Concerns over how bitumen spill at Cork water plant was managed

A bitumen spill at Uisce Éireann’s Cork harbour and city water supply shut down operations for 12 hours and was not suitably reported to protect public health, an Environmental Protection Agency (EPA) audit has said.

The EPA recently published a report based on an unannounced inspection at the end of August of the Cork Harbour and city public water supply facilities.

The area serves a population of 143,555, with an average output of 64,135 cubic metres a day. Raw water is abstracted from the River Lee at the Inniscarra Lake and taken for treatment at the Inniscarra water treatment plant.

On August 28, the operator became aware of a bitumen-type liquid that had entered the raw water sumps at the Cork Harbour and city water treatment plant in Inniscarra. The raw water intake was shut off, and the material was removed from the sump.

Bitumen is a black mixture of hydrocarbons, usually a substance such as tar or asphalt, which is commonly used for roofing.

Following the removal of the spill, an inspection of the water treatment systems was carried out, along with risk assessments and compliant water monitoring.

Upon investigation, it was found that contractors working on a roof had spilled a bituminous-type product, which entered the raw water sumps via a roof gully.

The incident was not “suitably alerted to the plant operators, escalated, and managed in order to maintain water quality and protect public health”, the audit said.

The report explained: “Contractors working on the roof of the pumping station spilled a bituminous-type product. The exact volume spilled is not known but was less than 20 litres. The spill was partially cleaned up but some of the spill entered a roof gully.

“It was not known at the time but the roof gully is designed to harvest rainwater from the roof of the pumping station into the raw water sumps. The roofing contractors did not report this incident to the plant operators.

“A separate team of contractors were working inside the raw water sumps and noticed a slick in the water. This was reported to the plant operators and the plant was shut down at approximately 8.15pm.”

The raw water sumps were emptied over the next 24 hours and examination of the water treatment system, risk assessments, and monitoring of the water quality were conducted.

Once it was confirmed that the spill did not have an impact on water quality, the plant was restarted the following morning. Samples analysis on the raw and treated water that day and four days later came back clear.

The EPA concluded that Uisce Éireann should “without delay” ensure all contractors at the water treatment plant report any incidents promptly. Uisce Éireann representatives were advised that action had to be taken to address the issues and were asked to submit a report detailing actions taken and planned.