Tennessee Ground Water Monitoring And Management

responsibility of the individual homeowner. Springs used by private individuals by theirvery nature are not regulated since they are not constructed. Users of a private watersource that have never tested the source do not know what they may be drinking.Chemical contamination is unusual; however, shallow wells and springs located in karstcan be impacted by surface water with regard to bacteria and other naturally-occurringpathogenic organisms. Failing septic tanks (leaking directly into the ground water) arealso a common cause of ground water contamination as is sinkhole dumping of garbageand other wastes. Wells and springs may contain pathogenic organisms and should befiltered and disinfected before being used.Abandoned wells, both drilled and hand-dug can also be a significant hazard forcontamination (illegal dumping, spills or contaminated runoff) as well as sinkhole dumps.Both the wells and sinkholes have direct connections to the ground water. There arethousands of abandoned wells across Tennessee. There is no mechanism or resourcesavailable for abandoned well identification and closure or for the cleanup of sinkholedumps. These are currently addressed on an as located basis and usually require anenforcement package that may include a fine as well as a corrective action placed on thecurrent property owner.For more information on private water wells and how to maintain them, homeowners cancontact the National Ground Water Association (NGWA) at www.wellowner .org orhomeowners may take the Private Well Class sponsored by the Rural CommunitiesAssistance Program (RCAP) through a grant from the Environmental Protection Agency(EPA) at www.PrivateWellClass.org. Other information on licensed water wellcontractors and information specific to Tennessee may be found at the State -well-water.6.0Critical Ground Water Issues in TennesseeGround water in Tennessee is an extremely valuable and finite resource. Ground watercontamination has had more than a quarter century of a head start over ground waterprotection and management. The Ground Water Classification under the TennesseeWater Quality Control Act has been revised to better classify the waters of the state andtrack those areas with ground water contamination and in managed remediation.Information on ground water site specific classifications can be found 40-03.20150406.pdf.There are a number of issues in ground water pollution prevention and ground watermanagement including, but not limited to, the following: Tennessee has variable and complex geology. The limestone aquifers that are prevalent in Middle and East Tennesseehave rapid movements of contaminants and more complex flow paths. East Tennessee faulting and folding associated with the Appalachians is acomplicating factor for that region.6

The unconfined sand aquifers in West Tennessee are also vulnerable tocontamination, particularly chlorinated solvents and degreasers. Contamination is not obvious or easily monitored. Ground water itself and ground water contamination cannot be seen. Each well is an extremely narrow “window” into the aquifer. A contamination plume is commonly limited in size (hundreds tothousands of feet), irregular in shape and not evenly distributed within theaquifer. The state has adopted a Ground Water Classification as it relates to theRemediation programs. This classification allows for tracking ofcontamination on a statewide basis. Variations in the physical and chemical characteristics of contaminantscan also cause the contaminants to take widely different flow pathsthrough the aquifer. Sampling a well is significantly different from sampling a stream. Upstream and downstream are not obvious when sampling ground water. Sampling protocol is and equipment varies from location to location. There are no aquatic indicators to reveal the health of the ground water. Locating the stream is not an issue, locating the ground water can be. Contamination in ground water tends to be from a different suite of chemicals andof much longer duration than in surface water. Surface water is subject to more natural attenuation of contamination, withboth physical and biological breakdown of the contaminants. In recent years, “emerging contaminants” such as human and veterinarypharmaceuticals, industrial and household wastewater products, andreproductive and steroidal hormones in water resources, have become more ofa focus (USGS Fact Sheet FS-027-02, Pharmaceuticals, Hormones and OtherOrganic Wastewater Contaminants in U. S. Streams; June 2002). Potentialenvironmental pollutants include pharmaceutical, veterinary and illicit drugs,as well as active ingredients in personal care products (collectively referred toas PPCPs). These potential pollutants include prescription drugs andbiologics, as well as diagnostic agents, fragrances, sun screen agents,ingredients in cosmetics, food supplements and numerous others. Theintroduction of PPCPs into the environment is not just by sewage treatmentplants, but also by nonpoint runoff and failing septic systems as well as largecapacity conventional and drip disposal systems. The Ground WaterManagement Section (GWMS ) has been working with the UnwantedPharmaceuticals Take Back Program in supporting the removal of unwantedmedications and personal care products from the environment. Informationon the Unwanted Pharmaceuticals Take Back Program can be found d-pharmaceuticals7

