San Rafael, CA – A sewage spill estimated at 75,000 gallons was reported November 18 in the Happy Valley and Montecito areas of downtown San Rafael. The preliminary cause was a pipe blockage, and those investigating said the leak might have gone undetected for more than two weeks.
The blockage was cleared by the San Rafael Sanitation District by about 8 p.m. November 18, three hours after it was first reported to the agency. The affected areas were disinfected, according to the Environmental Health Services (EHS) Division of the Marin County Community Development Agency. The sanitation district and Marin EHS are investigating the incident, monitoring impacts, and trying to learn whether sewage flowed into San Rafael Creek and eventually into San Francisco Bay.
The initial sewage flow problem was determined to be off Highland Avenue, about a half mile north of the canal in the hills above Happy Valley and San Rafael High School. EHS specialists believe the sewage flowed through storm drain pipes downhill toward the canal to a stormwater pump station behind the shopping center. Normally, the pump discharges stormwater into the canal.
Although the pump station has been operational, it was turned off as soon as the district was notified about the sewage leak November 18. District personnel are moving all water stored at the pump station into the nearby sewer system.
Marin County Public Health and Marin EHS have not received reports about any adverse effects on humans or wildlife in the area. As a precaution, signage about potential contamination has been posted at nearby marinas along San Rafael Creek, otherwise known as the Canal area.
Signs are posted at the Municipal Yacht Harbor behind the Montecito Plaza shopping center, the San Rafael Yacht Harbor off Francisco Boulevard East, and the Lowrie Yacht Harbor off Point San Pedro Road. Warnings will remain in place until at least two clean water samples are documented by EHS officials.
EHS normally monitors water quality at beaches around Marin, but not creeks and canals. City of San Rafael personnel checked water quality in the canal as recently as October, according to EHS records.
On the afternoon of November 18, a resident in the impacted area mentioned the sewage problem to the sanitation district, which then notified the Marin County Sheriff’s Office of Emergency Services that evening. EHS ordered the signs posted and is working with the sanitation district, which serves homes and businesses in the affected eastern San Rafael neighborhood and has responsibility for the pipes determined to be the source of the spill.
In case of a spill on land, all sewage on the ground or in catch basins is vacuumed for proper disposal and the impacted areas are disinfected with bleach, EHS said. If the public has access to an impacted area, the area is typically barricaded during cleaning to prevent exposure and contamination.
The sanitation district, affiliated with the City of San Rafael, has provided wastewater collection since 1947. It maintains 32 pump stations and 132 miles of sewer pipelines that deliver wastewater to the Central Marin Sanitation Agency for treatment.
The following agencies were notified of the spill: Marin County Public Health; City of San Rafael Parks and Recreation; City of San Rafael Public Works Department; the California Office of Emergency Services; the federal and state Departments of Fish and Wildlife; the U.S. Environmental Protection Agency; the San Francisco Bay Regional Water Quality Board; the Marin County Certified Unified Programs Agency.