Tennessee Water Sentinels
Memphis' Drinking Water
Get Involved: There are lots of ways to help the Tennessee Water Sentinels!
The Tennessee Water Sentinels Campaign is based with the Chickasaw Group of the Sierra Club in Memphis. We educate and advocate for the protection of local streams and rivers and work with local, state and federal water pollution control agencies to insure that ordinances and laws are enforced and polluters are held accountable for their actions. We're looking for interested folks to help conduct research, participate in public outreach events, and become volunteer water-quality monitors. There are plenty of ways to help! For more information, contact James Baker at (901) 826-2448, or email@example.com
Pure Memphis water. Photo: James H. Baker, TN Water Sentinels
Where does the City of Memphis get its drinking water? Over the past few years, Tennessee Water Sentinels have been asked this question a number of times. Those who ask these questions believe that Memphis gets its drinking water from the Mississippi River or other local streams.
The following information will clarify many misconceptions Mid-South citizens have about the source of this most precious substance, how it gets from that source to your water faucet, and the simple steps that folks can do to protect this resource for themselves, their children and grandchildren.
The source: Memphis gets nearly all of its drinking water from an underground source called the Memphis Sand aquifer, with the remainder coming from the deeper Fort Pillow Sand aquifer. Both of these are part of a larger system of fresh water aquifers called the Mississippi Embayment. As stated on the Ground Water Institute website, until 1885 Memphis tried to supply water to its citizens from the Wolf River, but the resulting water was too muddy and subject to contamination from various sources. In 1885, the first well into the Memphis aquifer was drilled in downtown Memphis, and Memphis hasn't used any surface water sources since. For more information, see the Ground Water Institute website.
Mississippi Embayment. Graphic courtesy of Ground Water InstituteTreatment of Memphis drinking water:
The water is pumped up from the aquifers at pumping stations, then aerated to remove iron, and sent through a series of sand and gravel settling tanks. Low levels of chlorine and fluoride are then added, as required by EPA. The chlorine kills any bacteria that may be present in pipelines that lead to your home. The fluoride helps prevent tooth decay. MLGW constantly tests the water quality at their pumping stations. See the latest water quality brochure from Memphis Light, Gas and Water Division
Two Main Threats to Memphis' Drinking Water
Side view of aquifers under Memphis, Tennessee. Graphic courtesy of Ground Water InstituteQuantity:
Overuse of ground water is one threat. In the Memphis and Shelby County area, over 250 million gallons of water are pumped from the aquifers each day for public water supply, not including over 500 private industrial wells. In surrounding eastern Arkansas and northern Mississippi counties, over nine billion gallons a day are withdrawn, mainly from the Mississippi Valley alluvial aquifer, which is a shallower overlying aquifer. Most of this water is for agricultural purposes. The water level has been dropping in these agricultural wells and some have dried up completely, so wells must be dug deeper and additional wells are being sunk into the Memphis aquifer creating additional demand for the precious resource.
As water is withdrawn from these aquifers at such tremendous rates, water must be replenished or recharged by rainfall infiltration into the ground. This happens in two places: in Memphis there are sandy "breaches" in the clay layer that allow rainfall to penetrate deep underground in a relatively short period of time. The other place is in recharge zones, such as Fayette and Hardeman counties, where the Memphis and Fort Pillow aquifers, and the deeper Cretaceous aquifer, are at or near the land surface. In these places rainfall penetrates deep underground in a relatively short period of time.
It is currently not known how much land area is required to "recharge" an aquifer from which tremendous volumes of water are withdrawn. There are land surface activities which inhibit aquifer recharge, such as parking lots and roads, buildings, deforestation and bulldozing that increases rainfall runoff rates into local streams, rather than letting the rain soak into the earth.
Left: Water well and pump. Right: Sheahan Pumping Station. Photos courtesy of Memphis Light,
Gas, and Water Division.
Quality: The quality threats to these aquifers can come from land surface sources and underground chemical and fuel storage tanks. A main threat comes from surface water making its way to the aquifers without spending up to 2,000 years being filtered by the naturally occurring sand and gravel strata. For years, it was thought that a thick, continuous impenetrable layer of clay was on top of the Memphis aquifer and this clay prevented surface contaminants from reaching the aquifer. Later research by the U.S. Geological Survey and the Ground Water Institute has shown there are areas where this upper clay layer is thin or non-existent and where water in the uppermost part of the Memphis aquifer has had contact with the atmosphere as little as 20 years ago.(1)
Bulldozing land increases rainfall runoff rates. Photo: James H. Baker, TN Water Sentinels
Areas where the upper clay layer is thin or non-existent are known as "breaches" or "windows." To date, there are 10 identified breaches in Shelby County that have been documented through subsurface testing.(2) The breach listed in the link below is near a closed municipal landfill south of Walnut Grove Road under the soccer fields at Shelby Farms Park. This landfill is known to not have a liner and to be leaking into the uppermost part of the Memphis aquifer.