Each chemical’s physical and chemical properties have an effect on itsmovement in ground water. A more accurate picture of the health of Tennessee’s aquifers is needed. Historically there had not been a systematic statewide study ofTennessee’s aquifers. The United states Geological Survey (USGS)conducted a “Reconnaissance of Quality of Water from Farmstead Wellsin Tennessee 1989-90” This study focused on nutrients in groundwater.The GWMS is currently looking at the USGS sampling location toaugment the states sampling program. Tennessee’s ambient (naturally-occurring or “background” water quality)ground water quality monitoring program is still in the formative stages. Public water systems sample the treated water served to their customers;however, less often sample raw ground water. Private wells and springs are not routinely sampled in Tennessee. Tennessee does not have an active statewide ground water contaminationdatabase.7.0Tennessee’s Complex GeologyThe geology of Tennessee makes certain aquifers (water bearing zones) more vulnerableto contamination where there is no clay confining layer or naturally filtering soil layer todeter contamination from reaching the ground water. The unconfined sand aquifers ofWest Tennessee, particularly the Memphis Sand Aquifer, are vulnerable to contaminationas are the limestone (carbonates) aquifers of Middle and East Tennessee (see Figures 2and 3). East Tennessee has the additional complicating factor of major rock deformationthrough faulting and folding associated with the forming of the Appalachian Mountains.Thevideo“HollowGround:LandofCaverns, Sinkholes and Springs”addresses karst limestone areas inTennessee. Additionally, the video “Drops of Water in Oceans of Sand: Ground WaterResources of West Tennessee” addresses the sand aquifers of West Tennessee. Further,there is a multi-part video on source water protection (protection of the sources of publicwater) available on the Division’s website.https://www.youtube.com/watch?v JEgNMEk6ojoTennessee has an abundance of limestone rock types (approximately 2/3 of the state),which are highly susceptible to contamination. These limestone rock types develop aterrain that is referred to as “karst.” The term “karst” is named for a region in what wasthen Yugoslavia. The term refers to limestone and dolomites (magnesium-richlimestone) where the dissolution of the rocks creates solution-enlarged channels, beddingplanes and micro fractures for ground water flow.8

Karst is characterized by sinkholes, springs, disappearing streams and caves. Karstsystems have rapid, highly directional ground water flow in discrete channels or conduits.Karst aquifers have very high flow and contaminant transport rates under rapid rechargeconditions such as storm events. This is a particular concern for public or private watersupplies using wells or springs in karst areas where pathogenic organisms that would notbe present in true ground water can survive in ground water under the influence ofsurface water.Karst systems are quite easily contaminated since the waters can travel long distancesthrough conduits with no chance for natural filtering processes of soil or bacterial actionto diminish the contamination. Transport times across entire karst flow systems may beas short as hours or weeks, orders of magnitude faster than that in sand aquifers.Water in karst areas is not distinctly surface water or ground water. Surface water canenter into the ground water directly through sinkholes and disappearing streams. It is notuncommon for ground water to contaminate surface water, making surface water problemsinto ground water problems in Middle and East Tennessee. The reverse can also occur.There are a number of water systems in Middle and East Tennessee relying on ground watersources that have been determined to be under the direct influence of surface water. Thesesystems are required to have filtration such as that required for surface water systems.Ground water contamination (see Figure 4) is typically chlorinated solvents or degreasersand gasoline. These are all very volatile (evaporate rapidly) and are thus not a problem insurface water; however, they are a serious problem in ground water where they do notbiodegrade and can be in the ground water for decades. Most chlorinated solvents ordegreasers and gasoline have a very low drinking water standard (several volatiles are at 5parts per billion or less). Another ground water problem for Middle and East Tennesseeowing to the shallow bedrock associated with caves and sinkholes is contamination fromseptic tanks. Bacteria from septic tanks are a leading cause of private water wellcontamination.Surface water contamination sources are typically nitrate (from fertilizer and animal waste),bacteria, protozoa and urban runoff (runoff from yards, asphalt, etc. that has heavy metalsand pesticides/herbicides, etc.). There has been testing across the state showing atrazine (aherbicide) is getting into streams (eight across the state) after rains during growing season.Ground water in karst areas that are impacted by surface water is also subject to these samecontaminants. Atrazine has also been detected at one Middle Tennessee water system whereits ground water source is under the direct influence of surface water.The protozoan cryptosporidium is a serious problem for surface water systems or groundwater systems under the direct influence in that chlorine will not kill it and it is abundant inthe environment. It is what gives cattle the “scours” (diarrhea). EPA’s Enhanced SurfaceWater Treatment Rule is predominantly the result of cryptosporidium concerns.9

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8.0Naturally Occurring RadonThere are increasing concerns over naturally-occurring levels of radon, uranium andarsenic in drinking water supplies nationwide. Tennessee is fortunate in that the geologyis such that the naturally occurring arsenic that plagues a number of the western states isnot present in this state. Neither does there appear to be a problem with uranium.Studies of public ground water supplies across the state have determined that there arelocations with elevated levels of radon (Figure 5). The Tennessee Department ofEnvironment and Conservation (TDEC) considers radon to be a very serious problem inour state. No matter where you live in Tennessee, there is the potential for radon to enteryour home.Zone 1 - red - has a high risk factor for radonZone 2 - orange - has a moderate risk factor for radonZone 3 - yellow -has a low risk factor for radonFigure 5Testing conducted for radon in public water systems across the state in 1999 indicatedthat the radon in some water systems measured well above the EPA proposed 300picocuries per liter (pCi/L) standard. Further radon testing was needed in that some ofthose systems were not in the expected geologic setting for high radon levels. The 1999testing also appeared to indicate that lower flow volume wells and springs tend to havehigher levels of radon, possibly due to there being less “flushing” of the relativelyvolatile radon gas. This trend of smaller systems having the higher radon readings isconsistently holding true in the 2001 sampling as well. The high radon readings weretypically from water systems with less than 200,000 gallons per day average dailyproduction. (Figure 6)13

