Eight months after town health officials first detected a contaminated plume running beneath Edgartown Meadows subdivision, they are turning their attention to installing clean drinking water in the neighborhood instead of pinpointing the cause.

"This has dragged on for more than half a year. It's obviously more of a long-term problem," said Matthew Poole, Edgartown health agent.

"The most important thing is for people to have safe drinking water regardless of whether the source is septic systems or the golf club or something we haven't even considered," he added.

Mr. Poole will be meeting with residents of Edgartown Meadows - a 70-lot subdivision off West Tisbury Road - tonight at 7 p.m. in town hall to discuss his most recent test results and his proposal to install town water and wastewater services.

"The board of health is committed to pursuing town water for the residents," Mr. Poole said.

A home inspector first alerted Mr. Poole to high nitrate readings in one Edgartown Meadows house last November. Nitrate levels exceeded 25 milligrams per liter (MGL) in this house; the state's drinking water standards deem levels above 10 MGL unsafe.

Through the fall and winter, Mr. Poole tested more than 150 water samples from 69 properties. He, along with William Wilcox, water resources planner for the Martha's Vineyard Commission, found dangerously high nitrate levels in five other homes and elevated readings in a handful of others. Homes with contaminated wells are centered around two general pockets of the Edgartown Meadows subdivision.

Finding the culprit has proven to be more of a challenge. Initially, neighbors and health officials suspected the Vineyard Golf Club, a two-year-old private luxury golf club neighboring the subdivision to the west. Groundwater flows beneath the golf club on its way to Edgartown Meadows.

Health officials have not been able to pin the problem on the golf club.

"We haven't been able to find anything, to date, to pursue the Vineyard Golf Club as the source of contamination," said Mr. Poole.

They have not quit looking, Mr. Poole said. The town is awaiting an analysis from a nitrate expert who will be able to find possible similarities between nitrate isotopes in Vineyard Golf Club fertilizers, neighborhood septic systems and well water. Those results are expected soon.

For the moment, Mr. Poole and Mr. Wilcox suspect several septic systems in the neighborhood could be causing the problem.

But even this determination is hard for the health agent to make. Water running beneath the neighborhood, which is more than two decades old, passes through only two smaller developments and the Vineyard Golf Club before it reaches Edgartown Meadows. The subdivision is not thickly settled, and none of the houses appears overcrowded, said Mr. Poole. All of the septic systems meet the most recent Title V regulations, a state law that governs installation of private septic systems.

"I find it nearly impossible to gather that it's septic systems doing this," said Mr. Poole. "But if you flip it and determine that it's the Vineyard Golf Club, the contamination would not be as isolated as we're seeing if it were as widespread as the golf club."

Simply correcting potentially problematic septic systems will not do the trick. Contamination is already in the groundwater and will not dissipate even if health officials address the source. As of last week, nitrate readings had returned to acceptable levels in only one of the problem wells.

The eventual destination of the groundwater in this neighborhood is the Edgartown Great Pond. Mr. Poole said he is uncertain what can be done to prevent this water from dumping into the pond.

But as for the neighborhood, supplying town water is the appropriate course of action, Mr. Poole said.

"The safe course is to move toward a reliable source of drinking water," said Mr. Poole. Extension lines from the town's wastewater treatment plant would likely be completed at the same time.

"When you tear up for water, you tear up for septic as well. If you are going to make a mess out there, you make it once," he said.

In other neighborhood news, the Vineyard Golf Club will appear before the zoning board of appeals Wednesday night seeking permission to build 16 homes for club members on 13 acres of land along West Tisbury Road. The Martha's Vineyard Commission approved the golf course in 1999.