Diary

Sewage study

A resolution adopted by the City Council will solidify an agreement between the City and County of Honolulu and the University of Hawaii Water Resources Research Center (UH-WRRC) to conduct an analysis of impacts from ocean sewer outfalls on the marine environments off of Oahu. The city will pay UH-WRRC as much as $2.5 million for biological and sediment studies in portions between now and June 30, 2017 .

An outfall is a discharge point where a waste stream flows into a body of water, whether it is a stream, lake or ocean. Oahu’s four main outfalls are off of Sand Island, Mokapu, Barber’s Point and Waianae. In 20 years of research,“We’ve never been able to determine any negative effects on the life around the outfalls,” says Philip Moravcik, technology transfer specialist for UH-WRRC.

In some places, Moravcik adds, the outfall pipe and supporting structure have served as an artificial reef of sorts and enriched the surrounding areas in arguably a positive way.

“In order to definitively say there have been effects from the outfall,” says Moravcik, “you need a large impact of some kind, and we just haven’t seen that.” The city has been exempt from having to have secondary treatment at its wastewater plants partly because deep outfalls dilute sewage in the ocean. The Environmental Protection Agency (EPA) had granted waivers on condition that Honolulu monitor the marine life around outfalls, until a recent consent decree compelled the upgrading of treatment plants. The monitoring, however, will proceed.