Results from a wastewater treatment study the town contracted CDM Smith to undertake suggest that septic systems in the region of Aucoot Cove contribute more to nitrogen pollution in the cove than the three unlined sludge lagoons at the wastewater treatment facility, with 31% and only 2%, respectively.
The data from the study suggests a prior study by the Buzzards Bay Coalition, of which the Environmental Protection Agency derived its data for the National Pollutant Discharge Elimination Systems (NPDES) permit, was wrong in its analysis of the lagoons.
“The lagoons don’t leak as much as the analysis suggests,” said Bernadette Klaft of CDM Smith on May 3 at the Marion Board of Selectmen meeting.
Klaft broke down the sources of nitrogen pollution in the cove, including agriculture/cranberry bogs in the vicinity (27%), undeveloped land (21%), and residential fertilizer use (9%), with the lagoons being the least polluting.
“Removal of lagoon nitrogen load would have an insignificant impact on the overall nitrogen load to Aucoot Cove,” reads the report.
Good news, say selectmen.
Furthermore, CDM Smith representatives say they have met with the EPA and were pleased to report that the EPA is willing to work with the Town of Marion to allow consideration for the suggested options for reducing pollution and meeting the NPDES permit pollutant limits – options other than eliminating the lagoons entirely, which would have forced the town to redesign and upgrade its entire wastewater treatment plant.
A study on eelgrass in the cove was also in the town’s favor, with data – including satellite imaging and aerial photographs dating back to 1988 – showing that the cove never was a viable habitat for eelgrass.
“Based on the available data,” the report states, “…the lack of evidence of eelgrass suggests that eelgrass would be a poor metric for interpreting the environmental health of Inner Aucoot Cove between Haskell Island and the salt marsh.”
As for viable solutions, the engineering firm conducted an analysis on the sludge lagoons and an outfall study.
The analysis done on the sludge lagoons and the plant itself show that only ten of the 20 acres is actually needed to effectively run the plant. The finding suggests the town could line the two five-acre lagoons and decommission the third and potentially re-purpose it as a constructive wetland.
“This is not technology that is widely used in New England,” said Klaft, “so it would need to be piloted…. But it’s a very green solution…”
The outfall study came up with four alternative routes to extend the outfall point further out into deeper water at Aucoot Cove. Another approach would be to discharge through land disposal, which would require transporting the treated effluent water to another area and into the ground, although Klaft said this part of the feasibility study was only in the very preliminary stage.
She said there are some undeveloped tracts of land that could accommodate this option, an option that is appealing because it would no longer require a NPDES permit from the EPA, but rather a groundwater discharge permit from the Massachusetts Department of Environmental Protection.
Klaft said the EPA looked favorably on the selectmen’s action to acquire a grant to work in partnership with Mattapoisett to study the feasibility of connecting residences in that area to Marion’s municipal sewer service, which could potentially reduce the nitrogen load that septic systems currently contribute to pollution in the cove by 60%.
“They (the EPA) see that,” said Klaft. “There’s nothing better you can do … than sewer those homes.”
The town’s recent option to explore regionalizing wastewater treatment with the Towns of Plymouth, Wareham, Carver, and Bourne, and also with Mass Maritime Academy, also appealed to the EPA.
Klaft said the EPA would consider entering an administrative consent order with the town to agree to terms for the NPDES permit and an attainable timeline, as well.
What are the potential costs of four viable options for the town laid out by the engineers?
Option 1, which would comply with the NPDES permit as written, entails the reduction in ten acres of the sludge lagoons, re-purposing the one 10-acre lagoon into a constructive wetland, transporting sludge offsite and using the existing outfall, ranges from $15 million to $18.1 million.
Option 2, which includes extending the outfall to the head of the salt marsh and lining ten acres of lagoons, was estimated at $15.7 million to $22.4 million; with the ten acres of constructive wetlands included in the project, $14.3 million to $17.2 million.
Option 3, which extends the outfall to the outer Aucoot Cove and lines ten acres of lagoon, ranges from $25.3 million to $32.6 million.
Option 4, which includes land disposal via infiltration basins in area undeveloped lands with ten acres of lined lagoons ranges from $15.4 to $30.1 million, and with the constructive wetland added, $14 to $24.9 million. The price tag would depend on the location of the infiltration basins from the wastewater plant, and the estimated costs are based on a range of 1 to 4 miles.
“We need to do whatever we need to … get to the next step and we need to at least explore the other alternatives,” said Board of Selectmen Chairman Stephen Cushing.
The selectmen voted to allow Town Administrator Paul Dawson and the engineers to move forward in further negotiations with the EPA, but only in discussions. No commitments yet, Dawson said.
“Ultimately, it may not happen,” said Dawson about the prospect of a favorable outcome for the town and one of the options. “But it could….”
In other matters, this was Selectman Jonathan Henry’s final meeting in the Town House as a selectman, and Cushing and Selectman Jody Dickerson had kind words for Henry. They also brought a cake to celebrate Henry’s 12 years on the board.
“It’s been quite a ride,” said Henry. “We respected each other’s opinions along the way … and there were a lot of people who helped show me the way.”
Where else could a furnace repairman find a better opportunity than the one Marion has given him, asked Henry. “It’s been a wonderful and rewarding experience, and I don’t regret a minute of it.”
The next regularly scheduled meeting of the Marion Board of Selectmen will be on May 17 at 7:00 pm at the Marion Town House.
By Jean Perry