Test runs for the hauling of raw sewage sludge from Sand Island are scheduled to begin in mid-August to Honouliuli, Mayor Peter Carlisle said at a news conference today.

Sewage will not be hauled to the Waianae and Kailua sewage treatment plants at this time because of mechanical issues at those plants, but the Waianae and Kailua plants remain in the long-range plan, city spokesman Markus Owens said.

Carlisle said he has ordered that an environmental assessment be conducted on the city’s plan to haul sewage to all three wastewater treatment plants.

“Since it may be inevitable, it would be a waste of time to wait until we are ordered to do it,” he said. “Therefore, we will do it now.”

A public information meeting has been scheduled for 7 p.m., Aug. 1 at the Mission Memorial Auditorium, where city administrators and engineers will be on hand to answer questions from the public.

Test runs will involve no more than one 5,000-gallon tanker a day, on intermittent days for no more than 30 days, and the city will use “all available means” to reduce odor,” the mayor said.

Hauling to Waianae and Kailua was ruled out in the short term because of issues related to the “digesters” at those facilities. The digester takes in the sludge — solid waste removed from raw sewage water — and converts it to composting material that can be discarded in the landfill.

City spokesman Johnny Brannon said sludge will initially be trucked only to Honouliuli, and the city will evaluate the impacts. The Waianae and Kailua plants have not been removed from consideration, he said.

The digester at the city’s Sand Island treatment plant is nearing its capacity, and hauling the sludge from that plant to outlying areas is seen as a temporary solution until a second digester, or other treatment technology, can be added at Sand Island.

Carlisle said the city’s other option was to place a moratorium on all new construction projects in the urban core, to prevent additional hookups to the sewage lines that lead to Sand Island. Doing so would have affect construction activity and job growth and could stall economic growth, he said.