Oyster harvesting in California’s Tomales Bay has been suspended after a sewage leak entered Olema Creek, prompting state health officials to close all shellfish-growing areas in the bay.
The closure followed the discovery of elevated bacteria during routine monitoring by the National Park Service. The affected creek flows into the southern end of Tomales Bay, one of western Marin County’s most important centres for commercial oyster farming and tourism.
Tomales Bay oyster harvest suspended
Marin County Environmental Health Services said the leak was traced to a failed septic system at the Due West Hotel and Tavern complex in Olema. A drainage pipe linked to the system was found to be leaking into the creek before the source was capped.
The county said the property’s septic system has been taken out of service and waste is being removed by tanker trucks while repairs, inspections and certification work are carried out.
Sarah Jones, Marin County’s community development director, said the state-ordered closure was “a very big deal” for local oyster operators and the wider economy.
Commercial beds cannot be harvested while the closure remains in force. Marin County and the National Park Service are continuing to take water samples to establish whether bacteria levels have returned to safe limits.
Marin County said on October 14 that it had received no reports of ill health among people or adverse effects on wildlife. The county’s environmental health deputy director, Greg Pirie, thanked the National Park Service for identifying the problem during its routine monitoring and urged property owners to check septic systems before the storm season.
Hog Island Oyster Co, one of the bay’s major producers, said it stopped harvesting and shipping Tomales Bay shellfish after being notified by the California Department of Public Health on October 12. The company said that morning’s harvest was returned to the water and that shellfish harvested between September 14 and October 12 was being withdrawn from the market as a precaution.
Hog Island stressed that the action was not a recall and said no illnesses or customer complaints had been reported. Its Humboldt Bay farm remains open, allowing the company to continue supplying customers with oysters from that site and from other certified partner farms.
The company said oysters served at its restaurants from Tomales Bay had been harvested from waters that were open and certified at the time.
Harvesting could resume next week
Under standard procedures, a precautionary closure lasts 21 days. However, the California Department of Public Health may allow harvesting to restart earlier if follow-up testing shows that conditions are safe.
Hog Island said sampling could begin as early as October 16, with harvesting potentially resuming between October 19 and October 21 if the results are satisfactory and the state gives its approval. Otherwise, the standard closure could remain in place until October 30.
Officials said the decision would depend on water-quality results rather than a fixed timetable. Visitors to Tomales Bay were also told that safe, inspected oysters from unaffected growing areas remain available.
