Water Quality

Our highest priority is the safety and quality of the water we provide. Learn what’s in water, how we treat it, and how we protect our water all the way to your faucet.

Our Water Resources

Colorado River

The Colorado River flows over 1,400 miles from Colorado to Mexico, and supplies water to seven western states.


State Water Project

The State Water Project was built to deliver water from northern California to central and southern California, through the 400-mile long California Aqueduct. Photo shows the confluence of the Sacramento and Feather rivers.


Local Water

Lake Cuyamaca was formed by the construction of Cuyamaca Dam in 1889. The lake offsets our need for imported water, but only when San Diego County has a wet winter.


What’s in Water

Water moves through many environments as it travels through the water cycle. As water travels through lakes, rivers, soils, rock and other features in the environment it takes with it characteristics of those environments.  Helix obtains water from three primary sources, Colorado River, State Water Project from northern California and locally from Lake Cuyamaca. Each source maintains characteristics associated from these environments. These characteristics are managed through our water treatment process.

How We Treat Water

We use a 5-step treatment process at our R.M. Levy Water Treatment Plant in Lakeside, and disinfect water with ozone to produce high quality, better tasting water.

Step 1: Coagulation-Flocculation
The organic material in untreated water have a negative electrical charge. Positively-charged chemicals called coagulants are added to the water to bind with the negatively-charged material to form a larger mass of material that clumps together. The clumps that form are called floc.

The source of the water coming into our plant can change throughout the year. During the last drought our water was mostly from the Colorado River. Once California and the San Diego region had a wet winter, we also treated water from the State Water project and Lake Cuyamaca. When the source of the water changes, the amount of chemical must change, too. Our treatment plant operators complete various tests to identify the correct coagulant dose, and then adjust as needed based on treatment results.

Step 2: Sedimentation
When floc is formed during the coagulation-flocculation process it becomes heavy and will sink. In the sedimentation basin, the formed floc will sink towards the bottom of the basin. Clarified water remains at the top of the basin where it flows to the next treatment process.

Step 3: Disinfection with Ozone
After flocculation and sedimentation remove organic and other materials in water, disinfection destroys or inactivates any organisms. We use ozone as our primary disinfectant because it offers important advantages:

Ozone destroys or inactivates a wide range of organisms in water

Ozone needs little contact time with the water to be effective

Ozone produces fewer potentially harmful disinfection by-products than other disinfectants

Ozone removes most of the smell and taste issues people associate with tap water

Ozone is created artificially by passing oxygen through high voltage generators. This process causes decomposition of the oxygen molecule forming oxygen radicals. These oxygen radicals bind to oxygen molecules forming ozone (O3). The ozone molecules are then diffused through a contact chamber with the water. The ozone molecules bubble up through the water column and destroy or inactivate the organisms present.

Step 4: Filtration
Filtration is physical process of removing materials and particles still present in the treatment process. Our filters consist of a layer of anthracite coal (charcoal) and a layer of sand. Filtration works through two basic process, straining and adsorption. Straining removes material and particles that are too large to pass through the filter material. Adsorption works through similar properties as coagulation. Material and particles that can pass through the filter material adhere or stick to the surface area of the anthracite and sand material. This happens on a very small scale removing very fine material and particles. After filtration, the water is ready to drink but needs one more step before heading into the distribution system and to your home or business.

Step 5: Chloramination
The State of California’s water quality regulations require that we maintain a disinfectant in our water as it passes through the distribution system to protect against possible contamination after it leaves the treatment plant. Chloramines are formed by combining chlorine and ammonia. Chloramines are more stable and provide a longer lasting disinfectant residual than chlorine to ensure the water is protected.

How We Protect Water Quality

Our chemist, biologist and treatment plant and distribution system operators assure that our water meets all standards set by the EPA and the State of California.

200 Tests per Day

We collect and analyze 200 water samples a day from multiple points throughout the water treatment process.

System Tests

We continuously test water samples from our distribution system to ensure water quality levels all the way to customer.

No Lead Pipe

We have no lead water mains or service lines in our distribution system and our water is treated to be non-corrosive to customer plumbing.

Backflow Prevention

Backflow prevention devices prevent the flow of water from potentially contaminated sources back into our distribution system.

Learn More About Backflow Prevention


Sediments can accumulate in the system over time and can be stirred up by velocity changes or main breaks — causing discolored water. And some areas of the system may experience longer retention times. Flushing is used to clear water from the system and maintain water quality.

Learn more.



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