Avoid Drinking Water Pending More Tests, Officials Tell Edgartown Meadows Homes
By MANDY LOCKE
A new round of private well tests in an Edgartown neighborhood this week intensified the mystery for Island officials working to pinpoint the source of groundwater contamination spreading through the West Tisbury Road subdivision.
"It's too much of a puzzle, too many unknowns at this point," said Matthew Poole, Edgartown health agent, noting that now 20 per cent of the homes tested have water unsafe for drinking.
While the cause of high-nitrate levels in the Edgartown Meadows subdivision is still unknown, the message from the board of health yesterday was clear: Don't drink the water.
As a precaution, the health agent will hand deliver a flier to every resident along Edgartown Meadows Road, Whaler's Walk Road, Codman's Spring Road, Duncan Close, Fisherman's Knot Road and Danalbin Close, advising them to avoid drinking from the tap until a lab test confirms safe nitrate levels.
"This notice is being delivered to you, via hand delivery to your residence, to err on the side of precaution," the notice reads.
Nitrate produces health risks to pregnant woman and small children.
High nitrate levels found by a home inspector in an Edgartown Meadows Road residence two weeks ago alerted Mr. Poole to the problem.
The test registered at 25 milligrams per liter (mgl) of nitrate. The state's drinking water standards deem levels above 10 mgl unsafe. Three doors down, another house showed nitrate levels at 9 mgl, and another on the street registered around 2 mgl.
A new batch of tests on Whaler's Walk Road, prompted by neighbors who attended a meeting with Mr. Poole last Tuesday, revealed another nitrate hot spot further east in the subdivision. Water from two Whaler's Walk homes triggered readings in the 20 range. Another test on the street exceeded 8 mgl. Normal levels in this neighborhood hover below 1 mgl.
"These [new tests] don't clarify anything," Mr. Poole said.
The contamination is forcing Mr. Poole and William Wilcox, Martha's Vineyard Commission water resources planner, to hunt for more than one problem.
"What it implies is that it may be multiple sources as opposed to a single, uniform source. There are intervening wells between the problem areas that are relatively clean. The investigation will go forward on that angle," said Mr. Wilcox.
Tests also revealed elevated sodium levels in the problem wells, a potential sign that the contamination may be linked to wastewater sources.
Last week, health agents eyed as the most obvious suspect the Vineyard Golf Club, a private 18-hole golf course that opened in May of 2002, directly abutting Edgartown Meadows subdivision. Routine tests in the golf course's observation wells throughout the last two years produced normal results. Another layer of testing using a lysimeter, a cup implanted just below the soil to collect moisture, has produced mixed results. In addition, the private firm hired to perform the lysimeter samples did not consistently gather data, Mr. Wilcox said last week.
"I would describe that program as being shaky so far," Mr. Wilcox told Edgartown Meadows subdivision residents last week.
Vineyard Golf Club - which received its approval from the commission in 1999 after extensive local, regional and state review - has not altered its turf management plan in light of recent events. Another round of samples from observation wells on the course took place yesterday, and more lysimeter tests are planned for this month.
The golf club is funding water testing within the neighborhood, though Mr. Poole said it accepts no blame for the contamination.
In its 1999 approval, the commission mandated Vineyard Golf Club owners only use organic fertilizers - a measure adopted to avoid groundwater contamination often caused by synthetic fertilizers. But the organic method throws another curve into the health officials' investigation of the source of contamination. Organic fertilizers may reveal traces of wastewater, a possibility which will make it difficult to determine whether the high nitrate levels come from wastewater sources or fertilizers.
"Organic fertilizers bear some resemblance to wastewater. There might be overlap and make it impossible to determine where it originates," said Mr. Wilcox.
In the meantime, both Mr. Poole and Mr. Wilcox devote large portions of their days to the investigation. They've pulled water samples from the private wells of 27 properties in the neighborhood. Mr. Poole has already filled a binder with water tests and detailed maps of the neighborhood. A survey of the golf club and neighborhood is underway - a map which will give officials more details about the route of groundwater flow.
The contaminated groundwater could linger beneath the homes for months, as water only flows at a rate of between one to two feet a day. The eventual destination for water flowing beneath this subdivision is the Edgartown Great Pond, another point of concern for officials.
For now, Mr. Poole is not concerned about residents beyond Edgartown Meadows subdivision.
"But all that's subject to change. The idea is to continue to track it," said Mr. Poole.