HOW WE KEEP YOUR WATER CLEAN AND SAFE

Mesa Water is committed to protecting the health of its customers by providing safe, reliable, high-quality water to the communities we serve. Here are just some of the methods we use to validate the safety and cleanliness of our water supply.

Backflow Prevention

Water distribution systems are carefully designed to ensure a smooth flow of water from the distribution system to the customers. While rare, certain hydraulic conditions can cause water to deviate from its "normal" flow and move in the opposite direction.

To safeguard the public water supply from potential sources of contamination and optimize water quality, Mesa Water implements a comprehensive cross-connection program. This program is specifically focused on identifying and eliminating potential cross-connections.

One of the most critical aspects of our cross-connection program is backflow prevention. Its primary objective is to prevent reverse flow into the water distribution system. This is achieved by installing reliable backflow prevention assembly devices at water meters to protect the integrity of the public water supply.

Cross-connections, whether permanent or temporary, can pose risks. At Mesa Water District, we take proactive measures and coordinate inspections to ensure that backflow prevention devices are installed correctly and in compliance with laws that protect the public water supply. We work with State, County, and other local agencies to assist our customers in following the proper procedures for installing and maintaining backflow prevention systems.

Compliance with these regulations is a crucial part of our commitment to water safety. The Safe Drinking Water Act Amendments of 1986, the California Code of Regulations, and Mesa Water’s Rules and Regulations all mandate that water users must have their backflow prevention devices tested annually. If necessary, any required repairs must be carried out by the customer, followed by a retest of the device. These annual tests must be performed by a backflow prevention device tester certified by the Orange County Health Care Agency and sent to Mesa Water District and the Orange County Health Care Agency.

Send Copies of Completed Test Reports to Both Agencies

Mesa Water District
Attn: Water Quality
1965 Placentia Avenue
Costa Mesa, CA 92627-3420 
Cross-connection@mesawater.org

Orange County Health Care Agency
Cross Connection
1241 East Dyer Road
Suite 120
Santa Ana, CA 92705-5611
OCBackFlowTests@ochca.com

Backflow Documents

• Blank Test Form 
• Tester List
• Change of Responsible Party Form 
• Standard specs for BF and FP services 
• USC PDF Updated Device

*PLEASE REPORT ANY BACKFLOW DEVICE THEFTS TO the water quality department 949-754-1031

Due to the potential of theft in commercial and industrial areas, installation of a backflow enclosure should be considered for the protection of your device.

Chloramines

The Mesa Water supply, like Metropolitan Water District, is treated with chloramines, a combination of chlorine and ammonia. Chloramines are effective in controlling the growth of bacteria and other microorganisms that may cause disease. Chloramines form fewer disinfection byproducts and may have no odor.

People who use kidney dialysis machines may want to take special precautions and consult their physician for the appropriate type of water treatment before consumption. Also, customers who use fish ponds, tanks or aquaria should also make necessary adjustments in water quality treatment, as the disinfectants may be toxic to fish.

Water Main & Hydrant Flushing

As part of Mesa Water's regular preventative maintenance program to remove normal sediment buildup from the pipes that deliver water to its customers, Mesa Water performs unidirectional flushing of the water mains and fire hydrants. This improves the quality and appearance of the water.

Customers will be notified when flushing is scheduled to begin in their area. During flushing you may notice some discoloration or sediment in your tap water, affecting only its appearance. The water is safe and will clear up in a few minutes when you run cold water through the faucet of your bathtub or other unscreened tap such as a backyard garden hose.

For more information on Mesa Water's flushing program call the Water Quality Department at 949.574.1031.

Lead Service Line Inventory

Mesa Water District (Mesa Water®) provides customers with reliable, clean, safe water and has completed the initial lead service line inventory required by U.S. EPA’s Lead and Copper Rule Revisions. The deadline for the initial inventories was October 16, 2024.

Through completing historical records reviews and field investigations, Mesa Water has determined it has no lead or galvanized services that require replacement in its distribution system.

Mesa Water reviewed all applicable sources of information, including:

• Construction and plumbing codes, permits, and existing records or other documentation which indicates the service line materials.
• Water system records, including distribution system maps and drawings, historical records on each service connection, meter installation records, historical capital improvement or master plans, and standard operating procedures.
• Inspections and records of the distribution system that indicate service line material, including inspections conducted during normal operations (e.g., checking service line materials when reading water meters or performing maintenance activities.) 

In addition to reviewing the above sources of information, Mesa Water used an alternative method to develop the inventory that was approved by the State Water Resources Control Board (SWRCB) Division of Drinking Water (DDW) on a case-by-case basis.

Mesa Water used stratified random sampling to develop the initial inventory. Stratified random sampling involves physically verifying a subset of randomly selected service lines in the distribution system. That subset is stratified or divided into groups based on characteristics (e.g., year the service lines were installed). Stratification allows for a sample or subset of service lines to be equally representative of the current service lines in the distribution system.

According to SWRCB DDW guidance, if no lead or galvanized requiring replacement service lines are discovered, the remaining service lines may be assumed as non-lead with a certain level of confidence. Mesa Water verified 2,674 service lines, and the services lines were verified non-lead. No lead or galvanized requiring replacement service lines were identified.