February 2024 Spill Updates

At approximately 8:24 a.m. on Saturday, February 17, 2024, District staff discovered a significant spill occurring from its 24” force main.

When discovered, wastewater was flowing from one of the District’s force main pipes, with some wastewater flowing into a tributary that drains the Airport’s stormwater. The tributary flows downstream and connects with Tecolotito Creek just before Tecolotito Creek joins San Pedro Creek, San Jose Creek, and Atascadero Creek and flows through the Goleta Slough Mouth into the Pacific Ocean.

The District immediately turned off the pump station to stop the flow in the force main, and closed both the 24-inch isolation valve in the valve vault as well as the 24-inch isolation valve at the treatment plant to stop wastewater from discharging into the tributary.

The District initially used observational data, wet well data, flow data, and data received from Goleta Sanitary District (who run and operate the Regional Treatment Plan) to estimate and update estimates of the volume spilled. The District then worked with an independent engineer to evaluate additional flow data and currently estimates that approximately 1,140,657 gallons spilled, and approximately 1,071,696 gallons were discharged into the tributary.

Note, estimating the approximate Spill volume has been an iterative process because directly prior to the Spill, the District was temporarily operating on a different force main and did not have flow readings on the 24-inch force main that failed. The collection system was slightly surcharged before switching flow to the 24-inch force main, adding additional volume that may have been lost in the Spill, and the entire collection system was still experiencing higher than normal inflow and infiltration due to recent large rain events.  The District continued investigating duration and flow volume with the assistance of an independent consultant to ensure the most accurate reporting.

With analysis and investigation support from independent engineers, the District currently understands that the Spill was primarily caused by external corrosion of the 24-inch force main.  The 24-inch force main is ductile iron with an exterior coating and asphalt lining. The external corrosion was caused by imperfect external corrosion protection, potentially caused by damage during installation, coupled with severely corrosive soils that contain high chloride concentrations.

A few weeks prior to the spill, the 24-inch force main and pump station were taken offline to isolate a different section of pipe that is located to the west of the Goleta Slough for an unrelated repair. The repair was to respond to a leak causing exfiltration that the District voluntarily notified the Central Coast Regional Water Quality Control Board about upon discovery. A bypass operation was used while repairs took place. When the repair was complete, on the evening of February 16th, after 4:00 p.m., the 24-inch force main and pump station were brought back into service with the intent of returning the District to normal operations before the expected severe rainstorm that began on February 18th.

Based on the flow data, it appears that at approximately 7:28 p.m. on February 16th, the 24-inch force main failed at the point of external corrosion and the Spill began. Pressurizing and depressurizing the force main when it was brought back into service may have put stress on the corroded segment of pipe, but based on independent investigation, failure due to the external corrosion was imminent. 

After flow to the force main was stopped on the morning of February 17th, the wastewater remaining in the pipe was removed and disposed of at the treatment plant. The portion of the 24-inch force main that failed was excavated, removed, and replaced. Upon removal, it was first observed that the leak was stemming from an area of the pipe showing severe exterior corrosion.

The District takes this spill very seriously. Independent investigation confirmed there were no signs of internal corrosion at the failure point and that the failure was not a result of an issue caused by the District’s operations.  The District is now evaluating additional corrective action to determine if other segments of its pipe are vulnerable to external corrosion.

The District immediately responded once it discovered the spill at approximately 8:24 a.m. Flow in the pipe was stopped by 8:40 a.m., and by 9:15 a.m. on February 17th, District staff had created a barrier with spilled solid material to stop spillage into the tributary. The District used a Vactor truck to vacuum the wastewater at the spill point to further eliminate discharges to the tributary and capture pooling wastewater on the ground at the spill site. A tractor was used on the service road at the spill site to gather solid waste and then that waste was removed using a dump truck supplied by Goleta Sanitary District. The Vactor truck disposed of twelve loads of collected wastewater at the regional treatment facility. 

At approximately 3:00 p.m., the District collected water samples above, at, and below the discharge spot in the tributary. District staff also gathered foreign material by hand throughout the spill site, including carefully removing materials by hand from a vegetated area closest to the tributary bank.

Between 5:55 p.m. to 6:05 p.m. that same day, the District was able to notify the appropriate agencies without substantially impeding the spill response. 

On Sunday, February 18th, District staff returned to the spill site to continue clean-up efforts until rain commenced. Rain continued through Monday, February 19th, with over 3 inches of rain falling in the area.

