Select Page
natural_resources_iconEnhanced protection and conservation of our water resources are priorities.

The strategic objective promotes continued investment and responsible management of Germantown’s aquifer. Water resources include potable water, sanitary sewer and stormwater. Potable water is the City’s greatest natural resource and protection of the aquifer in terms of quality and quantity is critical. Collecting, transporting and treating sanitary sewer discharges are musts for the health of the City. Stormwater discharge clarity is critical to maintaining clean lakes and rivers. The unpolluted discharge into drain laterals and further into adjacent rivers and lakes is an inherent and legislated necessity.

Below Plan Total coliforms

Description

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.

 

Analysis

The Wolf River's total cfu/100mg for fiscal year 2018 was 86cfu/100mg measured in Germantown (Lansdowne Park). Anything over 40 cfu/100mg is considered impaired. Compared to fiscal year 2016, there was a 8% decrease in total coliforms in fiscal year 2017. There are many factors that are increasing 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.

 

Impact

The City has a moderate impact on this measure.

On Target Turbidity

Description

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).

 

Analysis

Seasonal variations in turbidity will occur as noted in the quarterly changes on the graphs. Normal levels of turbidity can vary from less than 1 NTU in clear pristine streams/rivers to very much greater than 200 NTU in murky streams/rivers. Soils in this region have many suspended sediments such as silt or clay and inorganic materials making the turbidity levels higher, and in West Tennessee 200 NTU's or below would be an acceptable rating level for turbidity. The City continues to implement processes to reduce the amount of sediments and control run-off water effectively using TDEC best management practices. The City is also actively improving the stormwater management system each fiscal year to reduce sediment within the local watersheds.

 

Impact

The City has moderate impact on this measure.

On Target Total Dissolved Solids

Description

Total dissolved solids refer to any minerals, salts, metals, cations or anions dissolved in water. Total dissolved solids (TDS) comprise inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates) and some small amounts of organic matter (i.e. soil, leaves, etc.) that are dissolved in water. The amount (mg/L) of total dissolved solids is used as an indicator test to determine the general quality of the water within the City.

 

Analysis

Within the City the amount of TDS in streams/rivers can range from 50-250 mg/L depending on the time of year as noted in the quarterly changes on the graphs; however 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. 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 including work that will begin on Lateral G in fiscal year 2019 Q1.

 

Impact

The City has moderate impact on this measure.

On Target Water hardness

Description

The simple definition of water hardness is the amount of dissolved calcium and magnesium in the water, resulting in the water feeling different on your skin. Water is an excellent solvent and readily dissolves minerals it comes into contact with. As water moves through soil and rock, it dissolves very small amounts of minerals and holds them in solution.

 

Analysis

The City's water hardness level for the 4th quarter of fiscal year 2018 is 23.4. This water hardness is classified as soft at this level. Moderately hard begins at 60 parts per million, with hard water at 120 parts per million. There are procedures to reduce water hardness that the City's water treatment professionals will follow if our water hardness reaches the action level. Fortunately, the subsurface water from our aquifer historically has moderate hardness.

Staff took weekly samples of raw and finished water supplies from both the Johnson Road and Southern Avenue water treatment plants to test for water hardness.  The test were run in our laboratory at the Southern Avenue plant to determine water hardness parts per million and this information was recorded on a worksheet.  From this worksheet the hardness numbers were transferred to the monthly report which was submitted to the Tennessee Department of Environment and Transportation, Division of Water Supply.  Adjustments to the parts per million of added sodium hexametaphosphate will be initiated with TDEC’s approval should the hardness readings exceed the action level target.  

 

Impact

The City has minimal impact on this measure.

On Target Rate of change in aquifer level

Description

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 dryer conditions. Historically, the aquifer recovers nicely during the lower demand, higher rainfall months of winter and spring.

Measurements of both the Johnson Road and Southern Avenue monitoring wells are recorded as water depth to ground level. As water levels go down, the measurement of water depth to ground level will increase; as water levels go up, the measurement of water depth to ground level will decrease.



 

Analysis

The fourth quarter of fiscal year 2018 reflected a slow drop in aquifer levels overall from the third quarter.  We should see an additional drop in levels into fiscal year 2019 due to irrigation systems coming online and increased usage due to higher than usual temperatures for this time of year.

 

Impact

The City has minimal impact on this measure.
logo-image-orange-background

WWW.GERMANTOWN-TN.GOV
1930 SOUTH GERMANTOWN ROAD
GERMANTOWN, TN 38138 | (901) 757-7200
 
©2016 THE CITY OF GERMANTOWN. ALL RIGHTS RESERVED.

logo-image-orange-background

WWW.GERMANTOWN-TN.GOV
1930 SOUTH GERMANTOWN ROAD
GERMANTOWN, TN 38138 | (901) 757-7200
 
©2016 THE CITY OF GERMANTOWN. ALL RIGHTS RESERVED.