City considers hauling excess sewage sludge

Hawaii Independent Staff

HONOLULU—The City and County of Honolulu will be testing the feasibility of hauling sewage sludge from the Sand Island Wastewater Treatment Plant to the Honouliuli Wastewater Treatment Plant starting in mid-August.

Tests will include hauling no more than one 5,000 gallon truck load per day from Sand Island to Honouliuli, on intermittent days, for no more than 30 days. Future testing may also include hauling similar loads to the Waianae and/or Kailua treatment plants.

Prior to testing, a public informational meeting will be held on Monday, August 1 at 7:00 p.m. in the Mission Memorial Auditorium (Civic Center grounds, beside Honolulu Hale). The Department of Environmental Services will also set up a hotline for callers to report any problems encountered during the feasibility testing.

Mayor Peter Carlisle ordered an environmental assessment of the potential of hauling additional loads of sludge for a sustained period.

According to the City, the sewage sludge processed at the Sand Island plant currently exceeds the capacity of the single Sand Island digester, and a contingency plan must be in place to protect public health and safety. The efficiency of the plant was improved in 2008, and this led to increased amounts of sludge being removed from the wastewater. Like the water, the sludge must also be treated. By early 2010, the digester was reaching its designed capacity. The mayor’s proposed budget provided for funding a second sludge digester at the Sand Island plant, but a vote by the City Council on June 3 defunded the project.

“If the funding for a second digester had not been removed, some limited trucking of sludge would have been a remote contingency during the interim construction period,” said Environmental Services Director Tim Steinberger. “It is more likely now, and on a sustained basis, which is why test runs are necessary.”

“If circumstances go south at Sand Island, we will have no choice but to truck sludge to the other treatment plants on Oahu,” Carlisle said. “As an absolute last resort, if trucking is not available, the City must issue a moratorium on sewer hookups to limit the volume processed by the existing digester. A moratorium unnecessarily harms the economy and of the State and County during a time when jobs here are essential. To do nothing would be irresponsible.”