Gaithersburg, Maryland

What is the Water Quality in Gaithersburg, Maryland?

[Updated: June 9, 2023]

Compared to other US cities, Gaithersburg water quality ranks in the middle range for contamination excluding Lead.

Most of their 19 contaminants have cancer-causing attributes.

• Haloacetic acids (HAA5) are at extremely high levels: 254x health guidelines.
• Haloacetic acids (HAA9) are at extremely high levels: 443x health guidelines.
  • These are both byproducts of the chlorine treatment process most water supplies go through.

Let’s look closer at what’s in Gaithersburg water.

What’s in Gaithersburg water?

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

1. Bromodichloromethane – Potential effect: Cancer
2. Chloroform – Potential effect: Cancer
3. Haloacetic acids (HAA5) – Potential effect: Cancer
4. Hexavalent Chromium – Potential effect: Cancer
5. Total trihalomethanes – Potential effect: Cancer

These are five of the 19 contaminants analyzed by the Environmental Working Group (ewg.org).

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

Does Gaithersburg have Lead contamination?

No, Gaithersburg does not currently have lead in its water. The most recent Lead samples collected in 2018 showed concentrations of 0.0 parts per billion (ppb).

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 removed.

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

Where does Gaithersburg’s water come from?

Gaithersburg’s water comes from the Great Seneca Creek watershed.

All 4 EPA assessed water sources in the Great Seneca Creek watershed are in Impaired condition. These include:

• Clopper Lake
• Potomac River (Montgomery County)
• Seneca Creek

Ideally, a water source would be rated 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 Gaithersburg’s water.

What Can You Do?

Information about water quality in Gaithersburg can be surprising.

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

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 whole house.
  • These are more expensive than pitchers to purchase, but can be more effective.
  • They have the benefit of filtering out heavy hitters like:
    • 1,4-Dioxane – irritant of the eyes and respiratory tract. “Exposure may cause damage to the central nervous system, liver and kidneys.”
    • Atrazine – herbicide
    • Barium
    • Bromodichloromethane – Flame retardant and solvent for fats and waxes.
    • Chloroform
    • Fluoride
    • Haloacetic acids
    • Hexavalent chromium
    • Molybdenum
    • Nitrate
    • Strontium
    • Total trihalomethanes – byproduct of chlorination*
  • 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://www.gaithersburgmd.gov/ to find contact information for your local officials.

Water Quality in Other Maryland Cities

Maryland Water Quality Page