Sewage seeped out of a manhole behind California Highway Patrol office, overflowing between the railroad and California Blvd early Tuesday morning. Ninety percent of the 1,000 gallons released was removed from the storm drain system and an additional 100 gallons was removed from Stenner Creek near the U.S. Highway 101 on-ramp on Olive Street, according to the San Luis Obispo County Health Department.
A blocked sewer main caused waste to build, spill over and leak into a storm drain eventually trailing into Stenner Creek. Cal Trans workers working on 101 reported the leak to the Offices of Emergency Services who in turn notified Environmental Health Services, said Peter Hague, the on-call health officer who was paged around 1 a.m.
A pumper truck was stationed between the railroad and California Blvd. overpass vacuuming sewage, and another on Olive Street near the 101 on-ramp, intercepting sewage before it reached Stenner Creek, according to Hague.
“We responded to the sewage spill like any other,” he said. “We ensure there isn’t a threat to human health.”
Stenner Creek connects with San Luis Creek, which remained unaffected, but flows to Avila Beach. Samples of ocean water will be tested for harmful bacteria levels. Warning signs have been placed along the beach by Environmental Health Services and will remain until the health risks of elevated bacteria are determined.
“We would continue to sample it daily until bacteria levels return to normal,” Hague said.
Until results assess the danger of the water, the Health Officer of San Luis Obispo County recommends avoiding ingestion or contact with Stenner Creek and all surrounding waters near the contaminated ocean water.
The filtering process of sewage removes most harmful bacteria before it reaches the ocean and creeks. When it moves into a storm drain before the filtering process is over, however, it is a more exposed condition that can impact human health, Hague said.
“It’s not necessarily harmful, but it could be,” he said. “There’s no question that there’s a human health concern. Fortunately with this spill, where it occurred, there’s likely minimal contact until it reaches the ocean.”
A sewage spill two years ago released 20,000 gallons of waste near the California Men’s Colony that caused similar warning signs, postings and shellfish quarantining.
“If the estimates are correct, this is a pretty small spill relatively speaking, if, in fact, only 100 gallons made it to the creek,” Hague said.