State judicial officials are investigating why roof patching material washed off the Ukiah courthouse roof during Tuesday’s rainstorm, triggering a large-scale hazardous materials response that county officials estimate will cost tens of thousands of dollars.

“There was a failure somewhere,” said Wayne Briley, the county hazardous materials incident team member managing the effort to keep the milky runoff from going down storm drains and into creeks and rivers.

A state Judicial Council spokeswoman said her agency’s staff will be investigating why the patch application failed and who is at fault.

Briley said he got a call about white fluid running down the street at 8 a.m. He closed off one street adjacent to the courthouse while personnel from city, county, state and private agencies controlled the spill with sandbags and then suctioned the liquid into large tanks. He estimated about 5,000 gallons of diluted roofing material was collected and now must be disposed of properly.

The roofing material at the center of the cleanup effort was Tuff-Coat, Judicial Council spokeswoman Keby Boyer said. Its label states it is not toxic to humans in normal concentrations. But one ingredient, titanium dioxide, is a suspected carcinogen, Briley said.

He said the spill needed to be stopped, regardless of whether it was toxic. According to state water quality officials, “the only thing that should go in a storm drain is rainwater,” Briley said.

Fish and Wildlife officials monitoring the white runoff reported that it did not appear to have reached the outlets to any creeks, Boyer said.

The cleanup included workers from Madsen Roofing, the company that applied the Tuff-Coat. They power washed the courthouse roof to ensure there was nothing left to wash away in the future, Briley said. The cleanup concluded at about 9 p.m., he said.

You can reach Staff Writer Glenda Anderson at 462-6473 or On Twitter @MendoReporter