Surface Water

The term surface water encompasses all forms of water that collect on the earth's surface, i.e. lakes, rivers, streams, and creeks. Most surface waters are replenished through precipitation. Surface water bodies may be perennial (present year-round), ephemeral (present only part of the year), or man-made, such as reservoirs.

Stormwater

The term stormwater refers to water originating in precipitation (storm) events. In natural settings, most stormwater would infiltrate into the soil or slowly make its way into surface waters as runoff. However, the increase in impervious surfaces in urban areas can dramatically reduce the amount of infiltrated water, thereby increasing the rate runoff enters surfaces waters.

Groundwater

Groundwater is the water that exists within the pores of soil and rock beneath the land surface. Naturally flowing reservoirs of groundwater are known as aquifers, many of which are used by humans for drinking water or agricultural uses. Aquifers replenish slowly, as a function of the type of soil and rock layers that surround them.

Wetlands

Wetlands are a unique type of surface water. According to the EPA, a wetland is an area where water either covers the soil or is near the ground surface either year-round or through part of the year. Wetlands provide important environmental services including water filtration, species habitat, and carbon sequestration.

Surface Water

The Clean Water Acts requires states to monitor the water bodies within their borders and establish water quality standards for them. Water bodies that do not meet these standards are placed in the state’s 303(d) and 305(b) lists of impaired water bodies (though the EPA has since encouraged the merging of 303(d) and 305(b) lists). TMDL’s are then required for the restoration of the impaired water bodies. A TMDL, or Total Daily Maximum Load, is a plan drawn up for the restoration of an impaired waterbody that identifies the maximum amount of a pollutant that the water body in question may contain while still meeting state water quality standards.

According to TDEC's 2016 303(d) report, approximately 14,189.53 miles of rivers and streams in Tennessee were impaired, as well as 226,146.95 acres of its lakes and reservoirs. Of the sites sampled, 1143 were impaired  with no TMDL yet in place. 380 of the sampled sites were impaired  but did have a TMDL completed and approved for the site. 46 sites were impaired by something other than a pollutant, such as by flow alteration. The most common pollutants in Tennessee surface waters, according to TDEC's 2014 305(b) report, are pathogens, habitat alteration, and sediment. Pathogens impaired 26% of sampled sites, impacting 75,000 miles of streams. Habitat alteration impacted 24% of sites, and sediment impacted 22%, impairing 6,000 miles of streams. 

Groundwater

According to TDEC's 2016 Ground Water Report, 1.5 million people in the state of Tennessee rely on public groundwater while another 700,000 use private wells or springs. An additional 278,000 rely on a combination of public surface and groundwater resources. Currently, the state of Tennessee has no active, statewide groundwater contamination database, though TDEC has begun to build one. The main groundwater contaminants of interest are gasoline, chlorinated solvents/degreasers, pharmaceuticals, industrial/household waste, and reproductive/hormonal steroids. These contaminants enter into groundwater resources mainly through sewage/septic tank failures and surface water runoff into sinkholes and disappearing streams. 

Additional Information

 
 

Stormwater

The goal of stormwater management is to infiltrate as much precipitation as the natural landscape would have before being developed, thereby reducing contaminated runoff from entering surface waters. To accomplish this, the Clean Water Act stipulates that no one- governments, businesses, or individuals- may discharge pollutants into U.S. waters without a National Pollutant Discharge and Elimination System (NPDES) permit. NPDES permits require infiltration increasing, runoff reduction, and pollutant reduction practices be put in place by the permit holder, also known as stormwater management Best Management Practices (SWMBMP). These best management practices are vetted by the EPA to meet their Stormwater Phase II requirements.  Construction sites,  commercial and industrial wastewater, and municipal wastewater operators are the largest percentage of NPDES permit holders. 

 

Wetlands

Only about 40% of Tennessee's original wetlands still exist, at roughly 787,000 acres. Wetlands are protected under the 404 section of the Clean Water Act. Section 404 requires an entity that wants to impact a wetland to minimize any negative impacts, and compensate for any negative impacts that are unavoidable, such as the draining and paving over of a wetland. 

Developers in Tennessee often apply to the State's Department of Environment & Conservation (TDEC) for permits to destroy a wetland in exchange for an agreement to create one somewhere else in the state. This is ineffective for two major reasons: 1) wetlands support amazing biodiversity, and recreating the form and function of an original wetland is next to impossible, and 2) the 404 permits (as explained above) are often granted, but frequently unenforced.

One way you can protect your land from future development is with a permanent conservation easement. Contact the TN Parks & Greenways Foundation for assistance.

 

Tennessee Clean Water Network © 2020

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