Aerial photo of Lopez Lake Dam taken June 22, 2017. By David Spiegel
Aerial photo of Lopez Lake Dam taken June 22, 2017. By David Spiegel

Drinking Water Disinfectant Switches to Free Chlorine

Author: Faith Zenker, Water Quality Lab Manager
Date: Tuesday, November 14, 2017 4:12 PM

Public Works will change the disinfectant to free chlorine in the Lopez Project distribution system. Due to the County also providing water to the cities of Arroyo Grande, Pismo Beach, Grover Beach, Oceano, Avila Beach, and Port San Luis, these areas will also convert to free chlorine.


Conversion of Drinking water disinfectant to free chlorine for the FIve-Cities Area – November 15, 2017 to December 6, 2017 - Free chlorine is a stronger disinfection process than the blended chlorine treatment the County typically uses.  This annual switchover of disinfectants helps to ensure water mains remain free of potentially harmful bacteria. This is considered a best management practice in the water industry.

Each individual customer has his or her own sensitivity level to the taste and/or odor of chlorine.  Although many detect no change at all, others may notice a taste or chemical odor similar to a swimming pool. Free chlorine can be minimized or removed by boiling water, running water through a carbon filter, or filling a container with water and leaving it to vent overnight.

Chlorination is the most common disinfection practice used in the drinking water industry.  Most customers will not need to take any precautions as the water remains safe to drink by Federal and State drinking water standards.  If you have any questions or concerns about your drinking water, please feel free to contact your local water supplier.