Tennessee Overview of the State’s Water Infrastructure
In Tennessee, approximately 90% of the population is connected to a public water supply. This includes over 6.7 million private, industrial, and commercial customers. While many areas in Tennessee are fortunate to have adequate water supplies, there are areas in the state (predominantly in the Appalachian region of east Tennessee) that are lacking proper water delivery and sewage disposal systems. An estimated 112,000 people across rural Tennessee do not have public water.
Furthermore, many utilities in Tennessee were installed over 40 years ago and have been sporadically maintained. Old sewer pipes are cracked allowing groundwater to infiltrate. About 45% of the annual sewage flow treated in wastewater facilities originates from groundwater or rainwater leaking through deteriorated sewage pipes, joints, or manholes.
With the state receiving 3-times more heavy precipitation events in the current decade as in the previous decade, the added water overloads treatment plant pumps causing bacterial-laden raw sewage to back up into local streets and streams leading to fish kills, eutrophication, and other health problems.
In 2018, the small systems in Tennessee recorded 120 violations, with 55 of those violations being major monitoring violations and 24 violations related to exceeding maximum contaminant levels. The potentially harmful pollutants and bacteria found in eastern Tennessee streams and reservoirs were E. coli, mercury, PCBs, and other problematic (i.e., carcinogenic) contaminants. The impact of these contaminants may also extend beyond small communities as the
Tennessee River system is the most heavily used system in the U.S. in terms of gallons withdrawn per square mile (even more so than the Mississippi and Colorado Rivers), with 96% of the water being recycled back into the system
On the left, we see a water treatment facility in Johnson City, TN. To the right
is an image of a small-head near Athens, TN
Compounding the problem, roughly 20% of the community systems in Tennessee are under moratoriums because of excess overflows and many small towns are burdened by these moratoriums, preventing new business development. The leaky pipes pose another problem for small utilities, as deterioration of old infrastructure leads to unrecoverable water loss.
Tennessee water utilities will need to spend $15.6 billion by 2040 for repairs and upgrades to aging sewer collection and water distribution pipes, according to the Governor’s 2019 TN H2O plan. Extending water lines to every rural home in Tennessee would require an additional 18,470 miles of pipes costing an estimated $1.7 billion. In Appalachia, installation challenges are exacerbated by the elevation and terrain, which can leave communities isolated and difficult to reach. The current governor has made rural economic development a top priority by providing increased funding to restore old infrastructure and install new systems. But the small utilities in the state will still need technical assistance programs like ACTAT and its affiliates to overcome their many challenges.
Dr. Kristen Wyckoff is a Lecturer in the Civil and Environmental Engineering Department at the University of Tennessee, Knoxville. Her areas of expertise include water and wastewater treatment, water quality, urban stormwater runoff, point of use filters, environmental bacterial survival, and engineering education. Dr. Wyckoff received her Ph.D. in Civil Engineering from the University of Tennessee Knoxville, and her bachelor’s and master’s degrees from Mercer University in Macon, Georgia in general and environmental engineering respectively. She is an engineer in training, and has been approved by the Tennessee Board of Architectural and Engineering Examiners to sit for the P.E. exam in Environmental Engineering.
(865) 974-7730; email@example.com
Professor Eric Amarante directs the Community Economic Development Clinic at the University of Tennessee College of Law. Under Professor Amarante’s supervision, student attorneys in the Community Economic Development Clinic provide free legal representation to nonprofit organizations and small businesses in transnational matters. Professor Amarante received his J.D. from Cornell Law School and his B.A. from the University of Texas. After law school, he spent five years in private practice before entering academia.
(865) 974-5625; firstname.lastname@example.org
Assistance to Small Systems
The ACTAT team has instituted a land-grant university model program providing customized, face-to-face training and technical assistance to small Appalachian communities burdened by inadequate water services. The collective of scientists, engineers, economists, lawyers, and extension personnel have instituted a land-grant university model program providing customized, face-to-face training and technical assistance to those communities in need. The Tennessee team offers several means of assistance to local utilities, which are discussed below.
