Hidden Bacteria in Sound Shore's Calm Waters

Although the Long Island Sound’s waters may look pristine, according to a report by the National Resources Defense Council (NRDC), what seems apparent may prove to be deceptive.

The 2012 “Testing the Waters Report” put out by the non-profit environmental action group looked at the percentage of water samples in 2011 that exceeded state standards, causing beaches to close. The number of beach closures and advisory days rose from 94 in 2010 to 140 in 2011.

According to the report, two beaches in Mamaroneck had the highest percentage of samples exceeding the 104 colonies/100 ml for a marine beach allowable by the state, in Westchester County: Shore Acres Club had a 32 percent rate and had a 17 percent rate.  Other neighboring beaches had similarly elevated rates of bacteria that exceeded the state limit, including the Davenport and Green Tree Clubs in New Rochelle, both with 17 percent averages. Please see below for the full list or go to the NRDC website here.

County

Beach

Tier

Assigned Monitoring Frequency

Total Samples

% of samples exceeding state standards

Closing or Advisory days

Westchester

American Yacht Club

2

once a week

17

6%

0

Westchester

Beach Point Club

1

once a week

19

5%

14

Westchester

Beckwithe Pointe

1

once a week

18

11%

2

Westchester

Coveleigh Beach Club

2

once a week

17

12%

13

Westchester

Davenport Club

2

once a week

18

17%

13

Westchester

Echo Bay Yacht Club

1

once a week

14

0%

13

Westchester

Glen Island Park

1

once a week

17

6%

2

Westchester

Greentree Club

1

once a week

18

17%

13

Westchester

Harbor Island Beach

1

once a week

52

17%

14

Westchester

Hudson Park

1

once a week

37

14%

13

Westchester

Isle of San Socecci

3

none

0

n/a

0

Westchester

Larchmont Manor Park

1

once a week

16

6%

0

Westchester

Larchmont Shore Club

1

once a week

17

6%

0

Westchester

Mamaroneck Beach and Cabana Club

1

once a week

21

14%

14

Westchester

Manursing Island Club

2

once a week

16

6%

0

Westchester

Marinas Edge

3

none

0

n/a

0

Westchester

New Rochelle Rowing Club

3

once a week

16

6%

0

Westchester

Orienta Beach Club

1

once a week

20

5%

14

Westchester

Rye Playland Beach

1

once a week

17

6%

0

Westchester

Rye Town Park - Oakland Beach

1

once a week

16

0%

0

Westchester

Shenorock Shore Club

2

once a week

18

11%

0

Westchester

Shore Acres Club

1

once a week

19

32%

13

Westchester

Surf Club

1

once a week

18

11%

0

Westchester

VIP Club

2

once a week

19

11%

2

Westchester

Westchester Country Club Beach

1

once a week

17

6%

0

According to Mamaroneck Village Manager Richard Slingerland, one explanation for the seemingly large 48 percent increase in bacteria count from 2010-11 could be related to the lower than average rainfall the village experienced in 2010. Anecdotally, Slingerland said, in 2010 more people were watering their lawns than usual and the village received an influx of complaints regarding unusually high water bills.

Tropical Storm Irene, which dumped many inches of rain in Mamaroneck, occurred in 2011, potentially adding to the overall precipitation rate that year.

“Because of the low amount of rain there was less runoff out of parks,” he said, referring to bacteria laden overflow like dog and goose waste.

“The county does very regular tests to determine whether there is bacteria in the water,” said Slingerland. 

One method the village has for combating bad bacteria is with a Gunderboom, a filtration fabric boom (a floating barrier used to contain spills) that keeps out harmful bacteria in the water. The current Gunderboom has been in place since 2009.

The Westchester Department of Health regularly tests beaches along the Long Island Sound—between late May and a little after Labor Day—that studies have shown are impacted by heavy rainfall, said the Department’s Spokesperson Caren Halbfinger. These beaches include Harbor Island, , , Shore Acres Point Club, and the Davenport and Greentree Clubs in New Rochelle, among others.  Click here for the full list.

“Sampling has shown us that this is a prudent step for us to take,” she said, referring to the impacted beaches.

Further, the beaches are preemptively closed during periods of heavy rainfall exceeding ½ inch, with the number of closure days directly correlated with the amount of accumulated rainfall.  The Health Department continues to monitor the situation, with more frequent resampling of water if the amount of bacteria showing up is abnormally high.

The frequency of beach testing at New York beaches depends on a number of factors, said Leah Schmalz, the director of legislative and legal affairs for Save the Sound, a program of the Connecticut Fund for the Environment.  The organization circulated the NRDC report in a press release earlier in the week to draw attention to the growing issue of beach closures due to environmental contaminants.

“[It] is based on a number of factors:  high swimmer volume, excess rain storms, sewage spills etc…Additionally, some beaches that might only normally test once a week, will retest numerous times if the bacterial level from the initial test is too high,” she said.

“While Westchester has taken strides to improve water quality, the tide has not yet turned,” she said. “If we want to enjoy our coastline, eat local seafood, and promote tourism along the shore, rain or shine, we must curb pollution at the source— investment in sewage treatment upgrades and Green Infrastructure are two critical solutions.  While much progress has been made in the last decade, improvement on these two fronts will decide whether the citizens of Westchester will have the clean water they deserve."