Guidance for Customers Following Water Supply Contamination

This applies to all customers on Office Park Drive, Commercial Way, Commerce Drive, and Truxtun Avenue (between Mohawk Street and Westside Parkway).

On June 4, 2024, it appears that activities on a commercial customer’s property caused oil to backflow into the water distribution system, after the facility improperly connected its equipment to a hose bib on its property. After the service was disconnected from the water system, crews worked to flush the residue out of the system.

Anytime the public water supply has experienced contamination by an outside substance, we conduct water quality testing within the water distribution system. A utility’s distribution system ends at the customers’ meter(s); after the meter, customers are responsible for the water going to their property and into their home or business.

Some customers may seek to conduct water quality testing within their internal plumbing. Following is guidance for water customers in Bakersfield.

Local Plumbers

You should hire a licensed plumber to flush your internal plumbing and remove standing water before water quality samples are taken at your facility. Below are some local, licensed, third-party plumbers:

  • Stan’s Discount Rooter & Plumbing
    (661) 861-1356
  • HPS Plumbing Services
    (661) 397-2121
  • Hector’s Plumbing
    (661) 588-3187

Independent, Licensed Samplers

For accurate and reliable water testing, you should use a licensed, third-party (independent) sampler. For a list of licensed, third-party samplers, please visit:

Certified Laboratories

For accurate and reliable testing, you should use a state-certified water quality laboratory. Please work with the laboratory to interpret the data. For a list of certified laboratories, please visit:

Recommended Testing Methods & Analytes

The following tests are recommended when crude oil has entered the water supply. Explanations of lab methods are provided to guide you through the sample process:

  • Volatile Organic Compounds (EPA Method 524)
    • Used to identify and measure volatile organic compounds in water, primarily in drinking water samples.
  • Semi-Volatile Organic Compounds (EPA Method 525)
    • Used to identify and measure a wide range of organic compounds in water, primarily in drinking water samples.
  • Oil and Grease (EPA 1664)
    • Used to identify and measure oil and grease along with total petroleum hydrocarbons in water, primarily in non-drinking water samples.
  • Total Petroleum Hydrocarbons (EPA 8015)
    • Used to analyze petroleum hydrocarbons, including gasoline range organics (GROs) and diesel range organics (DROs) in water, primarily in non-drinking water samples.

If you have any sensitive, water-connected equipment on site, please follow the manufacturer’s recommendations for maintenance.

It is also recommended that you contact your respective regulatory agency, if you have one, to determine if there are any additional requirements needed prior to reopening.


If you have any questions related to a claim, please contact the City of Bakersfield’s Risk Management Department by calling (661) 326-3738 or visiting:

Businesses with a Kern County Public Health Environmental Health permit are encouraged to call (661) 862-8740 or email [email protected] for additional guidance specific to your respective operations.

For questions regarding drinking water quality, you may contact the State Water Resources Control Board’s Division of Drinking Water at 559-447-3300, or by email at [email protected].

For questions regarding this incident, please contact California Water Service’s Emergency Operations Center at (661) 837-7243.