Under the federal Clean Water Act, the U.S. Environmental Protection Agency (EPA) establishes Ambient Water Quality Criteria (AWQC) for bacteria to protect human health. Currently, the EPA uses Escherichia coli (E. coli) as an indicator of fecal contamination of receiving waters. These federal criteria state that for fresh waters designated for use as recreational waters, the mean over a year period should not exceed 40cfu/100 mg for E. coli.

The Wolf River's total cfu/100mg for fiscal year 2023 was 64 cfu/100mg measured in Germantown (Lansdowne Park). Anything over 40 cfu/100mg is considered impaired. There are many factors that add to this number in the City that include agricultural uses to the east as well as domestic animal waste in the City. Germantown is one community within the Wolf River watershed that includes Collierville and Fayette County communities to the east. The City is working with other communities to reduce the rate of cfu/mg in the Wolf River watershed as a whole and the significant decrease over five years shows the effort is working.

Turbidity is the measure of clarity of a waterways in Germantown. In streams, erosion and other surface runoff can increase, which can result in harm to habitat areas for fish and other aquatic life. Sediment particles, for example, can provide attachment places for other pollutants, notably metals and bacteria. For this reason, turbidity readings can be used as an indicator of potential pollution in a water body. Turbidity is normally measured by an instrument called a Nephelometer. This instrument determines the scattering of light and is measured in standard Nephelometric Turbidity Units (NTU).

Within the City, the amount of TDS in streams/rivers should range from 50-250 mg/L depending on the time of year as noted in the quarterly changes on the graphs. Changes in the amount of TDS can be harmful to the health of watersheds within the City. Concentration of TDS that are too high or too low can limit the growth and may lead to the death of many aquatic organisms. One factor that can result in a low value for TDS is low precipitation. This causes less disturbance in streams/rivers. As a result, solids are not disturbed and introduced into the water.

 The area had freezing precipitation/snow for the 7 days previous to this data collection. This explains the slight increase in TDS for the Q2-FY24 data. The City is actively working to control run-off water and improve the natural areas within the City's stormwater system through stream/river bank stabilization repair projects.

Germantown draws it water from the Memphis Sand Aquifer that is a shared resource of Arkansas, Mississippi and Tennessee. The level of the water table can naturally change over time due to changes in weather cycles and precipitation patterns. In addition, the pumping of wells can have a great deal of influence on water levels below ground, especially in the vicinity of the wells. If water is withdrawn from the ground at a faster rate than it is replenished, then the water table can become lower, resulting in a "cone of depression" around the well. It is expected that the aquifer will draw down during summer and early fall due to higher usage and drier conditions. Historically, the aquifer recovers nicely during the lower demand, higher rainfall months of winter and spring.

Water Depth

The 2nd quarter of FY24 reflects a rise in aquifer levels at Johnson and Southern as water use is slowing down during the cooler months. Next quarter we should see another rise in the aquifer levels due to decreased water usage going into the winter months.