Large Wastewater Spill in Hilo Result of Pounding Rains, County Says

Persistently bad weather Tuesday resulted in consequences beyond dangerous road conditions and flooded areas on the windward side of the Big Island.

An estimated 400,000 gallons of wastewater has made its way into Big Island waters fronting the Papaikou Wastewater Treatment Plant as a result of heavy rains that continue to pound much of Hawai´i County.

The county listed the official time of the spill as 8 am Tuesday morning. It occurred at the wastewater treatment plant located on Hawai´i Belt Road.

A description of the problem noted an overflow of the plant’s diversion box, which led to the spill of partially treated wastewater. The contaminated water then flowed from the ground into a drainage swale off the property. The drainage swale flows into the nearshore coastline at an area identified as Waipahi Point.

A report from the county said high rainfall created an excess of material into the collection system, creating high flows that fed into the treatment plant.

“When the operator arrived at the WWTP at 8 am, he noticed the overflowing diversion box,” according to the county’s statement. “He opened the valve to the unused secondary clarifier and diverted wastewater into this clarifier. This diversion stopped the spill.”

Warning signs have been posted advising the public to stay out of coastal waters from Kekiwi Point to Waipahi Point, as well as further north along the shoreline.