The following is the full article quoted from _The Falmouth Enterprise_ published on Friday, 6/12/26, page 9, entitled, “Falmouth Select Board Advances Wastewater Outfall Report For State Review”.
Click here to view the “map shows the planned route of the ocean outfall pipe from the treatment plant to the waters of Nantucket Sound.”
The Select Board voted Monday to submit a draft environmental impact report for state review, advancing Falmouth’s proposed wastewater outfall project.
According to the report, the plan is to discharge highly treated wastewater into Nantucket Sound through a new ocean outfall while having minimal effects on water quality, groundwater resources, eelgrass habitat, fisheries and shellfish. The system would also provide capacity for future sewer expansion and reduce nitrogen pollution from septic systems.
The proposed project would replace the town’s current groundwater discharge system, which uses land-based treatment beds, while maintaining tertiary treatment and ultraviolet disinfection at the Main Wastewater Treatment Facility. Approximately six miles of pipeline would carry treated effluent to an outfall extending roughly 2,300 feet into Nantucket Sound from Kite Park in Falmouth Heights.
While the system is being designed to accommodate average flows of up to three million gallons per day, current discharge from the treatment facility averages about 490,000 gallons per day. Wastewater Superintendent Amy A. Lowell said projected flows when the outfall begins operation are expected to remain below the town’s existing permitted discharge limit of 710,000 gallons per day average annual flow. The outfall is designed to accommodate future increases as more neighborhoods are connected to the sewer system.
The report is based on more than two years of environmental monitoring, modeling and coordination with regulatory agencies.
Hydrodynamic studies found that Nantucket Sound’s strong tidal currents create a well-mixed environment that rapidly disperses discharged water.
“So you’re not going to see that water sitting in one place,” Lowell said, adding that nutrient contributions from the outfall would be indistinguishable from natural variability within Nantucket Sound.
Groundwater impacts are also expected to be limited. Modeling conducted by the US Geological Survey found that changes to water table elevations and streamflow would be relatively small compared to natural fluctuations. The report states that reductions in septic return flow and treated wastewater recharge would represent only a small percentage of overall groundwater recharge.
Lowell said environmental reviews also found minimal impacts to eelgrass habitat. Survey work identified the nearest eelgrass meadow at least 250 meters inshore of the proposed outfall location, and the report concluded that neither water clarity nor nutrient concentrations at any of the meadows are expected to be affected because of the level of treatment and the offshore discharge location. Seasonal construction restrictions would also prohibit drilling work during the eelgrass growing season.
No significant impacts are anticipated for fisheries or shellfish resources, according to the report. Lowell cited the high level of wastewater treatment, dilution at the diffuser and strong tidal mixing as factors limiting environmental effects. Construction-related disturbances are expected to be temporary and minimized through seasonal work restrictions.
The report also indicates no significant impacts to water quality are anticipated. However, Lowell said treatment modifications could be considered before transitioning from groundwater to surface-water discharge if changes are needed to increase dissolved oxygen, pH or disinfection levels. She estimated the project would result in a net reduction of at least 12,000 kilograms of nitrogen entering Nantucket Sound each year.
When Select Board member Elizabeth M. Klein asked how she would respond to advocates of alternative approaches to reducing nutrient discharge, such as urine-diversion systems and composting toilets, Lowell said those technologies can be effective for users committed to them but are difficult to implement at the scale necessary to meet the town’s nitrogen-reduction requirements.
If the project proceeds, routine discharge into the treatment beds would cease, though some beds would remain available as a backup option, Lowell said.
Select Board member Robert P. Mascali asked whether the town had contingency plans if the outfall proposal fails to secure regulatory approval.
Lowell said the town has evaluated land-based discharge alternatives and could pursue them if necessary, but described them as “not good options.”
“That’s why we’re going with the outfall,” Lowell said. “This is a better option for the environment and for the town.”
The Select Board’s vote allows the draft environmental impact report to be submitted for state review and public comment before a final report is prepared. Lowell said she expects to hold a public meeting on the project in July and anticipates submitting a final environmental impact report by the end of the year.
The town expects to seek funding for final design and remaining permitting work at the April 2027 Town Meeting, followed by a request for construction funding in April 2028. If permitting and funding proceed as anticipated, construction could begin in 2028, with completion projected between 2031 and 2032.