GROTON -- Looking to expand the role of the Lost Lake Sewer Advisory Committee, members brainstormed ideas with the aim of approaching selectmen for a change in its mandate.

Originally established to study septic conditions at Lost Lake, the committee's recommendation to build a $12.9 million sewer system that would have connected the neighborhood with a treatment plant in Ayer was rejected at a 2012 Town Meeting.

One reason for the rejection was due to the uncertainty that the source of the contamination of the lakes was coming from neighborhood septic systems. Instead, residents insisted a more thorough study of the area around the lakes be undertaken.

A reconstituted Lost Lake Sewer Committee was appointed and consultants were hired to proceed with testing, which proved inconclusive.

Findings did indicate unexpected "emergent contaminants" at different points, including those near the Water Department's Whitney Well site.

Emergent contaminants is a new category of potential pollutants of ground water that is little understood in how it travels in the groundwater or how much of a threat to people its presence might be.

Comprised mostly of prescription medicines, testing at two sites on the lakes indicated the presence of five kinds of drugs and chemicals, including tranquilizers, nicotine, insect repellent, pain relievers and medicines needed to control seizures.

Initial results of the testing indicated relatively low concentrations of nitrates and phosphates, the more common pollutants.

The results left the committee with little support for the installation of an expensive sewer system, particularly if that system could potentially address only part of the contamination problem.

"The testing raised more questions than it answered," said Chairman Jack Petropoulos Thursday.

Petropoulos said the committee lacked direction and asked members for ideas.

Member Susan Horowitz suggested asking selectmen to expand the group's mandate from researching the need for a sewer system to protecting the Lost Lake watershed in general; reviewing the town's bylaws with an eye to beefing them up to better protect the watershed; exploring financing to help Lost Lake residents improve failing septic systems; and identifying specific areas where contaminants are concentrated and try to find ways to correct the problem.

Member Jay Prager agreed the focus of the committee should be on the watershed and not just the lake.

In addition, continued Prager, the committee should not limit itself to contamination originating with local homes, but should look at area runoff as well.

Prager also cautioned members that of all the solutions, construction of a sewer system to solve the problem would be the most expensive project the town had ever undertaken.

As things stood, said Prager, the town has so far spent "chicken feathers" in terms of testing for contaminants in the Lost Lake neighborhood -- not enough to justify recommendation of a $12.9 million sewer system.

Horowitz asked what interest if any the state had in seeing a sewer system constructed in the area. Could it force the town to install one?

Members decided to draw up a report of their discussion listing reasons why it should remain active and for an expansion of its mission to include general protection of the Lost Lake watershed area.

When completed, the report would be submitted to selectmen for review and possible approval.