The East Strand beach in Portrush was closed earlier this week after a sample of sea-water failed to meet European bathing water standards.
In a statement, the DOE said the water, at Curran Strand, had been tested for ‘faecal indicator bacteria’ and a sample taken on Tuesday ‘failed to meet the required standard of the EC Bathing Waters Directive’.
However, a sample taken on Wednesday indicated that water quality had returned to normal.
In a statement, Coleraine Borough Council confirmed that the water quality was ‘back to normal’.
“Coleraine Borough Council confirms, following some water tests by the NI Environmental Agency, water at East Strand Beach has been confirmed as returning to the high quality as expected.
“The heavy downpour of rain over the past number of days had impacted on the area, but now everything is back to normal and ready for the summer days ahead.”
East Strand is one of 23 beaches in Northern Ireland where the water quality is regularly tested during the annual bathing season, which runs from 1 May to 15 September each year.
The DOE said it works closely with beach operators to notify members of the public “in order to protect public health in the event of poor water quality”.
In a statement the DoE added: “The general advice remains - to exercise caution for 48 hours after heavy rainfall, when pollution from the land can be washed out to sea. More information is available at BeachNI.com