Seth’s Pond in West Tisbury remains closed for swimming

In this file photo taken last summer, West Tisbury health officials posted signs prohibiting swimming at Seth's Pond. — File photo by Mae Deary

West Tisbury health officials ordered Uncle Seth’s Pond closed to swimming on July 3 due to high bacteria levels. The most recent water samples tested indicate that bacteria levels remain higher than state regulations allow, so the pond must remain closed to swimmers.

According to West Tisbury health agent John Powers, water samples taken Monday, July 9, indicated 216 colony forming units per 100 milliliters (cfu/100ml) of enteroccoci bacteria in the water. State regulators require fresh water ponds closed if the bacteria counts exceed 61 cfu/100ml.

Mr. Powers said he is testing the water nearly every day, and the results vary widely.

“It’s up and down,” Mr. Powers said. “The pond is very low. We haven’t had any rain, and it didn’t get any recharge over the winter, very little snow and very little runoff.”

The pond must remain closed until water testing indicates it is safe for swimming.

Enterococci are a group of bacterial species within the streptococcus genus, some of which (e.g. streptococcus faecalis) are typically found in human and animal intestines and are therefore present in sewage. These tests are also referred to as indicator organisms.

The Massachusetts Bureau of Environmental Health advises that swimming in polluted water can cause gastrointestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain; respiratory symptoms such as sore throat, cough, runny nose, and sneezing; eye and ear symptoms including irritation, earache, and itchiness; dermatological symptoms like skin rash and itching; and flu-like symptoms such as fever and chills.

Most of these symptoms are minor most of the time but can occasionally be more serious, especially in sensitive populations like immuno-compromised children and the elderly.