MILLSBORO — A state agency on Wednesday ordered the Indian River Bay to be closed for weeks to recreational clamming and mussel harvesting due to potential fecal contamination.

A  pump station for Millsboro's sanitary sewer system failed, sending raw sewage into the Iron Branch, a tributary of the Indian River,  which flows into the bay, the Delaware Department of Natural Resources and Environmental Control said in a press release after the agency issued the mandatory closure. The spill was halted Wednesday afternoon, the department said. The closure will last through Aug. 24, per federal guidelines on bivalve shellfish.

The department also advises recreational water users to limit water contact in the upper Indian River Bay for the next few days, particularly in waters near the location of the spill.

The harvesting of crabs, conch and finfish is not affected by the closure, nor are oysters grown commercially under aquaculture leases in Rehoboth Bay. The recreational harvest of oysters is prohibited in Delaware.

The wastewater spill has potentially caused the fecal contamination of shellfish in Indian River Bay, which, according to National Shellfish Sanitation Program requirements, must be closed to bivalve shellfish harvest for 21 days to protect public health. The  21-day period, which is a federal guideline, gives bivalves time for natural cleansing.

DNREC Division of Water staff are monitoring repairs at the Millsboro pump station. Delaware Fish and Wildlife Natural Resources Police working with the DNREC Delaware Shellfish Program are patrolling and monitoring Indian River Bay to enforce the closure to recreational bivalve harvesting, and to ensure recreational clammers are aware of it. More information about the closure and the Delaware Shellfish Program under DNREC authority can be found at de.gov/shellfish.