The clean-up operation following a spillage from the Irving Oil refinery in Cork Harbour at the end of January is continuing.
In its most recent incident report on the leak, the Environmental Protection Agency said there is still some residual oil contamination on the water and mudflat surfaces and along the rocks on the shoreline close to the facility.
But it said this should decrease with time due to the ongoing remediation work by the company's cleanup teams and the effects of wind and wave activity.
While the public is being advised to continue to avoid areas where sheens, odours and other visible signs of oil are spotted, the EPA says the shoreline can be used again "with appropriate vigilance".
The EPA has said water sample results near the spill location at Corkbeg Marsh and Whitegate Bay continue to improve.
Irving Oil's spill response team and contracted oil recovery specialists are continuing to recover the remaining gas oil residues using techniques such as low pressure washing, containment by floating booms and recovery by absorbent materials, the agency said.
"Recent results of the water quality monitoring work shows that evidence of oil is now effectively restricted to Whitegate Bay.
"Ecologists have not observed any significant impacts on the aquatic ecology of the shoreline or the Harobur beyong localised coating of seaweed along rocky shoreline areas in Whitegate Bay".
The EPA was notified of a spillage at the facility on 22 January when Irving Oil discovered gas oil had leaked from a small gauge pipe into Cork Harbour.
The EPA said a full report on the incident will issue in due course.
