CHESTERTOWN — The Maryland Department of the Environment and Shore Medical Center at Chestertown have signed a consent order dictating the conditions for ending remediation of an oil leak on the hospital grounds.
The document, which the MDE made public May 17, said testing currently indicates “a decreasing trend in the concentrations of dissolved phase petroleum constituents within the majority of the monitoring well network” and no evidence of contamination in wells downhill from the initial leak or at the hospital property line.
In the order, the MDE requires the hospital to continue monitoring the presence of oil residue in groundwater for at least two years and to test for surfactants, detergent-like chemicals used to free oil residue from the soil so it can be pumped out in a water solution.
The pump-and-treat system that the hospital has used since 1991 is to be continued until oil residue is measured at less than one part per million in the groundwater with no detectable amount of surfactants found. The wells downhill from the leak site are to be completely free of oil residue or surfactants.
The hospital is required to keep the pump-and-treat equipment in place and to restart it at the request of the MDE. The order specifies the methods to be used to determine whether the concentration of oil in the groundwater is stable or decreasing.
The hospital has also agreed to do test borings of the soil on its property to determine the composition of the soil and to sample the concentration of petroleum residue at different levels. This procedure can help determine the probability of contaminants being carried downhill toward Chestertown’s drinking water wells two blocks away at the corner of Kent Street and Philosophers Terrace. Possible contamination of the wells has been the town’s main concern ever since it learned of the oil leak nearly 30 years ago.
The consent order does not address the issue of whether the hospital must compensate the town in the event oil from the site enters the drinking water supply and the town must clean it up.
Bob Sipes, Chestertown utilities manager, said in an email May 25, “I have reviewed the consent order, it’s about what the public could have expected. No mention of any protection for the town. It all looked pretty generic.”
The Chestertown council and the hospital are negotiating a separate agreement in regard to the question of protecting the town’s wells, Town Manager Bill Ingersoll said Thursday, May 26. Ingersoll said he would like to see an agreement without a fixed compensation figure, since it is hard to predict the cost of drilling new wells or filtering contaminants out of the water before such measures are needed.
Included in the MDE order is a detailed timeline for the oil leak and remediation efforts the hospital has undertaken since June 1987, when it informed the state of leaks in two oil tanks with 1,000- and 10,000-gallon capacities. Monitoring wells were installed in June 1989, and tests showed the presence of oil residue in groundwater at the site.
The pump-and-treat remediation system was first installed in 1991. By 1999, it had recovered 66,287 gallons of oil, according to the consent order. Various upgrades to the system were installed over the next few years, and by March 2012, more than 83,000 gallons of oil were removed.
In July 2012, the MDE agreed to allow a temporary shutdown of the pump-and-treat system to determine whether enough oil had been removed to justify ending the program. Monitoring continued and, by June 2013, it was clear that there was still oil in the hospital groundwater. The hospital turned the pumps back on and began searching for other ways to attack the problem.
In 2014, the hospital received approval to test Ivey-Sol, a proprietary surfactant, to remove the oil. After testing appeared successful, the MDE approved use of Ivey-Sol to remove the remaining oil. That program ran from August 2015 to March 2016, and has now been shut down. The pump-and-treat system continues to operate, as it will until the MDE grants permission to terminate it.
David Foster, a former Environmental Protection Agency worker, said at a Chestertown council meeting that the EPA estimates no more than 50 percent of an underground oil spill can be removed by pump-and-treat methods. By that measure, 83,000 gallons or more could remain unrecovered at the site.
When the hospital first proposed the use of Ivey-Sol, Sipes said the substance had never been used in such close proximity to a municipal water supply. In reports to the mayor and council, Sipes said the remediation program wasn’t designed to detect oil more than a few feet from the wells used to inject the Ivey-Sol.
Sipes said significant amounts of oil could remain in the ground even if the area around the test wells appears clear. If the testing program is then ended on that basis, undetected oil could migrate downhill toward the town well field, Sipes said.
The consent order is online at mde.maryland.gov/programs/Land/OilControl/Remediation Sites. It is the last item listed under Kent County.