The Town of Marion might realize more benefit than a healthier harbor from its recent regulations requiring any new septic construction in town to include denitrification technology.
“Nitrogen mitigation is something you should hang your hat on,” Kent Nichols of Weston & Sampson told the Marion Select Board and Town Administrator Jay McGrail during Monday afternoon’s Comprehensive Wastewater Management Plan Workshop.
Marion is asking the state for additional sewer capacity to accommodate what it expects will be a dramatic rise in users once a pair of residential developments are constructed along Route 6 near the Weweantic River.
“If we’re asking for a little more flow … we can add discharge at the (wastewater-treatment) plant but lessen the net effect due to nitrogen reduction,” suggested Nichols, whose presentation included basic financial scenarios and discussion on how to procure funding in next steps to modernize and stabilize the town’s sewer infrastructure.
Ultimately, Marion prospers with more sewer ratepayers spreading the cost of massive upgrades that lie ahead in some scenario.
On Monday, Nichols presented a series of breakdowns on four general approaches including full and minimal options with notes and discussion regarding short and long-term pros and cons of each scenario. “Every option requires permitting … nothing is a slam dunk,” qualified Nichols.
Financial outlooks were presented in “apples to apples” comparisons that omitted discussion about aspects present in all options such as infiltration and inflow (I/I) and sewer extension. Key issues compared included: Capacity, (Marion plans on handling 686,000 gallons per day) Nitrogen, Phosphorus, Copper and Solids.
Technological differences among the four basic approaches cancel out the need to deal with every issue listed above, but each of the four brings its own set of advantages and disadvantages.
Nichols categorized the following treatment alternatives as feasible: A. process improvements to Marion’s existing facilities; B. groundwater discharge of Marion-produced effluent; C. Relocating Marion’s outfall; and D. Regionalization with the Town of Wareham. In the case of regionalization, Marion would need to build a pipe to connect to Wareham’s infrastructure and continue a level of operation that would prevent buildup via the usage of the wastewater lagoon for equalization.
Option A1 would require $2,500,000 in discreet capital costs but a total of $10,800,000 including ancillary costs; A2 would include a third lagoon and require $4,500,000 in discreet capital costs and with ancillary costs total $12,800,000.
A1 is the hedging of A2, which is “what really should happen to your plant,” Nichols told the board.
Approach B1, 100,000 gallons per day of groundwater discharge requires $7,300,000 in discreet capital but $15,600,000 including ancillary costs. B2 is the groundwater discharge of all effluent. The cost is $9,200,000 in discreet capital and $17,300,000 altogether.
Nichols said making the “B” approaches work “depends on soils being conducive to this.” The main advantage of B, he said, is in permitting. “It just doesn’t address your whole issue.” B2, for instance, does not meet phosphorus removal. Given the site’s lack of permeability, Nichols said, “We’re not convinced B2 would be a workable alternative out there.”
Category C1 is outfall extension to Salt Marsh and C2 outfall extension to Outer Cove. While Category-C options would not need to remove phosphorus, Nichols recommended against Salt Marsh as a most risky plan due to the nature of the soils, noting that engineering firm CDM Smith also commented accordingly on soils in its report.
Category D is regionalization with Wareham, the options determined by which option Marion would choose for its connection to the out-of-town infrastructure. In either case, Nichols estimated costs that soar past all other options to $71,000,000 for discreet capital spending and $76,000,000 total counting ancillary costs.
Select Board member John Waterman said he found the second option with the third batch processor most appealing. That option requires Marion being granted an increase on its permit. The backup plan would be the groundwater option.
“The goal ought to be if we can get one area of town sewered as soon as we can and moving on that track as soon as we can. The more users we can get on the system, the more we can spread the debt service,” said Waterman.
Nichols and Select Board Chairman Norm Hills agreed.
A public-input session was discussed, as well as funding opportunities including ARPA.
“(Coastal Zone Management) has been very supportive of the town. I don’t think that can be overstated,” said Nichols. “One of the reasons they really like supporting Marion is … your very programmed approach.”
While the matter will come up in future Select Board meetings, the CWMP public meeting will be held in person at the Music Hall on Monday, May 23, at 6:00 pm.
Marion Select Board
By Mick Colageo