In addition to leaking landfills, surface sources of hazardous materials can contaminate the aquifer. It's important for citizens of Memphis, Shelby County, and surrounding states and counties to properly dispose of used motor oil and other hazardous wastes. For Memphis and Shelby County residents, see the location of the household hazardous waste drop-off site and a list of acceptable items.
Improper disposal of used motor oil into a creek. Photo: James H. Baker, TN Water Sentinels
It is also important to properly dispose of hazardous wastes so that these substances will not reach local streams and the Mississippi River. Other municipalities, such as the City of New Orleans, use the Mississippi River as their source of drinking water.
Other threats to the Memphis aquifer include development projects that will be located in the recharge zone. In order to maintain sufficient quantities for future generations, we should carefully consider the impact of paving or otherwise restricting recharge to these recharge zones. Also, projects that have a potential of pollution of the aquifer and its recharge zones must be carefully considered.
How to get involved in quantity issues:
- Educate yourself and your family about water conservation steps.
- Advocate that your local elected officials take water conservation measures at government facilities.
- Advocate that local elected officials ask local industries to undertake water conservation measures.
- Advocate to local elected officials the importance of land use decisions that affect the recharge zones of the aquifer.
- Advocate to regional elected officials the importance of having a regional Ground Water Quality Control Board (GWQCB) in addition to the Memphis and Shelby County GWQCB. Land use decisions in neighboring counties in Arkansas, Mississippi, and Tennessee have the potential to affect the resource for all concerned.
How to get involved in quality issues:
- Educate yourself and your family about the proper use and disposal of household hazardous wastes. Household hazardous wastes can contaminate local surface streams, which flow to the Mississippi River, which is the source of drinking water for downstream communities, most notably, New Orleans.
- Educate yourself and your family about the proper use of lawn chemicals. Overuse of lawn chemicals requires overuse of water sources for irrigation, and can chemically contaminate local streams.
Top: Using a driveway's slope to eliminate soapy water runoff to street. Bottom: Storm drains are for rain. Photos: James H. Baker, TN Water Sentinels
- Educate yourself and your family about more efficient ways to wash the car. Use a commercial car wash where the waste water is treated at the wastewater treatment plant. If the car is washed at home, wash it in such a manner to reduce or eliminate wash water runoff to the street and storm drains.
- Educate yourself and your family about where the water goes once it enters storm drains. In Memphis and Shelby County, it flows directly into local streams and rivers, not to a wastewater treatment plant.
- Advocate that local elected officials enforce requirements that local industry and government facilities obtain and comply with all applicable water quality permits.
- Advocate to regional elected officials the importance of a complete regional map of the aquifers, including mapping all breaches that may be allowing contaminants to leak downward into our future water supplies.
If you have questions/concerns about water quantity/quality issues, or to become involved in these issues, please contact James Baker at (901) 826-2448, or firstname.lastname@example.org
In a nutshell: Tennessee Water Sentinels Watershed, Mississippi River
- Number of streams monitored: 4
- Stream names: Mississippi River, Loosahatchie River, Wolf River, Nonconnah Creek
- Number of stream miles monitored: 59
- Number of square miles in watershed: 1,534
- Human population of watersheds: 1 million-plus
- Cooperating organizations: Tennessee Clean Water Network, OutDoors, Inc.
- Cooperating academic institutions: Rhodes College
News: Hunter/Angler' Outreach
In 2008 and 2009, Tennessee Water Sentinels hosted an information table at the Mid-South Hunting & Fishing Extravaganza in Memphis, TN. At these two shows, volunteers from the Chickasaw Group, with Sierra Club staff support, outreached to over 800 people and collected over 250 e-mail addresses for the Sierra Sportsmen Network e-mail list.
Find out more
Mississippi River Ambient Sampling: 2005, 2006, 2007
October 2005 Update: Fouling
the Father of Waters (download
164 kB PDF)
September 2004 Update: Fouling
the Father of
Waters (download 1.82MB
the Father of Waters (download
710 kB PDF)
Industrial Storm Water Pollution in Wolf River Harbor and TDEC's response
(download 1.01MB PDF)
Industrial Storm Water Pollution in Cypress Creek (download
875 kB PDF)
About the Organizer: James Baker
James H. Baker retired in 2002 after 25 years of environmental experience with the City of Memphis. His experiences are in wastewater laboratory analyses, operation of a municipal wastewater plant, and in storm water inspections and sampling.
"Now is the time to take that training and experience and put it to work for the Sierra Club's Water Sentinels Program," says Baker. "Volunteers need training so as to become empowered to play an informed and active role in water pollution reduction issues in Memphis."
Clean water is a requirement of all life on Planet Earth. Trained citizen water-quality monitors can help insure that the agencies charged with enforcing the Clean Water Act maintain an active program of inspections, water-quality monitoring, and appropriate timely enforcement. As James likes to say, "Results, not process, make for improvement."
- Groundwater leakage through a confining unit beneath a municipal well field, Memphis, Tennessee, USA.
- Mapping an aquitard breach using shear-wave seismic reflection