The University of Hawaiʻi notified the Hawaiʻi Department of Health that it was investigating two fluid leaks from the chilling system of the UH 88 inch observatory on Maunakea, operated by the Institute for Astronomy (IfA).
The fluid is estimated to consist of 70% water and 30% ethylene glycol, which is commonly used as an antifreeze in cooling systems. In pure form, ethylene glycol is classified by the Environmental Protection Agency as a hazardous substance. An independent laboratory is being contracted to determine the exact mixture of the fluid leaked.
Two leaks in the chilling system were detected on January 10 when telescope staff were unable to restart the system after it had been turned off in mid December, ahead of a winter storm. The chilling system will remain off until the investigation is completed. The closed system had been working properly prior to the shutdown and had been restarted before without issue. The leaks located in a drain valve and a pump inlet tube have been stopped and contained.
The State of Hawaiʻi requires that any spill of one pound or more of ethylene glycol should be reported, while the federal government puts the reporting threshold at 5,000 pounds. Given the current lack of certainty about the exact details of the leak relative to reporting requirements, UH notified relevant government agencies of the event out of an abundance of caution.
