A blocked sewer pipe sent an estimated 41,000 gallons of untreated sewage into the Wailuku River and Hilo Bay on Monday, causing the closure of the entire bay area to fishing, swimming and other water activities until further notice.
Warning signs alerting the public about contaminated water were posted along the river and throughout the bay area, according to county Department of Environmental Management Director Bill Kucharski.
“(The department) has taken water samples in the Wailuku River and west-east of the river outfall into the bay,” Kucharski said in a news release Monday evening.
The department took water samples as far east as Reed’s Bay, and will be doing the analysis.
“We will continue to post warnings about the safety of the bay until it is established that the water quality is safe,” Kucharski said in the release.
The blockage that caused the spill was “in one of our main sewage lines going to our sewage treatment facility,” Kucharski said. A main sewer feeder line was blocked by debris, sending sewage through a manhole and into a stream adjacent to Waianuenue Avenue and Laimana Street. At the top of the manhole was a 4-inch overflow pipe that “we didn’t know about,” Kucharski said.
Dora Beck, wastewater division chief, said sewage was released for about four hours. The blockage was cleared at about 1 p.m., and cleanup operations were ongoing as of press time.
The location of the blockage was at the corner of Waianuenue and Laimana next to Hilo High School, she said.
Kucharski said sewer systems from the school, Hilo Medical Center and the prison all connected into the main sewer line, along with private homes in the region.
Beck said workers found rags and fabric inside the main 10-inch pipe and were clearing it of additional debris.
Raw sewage might contain material from the toilet, tub, kitchen sink and laundry, said Misty Pacheco, an assistant professor at the University of Hawaii at Hilo who has a doctorate degree in public health.
“All that stuff is in there,” she said.
Pacheco warned “any time you expose yourself to a body of water that has sewage, it contains disease-causing bacteria, viruses or parasites.”
Since the sewage hasn’t been treated, even the aerosol — mist from the ocean or river — could be bad to get near, she said.
Exposure could cause gastrointestinal ailments and vomiting, pain and diarrhea, Pacheco said. It also could cause skin rashes and infections of the eyes, nose and mouth — the three routes through which a person can get infected by contaminated water.
“A lot of people I know, they fish in those bodies of water,” Pacheco said. Even eating fish caught from sewage-contaminated water “is a danger, it’s a risk.”
Pacheco cautioned that keiki will mirror what adults do. If an adult goes into contaminated water, a child might think it’s OK, even though young children are at greater risk for serious illness. She said people should obey warning signs when they see them.
The Clean Water Branch of the state Department of Health said in a statement that it generally takes several days before the DOH “authorizes the removal of warning signs posted in response to a sewer spill.”
The department makes that decision based on water sample results.
“The County of Hawaii has begun daily water quality sampling in response to (Monday’s) spill and will be submitting the data to the Department of Health,” according to the DOH statement.
Email Jeff Hansel at jhansel@hawaiitribune-herald.com.
Tribune-Herald reporter Tom Callis contributed to this article.
