A few weeks prior to the spill, the 24" force main and pump station were taken out of service to isolate a different section of force main pipe (located directly outside of pump station 1 to the West of the Goleta Slough), for repair and a bypass operation was used while repairs took place. This repair was a result of a leak causing exfiltration that GWSD voluntarily notified the Central Coast Regional Water Quality Control Board about. The bypass utilized the District’s back-up 18" force main. The 24" force main was left in ready and working state, but not pressurized, while the bypass was in place. Best practices were used to ensure the force main could safely be brought back into service. When repairs were completed on the evening of February 16th, the 24" force main and pump station were put back into service following GWSD's written procedures.

The District ascertained that the spill began around 8:00 p.m. on the night of February 16th. The spill was discovered at 8:24 a.m. on the morning of Saturday, February 17th when District personnel followed up to check on the pump station and force mains as is standard procedure whenever changes are made to force main operations.

Upon discovery of the spill, GWSD staff immediately took action to stop the flow to the 24" force main and worked urgently to contain the spill. Additionally, District staff activated mutual aid response with Goleta Sanitary District and the City of Santa Barbara to support the containment and clean-up effort. Response urgency was heightened by the forecasted atmospheric river that would bring 3 inches of rain in the coming days.

Post-spill investigation and analysis by both the District and 3rd party engineers revealed external damage to a 12 inch long area of the 24” force main. Because the pipe was well within its projected life span, it is theorized that the damage to the exterior coating was sustained during installation decades earlier, facilitating the external corrosion witnessed on the pipe. Internal and external pipe coating materials are intended to guard against normal corrosion, but the soil conditions near the Goleta Slough are highly corrosive and appear to have contributed to the failure in a way that could not have been anticipated without knowledge of the installation damage.

District staff created improvised containment to prevent the flow of wastewater into a tributary to the Goleta Slough in an effort to minimize impacts to the environment. A sewage vacuum truck collected and disposed of 12 loads of standing wastewater and a dump truck and tractor were deployed to carefully collect and remove solids.

Collaborative corrective actions

Local, county, and state agencies responsible for ensuring proper handling of wastewater have been closely involved in the spill response efforts. Additionally, since Goleta West Sanitary District conveys wastewater near to sensitive wetland areas, agencies with oversight responsibilities over these areas have been involved in evaluating how to prevent future occurrences. GWSD has dedicated itself to responding appropriately and vigorously to ensure incidents like these do not happen in the future.

The state Regional Water Quality Control Board (RWQCB) is the primary oversight agency for spill incidents. GWSD followed all protocols and continues to satisfy agency requirements. By March 1, 2024, the District submitted a certified spill report, and a month later, the District followed up with a technical report. These reports have been updated when warranted by further investigation.

The District arranged for stress testing by certified engineers to verify the integrity of the entire force main pipe repairs before the 24” force main was brought back online on May 1st.

Prior to the spill in February 2024, GWSD was in the process of assessing the condition of its pipes, including the force mains, as part of its Sewer System Management Plan (SSMP). GWSD engaged an engineering firm for this assessment in November 2022. The engineering firm was finalizing its condition assessment into a report at the time of the February 2024 spill. The District then asked the firm to consider the spill event findings and authorized a more extensive condition assessment utilizing Best Available Technology (BAT). The scope of the assessment utilizing BAT included additional field inspections and detailed data collection to provide comprehensive information that was not in the scope of the original assessment. The District expects to have a final condition assessment report in the Winter of 2025, and will use it to inform future rehabilitation and/or replacement efforts. The District anticipates presenting the final report to the District’s Board of Directors for consideration and approval in Winter 2025.

At about 12:13 p.m. on October 30, 2024, District personnel discovered a spill from a manhole cover above the 24” force main near a secure access road at the Santa Barbara Airport, a separate location from that of the February 2024 spill. District personnel acted immediately and stopped flow from the force main by 1:10 p.m. The District contained all of the estimated 8,500 gallons of spilled wastewater in an Airport stormwater drainage outfall retention basin, where the flow pooled and was then recovered and removed for treatment.

A minimal amount of wastewater may have absorbed into surface soils in the spill area, but it was determined that a more intensive cleanup effort involving soil removal would do more harm than good to native plants in the area. Like the February 2024 spill, the October spill also occurred within the Airport’s restricted access area with little to no risk of public exposure to the spill site.

The District determined that the October spill was caused by the failure of a gasket where an air release valve was previously removed several decades ago. The cause of the leak appeared to also be attributed to external corrosion of the decommissioned air release valve steel coupling gasket, likely from exposure to the corrosive soils in the area.

Once it was determined that corrosion of a gasket on the steel coupling caused the leak, the District swiftly and proactively replaced all similar couplings along the force main. Additionally, a recently installed flow meter alarm system showed the spill had started just before it was discovered by District staff. The District has since recalibrated its flow meter to a more sensitive level in order to receive immediate notification of even small deviations in flow. Any leaks or disruption in flow, even very minor changes, will trigger the alarm and immediately alert staff.

The District’s Board of Directors approved of and commissioned a more extensive assessment of both force mains utilizing Best Available Technology (BAT). The field assessment work was completed during the final months of 2024 and start of 2025. As part of that process, the District installed new pipeline access to facilitate future internal assessments of pipes. The GWSD Force Mains Condition Assessment Report should be ready for Board approval in Winter of 2025.

Collaboration and Communication

Collaboration with oversight and interested agencies commenced immediately following both spills and the District has continuously maintained thorough contact in the weeks and months since the event.

Immediately upon discovery of the spills, the District activated mutual aid by coordinating spill cleanup assistance from Goleta Sanitary District and the City of Santa Barbara.

The District coordinated site visits with the California Department of Fish and Wildlife and Central Coast Regional Water Quality Control Board.

GWSD has developed relationships with oversight agencies over the past year and continues to be in regular, meaningful contact with a network of interested parties.

Additionally, the District maintains regular communications with Airport staff and has provided in-person updates to the Goleta Slough Management Committee.

GWSD is responsible for handling 2.2 million gallons of wastewater each day under normal dry-weather conditions and maintains just over 70 miles of pipeline and services 6,200 connections to homes and businesses. Because our community borders important natural resources and ecosystems, the district views protecting the environment as an integral aspect of our operations. As a result, February and October 2024 failures have led to thorough introspection into our systems, operations, and infrastructure with a sincere willingness to learn and improve. Spills are unacceptable to the District, and the only way to prevent them in the future is to work intentionally and intensively to detect and correct any potential flaws in the system.

The District regularly reviews its Sewer System Management Plan (SSMP) to ensure effectiveness of its implementation. Additionally, in response to the spill, the District has committed additional funding resources and installed deployment and retrieval infrastructure to increase the frequency of its force main condition assessments more easily to once every 5-years with best available technology.

While extremely disappointing, these failures have provided lessons that have led to updates to our Standard Operating Procedures and methods of testing our collections systems to ensure pipe integrity, including lessons with respect to pipeline corrosion in coastal wetland conditions. Additionally, our experience in responding to these spill events have allowed us to identify improvements to communication and mutual aid activation efforts.

These lessons, and the changes implemented, will serve to minimize the potential for future spills and will benefit not only our customers, but also our natural resources and our community as a whole.