Matadero Creek/VA Palo Alto Health Care Diesel Spill Community Update

Published on June 04, 2021

Matadero Creek  VA Palo Alto Health Care System (VAPAHCS) Diesel Spill Joint Community Update

June 4, 2021 Community Update

The Palo Alto Fire Department remains in Unified Command, which means the fire department is working as a cohesive unit through all phases of this incident with, California Department of Fish and Wildlife, and other regional regulators, and in partnership with the VA Palo Alto Health Care System. The Palo Alto Fire Department continues to consider the incident as stable at this time.

Representatives from regulatory agencies continue to meet to review all aspects of the incident, including cause of the release, continued containment of the diesel and remediation of the soil and water. Action plans continue to evolve based on daily testing, other analysis completed and expert recommendations. VA Palo Alto representatives, 3rd party remediation scientist/water sample experts, Palo Alto Fire Department Hazmat Bureau, California Department of Fish and Wildlife, City of Palo Alto Stormwater staff, and Santa Clara Valley Water Board are all working collaboratively.

Creek Water Sampling/Testing Continues & Interpretation of Data Underway

Regulatory agencies continue to monitor the diesel values in the creek. The data demonstrates that a spill occurred. Additional testing and different type of testing is underway, to better understand the specific contaminates in the water, specific diesel spill levels and to rule out amounts of chemicals within the sampling site not related to the incident. It is not uncommon for these types of water ways to have contaminants from street runoff or other sites. Creek water testing continues regularly.

Creek analysis and data showed three past results that were outside of normal limits downstream from the last containment boom; however, VA third party experts suggests the most recent results from the same location show levels within normal limits. The early results could be indicative of several potential contributing factors such as organic sediment naturally occurring in the creek affecting the sample, contaminated soil disruption around the creek bank or movement/replacement of containment booms. Other causes will be ruled out with more data collection.

Preliminary Creek Data and Map Released

Water quality samples have been regularly collected within the boom containment area since the diesel spill occurred. The tables(PDF, 417KB) present data collected at two locations (see Map for reference point locations). Data was collected immediately after the spill upstream as a control (point of reference) location (W-016) and downstream of the boom containment area (W-003). Since the release of the data, two more booms were installed upstream of W-003 and upstream of W-002, since it appears that some of the contaminants may be making their way through the containment zone, as indicated in the W-003. In addition, samples were collected within the boom containment area and as anticipated with a diesel spill, the values of Total Petroleum Hydrocarbons-Diesel remain above the water quality habitat goals of 640 micrograms per liter, in four locations. California Department of Fish and Wildlife anticipates that the diesel will naturally attenuate over a timeframe of months; therefore, other clean up alternatives are currently being explored. With the movement of the creek, the booms in place to absorb any remaining fuel products, and the natural degradation of fuel, VA third party experts expect the values to continue on a downward trend. Sampling results have been provided to the City as the VA receives them and results will be released publicly online as they become available.

DOWNLOAD: Creek Water Sampling Table 1 and 2 With Map(PDF, 417KB)

Extension of Containment Booms Downstream

Containment booms have been inspected regularly, and verified by California Department of Fish and Wildlife, and Palo Alto Fire Hazmat Inspectors. In an abundance of caution, Palo Alto Fire Department has directed the extension of the containment boom network by adding two additional boom systems downstream, as noted above. 

Public Assistance Requested & New Signage

California Department of Fish and Wildlife has reiterated that the creek is not classified as a recreational waterway. There have not been any reports of dead or injured wildlife related to this incident. 

As the investigation continues, the Palo Alto Fire Department is asking the public’s help to ensure the creek and surrounding habitat are avoided so that regulatory agencies can continue to monitor the creek water and related areas. As a result, signage will be posted to remind the public of this active investigation and to avoid the creek until the investigation is concluded, which could continue for several weeks.

Soil Mitigation & Other Completed/Ongoing Work

  • Regulatory agencies involved will continue to adjust action plans as data is analyzed and reviewed with experts.
  • Initial soil mitigation has been completed around the VA generator building. Vacuum trucks have removed contaminated soil and remaining soil has been tested.
  • The initial deep cleaning of the generator and room has been completed.
  • The storm drain in the area remains covered and the outflow pipe is plugged to ensure containment of any diesel. A plan is being developed to clean the entire system, collect any runoff, and provide laboratory sampling to ensure no contaminants remain in the system.

Additional Sampling Data


More information will be released as details become available.

Read the initial joint community update on this issue.

Previous Updates

May 21, 2021 Community Update

The Palo Alto Fire Department Prevention Bureau accepted submittals for all four focus areas of the incident from the contracted 3rd party mitigation company on behalf of the VA Palo Alto Health Care System.  These four focus areas include: soil remediation, water in the creek, storm drainage system, and the building.  Each division will have associated Hazmat Closure Permits, and follow closure protocols for Palo Alto Fire Prevention, and the City of Palo Alto. Soil remediation has been approved to start final remediation work beginning on Monday, May 24, 2021. This will include contaminated soil removal on the ground around the generator building witnessed by Hazmat Inspectors from the Palo Alto Fire Department, and soil sampling and reviewing results will occur prior to completion of this work.

Creek inspections and water samples have continued throughout the week with contracted 3rd party remediators, California Department of Fish and Wildlife, and Palo Alto Fire Department. Containment and absorbent booms (pads floating on the water to absorb any diesel) remain in place as recommended by experts and California Department of Fish and Wildlife. There are no signs of saturation of diesel reported in the booms and they will continue to be inspected daily. Water samples have continued both in and out of the containment area of the creek and are expected to show trends towards normal limits.

California Department of Fish and Wildlife noted that no animals have been reported injured or harmed as a result of the release into the creek. One deceased rat was collected, but it is not suspected to be related to the incident. California Department of Fish and Wildlife has expressed their content with containment and mitigation efforts for the creek and will continue to support the process.

On May 21, a meeting was held with the VA contracted site sampling expert with all involved agencies. Water sampling will continue on a regular basis in areas identified by the hired industry expert and approved by California Department of Fish and Wildlife staff Biologist and the Palo Alto Fire Hazmat Plan Examiner. Preliminary results have been reviewed and discussed by the contracted expert in the May 21, 2021 briefing, including:

  • The majority of the samples have come back within normal limits.
  • There are a couple of areas within the containment booms, the mitigation zone, that samples showed values outside of normal limits.
  • Lab values downstream, outside of the containment zone, show to be within normal limits with new sample results pending to confirm the situation remains stable.
  • Samples have been processed from the same area this week and are expected to trend downwards towards acceptable limits, results pending.

An all agency meeting is being formed with regulators and experts next week to analyze data, review submitted creek plan, and provide feedback. California Department of Fish and Wildlife will remain as lead on the Matadero Creek remediation with Palo Alto Fire Department and regulatory authorities.

All agencies are working well together and are committed to applying scientific methodology as all continue to work toward the goal of incident closure.

May 17, 2021 Community Update

VA Palo Alto Health Care System (VAPAHCS) will continue testing of the Matadero Creek as directed by the Palo Alto Fire Department. While absorbents are not showing any additional diesel in the creek and the Palo Alto Fire Department has noted the incident as stable, official testing results are currently being reviewed by a VAPAHCS third party vendor. Once the lab results are analyzed and interpreted, an incident closure plan will be developed in collaboration with all agencies involved, including VAPAHCS, the Palo Alto Fire Department, Palo Alto Public Works Department and the State Fish and Wildlife Department. Review of lab results is expected to conclude this week.

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