What is in Our Water?
As residents along the Wasatch Front, we have unique access to fresh water- a large amount of which comes directly from our mountain streams. In a previous blog post we explained what a watershed is and what you can do to help protect it, but why is that important?
Image taken by Carly Lansche
About 60 percent of our drinking water comes from the Wasatch Mountains.¹ Salt Lake Public Utilities shared that, “as water travels over land or through the ground, it dissolves naturally-occurring minerals and can pick up contamination from animal or human activity”. This means that whatever ends up in the lakes, rivers and streams in the canyon will end up in our drinking water unless it is cleaned previously. Drinking water managed by Salt Lake Public Utilities is tested for over 170 contaminants and in 2021 over 18,000 tests were performed, ensuring the highest quality of drinking water.²
How is our water treated?³
Water that flows from the rivers, reservoirs and aquifers is sent to a water treatment plant. It then undergoes a multi-step treatment process. The first step is flocculation and coagulation which means that ferric chloride (coagulant) is used to stick small particles together and form larger particles. The next step is sedimentation where these larger particles naturally settle and are then filtered out using anthracite and sand filters. After the water is filtered, pathogens are removed using chlorine.
Once the water has been treated, it is then stored and distributed to local communities as needed. Groundwater does not require special treatment because it is naturally filtered as it travels through the subsurface geology.
What can be in our water before it is treated?
Water has both biotic and abiotic components that indicate its quality. Common abiotic components include pH, dissolved oxygen, temperature, and conductivity. Biotic components include e coli and macroinvertebrates.
Abiotic components:
- pH measures the acidity of water and determines the solubility and biological availability of nutrients and heavy metals, such as nitrogen, carbon, lead, and copper.⁴
- Dissolved oxygen is the amount of oxygen present in water. Running water dissolves more oxygen than still water, and this oxygen is used by all aquatic organisms to breathe. Water sources with more dissolved oxygen can support more life and are healthier.
- Temperature is what determines what can or cannot live in the water in an area. Fish, insects, zooplankton, phytoplankton, and other species all have a preferred temperature range. If water temperature shifts too far above or below those ranges, the species decreases until they go extinct.⁵
- Conductivity is water’s ability to pass an electric current and is increased by more dissolved salts and a higher water temperature. Every body of water tends to have a constant range of conductivity, so if the conductivity suddenly changes it can indicate that discharge or other pollution has entered the water source.
Biotic components:
- E coli is a type of fecal coliform bacteria that is used to indicate whether other potentially harmful bacteria are present in water. E coli is a strong indicator of sewage or animal waste contamination which can contain many types of disease-causing organisms.⁶
- Macroinvertebrates are small aquatic animals and aquatic larval stages of insects, such as dragonfly larvae, snails, worms, and beetles, that live on the bottom of water resources. These organisms are used to help determine the condition of water because they have different tolerances to pollution. Bodies of water in a healthy biological condition can support a variety and high number of macroinvertebrates.
Other pollutants in our water sources come from human interactions and the storm water system. Storm water is what drains from our streets and communities directly into creeks and rivers and there is no opportunity for soil and plants or a water treatment facility to filter out pollutants beforehand.⁷ This water often contains nitrogen and pollutants from fertilizers, pet and yard waste, and other trash that may be in the area. It is important to keep our water clean by picking up trash, not over fertilizing, and clearing debris so the storm water system does not clog.
Image taken by Carly Lansche.
To learn more about water quality around the Central Wasatch, take a look at the Environmental Dashboard.
Article written by Madeline Pettit.
Endnotes:
- https://www.fs.usda.gov/detailfull/uwcnf/landmanagement/resourcemanagement/?cid=fsem_035491&width=full
- https://www.slc.gov/utilities/wp-content/uploads/sites/22/2022/06/WQR-Salt-Lake-City-UT-R01.pdf
- https://www.slc.gov/utilities/wp-content/uploads/sites/22/2022/06/WQR-Salt-Lake-City-UT-R01.pdf
- https://www.usgs.gov/special-topics/water-science-school/science/ph-and-water#:~:text=oil%20or%20alcohol.-,pH%20is%20a%20measure%20of%20how%20acidic%2Fbasic%20water%20is,hydroxyl%20ions%20in%20the%20water.
- https://www.usgs.gov/special-topics/water-science-school/science/temperature-and-water
- https://cwcedb.utah.edu/water/e-coli/
- https://www.epa.gov/nutrientpollution/sources-and-solutions-stormwater