State lifts Kaktovik do-not-drink water order

Kaktovik residents can drink their tap water again. The Alaska Department of Environmental Conservation Drinking Water Program rescinded the Do Not Drink order Saturday, three weeks after a lab result overturned the state's first read on the contamination, according to the Sept. 26 public service announcement.

The announcement says residents may resume using the public water system for drinking, cooking, brushing teeth and making ice. North Slope Borough Public Works offers optional glycol field tests at household taps at 907-640-6514 or 907-640-6515, and will provide bottled water to anyone who requests a test until it is complete. Residents do not have to wait for results.

The contamination began Aug. 16, when a plant operator used a mislabeled chemical container while preparing a disinfectant solution, according to the borough's water-incident FAQ. The South Tank was isolated. The North Tank was believed unaffected.

DEC and the Alaska Department of Health initially calculated about 0.024 milligrams per liter of ethylene glycol, and residents were told the water was safe. A Sept. 5 lab result showed 26 milligrams per liter in the distribution system, more than 1,000 times the estimate. The order came that day.

The borough planned to discharge 1.5 million to 3 million gallons of water with low levels of ethylene glycol to Kaktovik Lagoon while pumping the North Tank, starting Sept. 13.

Crews later removed a failed heat exchanger tied to the North Tank. Six samples collected Sept. 14 showed no glycols above a 3 milligram-per-liter detection limit, according to the Sept. 23 operational update. Samuel Simmonds Memorial Hospital found no evidence of ethylene glycol toxicity in more than 65 residents tested.

The borough has said its initial assessment rested on the reported amount of chemical involved, the South Tank's isolation and the understanding that the North Tank was unaffected.

The borough also planned to upgrade all heat exchangers and pressure-test reservoir heating-loop piping. The records reviewed do not say why the first calculation missed so badly, or whether those steps will prevent a repeat.