Important Update About Your Drinking Water

Small Portion of Kernville Water System Has Levels of Haloacetic Acids (HAA5) Above the Drinking Water Standard

February 9, 2018

You have been receiving this notice on a quarterly basis about elevated levels of haloacetic acids (HAA5) affecting approximately 50 customers in a small portion of the Kernville water system. The most recent notice that you received in mid-January 2018 was for the fourth quarter of 2017. The purpose of this letter is to inform you that prepared notices for the second and third quarters of 2017 were inadvertently not mailed to you. Corrective actions have been implemented to ensure this does not happen again, and we apologize for this oversight.

The Kernville water system is required to take samples from two sites [107 Juniper and 1235 Sycamore] approved by DDW, every quarter, in the water distribution system.  In the second quarter of 2017, two samples were taken from 107 Juniper with an average result of 73.5 parts per billion (ppb) for HAA5. The sample taken at 1235 Sycamore was 10 ppb. In the third quarter of 2017, the samples taken at 107 Juniper and 1235 Sycamore were 51 ppb and 10 ppb, respectively.

Compliance with the HAA5 maximum contaminant level (MCL) is determined by the locational running annual average (LRAA) of samples collected at each sampling location, each quarter, over the past 12 months. The LRAA at 107 Juniper for the second, third, and fourth quarters of 2017 were 64 ppb, 69 ppb, and 84 ppb, respectively, which exceeds the HAA5 MCL of 60 ppb and requires us to notify the entire system. The LRAA for 1235 Sycamore for the second, third, and fourth quarters of 2017 were 17 ppb, 12 ppb, and 10 ppb, respectively. This location remains in compliance with the MCL for HAA5.

What should I do?

  • You do not need to use an alternative water supply (e.g., bottled water).
  • This is not an immediate risk.  If it had been, you would have been notified immediately. However, some people who drink water containing HAA5 in excess of the MCL over many years may have an increased risk of getting cancer.
  • If you have other health issues concerning the consumption of this water, you may wish to consult your doctor.

What happened? What is being done?

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 and 2017, runoff from winter storms contributed to higher levels of total organic carbon (TOC) material in the Kern River supply.  The presence of higher levels of TOC creates a treatment challenge in our state-of-the-art surface water treatment plant.  Higher than normal TOC levels along with chlorine from our disinfection process contribute to the formation of disinfection byproducts, which are measured as HAA5 and total trihalomethanes (TTHM).

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.  Please see the attached map for more precise details about the affected area within our Kernville system.

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 disinfectant used to effectively treat the water and modifying storage tank levels to encourage turnover and decrease water aging in the system.  The State-mandated reductions in water use during the historic drought increased the aging of water in the distribution system.

Since April 2016, we also installed a pilot granular-activated carbon (GAC) treatment unit that removes TOC from the source water.  Initial sampling of the pilot system demonstrated effective removal of TOC.  We recently met with the State Water Resources Control Board’s Division of Drinking Water in an effort to receive grant funding from the State for full-scale GAC treatment at the Kernville treatment plant. We will continue to investigate this option so that customers do not have to bear those costs.

We will continue to work diligently to improve water quality, as well as increase sampling of the affected area to track progress. Should we continue to exceed the LRAA in any part of the Kernville water system quarterly, we will notify you in accordance with Title 22 of the California Code of Regulations.  For more information, please contact the 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 tenants.
  • BUSINESS PROPERTY OWNERS, MANAGERS, OR OPERATORS:  Must notify employees of businesses located on the property.

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: February 9, 2018