NEWBURY — Mount Sunapee Resort’s base lodge was packed Tuesday morning, but instead of skiers and snowboarders gearing up for a day on the slopes, the crowd was there to talk about the resort’s aging wastewater treatment system.

The ski resort played host to over 150 concerned residents, lawmakers, and state and local leaders at a regular meeting of the Mount Sunapee Advisory Commission. The MSAC advises New Hampshire’s commissioner of Natural and Cultural Resources on the lease between Colorado-based Vail Resorts, which operates the ski area, and the state, which owns the land.

Environmental groups including the Newbury Conservation Commission and Lake Sunapee Protective Association, with support from several town selectboards, have been organizing for year around concerns with the 50-year old septic system and lagoons.

They have urged the state to compel Vail to replace the system by the end of next year.

“I don’t think we want to wait until there’s a catastrophic failure, there’s no reason to wait for that to happen,” Elizabeth Harper, executive director of the Lake Sunapee Protective Association and member of the advisory commission, said at the meeting. “We don’t want to wait until permits are violated to an extreme extent.”

Others in attendance also urged Mount Sunapee’s leadership and the regulators in the room to make a change.

“My ask of you, my ask of the commission, my ask of (the New Hampshire Department of Environmental Services) is for everyone to collaborate and to spread the wealth and do what’s right for the community and what’s right for the environment,” Newbury resident Jeff Estella said to the commission.

The MSAC can only offer advice on the operating plan that covers types of recreational opportunities to be offered, days of operation and environmental matters.

Final decisions are in the hands of DNCR Commissioner Sarah Stewart.

Stewart is supposed to deliver a written response to the mountain that gives her final approval of the plan and confirms the mountain’s operating schedule by June 30.

As part of this approval, Stewart could include certain conditions that the mountain has to meet.

On Tuesday, advisory commission member Dan Wolf recommended that as a condition of approval for Mount Sunapee’s Annual Operating Plan a committee of stakeholders should be formed within 30 days to “set benchmarks” to replace the existing septic system by the end of 2026.

“I’m not going to get into playing games… trying to figure out which scientist is correct and which is not,” Wolf, a former Republican state representative, said. “I’m just looking at simple facts: We’ve got a 54-year-old system that is outdated.”

Meanwhile, the state’s Department of Environmental Services maintains that there is no immediate environmental threat from the system.

State says system still viable

Built in 1971, it serves Mount Sunapee’s base area and takes on up to 20,000 gallons of flow a day during busy winters, Drew Koff, a hydrogeologist within DES’ drinking water and groundwater bureau said during a presentation. The flow ebbs to as low as a few hundred gallons per day in the summer.

The solids in the system settle and are collected from septic tanks in the base area, while liquids flow down to open septic lagoons where it is stored and sprayed onto fields on the side of the mountain during the growing season.

“While the lagoons and the spray irrigation may seem unconventional relative to a septic system, they actually provide a high level of treatment that you don’t get when the water flows from a septic tank directly out to a leech field and directly into the ground,” Koff said.

But environmental groups aren’t convinced.

They have argued that the unlined septic lagoons leach waste into groundwater that flows into Lake Sunapee and some of the spray goes directly into wetlands causing contamination. They presented many of their findings Tuesday, including a historic record of permit violations and concerns with the septic system.

DES representatives countered these claims in their own presentation.

One of the pieces of water quality data that the environmental groups emphasized was the amount of solids over a certain size that were suspended in water sampled at the treatment system.

Koff said while the readings were over regulatory limits, they do not actually indicate contamination.

“It’s not a cause for us to enforce anything or change anything with the system,” Koff said during a presentation.

Koff explained that many of these solids are plant material which are not problematic in the kind of septic system that Mount Sunapee has.

Koff also said that DES is vigilant about monitoring Mount Sunapee’s septic system and does so even more frequently than other septic systems that it regulates.

“The system is old, but I actually think that’s an advantage,” Koff said. “... It’s old because it has worked for a long number of years and it’s a proven solution for the mountain at this time.”

At the meeting, NHDES officials said that while the system does not need to be immediately replaced, they recommend that Mount Sunapee conduct a feasibility study for alternative septic systems as part of its 2026-2030 master development plan.

This proposal was not popular with the crowd or with most members of the MSAC.

“I’m a planner, feasibility studies are our jam, we love that. However, implementation is key,” Meghan Butts, a MSAC member and executive director of the Upper Valley Lake Sunapee Regional Planning Commission, said to the crowd.

Butts said she is worried that if the project progresses “at the rate the state does sometimes in their planning” it could be decades before a change is made.

Resort plans some upgrades

For its part, Vail Resorts does have plans to upgrade and improve some portions of the system through 2027, per a requirement from DES.

For example, the company plans to build a new pump building and take steps such as cleaning, removing vegetation and posting signs around the system.

But Vail does not plan to replace the unlined septic lagoons or spray system.

Mount Sunapee’s proposed annual operating plan is available online at nhstateparks.org/about-nh-parks/park-administration-legislation/commissions-and-committees/mount-sunapee-advisory-commission.

Public comments on the plan can be submitted via mail to: Mount Sunapee Comments, Department of Natural and Cultural Resources, 172 Pembroke Road Concord, NH 03301 or emailed to MountSunapeeComments@dncr.nh.gov until 4 p.m. on Tuesday, June 10.

Clare Shanahan can be reached at cshanahan@vnews.com.