What is Water Quality?
Water quality is the measure of the suitability of water for a particular use. Will the water be used for drinking? For swimming? For fish and salamanders? We probably think of different definitions of “good quality” when we think of each of these uses. Water that is safe for fish isn’t necessarily safe for drinking. And water that is safe for drinking probably isn’t safe for fish.
But what’s the actual definition?
Water quality definitions are tied to tests that provide information about a water’s properties. Most of these tests are done many times over weeks, months, and years. Long-term testing results are often the best indicator of water quality, especially when determining stream water quality.
MSD is driven to improve the water quality in Jefferson County’s streams and rivers and uses the Kentucky Division of Water’s (KDOW) definitions for surface water quality standards. These definitions are aimed at ensuring waters are healthy for humans to enjoy and other animals to thrive. In the end, our waterways should provide opportunities for human recreation (swimming, wading, canoeing, fishing, etc.) during warmer months, and healthy aquatic habitat all year-round.
What contributes to water quality?
To learn more about the watershed you live in and how to become more involved, explore the icons below.
How do we measure water quality?
MSD evaluates water quality by sampling stream water, habitat, and organisms. We operate a Long-Term Monitoring Network (LTMN) comprising 27 regional sites. These LTMN sites reach from Mill Creek (southwest Jefferson County) to Harrods Creek (Oldham County) to Cedar Creek (Bullitt County). These sites are continuously monitored in partnership with the United States Geological Survey (USGS) and provide a data feed that updates every 15 minutes. Additionally, we visit all sites regularly – weekly during the warmer months of May through October and three times during cooler months. Site visits include observation, verification of remote readings, and sample collection. Samples are analyzed for many things, including bacteria, nutrients, metals, hydrocarbons, and sediment loads. Every two years, we conduct biological assessments that include surveys of habitat, fish, benthic macroinvertebrates (bugs, crayfish, snails, etc.), and algae.
Results from all assessments are compiled, providing an overall view of water quality and stream health. Ultimately, results help MSD identify opportunities for improvement and evaluate long-term effectiveness of water quality improvement projects.
How do we report our findings?
MSD publishes the State of the Streams report at least once per MS4 permit cycle. Real-time and historical data from Jefferson County’s waterways can be found here. The stream’s physical properties of depth, flow rate, and temperature accompany its chemical properties - pH, dissolved oxygen, specific conductance.
Every five years MSD publishes the State of the Streams report. This report details all watersheds in Jefferson County, interpreting results of water quality and biological monitoring, discussing land use changes and water quality improvement work, and providing information about capital projects that affect water quality. Other MS4 Assessments and Reports can be found here.
MSD’s Project WIN website hosts a library of information, including historic State of the Streams reports dating back to 2009. You can also learn about MSD’s work on sewerage projects, which can directly impact water quality and monitoring results.
If you’d like to learn more about monitoring efforts in your watershed, feel free to drop us a note.
Need more in-depth info?
Bacteria (E. coli): E. coli is an organism that’s found in the gut of warm-blooded animals (e.g., people, dogs, ducks, cows). The presence of E. coli in a stream suggests the presence of waste. Stream samples are analyzed for bacteria to determine if a water body is safe for swimming or other recreation. Take a deep dive into E. coli here.
Nutrients: Nitrogen and phosphorous are essential nutrients for plant growth but can also be an indicator of excessive fertilizer runoff and/or organic waste found in raw sewage. Go in-depth here.
Metals: Metals are naturally occurring elements that exist in varying levels, based on local geology. Metals are also present in the built environment, industrial processes, and vehicles. High metal concentrations can be toxic to aquatic life, and bioaccumulation of metals can be devastating to populations of birds, fish, and humans. Read more about metals in the environment here.
Hydrocarbons: Hydrocarbons are organic compounds found in crude oil, natural gas, and coal. Hydrocarbons can make their way into waterways through contaminated soils, fuel and oil spills, pesticide runoff, and stormwater runoff from paved surfaces.
Sediment: Sediment is soil, sand, silt, or clay particles that are transported and deposited in our waterways. These particles are typically transported by wind and water erosion. Sediment can fill in stream channels, smother aquatic habitat, and release pollutants into the waterways. More info is here.
Dissolved Oxygen: Dissolved oxygen (DO) is a measure of water’s oxygen content. High concentrations of DO are vital for healthy fish populations; periods of low DO can cause fish kills. Several factors influence a stream’s DO, including temperature, nutrient loads, and algae populations. Learn more here.
pH: pH is the measure of a water’s acidity, and a waterway’s acidity can be influenced by its surrounding geology. Neutral (neither acidic nor basic) water is essential for aquatic life and human recreation. Changes in pH can often be traced to industrial discharges or spills. Here’s more on pH.
Specific Conductivity: A water’s specific conductivity indicates how much dissolved material it’s carrying. Dissolved materials can come from our local limestones, road salt, or illegal industrial discharges. Learn more about specific conductivity and waterways here.
Temperature: A waterway’s temperature can influence its health, and increased stream temperatures are common with urban development. Keeping temperatures normal can be achieved by keeping waterways shaded and not allowing rainwater to run directly off of paved surfaces into the stream. More on temperature here.
