The decision, issued by the Executive Office of Environmental Affairs on July 24, could alter the town's plans to irrigate the golf course with water drawn from the recently dug well. Town officials said it was too early to tell what affect the decision will have on the plan, but Town Administrator Philip Lemnios did say that, "depending on the depth of analysis they are looking for," the cost for preparing an environmental impact report may prove too costly to warrant going forward .

"It adds another step in the process," Lemnios said of the EOEA decision. "We plan to contact them and seek clarifications on some of the points."

Natick Environmental Compliance Officer Bob Bois said some of the issues the EOEA wants researched in the environmental impact report were already "addressed in original proposal," known as a notice of project change, submitted in June by the town to the Massachusetts Environmental Policy Act office, a state office that is part of the EOEA.

"I thought we had enough detail in the original proposal," he said. "This is what we have to work on with MEPA. It looks like they would like to have a little more field work on the impact on the wetlands."

Bois, who just received the decision Monday, said it was too early to say how costly it would be to prepare an environmental impact project or when a meeting with MEPA might be scheduled.

After looking over a copy of the EOEA's three-page decision, a biologist and a hydrologist with ESS Group in Wellesley estimated the cost of preparing the environmental impact report at $15,000 to $35,000, because of the relatively limited scope called for in the decision

Town officials said last month that about $1,000 had been spent to dig the 60-foot well recently located on West Street. They said the overall cost, including installing about 1,100 feet of pipe, would be around $50,000.

The town in essence is paying itself for the water it currently uses at the golf course, which is fluoridated municipal water from the town's Springvale Treatment plant.

In the notice of project change, Natick said it "is pursuing this project change in an effort to reduce water withdrawal on the municipal drinking water production wells."

However, according the notice of project change, prepared for the town by Haley and Ward, Inc. in Waltham, the golf course used 5.8 million gallons of water, just a fraction of the more than 1.2 billion gallons the town uses annually.

Lemnios said since the golf course is an enterprise operation - one whose receipts are supposed to offset its costs - it would be advantageous to eliminate from its expenses the cost of paying for town water, even though it is an expense that doesn't affect the town's overall bottom line.

Sassamon Trace, which opened in September 2001, had an operational deficit of nearly $300,000 in fiscal year 2003. Last season Sassamon Trace paid about $50,000 for water, according to Lemnios.

On some days during the dry weather last August, Sassamon Trace used nearly 40,000 gallons of town water, said Bois. He said the new well would be able to produce up to 72,000 gallons a day and would be equipped with a meter to monitor the water use.

"My biggest concern is how would the well impact the habitat in the large northern marsh vernal pool," said Natick resident Jacqueline Boucher, who wrote a letter of comment to the EOEA regarding the well proposal. "This is not an isolated wetlands. It is part of an entire wetlands system. ... We're not talking about changing one little thing. It could have a domino effect - if you mess up one little thing, it could mess up the whole area."

Like Boucher, Nigel Pickering, a senior engineer with the Charles River Watershed Association, was concerned about the possible far-reaching effects of water drawdown in a wetlands. He said the town needs to provide more detailed analyses of the impact of lower water levels in that area and what corrective measures it planned, if needed.

"Wetlands areas can be very sensitive to water fluctuations," he said. "Just to put the well in there and say it is going to have no effect - we know better. There is probably going to be some effect. They need to put together some sort of conservation management plan."

Part of the Sassamon Trace Golf Course is located in Sherborn, whose residents use well water. Asked if switching from municipal water to well water for irrigating the course would raise in any concerns for Sherborn, Sherborn Town Administrator Robert Reed said, "that is something that is being looked at. I don't think any final decision has been made."

The golf course project, partially built on Natick's capped landfill, was initially subject to MEPA review, according to Department of Environmental Protection spokesman Felix Brown, because it required a DEP landfill post-closure permit and because the construction involved the alternation of more than 25 acres of land. Because the proposed well requires an alteration to the golf course plan that was approved in 1999, the town had to file a notice of project change with MEPA.

Because of the EOEA's decision last week, Natick will have to prepare the environmental impact report before it can apply for permitting it needs for the project from the DEP and the Natural Heritage and Endangered Species Program, Brown said.

In her decision last week, EOEA Secretary Ellen Roy Herzfelder wrote that after a review of the Natick's notice of project change and comments from the Division of Fisheries and Wildlife, the Department of Environmental Protection, the Charles River Watershed Association, and Boucher, "I am requiring an EIR to evaluate potential alternatives to the proposed well, and to develop further information on impacts and mitigation."

The letter also stated, "The Natural Heritage and Endangered Species Program (NHESP) has determined that the proposed well would '... cause significant negative impacts to state-protected rare species habitat,' and thus may require a Conservation Permit. The Department of Environmental Protection (DEP) has also raised concerns with potential drawdown effects and has requested preparation of an EIR."

Before Sassamon Trace was built, the plans underwent MEPA review in July 1999. At the time, the project included "a proposed water withdrawal well," according the decision issued last week by the EOEA

The EOEA originally required an environmental impact report for the project, but lifted that requirement in September 1999 after Natick eliminated the proposed well from the original plan and said it would irrigate the course with municipal water.

The new well is in a different location than the site proposed in the town's original proposal in 1999, but it is "near the original well location," according to the EOEA decision, and "located adjacent to a vernal pool and a wetland with priority habitat."

In her comment letter to the EOEA, Boucher noted, "The proponent is proposing to use a new site for this well, but it is merely across the street from the previous well. This proposed well is also in Natick's designated Aquifer Protection area."

In their comment letters, Boucher and Pickering both raised concerns that drawing water from the proposed well area could reduce surface water levels enough to endanger rare species in the nearby wetlands area.

"Important state-protected species have been identified in these systems, such as Spotted Turtle, Mystic Valley Amphipod, and Blue Salamander," wrote Pickering.

"Not only is the vernal pool 'at stake', but potentially the entire wetland system, including two additional [certified vernal pools] #1292, 1319, that are on this site," Boucher wrote. "The golf course area wetland system forms the headwaters for Indian Brook, which flows into the Charles River. Indian Brook is one of the focal points of the Mass Audubon Broadmoor Sanctuary and is a significant contributor to the Charles River."

In its written decision, the EOEA wants Natick to "address the concerns raised in the comment letters" with both "narrative and technical analysis."