CPI (Communication & Power Industries) leaked 40 to 50 gallons of water containing chemicals in the Palo Alto storm drain Monday morning and then into nearby Matadero Creek, according to Palo Alto Fire Marshal Dan Firth.
The water had a concentration of 25 parts per million of copper and a smaller concentration of nickel, Firth said.
The company, located at 607 Hansen Way, is reporting different numbers than the fire department, however.
The spill was "closer to 40 gallons" and the highest concentration of copper detected was at 9.3 parts per million, Amanda Mogin, CPI director of investor relations, said.
Mogin said the company took measurements at several locations, including in the storm drain and creek. The highest concentration was found on the pavement near where the spill occurred.
Mogin said the "overflow" was from a waste neutralization tank that had a malfunctioning sensor. Additional sensors have been installed, she said.
CPI notified the Palo Alto Regional Water Quality Treatment plant but not the fire department, Firth said. The department is still investigating to determine if the company erred by not reporting the spill to the fire department.
The company failed to contact the fire department on Feb. 2, 2006, when a plume of nitric-acid gas leaked from the plant into the adjacent Barron Park neighborhood, sparking outcries from residents and scrutiny from city and county officials.
The company did not notify the fire department of the gas plume because company engineers determined it posed no health hazard, company officials said at the time.
The company paid a $20,000 settlement with the city in early 2007 for the toxic gas leak.
However, a risk management plan since prepared by the company has been found wanting by the fire department and the Santa Clara County Department of Environmental Health.
That plan is still in the process of being modified, CPI's Mogin said.