Rapid City, South Dakota

Rapid City, South Dakota Rapid City, South Dakota

What is the Water Quality in Rapid City, South Dakota?

Compared to other US cities, Rapid City water quality ranks in the lower-middle range for contamination excluding Lead.

Most of the 15 contaminants have cancer-causing attributes.

  • Radium is at very high levels: 8.1x health guidelines.
  • Haloacetic acids (HAA5) are at high levels: 15x health guidelines.
  • Haloacetic acids (HAA9) are at very high levels: 101x health guidelines.
    • These are both byproducts of the chlorine treatment process most water supplies go through.

Let’s look closer at what’s in Rapid City water.

What’s in Rapid City water?

Here are the top 3 chemical compounds in Rapid City water and what health issues they can potentially cause:

  1. Hexavalent Chromium – Potential effect: Cancer
  2. Radium – Potential effect: Cancer
  3. Total trihalomethanes – Potential effect: Cancer

These are three of the 15 contaminants analyzed by the Environmental Working Group (ewg.org).

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

Does Rapid City water have Lead contamination?

Yes, Rapid City has lead in its water. The most recent Lead samples collected in 2018 showed concentrations up to 4.0 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 Rapid City’s water come from?

Rapid City’s water comes from the Cyclone Ditch – Rapid Creek watershed.

Both EPA assessed water sources in the Cyclone Ditch – Rapid Creek watershed are in Impaired condition. These are two sections of Rapid 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 Rapid City’s water.

What Can You Do?

Information about water quality in Rapid City 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:

There is one solution that beats Brita, PUR, and some whole house systems.

  • It costs less per gallon.
  • Needs fewer filter changes.
  • And it doesn’t make your water taste weird.

  • Use Berkey filters with activated carbon to filter out the majority of contaminants in your drinking water.
    • Berkey filters can also remove up to 99.99% of Lead in Rapid City water.
    • Brita can filter 4 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 11 of the 15 contaminants in your whole house, consider a Reverse Osmosis water filtration system for your home.

*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.rcgov.org/government.html to find contact information for your local officials.

Water Quality in Other South Dakota Cities

South Dakota Water Quality Page

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