The Rochester Conservation Commission held its March 21 meeting at the Council on Aging to accommodate the larger crowd that was expected for the continued public hearing on the permit violation of the Decas Cranberry Co. project. While the public hearing did provide new information regarding the impacts of the project on the adjacent ponds, Decas also submitted a request for an amended order of conditions to attempt to address the issues arising from the violation.
Brian Grady, an engineer from G.A.F. Engineering representing Decas, stated that they had completed an as-built plan of the tailings pond as requested by the commission. Their surveying indicated that approximately 50,000 yards of material were removed from the site in excess of what had been permitted. Another 35,000 yards of material was stockpiled on-site.
G.A.F. used United States Geologic Survey data to compare historical surface elevations of Long, Snipatuit, and Snows Ponds with current elevations. The data showed that Snows Pond surface elevation was approximately 2 feet below average, Snipatuit Pond was 1 foot below average, and Long Pond was roughly at its average elevation.
Grady concluded from the data that Snows Pond water levels were low due to the moderate to severe drought conditions the region has experienced recently.
As suggested during the previous hearing on March 7, the commission hired a hydrogeological consultant to investigate the question as to whether the tailings pond, dug 8 feet deeper by Decas than their permit allowed, and the concurrent dewatering during the project had an impact on the historically low water levels at Snows Pond.
Peter Newton of Bristol Engineering Advisors discussed at length the geological history of the area and its influence on groundwater movement. He stated that the dewatering is likely pulling a lot of water from Long Pond. However, due to local geology with regard to Snows Pond, he stated, “I can’t quantify the impact the excavation is having on Snows Pond … the drought conditions are likely having the lion’s share of the impact.”
Newton noted that, based on a monitoring well in Lakeville, the regional water table is down 4 feet below average. Snows Pond, which relies solely on groundwater, has a 30- to 50-acre watershed; therefore, its water recharge area is small and its recovery from drought is slow and entirely dependent on rainfall.
Once the dewatering wells are shut off, Snows Pond will return to a steady state, but it will not recover fully until it rains. Newton addressed the idea of returning the excavated material to the tailings pond to raise the bottom elevation. He stated that there was a greater risk to hydrogeology from moving the dirt rather than doing nothing, due to the possibility of equipment failure.
Newton did see value in installing two monitoring wells between the tailings pond and Snows Pond. The wells would be installed prior to shutting off the dewatering pumps to gather baseline data during dewatering, and for two months subsequent to the pumps being shut off.
If the commission were to issue an amended order of conditions, Newton stressed that “if the grades were to be restored, that there be tight protocols on types of material used – the material should ideally be from on-site, and should be free of fines and organic matter.”
The residents attending the meeting expressed their concern over the low water levels of Snows Pond and dismay and disbelief that Decas was unaware of their error in over-digging the pond.
One resident, Rich Charon, who is also a member of the town’s Soil Board, raised a broader point, which was echoed by Town Counsel Blair Bailey and Conservation Agent Laurell Farinon. Charon stated, “We can speculate about the water level in the pond and if a twenty-four foot cut is the same as a sixteen foot cut. But what we can’t speculate about is that this violation is breaking the integrity of our permitting process.”
Bailey suggested that future projects will need to be monitored much more closely, and perhaps a bond will need to be issued for such projects. Farinon stated that this violation was discovered expressly because she was monitoring the project; however, Chairman Michael Conway noted that there are more projects happening at the same time than staff can effectively monitor.
Commission member Dan Gagne suggested that a full-time engineer be required to be at the Decas site during any further work that occurs on this project.
Despite numerous attempts by the commission to come to a consensus over the amended order of conditions or violation remedy, Decas attorney Adam Brodsky requested that the hearing be continued so that his client could further study possible solutions. The commission requested that any submission be accompanied by an engineered site plan.
The next Rochester Conservation Commission hearing is scheduled for April 4 at 7:00 pm at the Rochester Council on Aging.
By Sarah French Storer