The availability of water resources is often overlooked. However, population and industry growth in the region put additional strains on a utility which are exacerbated during periods of drought. Conversely in periods of excess rainfall the increased development and associated impermeable land cover burden wastewater facilities to process the stormwater runoff. Tennessee has developed a protocol that uses a coupled hydrologic-hydraulic modeling framework that focuses on the infiltration capacity of the soils in the region. This modeling framework is coupled with field measurements of
The Tennessee Hydrologic-Hydraulic Modeling Framework to assess water availability
stream flow using Large Scale Particle Velocimetry and infiltration using automated double ring infiltrometers. These two techniques are specialties of the UTK Hydraulics & Sedimentation Lab. This methodology can be used for the watersheds feeding the utilities to project forward the amount of the water they expect to receive in the future so that they can assess needed enhancements a priori. The Tennessee team is conducting a case study for this protocol in the Beaver Creek watershed of northeast Tennessee.
Building from our strengths, we are looking at ways to project rainfall-induced inflow and infiltration (I&I) to the sanitary sewer systems in the region, along with field measurements using quick and mobile monitoring techniques. I&I is a prominent problem in east Tennessee, especially with high rainfall amounts and increasing intensities, as well as changes in land cover from rural to urban that are becoming more frequent. Since 2018, renewed wastewater system permits in the state require more extensive reporting of sanitary sewer overflows. Rainfall-derived I&I is a serious public health challenge and must be considered for sewer rehabilitation and replacement plans.
We are exploring ways to identify and estimate I&I that consider the local geologic and topographic conditions. Experience has shown groundwater can migrate along sewer pipes for long distances, making it difficult to control. Extending from these site-specific considerations and incorporating our advanced instrumentation and modeling capabilities, we are uniquely positioned to help identify and better estimate I&I. Identifying the most representative I&I indicator for modelling is important for its estimation in a sewer system. Certain wastewater quality indicators (e.g., temperature, conductivity) can also be more cost-effective for estimating I&I than dye or smoke tests and they are characteristics not influenced by complex hydraulic conditions such as backwater and overflows.
Thermal imagery both locally and via satellite can be used to identify potential areas of Inflow & Infiltration.
In addition to the above strengths, we are exploring ways to help utilities improve Operational Optimization and Financial
Viability by looking at ways to identify economically recoverable water losses. Tennessee may lack utilization of several opportunities and resources available for its utilities; but, it is the only state in the country that requires (since 2013) annual water audits using the AWWA M36 Water Audits and Loss Control Software and Reporting Worksheet. Tennessee has created a data collection process and established performance thresholds to identify which utilities need assistance to improve their operations. As an outcome in 2017, only 7% of Tennessee utilities exceeded the threshold of 20% non-revenue water as a percent by cost of operating the system. We plan to develop an additional training module tailored towards small utilities using the M36 water audit.
Assessing economically recoverable water losses is a common need for utilities in Tennessee, as well as Kentucky and West Virginia.
The Tennessee team also has developed of an infrastructure assessment database tool that is linked to a Geographical Information System. The assessment tool not only quantifies and locates the assets of the utilities, but it also provides a qualitative assessment of the state of the asset. This assessment tool can help the utility develop a capital replacement plan for its infrastructure. The inventory and assessment protocol involve the use of snake camera that view the inside of the stormwater drains. This tool has helped a small municipality outside of Knoxville conduct a stormwater asset.
(Starting from upper right and moving clockwise. (A) A trained undergraduate student from UT is using a snake camera to look inside a stormwater catch basin. (B) The camera allows for assessing the inside condition of an asset for immediate structural needs including cracks and potential leaks. Following well documented steps, the stormwater assets can be compiled in a database with either a (C) Google Earth or (D) ArcGIS visual interface that can present asset notes as well as collected images and videos.
UT student-intern Sean Ryan and Lori Saal, the Farragut Stormwater Coordinator
discuss the neighborhood catch basins.
How to Get Involved
Please contact Christopher Wilson at the University of Tennessee at (865) 974-7724 or email@example.com
Institute for a Secure and Sustainable Environment (ISSE) - University of Tennessee
University of Tennessee Extension
Municipal Technical Advisory Service
Phone: (865) 974-0411
https://www.tn.gov/environment Tennessee Department of Economic and Community Development
First Tennessee Development District
Tennessee Association of Utility Districts - National Rural Water Association
Communities Unlimited - Rural Community Assistance Partnership