It is not unexpected that there are high radon readings without corresponding uraniumresults in that the wells are typically going to be finished above shale formations. Wellsare typically not drilled into shale formations that contain uranium for a ground watersource because they have water quality problems from high metal and sulfur content.Radon as a gas will enter the wells drilled into the carbonate rocks overlying shaleformations.Of the 92 wells and springs sampled in 2001, 34 were above the proposed 300 pCi/Lstandard and six were above 1000 pCi/L. With the exception of West Tennessee (whereno radon was expected) and the Cumberland Plateau, the sample choices wereintentionally chosen that would likely have high radon readings. Of the 92 samples, 33of the wells/springs have been determined to be under the direct influence of surfacewater. Of those 33, 13 yielded radon results of 300 pCi/L or higher.In 2013, GWMS staff sampled 85 wells and springs in which 45 were above the proposed300 pCi/L standard and 13 were above 100 pCi/L. Again, in West Tennessee (where noradon was expected) and the Cumberland Plateau, the sample choices were intentionallymade that would likely have high radon readings. Of the 85, 34 of these wells /springswere under the influence of surface water.Table 1shows the range by pCi/L of the samples for Radon taken in the 2001 and 2013study. The number in parenthesis is the highest number for that sample year.The most consistently high readings were for small community/noncommunity systemsin the Highland Rim area of Middle Tennessee, although the highest reading was in EastTennessee. The majority of the high values for radon are from small community(subdivisions, trailer parks) or noncommunity (campgrounds) systems.The Highland Rim wells/springs either side of Nashville have high readings as would beexpected for Mississippian carbonates above the Chattanooga Shale. The ChattanoogaShale is the expected source of the radioactivity in that it has low levels of uranium foundin it in much of the areas where it occurs. Similarly, in the Valley and Ridge (CambrianOrdovician Carbonates) and Unaka Mountains (Crystalline Rock) of East Tennessee,there are shale formations that are expected to be low sources of low level radioactivity.The highest radon result in 2001 (3103 pCi/L) was from a subdivision in Polk CountyTennessee in the southeastern corner of the state. The highest radon result in the 2013study was from a school in Cocke County (8792 pCi/L).The GWMS attempted to recreate the 2001 study in 2011-2012 but due to a laboratoryerror only Gross Alpha and Gross Beta were analyzed. Staff collected a total of 106samples, ninety five (95) individual systems and eleven (11) duplicates samples. Incomparison of the gross alpha and gross beta run in the 2001 sample event, there were nostatistical differences to the 2001 and 2012 studies. Of the Gross Alpha, only threesystems were above the initial 5 pCi/L screening result which would have them scannedfor Radium 226. None of these were above any published limits.14

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Figure 7Range by 00901-10001001-20002001-30003001-2001 number of Systems6213745301411 (3103)Table 1162013 number of Systems4011633531832 (8792)

9.0Ongoing ActivitiesThe Drinking Water Unit has been using EPA 106 Ground Water Grant monies tofurther ground water investigation and management activities.9.1Well Head Protection WorkTennessee has completed the latest round of Well Head Protection updates on allnoncommunity and community water systems. The updates are completed every threeyears. The update includes the observation and documentation of any new potentialcontaminant source, new photographs and maps showing any new protection strategiesthat have been employed by the water system. The next new plan for community watersystems is due to the Division by 2018. The noncommunity and small community watersystems have a new plan every three years based on the grand division that they arelocated in, the 2017 series began with West Tennessee, 2018 is Middle Tennessee and2019 is East Tennessee.9.2Department of Agriculture Pesticide Sampling Micro Pesticide DataProgram (MPDP) and Ground Water Quality Assessment StudyThe Division assisted the United States Department of Agriculture (USDA) in thecollection of pesticide samples from twenty schools and head start facilities that utilizeground water across the state. (Figure 8) These samples were collected by Division stafffrom March 2011 through November 2011 and were analyzed by the Department ofAgriculture. The study was one of the most comprehensive studies completed inTennessee for ground water systems. The study was conducted in order to establish abaseline of micro pesticides data (MPD) in ground water. Previously, there had beenvery little MPD testing in Tennessee. From a health perspective, none of the MPDchemical concentrations analyzed were above any sort of hazard index or health basedguidance.This research was conducted through a partnership with the US Department ofAgriculture and the Division of Water Resources’ Ground Water Management Sectionand reflects a proactive effort to gain a statewide snapshot into certain micro pesticidelevels in ground water sources. Perhaps equally as important, th

2016 305(b) Report serves to fulfill the requirements of both the federal and state laws. This report covers only ground waters in Tennessee. The epartment’s Division of D Water Resources Surface Water Unit is developing a report on ground water quality as well to