Friday, June 30, 2000
Cleanup plans underway at most recent MTBE site
The Carlisle Conservation Commission on June 22 heard a fairly reassuring description of the planned cleanup of recently discovered water contamination at 106 Concord Street. The Carlisle Board of Health (BOH) ordered a 21E site assessment after new owners Bronnie and Christoph Karpeter reported the presence of small amounts of methyl tertiary butyl ether (MTBE) in their well and subsequently summoned conservation administrator Sylvia Willard and BOH agent Linda Fantasia to inspect a possible source of the contamination.
Both Willard and Fantasia verified the existence of a mini dump in the wetland to the rear of the property. Old paint cans, car parts, a lawnmower, a bottle of antifreeze and assorted metal items were plainly visible, but the extent of the cache was impossible to ascertain.
The original owner/landlord Juergen Lemmermann and the Karpeters were present at the commission hearing, and commissioner John Lee publicly thanked Lemmermann for "stepping up to the plate" to help solve the problem, even though he doesn't know how the mess got there. Said Lee, "That's a very honorable thing to do."
Jeffrey Morrison of H-Star Engineering, which is undertaking the exploration and cleanup under the supervision of the owners' licensed site professional (LSP) Pine & Swallow Associates, Inc., described a tightly-controlled process. "The problem is, no one knows how much is really involved, so our plan must remain pretty general," he cautioned.
Protecting the wetland
Noting that there is debris both inside and outside the wetland, Morrison said he did not plan to use haybales because of the danger of introducing unwelcome invasives like loosestrife to a pristine wetland. The plan, therefore, is to remove the surface debris by hand. Any possible source of contamination such as oil cans, will be reported to the consultants, who will extract soil samples and take them to their laboratory for analysis. The next step will depend on what that analysis shows. Unfortunately, when the excavation encounters heavy metal items, Morrison said the use of machinery will become unavoidable.
Lee summarized that the applicants required ConsCom permission to explore in and around the wetland but needed to come back for further approvals depending on what is found. The commission also required notice before machinery is introduced.
Commissioner Tom Brownrigg inquired about the kind of barrier that could be used to protect the wetland in case of an accidental spill. Morrison responded that with so many potential toxic materials involved, the protection methods would vary according to the material uncovered.
Lee then posed a series of questions to which many residents would like answers: If you do find contamination within the state's "action level," what confidence do you have that it's accurate? Do you know precisely how they (the state) set the so-called "acceptable" levels? How does the LSP determine an acceptable reduction level? In other words, what is a reasonable level of cleanup? The engineer told him that those questions were not within his area of expertise and implied that they could better be directed to the LSP or the state Department of Environmental Protection.
To a question from Lemmerman as to whether the MTBE could have come from the 21E contamination site on land around the former Daisy gas station, Lee advised that the town's water quality committee has maps that show where the plumes have moved from that location, and felt that answers to questions of that kind should come from them.
The public hearing was closed and the project conditioned for ConsCom to receive piece by piece findings as they occur. The commission also will require that the areas of wetland disturbance be appropriately re-established once the project is complete. All commissioners agreed that first priority should go to cleaning up hazardous materials from the wetland to protect water quality for all the Karpeters' neighbors.
© 2000 The Carlisle Mosquito