Wastewater Spill at Pāpaʻikou Treatment Plant Prompts East Hawaiʻi Shoreline Closures

A malfunction at the Pāpaʻikou Treatment Plant allowed up to 98,300 gallons of "fully treated, insufficiently disinfected" wastewater to be discharged along the East Hawaiʻi shoreline, the Hawaiʻi County Department of Environmental Management reported, prompting closure of the coast from Lyman Bay (Mill Beach) to Waipahi Point. The county said the closure covers shoreline activities and is in the vicinity of the plant outfall.

Hawaiʻi County DEM said the problem stemmed from a "failure in the automated disinfection system" that occurred sometime between 2 p.m. on Feb. 11 and 8:45 a.m. on Feb. 12. The agency characterized the released effluent as "fully treated, insufficiently disinfected" and gave the spill amount as "up to 98,300 gallons."

DEM crews "took immediate remedial actions to manually disinfect the effluent" after discovering the issue and "restored the automated disinfection system by 9:03 a.m.," the county release stated. Emergency procedures were activated and the county communicated the incident to relevant state agencies as part of the response.

After consultation with the State Department of Health, officials closed the shoreline "from Lyman Bay (Mill Beach) to Waipahi Point" and described the measure as precautionary. The county release says the area is "closed to shoreline activities like swimming, fishing, and boating as a precautionary measure." Contaminated water warning signs have been posted along the affected coast.

Public safety postings will remain until testing confirms it is safe to reopen. "Contaminated water warning signs have been posted and will remain in place until bacterial levels are within acceptable levels and approved for removal by the state Department of Health," the release said. The public will be notified when sampling meets reopening criteria: "The public will be advised when sampling has confirmed that levels are within acceptable levels for shoreline activities."

Local social media amplified the closure, with a community post sharing a closure map and safety warnings for swimmers and fishers near Mill Beach and Waipahi Point. DEM did not include bacterial counts or laboratory results in its initial statement, and the county has not released a detailed incident report or the specific mechanism of the disinfection-system failure.

County and state officials say they will continue sampling and monitoring before lifting the closure. Residents and visitors in the Pāpaʻikou area should heed the posted warnings and avoid shoreline activities between Lyman Bay (Mill Beach) and Waipahi Point until the State Department of Health approves sign removal.