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Emergency Rainfall Closure Criteria

On October 20, 1989, the New York State Department of Environmental Conservation designated most bays and harbors in Nassau and western Suffolk counties as temporarily uncertified for the harvest of shellfish following a rainfall that measured nearly 4.5 inches in some areas. That first "Emergency Rainfall Closure" of shellfish harvest areas lasted between four (4) and seven (7) days. During that time the DEC, in cooperation with bay constables and other staff from the environmental bureaus of several towns, was able to collect and examine water samples from nearly all the areas affected by the closures. The results indicated that all areas closed on an emergency basis were adversely affected by the runoff from that extraordinary rainfall and the closures were appropriate and necessary to protect public health.

Since that first emergency closure there have been many more heavy rainfalls that were followed by emergency closures of harvest areas. In each of those cases, water sampling was done in key areas to determine when it was possible to re-open. The results clearly indicated that excessive storm water runoff following rainfalls greater than three (3) inches had significant adverse effects on water quality. The results also showed that water quality improvements were detectable by the third and fourth days of the closures, when compared to results from samples collected on the first and second days of the closure. Areas will only be re-opened after water quality has been demonstrated to meet certified area criteria and shellfish have adequate time to naturally cleanse themselves of potential pathogens.

Please Note: DEC has since determined that it may be necessary to implement emergency closures in some areas, during the summer months after rainfalls that are less than 3 inches. Recent events have shown that certain areas are adversely affected by less than 3 inches when water temperatures are warmer. It also may be necessary to extend closures beyond seven (7) days when water quality does not improve by the sixth day (per Title 6NYCRR, Parts 42.17 "Sanitary Control over Shellfish" and 47.4 "Certification of Shellfish Lands").

Based on what we have learned from our experience with several emergency rainfall closures, any area that is closed on a temporary emergency basis following a rainfall of more than 3 inches will remain closed for at least 3 full days.

NORTH SHORE: All north shore embayments affected by extraordinary rainfall will be closed for at least three days. However, due to the relatively large tidal ranges on the north shore, north shore areas may re-open on the fourth day if testing of water samples demonstrates acceptable water quality. Likely exceptions are Stony Brook and Mount Sinai Harbors which are relatively shallow and have very narrow inlets to the Sound. In those areas it may take a day or two longer for water quality to return to acceptable levels.

SOUTH SHORE: On the south shore, areas SS1 (Hempstead Bay), SS2 (South Oyster Bay) and SS3 (Great South Bay, Babylon) will be entirely uncertified for at least four days when emergency closures are necessary. East of the Robert Moses Causeway, the northern portions of areas SS4, SS5, and SS6 and the western portion of SS7 (Bellport Bay) will be included in the emergency closures, but areas in the southern portion of Great South Bay, SS4, SS5 and SS6, as well as the eastern portion of SS7 may remain certified. During most recent closures, a line running from where the Robert Moses Causeway comes ashore on the north side of Captree Island, running through several navigational buoys along the east/west channel in the northern part of the bay to a buoy south of Howells Point then proceeding southeasterly to the flag pole at Bellport Beach on the barrier beach, has been used as the temporary closure line.

The large drainage area, smaller tidal ranges and small ocean inlets all cause contaminated runoff to adversely affect water quality in portions of Hempstead, South Oyster Bay and Great South Bay for several days. Therefore, some south shore embayments may remain closed for 7 days, excluding the day the closure designation is made, or longer if water quality has not improved by the sixth day.

EAST END EMBAYMENTS: Generally, all of Moriches Bay and Shinnecock Bay will be closed following extraordinary rainfall events. In the Flanders Bay, Peconic and Gardiners Bay areas, all the enclosed bays, harbors and creeks within the Towns of Riverhead, Southold, Shelter Island, Southampton and East Hampton will be designated as uncertified following rainfalls of more than 3 inches.

Based on results of sampling during recent emergency closures, many east end embayments may re-open after 4 or 5 days if water sampling demonstrates acceptable water quality. However, on a case-by-case basis some areas may remain closed for longer periods. For example, Flanders Bay has remained closed for as long as 7 days.

NOTIFICATION: The Department immediately notifies the affected towns, including the bay constables or harbormasters, about all emergency closures. The Department also advises local news media, including cable channel 12 (News 12), Newsday and local radio stations. Although the Department has contacted news media regarding emergency closures, they have not always carried the information provided to them.

You can reach the Shellfisheries Emergency Closure Information Line by calling (631) 444-0480. A recorded message is available 24 hours a day, including weekends. During emergency closures, the recording will give the most up-to-date information about which areas are affected by the closures; descriptions of the closure lines will also be provided.

REOPENINGS: When possible, the Bureau of Marine Resources/Shellfisheries Section will begin sampling on the second day of an emergency closure and will attempt to collect samples from as many areas as possible. In the event of widespread closures, north shore areas will usually be sampled on the 2nd and 4th days, and south shore and east end areas will usually be sampled on the 3rd and 5th days. Areas will be re-opened based on demonstrated improvements in water quality, as described above. Sampling assistance from towns may allow earlier openings.

Beginning on the afternoon of the 3rd or 4th day after an emergency closure, an updated message about re-openings will be available at (631) 444-0480 after 4:00 p.m. The updates will be based on the results of water quality testing during the closures.

We ask that all shellfish harvesters make an effort to be aware of weather forecasts that predict unusually heavy rainfall, especially from thunderstorms, tropical systems and nor'easters. Emergency closures will be put into effect in all areas affected by runoff from rainfalls of more than 3 inches that occur over a 24-36 hour period. If you have any questions, please contact us at (631) 444-0492.


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