On February 20th, a contractor mobilized to repair the force main, and on the 21st the contractor carefully excavated the section of failed pipe. Wastewater remaining in the pipe was pumped out of the pipe with mutual aid from the City of Santa Barbara, Goleta Sanitary District and Marborg Industries. The failed section of the pipe was removed and replaced with new pipe and repair couplings per District Standard Construction Specifications. The contractor backfilled the new pipe on February 22nd.

In March, the District removed an additional 10.35 tons of spill solids using hand tools from the upland area and reseeded the disturbed upland area with professional guidance from environmental consultants and a local ecologist, in coordination with the Santa Barbara Airport. In total, the District recovered and removed approximately 68,961 gallons of spilled wastewater plus additional semi-solid and solid materials in February and March.  The District also reseeded the disturbed upland area to restore vegetation.  The District also temporarily installed straw wattles between the disturbed upland area and the tributary out of an abundance of caution to prevent any erosion during forecasted rain events.

On March 21^st, the District presented an update to the Goleta Slough Management Committee and requested agency involvement in a future inter-agency communications roundtable.  The District has updated its communications plans and continues to coordinate with other agencies to ensure it has the most up-to-date contact information.

During the first week of April, the District conducted a successful hydrostatic pressure test on the 24-inch force main. The test was done as a precaution and further investigation into whether the pipe is stable for recommissioning. This test was the culmination of several weeks’ worth of preparations with several independent engineers and professionals. The results of the test indicated that the 24-inch force main meets sound engineering criteria and could be successfully placed back in service.  As a result, the District, with support from independent engineers and in coordination with the Santa Barbara Airport, successfully recommissioned the 24-inch force main on May 1st.

The District has continued sampling and monitoring water quality in the tributary, Tecolotito Creek, and the Goleta Slough. The District staff also completed updated training on the District’s Spill Emergency Response Plan (SERP) with an independent consultant, which included training on a few updates.

The District has received information that Goleta Beach was intermittently closed on February 8, 13, and 15th for the County’s Flood Control and Water Conservation District’s Beach Nourishment Project (“Beach Project”) preparations. The Beach Project involves dredging Tecolotito Creak upstream of the spill site and mechanically replenishing Goleta Beach with dredged sediment. The County had already planned to close at least part of Goleta Beach on February 20th for the Beach Project to begin.

On February 16th, the County issued a beach advisory in advance of the rain that was forecast to begin on February 18th.

On February 17th, just after 6:00 p.m., the District notified the County Public Health Department of the spill. Throughout the week of February 20th, the District communicated with the County Public Health Department to ensure beach closure. The County noticed closure in response to the spill on February 21st.

The County guidelines are to lift a closure once 2 consecutive water quality results are below certain health-related thresholds. The County has been sampling the water at the Goleta Slough mouth 2 to 3 times a week. The March 1st and March 4th water quality sample results at the Goleta Slough Mouth were below the health-related thresholds and the County Public Health Department would have been able to remove notice of a beach closure related to the spill. However, water samples at a different location at Goleta Beach were still not meeting the thresholds related to the County’s dredging operation and Beach Project, and stormwater runoff contributed separate water quality impacts after March 4th, so Goleta Beach remained closed until Friday March 15th for these other reasons.

It is possible additional beach closures may occur depending on on-going water quality testing for the on-going dredging operations or more rain events creating unrelated polluted stormwater runoff, but Goleta Beach is no longer closed because of the February Spill.

The District is in regular communications with relevant agencies regarding the spill and our response actions. On March 1st, the District submitted a certified spill report to the Central Coast Regional Water Quality Control Board pursuant to a state sanitary sewer system general order for waste discharge requirements (“General Order”), and will update and recertify this report as necessary while the District continues its investigation.

On April 2^nd, the District submitted its Technical Report to the Regional Board, including several updates on its investigation, an impacts assessment, and the District’s initial corrective actions.  The investigations into the spill duration and volume, as well as the cause of the pipe failure, are still ongoing and involve several independent engineers and consultants for technical support and additional expertise.

On May 17th, the District submitted updates to its Technical Report to the Regional Board, including updates on its Spill duration and volume investigation, cause investigation, and the District’s updated corrective actions. 

In November 2022, the District proactively hired an engineering firm to complete an assessment of the District’s force mains as part of its routine infrastructure maintenance efforts. The engineering firm was drafting the final condition assessment report when the February Spill occurred. The District will incorporate the spill event findings with this condition assessment report to evaluate future rehabilitation or replacement of its force mains to avoid future failures.

The District is also working to identify several other corrective actions to ensure future failures of this magnitude are prevented.