1501 Page Mill Road Incident Update
Published on October 25, 2024
OCTOBER 25, 2024 UPDATE
This update shares more about the test results, noticing, and ongoing work.
Cleanup work continues off Park Boulevard with work out in the residential areas from 8 a.m. to 8 p.m. with weekend work planned.
Test Results of Spill Substance
As noted in our update on October 24, the Palo Alto Fire Department (PAFD) received test results of initial sampling confirming the substance, at the levels of concentration observed, is not a risk to life or health. The results of sampling from the point of discharge of the spill indicate the liquid released is non-hazardous in nature, with additional documentation provided to PAFD indicating the spill consisted primarily of Bright Dyes FLT Yellow/Green Liquid, Meras 1020, and water. The exact quantities of the materials released are still being determined with an update provided when available.
- Bright Dyes FLT Yellow/Green Liquid, is a non-hazardous coloring commonly used to aid in leak detection. It has a bright yellow/green hue to aid in visual tracking and is highly water soluble.
- Meras 1020 is composed of Disodium Tetraborate pentahydrate (1-2%), and Sodium hydroxide (less than 1%).
Operational Details & Public Notifications
PAFD worked quickly with Tesla to contain and remediate the substance following the 9-1-1 call notification. That same evening, PAFD determined the substance was not a risk to life and health and the scene was transitioned from a hazardous materials emergency incident to a stable clean-up effort.
Weighing several factors including the rapid transition and progress of remediation and clean-up at all sites, and understanding that clean-up efforts would remain limited to industrial areas both at 1501 Page Mill Road and the concrete lined Matadero Creek channel near the Park Boulevard intersection, staff was focused on incident stabilization. Residential notifications occurred the day that clean-up activities affected the North Ventura neighborhood.
In hindsight and with appreciation for the input received since, staff recognizes that we should have made public notifications sooner. We apologize for our delay in making notifications.
Next Update
An update will be provided upon completion of clean-up activities and secondary testing to validate the clean-up effort and conclusion of the incident.
OCTOBER 24, 2024 UPDATE
In response to community questions about the hazardous material incident that occurred on Thursday, October 17, additional items on this matter are noted below. As a reminder, this continues to be an active investigation.
TIMELINE/RESPONSE
The hazardous materials incident was initially reported via 9-1-1 call on Thursday, October 17 around 5:00 p.m. PAFD responded to 1501 Page Mill Road noting a green liquid substance flowing into the street; initial field testing determined the substance was not a risk to life and health. Protocols for a hazardous material incident were followed including reporting details to the California Office of Emergency Services (includes notification to Valley Water, California Fish and Wildlife, etc.). Valley Water confirmed notification and has been in communication with PAFD Haz Mat Investigator. An initial estimate of 500 gallons of water and the spilled substance was reported. Containment, remediation, and clean up concluded at 1501 Page Mill Road on Friday.
Continuous PAFD visual inspection of the creek at various storm drain/creek locations to monitor the situation and residual impacts were conducted and secondary locations were identified around the concrete lined channel of Matadero Creek near Boulware Park to the industrial area near Park Boulevard. Clean-up was initiated on Friday, October 18 and originally estimated to be complete by Monday, October 21.
Early on Tuesday, October 22, increased clean-up efforts were required in the North Ventura neighborhood. This was due to an unrelated natural watershed flow upstream that increased creek flow. Resident notifications were provided on Wednesday, October 23 at approximately 5 p.m. Clean-up near this location continues.
What was spilled and where?
The hazardous materials response occurred at 1501 Page Mill Road.
Tesla reported 12 gallons of the substance released into the storm drain. The substance continued through the concrete lined Matadero Creek channel to the area near Boulware Park, and was confined to a lower channel with no contact with the natural areas of the creek. The quantity of release remains under investigation. Tesla indicated the substance is sodium hydroxide, a common additive to water in cooling systems. Staff sent samples for testing and results typically take one to two weeks. Initial testing results have been received today and are under staff review. Preliminary review substantiates initial field determination that the substance is not a risk to life and health. Secondary testing is planned after clean-up is complete to validate clean-up effort.
What are the City’s next steps?
In addition to cleanup, an investigation of the cause is under way. Storage of sodium hydroxide requires a City permit, which Tesla had not obtained. Staff will complete its investigation upon completion of this incident and appropriate regulatory actions will follow, including reimbursement for remediation and clean-up costs as well as potential fines.
When is clean-up expected to conclude?
At this time, clean-up of the secondary location in the concrete line channel near Park Boulevard is anticipated to conclude this weekend. Clean up from Lambert towards El Camino is complete though a pump is diverting watershed water towards Park Boulevard outside the clean-up area.
INITIAL OCTOBER 23 UPDATE
Late last week, Palo Alto Fire Department responded to a hazardous materials incident at 1501 Page Mill Rd in Stanford Research Park, the former HP and current Tesla property. Initial hazardous material containment and clean-up is complete at the incident location, with testing of the substance underway. Importantly, it has been determined that the substance is not an immediate threat to life and health.
PAFD has identified areas east of the initial spill near Park Boulevard, Lambert Avenue and Ash Street, for remediation and additional clean-up, with anticipated work continuing into next week. While initial work was limited to industrial areas, PAFD was notified late Tuesday of work shifting closer to residential areas, with notifications occurring Wednesday. No 24-hour work will occur in residential areas, with authorized weekend work.
The investigation is ongoing and coordination with various agencies continues.