The town of Oak Bluffs has re-opened two Lagoon Pond beaches Monday morning to swimming. Medeiros Cove off the Sailing Camp Park and the drawbridge beach at Eastville were closed last week when water samples revealed high counts of enterococci, a bacteria that can indicate the presence of fecal contamination. Follow-up tests this week confirmed that water quality now meets state standards.

Swimming in water with high levels of enterococci can pose a safety risk to those with sensitive immune systems, such as the very young and the elderly.

Bacterial contamination of bodies of water is often associated with high rainfall. Though the Island experienced heavy rainfall this past weekend, the town board of health would not confirm this explanation.

The pond at Lucy Vincent Beach in Chilmark has remained closed for several weeks after repeated tests of that water showed high levels of enterococci. The pond is shallow, stagnant and subject to contamination from goose excrement, said Marina Lent, town health inspector.