Important Update About Your Drinking Water

Important Update About Your Drinking Water: Average Levels of Haloacetic Acids (HAA5) in Previously Affected Area of Kernville Water System Returned to Compliance

Dear California Water Service (Cal Water) Customer:

The Kernville water system is required to test water quality samples collected from the distribution system at two Division of Drinking Water (DDW) approved sites [107 Juniper and 1235 Sycamore] for HAA5 each quarter. HAA5 has a Maximum Contaminant Level (MCL) of 60 ug/L (parts per billion), which is calculated through a Locational Running Annual Average (LRAA). The LRAA is an average over 4 consecutive quarters. Water quality testing at 107 Juniper in the first quarter of 2020 had a result of 5 ug/L. This resulted in a LRAA of 48 ug/L for HAA5, which is below the MCL. The LRAA at 1235 Sycamore was 10 ug/L, also below the MCL.

Samples collected during the first quarter of 2020 at 107 Juniper had detections of HAA5 that averaged 5 ug/L, which is lower than in the previous quarter and, by itself, is well below the limit. Residents living on Oak Court, Oak Place, Juniper Drive, Alder Court, and Grandview in Kernville are in the same zone as 107 Juniper and, therefore, have similar water quality. Testing at this location affects about 50 customers. Please see the attached map for more precise details about the area within our Kernville system. The samples taken at 1235 Sycamore had a first-quarter average of 12 ug/L.

Background and new treatment

We closely monitor our water system for the presence of drinking water contaminants. The Kernville water system uses the Kern River as its water source. In 2016, 2017, and 2019, runoff from winter storms contributed to higher levels of total organic carbon (TOC) material in the Kern River supply. In the most recent quarter, Cal Water completed installation of a granular-activated carbon (GAC) treatment system, which removes TOC from the water before it is disinfected and enters the distribution system. During the first quarter of 2020, the TOC level in the river was lower and, in addition to the TOC removal by the GAC, resulted in significantly reducing the HAA5 level.

Protecting your health and safety is our highest priority. Upon receiving the first high result in February 2016, we immediately began making operational changes in the water treatment plant and water distribution system to reduce HAA5. These changes included adjusting the amount of disinfection used to effectively treat the water and modifying storage tank levels to encourage turnover and decrease water aging in the system. State-mandated reductions in water use during the historic drought had increased the aging of water in the distribution system.

To improve the water quality long-term, we installed a two-vessel GAC treatment system at the Kernville surface water treatment plant. This treatment removes TOC from the water before it enters the distribution system. We also conducted a six-week, system-wide study during the first quarter of 2020 that showed a decline of HAA5 levels to near non-detectable levels throughout the system, when fed by GAC-treated surface water.

We will continue to work diligently to maintain water quality, and we thank you for your patience as we worked to complete construction and installation of this treatment system to ensure compliance with water quality standards long-term.

This letter serves as notification in accordance with Title 22 of the California Code of Regulations. For more information, please contact our local Cal Water Customer Center at (760) 379-5336.

Please share this information with all the other people who drink this water, especially those who may not have received this notice directly (for example, people in apartments, nursing homes, schools, and businesses). You can do this by posting this public notice in a public place or distributing copies by hand or mail.

Secondary Notification Requirements

Upon receipt of notification from a person operating a public water system, the following notification must be given within 10 days [Health and Safety Code Section 116450(g)]:

  • SCHOOLS: Must notify school employees, students, and parents (if the students are minors).
  • RESIDENTIAL RENTAL PROPERTY OWNERS OR MANAGERS (including nursing homes and care facilities): Must notify
  • BUSINESS PROPERTY OWNERS, MANAGERS, OR OPERATORS: Must notify employees of businesses located on the

You can do this by posting this public notice in a public place or distributing copies by hand or mail. This notice is being sent to you by California Water Service’s Kernville system.

State Water System ID#: 1510033
Date distributed: April 10, 2020