Disinfectants are required because they prevent the spread of germs that cause diseases. Years ago, before disinfectants were used for drinking water, diseases such as cholera, typhoid fever, and dysentery were common. Drinking water disinfection has vastly improved the quality and safety of drinking water.

Dirt or sand can occur naturally in groundwater or as a result of a water line repair. We try to reduce the instances of dirt or sand in the water through regular flushing, which improves water quality by increasing the circulation of water in the pipes and removing most of the sediment from the water.

At Cal Water, we conduct periodic flushing as part of our ongoing water quality and water system maintenance program. By opening certain fire hydrants under controlled conditions, we remove minerals and sediment that build up in water lines over time. This improves water quality and increases the amount of water that can flow through the … Read more

Water is considered soft if total hardness is less than 75 ppm, moderately hard at 75 to 150 ppm, hard at 150 to 300 ppm, and very hard at 300 ppm or higher. To convert the hardness of your water from parts per million to grains per gallon, simply divide by 17.1 Water’s hardness varies … Read more

Trihalomethanes (chloroform, bromoform, bromodichloromethane, and chlorodibromomethane) are commonly found in drinking water that has been chlorinated or chloraminated. Trihalomethanes (THMs) form when chlorine reacts with organic matter in the water. THMs are found mainly in water that originally came from surface sources, such as rivers and lakes. THM levels are typically low in groundwater (produced … Read more

Drinking water is often chlorinated or chloraminated to kill microorganisms that could cause serious illnesses. Overall, chlorination of drinking water has benefited public health enormously. There are other methods of disinfecting public drinking water, but they are often more expensive, and the potential health effects of using these other methods are generally less well understood. … Read more

Drinking water utilities that use chlorination or chloramination are required by law to sample water throughout their distribution system, average the total THM measurements, and report the results to the Division of Drinking Water. The Maximum Contaminant Level (MCL) permissible for total THMs in drinking water by California and federal law is currently an average … Read more

In 2006, the MCL for THMs and HAAs was revised so that the MCL was met at every location, and not just in the system as a whole.

Cal Water’s rates are set by an independent third party, the California Public Utilities Commission (CPUC). The CPUC’s job is to protect customers and make sure that rates are fair and reasonable. Oversight by the CPUC helps determine necessary improvements that are made to the water system, that the system is operated efficiently, and that … Read more

The Water Revenue Adjustment Mechanism (WRAM) is a rate-making mechanism adopted by the California Public Utilities Commission that breaks the link between water sales and revenues to encourage conservation. The WRAM works with the Modified Cost Balancing Account (MCBA) to balance out cost savings and revenue under collection. Each year, Cal Water is allowed to … Read more