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

Press release from the City of Palo Alto:

June 04, 2021

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.

Regulatory agencies continue to monitor the diesel values in the creek, as experts have advised that not all detectable amounts of chemicals within the sampling site may be 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.

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)

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. 

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.

• 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.

• Water Quality Data Summary - As of May 28, 2021(PDF, 162KB)

More information will be released as details become available.

Read the initial joint community update on this issue.

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This press release was produced by the City of Palo Alto. The views expressed here are the author’s own.