The Edgartown board of health has detected elevated nitrates in water drawn from two private wells in a neighborhood off the Edgartown-Vineyard Haven Road that includes Shady Oak Lane, Price’s Way, Huckleberry Hill Lane and Dubud Lane.

Town health agent Matt Poole said the town issued a targeted reverse-911 call to the neighborhood last night and urged people in the affected neighborhood to have their water tested. He stressed that the advisory was applicable only to those with individual, on-site private wells and did not affect those who are on town water. The source of the contamination is unknown.

“It’s not known for certain,” Mr. Poole said. “Nitrate is linked to wastewater so it could be from agricultural use from animals or fertilizer. It can also be landscaping but that neighborhood has generally modest lawns so the likelihood is best that it’s related to the normal operation of on-site septic systems. It’s generally not linked to how well those systems are performing.”

Mr. Poole said nitrates pose a risk to vulnerable populations.

“It’s a potential risk to the elderly and anyone who has any sort of immune-compromised system, pregnant and nursing women and infants under the age of six months,” he said. He said in “incredibly rare cases” elevated nitrates had been associated with blue baby syndrome.

More information can be found on the town Web site at edgartown-ma.us/cms/.