Seattle, Washington

Water Quality in Seattle, Washington

Watershed: Shell Creek – Frontal Puget Sound

What is the water quality like in Seattle, WA?

Let’s dive deeper into what’s in Seattle water.

What’s in Seattle 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 – Potential effect: Cancer
4. Hexavalent Chromium – Potential effect: Cancer
5. Total trihalomethanes – Potential effect: Cancer

These are five of the 20 contaminants analyzed by the Environmental Working Group (ewg.org).

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

See the What Can You Do? section below for all of the contaminants you can filter out and how to do it.

Where does Seattle’s water come from?

Seattle’s water comes from the Shell Creek – Frontal Puget Sound watershed.

78 of the 79 EPA assessed water sources in the Shell Creek – Frontal Puget Sound watershed are in Impaired or Unknown condition. These include:

• Duwamish East Waterway
• Duwamish Waterway
• Elliott Bay – 20 segments
• Lund’s Gulch
• Mohlendorph Creek
• Norma Creek
• Picnic Creek
• Pipers Creek
• Possession Sound
• Puget Sound – Over 20 segments
• Venema 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 Seattle’s water.

Conclusion – What Can You Do?

Information about water quality can be surprising.

But there’s no reason to lose hope. There are things you can do in your household as well as things you can do at a community level.

In Your Household:

• Use Berkey filters with activated carbon to filter out 15 of the 20 contaminants in your drinking water.
  • Berkey filters can also remove up to 99.99% of Lead in Seattle water.
  • Brita can filter 13 contaminants (and Lead depending on the filter).
  • Note: We may receive a commission if you decide to purchase filters through links on this page.
• To filter out 18 of the 20 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:
    • Bromate
    • Bromide
    • Bromodichloromethane – health risks in drinking water
    • Chloroform – side effects
    • Chromium (total)
    • Dibromoacetic acid
    • Dibromochloromethane
    • Dichloroacetic acid
    • Haloacetic acids – chlorination byproduct*
    • Hexavalent chromium – health effects
    • Monochloroacetic acid
    • Nitrate
    • Nitrite
    • Strontium
    • Total trihalomethanes – byproduct of chlorination*
    • Trichloroacetic acid

*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: http://www.seattle.gov/ to find contact information for your local officials.

Water Quality in Other Washington Cities

Washington Water Quality Page