergency responders or a ‘typical’ local resident,” Wagner wrote.
The council prepared the letter on behalf of the Greene County Izaak Walton League, Center for Coalfield Justice and the Sierra Club. A spokesman for the council could not be reached for comment.