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

The CPUC supports increasing block rates, also called tiered or conservation rates, because they provide an incentive for customers to conserve water. They do not change the overall amount collected by Cal Water, but high-water-using customers will pay more, and low-water-using customers will pay less.

Flat-rate customers will be charged conservation rates when their meters are installed as required by section 527 of the water code. All Cal Water customers must be converted to meters by 2025.

That depends on your water usage. A residential customer who uses the system-wide average will see very little difference on the bill; it may be slightly lower in the winter and slightly higher in the summer. You will see a bigger difference if your water usage is above average.

The tiers are based upon the average residential customer’s annual water usage in your rate area or city.

Businesses are more likely to be different from one another, and they do not have a clear pattern of use from season to season. The Commission has adopted non-residential rates that push more of the cost of water to the quantity rates, so these businesses may see a bigger incentive to conserve. Non-residential use varies … Read more