Mission Viejo, California

What is the Water Quality in Mission Viejo, California?

[Updated: June 9, 2023]

Compared to other US cities over 50,000, Mission Viejo water quality ranks in the middle range for contamination excluding Lead.

Most of their 21 contaminants have cancer-causing attributes:

• Chloroform is at very high levels: 28x health guidelines.
• Haloacetic acids (HAA5) are at extremely high levels: 186x health guidelines.
• Haloacetic acids (HAA9) are at extremely high levels: 345x health guidelines.
  • These are both byproducts of the chlorine treatment process most water supplies go through.

Let’s look closer at what’s in Mission Viejo water.

What’s in Mission Viejo water?

Here are the top 4 chemical compounds in your water and what health issues they can potentially cause:

1. Chloroform – Potential effect: Cancer
2. Haloacetic acids – Potential effect: Cancer
3. Nitrate – Potential effect: Cancer
4. Total trihalomethanes – Potential effect: Cancer

These are four of the 21 contaminants analyzed by the Environmental Working Group (ewg.org).

11 of these contaminants are rated as exceeding EWG Health Guidelines.

Does Mission Viejo have Lead contamination?

Yes, Mission Viejo has lead in its water. The most recent Lead samples collected from 2015 through 2017 showed concentrations up to 2.3 parts per billion.

The legal limit for lead is 15 parts per billion. Being well-below this level is a good thing.

Concentrations between 3.8 ppb and 15 ppb put a formula-fed baby at risk of elevated blood lead levels. Read more about the symptoms of Lead in water.

There is no safe level of lead for humans.

The good news is that 99.99% of the lead can be filtered out.

See the What Can You Do? section below to learn how to filter out contaminants.

Where does Mission Viejo’s water come from?

Mission Viejo’s water comes from the Arroyo Trabuco watershed.

7 of the 8 EPA assessed water sources in the Arroyo Trabuco watershed are in Impaired or Unknown condition. These include:

• Arroyo Trabuco Creek – three segments
• Holy Jim Canyon Creek
• Oso Creek – two segments
• Tijeras Canyon

Ideally, a water source would be rated in Good condition. Falls Creek is in Good condition.

Whether a water source is in Impaired or Good condition refers to the quality of these uses:

1. Drinking Water
2. Aquatic Life
3. Fish and Shellfish Consumption
4. Recreation

Learn more from How’s My Waterway

See below for what you can do to improve Mission Viejo’s water.

Conclusion – What Can You Do?

Information about water quality in Mission Viejo can be surprising.

But there are things you can do in your home to clean up your water.

1. Test Your Water using Varify Home Test Kits or similar.
2. To Remove Lead and Other Contaminants In Your Home:

• Use Activated Carbon filters to remove most contaminants in your drinking water.
  • Faucet-mount filters work better than pitchers.
  • PUR and Brita are low-cost and effective.

• To filter out even more contaminants, consider a Reverse Osmosis water filtration system for your house.
  • These are more expensive than pitchers to purchase, but can be more effective.
  • They have the benefit of filtering out heavy hitters like:
    • Aluminum
    • Arsenic – health risks
    • Barium – health risks in water
    • Bromate
    • Bromochloromethane
    • Bromodichloromethane – health risks in drinking water
    • Bromoform
    • Chloroform – side effects
    • Chromium (total)
    • Dibromoacetic acid
    • Dibromochloromethane
    • Dichloroacetic acid
    • Fluoride
    • Haloacetic acids – chlorination byproduct*
    • Hexavalent chromium – health effects
    • Molybdenum
    • Monobromoacetic acid
    • Monochloroacetic acid
    • Nitrate
    • Nitrite
    • Radium
    • Selenium – health risks
    • Strontium
    • Strontium-90
    • Total trihalomethanes – byproduct of chlorination*
    • Trichloroacetic acid
    • Uranium
  • Our recommendation: APEC Reverse Osmosis Systems

*Chlorination is an effective method of disinfecting/treating drinking water. You can then use a water filter to reduce the effects of chlorination byproducts to get the safest, cleanest water possible.

In Your Community:

Contact your local government officials and put pressure on them to invest in cleaner waterways and upgraded city water filtration and treatment.

Go to: https://cityofmissionviejo.org/ to find contact information for your local officials.

Water Quality in Other California Cities

California Water Quality Page