PORTSMOUTH — Once again, the R.I. Department of Environmental Management (RIDEM) is not taking any chances on shellfish grounds being contaminated by a big party on the water that’s attended by thousands annually.

Ahead of the “Aquapalooza” event scheduled for this Saturday at Potters Cove, Prudence Island, RIDEM is preemptively closing 700 acres of shellfish grounds on the north end of the island. 

RIDEM says the increased risk of accidental or illicit discharges of sewage from hundreds of boats gathering off Prudence Island this weekend is necessitating the shutdown, which was also enforced last year. 

The precautionary closure is from sunrise on July 27 until sunrise on Aug. 3, and extends from the shoreline and all waters south and west of a line from Providence Point to the northwest extension of Warner Avenue on Prudence Island.

The Aquapalooza gathering — an unaffiliated, social media-driven event — typically draws more than 1,000 boats and personal watercraft. With so many boats concentrated in such a small area for hours, federal and state public health guidance requires that the shellfish harvest area, which includes Potters Cove and adjacent waters, be closed to protect public health, according to RIDEM.

Although most recreational boaters follow Rhode Island’s “No Discharge” law, a high concentration of vessels increases the chances of accidental or illicit discharge of sewage into shellfish waters. The precautionary closure will provide a sufficient volume of water and time for the dilution of inadvertently discharged sewage before the area is reopened to shellfishing. 

There are currently 15 pump-out boats and 59 facilities located across Narragansett Bay and Rhode Island coastal waters, according to RIDEM. However, these facilities are not routinely in operation along the undeveloped north shore of Prudence Island. Some 40,000 boats are registered in Rhode Island, and the state welcomes many thousands more visiting boats each year. Last year, a total volume of over 600,000 gallons of sewage was pumped out at these facilities and diverted from directly entering Rhode Island’s coastal waters.

For more information on the shellfish harvesting classifications, review the annual notice available at www.dem.ri.gov/shellfish. An interactive shellfishing map is also available.

For information on emergency and conditional area water quality related shellfish closures, call RIDEM’s 24-hour shellfishing hotline at 401/222-2900, or sign up for DEM’s Office of Water Resources' shellfishing listserv at RIshellfishOWR-subscribe@listserve.ri.gov.