Diamond Bar, California

What is the Water Quality in Diamond Bar, California?

[Updated: June 10, 2023]

Compared to other US cities, Diamond Bar water quality ranks in the high range for contamination excluding Lead.

Most of their 34 contaminants have cancer-causing attributes.

• Arsenic is at extremely high levels: 68x health guidelines.

Let’s look closer at what’s in Diamond Bar water.

What’s in Diamond Bar water?

Here are the top 5 chemical compounds in your water and what health issues they can potentially cause:

1. Arsenic – Potential effect: Cancer
2. Chloroform – Potential effect: Cancer
3. Hexavalent Chromium – Potential effect: Cancer
4. Haloacetic acids (HAA5) – Potential effect: Cancer
5. Uranium – Potential effect: Cancer

These are five of the 34 contaminants analyzed by the Environmental Working Group (ewg.org).

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

Does Diamond Bar have Lead contamination?

Yes, Diamond Bar has lead in its water. The most recent Lead samples collected from 2014 through 2016 showed concentrations up to 4.5 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 Diamond Bar’s water come from?

Diamond Bar’s water comes from the Upper San Jose Creek watershed.

The Upper San Jose Creek watershed is in Impaired condition.

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

Learn more from How’s My Waterway

See below for what you can do to improve Diamond Bar’s water.

What Can You Do?

Information about water quality in Diamond Bar 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 in your whole house, consider a Reverse Osmosis water filtration system for your home.
  • These are typically more expensive than pitchers to purchase, but can be much more effective.
  • They have the benefit of filtering out heavy hitters like:
    • 1,4-Dioxane
    • Aluminum
    • Arsenic
    • Barium
    • Chloroform
    • Chromium (hexavalent)
    • Fluoride
    • Haloacetic acids
    • Nitrate
    • Nitrite
    • Selenium
    • Strontium
    • Thallium
    • Total trihalomethanes
    • Uranium
  • Our recommendation: APEC Reverse Osmosis Systems

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://www.diamondbarca.gov/ to find contact information for your local officials.

Water Quality in Other California Cities

California Water Quality Page