Groton — The first comprehensive overhaul of regulations enacted in 1987 to protect the town’s drinking water supply is underway.

Deborah Jones, the town's assistant director of planning and development services, said Thursday that the zoning regulations governing the Water Resources Protection District — a large area of town that includes lands around the reservoirs and feeder streams that supply the public drinking water provided to customers of Groton Utilities — is overdue for revisions.

The consulting firm Horsley Witten Group, an environmental services firm based in Sandwich, Mass., is working with town officials on the revisions, which will be presented to the Zoning Commission and at a public hearing later this year.

The goal is to have new regulations in place by the end of the year, Jones said.

“The water resources protection area really does cover a large area, at least a third of the town or more,” she said.

The current Water Resources Protection District covers about 7,700 acres, mostly in the northern half of town.

About 70 percent of that land is in forest, wetlands and open water, "very favorable conditions" for water quality protection, the consultant said in a December report.

About 774 acres is covered with high- or medium-intensity development, the report said, and about 424 acres is covered by low-intensity development.

Overall, Jones said, the purpose of the regulations is to protect current and future drinking water supplies without being overly restrictive and stifling economic development.

They were created to prevent contamination of water resources by putting restrictions on land uses, waste disposal and storage of materials, and cover both current and future water supplies in reservoirs and other surface waters, as well as aquifers where groundwater flows.

Rick Stevens, manager of the water and wastewater division of Groton Utilities, said he is grateful that he and GU’s environmental engineer were invited to be part of the process when it began last year.

While the revision process is still ongoing, in general the changes made thus far will enhance protection of the drinking water supply, he said.

“They’re making sure all the critical areas and future areas are protected,” he said. “It will afford the town more protection for its water resources.”

Some small streams that feed into the main streams going into the reservoirs, for example, were not shown on the map created in 1987.

The new map being created will include those streams, he said.

Under the current regulations, owners of property in the district must maintain a setback — a 50-foot buffer of vegetation — along any streams or wetlands that supply the reservoirs.

Under consideration is language that would tie the setback requirements to the soil type and the proposed use in the area, Jones said.

“It would depend on how dangerous the use is,” she said.

In March, Mystic resident James Furlong wrote to the Zoning Commission urging that the new water protection regulations match current Inland Wetlands Agency regulations for setbacks from streams.

Under inland wetlands regulations, permits are required for certain activities with 150 feet to 200 feet of the main streams that flow into reservoirs.

Jones said the two setback requirements do not have to match, because the 50-foot zoning setback prohibits certain activities, while the wider inland wetlands regulations require a permit for particular activities.

She said the new regulations, in their current form, would make four main changes to the existing ones:

• The new version would be reorganized and “much easier to read,” Jones said.

• It will call for stricter controls on hazardous waste in the protection area, and how much will be allowed.

• It will upgrade the standards and requirements for the types of businesses allowed, to account for new technology that makes some once-prohibited activities safer, and adds conditions for certain uses that are not mentioned in current regulations.

• It will put more emphasis on sediment and erosion control and stormwater management plans for businesses in the district.

j.benson@theday.com