Progress 03/01/04 to 09/30/09
Outputs
OUTPUTS: Information gained by this project has been shared with several stakeholder groups within the onsite wastewater management industry. Stakeholders include citizens who depend on onsite systems to renovate and disperse residential wastewater; practitioners who install and maintain residential and commercial onsite wastewater systems; and regulators who need the latest science-based information. During life of this project, the P.I., Dr. John Buchanan, used community events, professional meetings, educational workshops, and for-credit college classes to inform people about some of the project's findings. Five small communities invited Dr. Buchanan to make presentations about how soil-based onsite wastewater treatment systems operate and how they should be maintained. Three of these communities are not sewered and many of the individual septic systems have failed. In each of these meetings, the Mayors and Aldermen were informed about the potential of developing a wastewater infrastructure in each of their communities that combines centralized wastewater collection with inexpensive soil-based treatment and dispersal (Huntland, Eagleville, Estill Springs - all in Tennessee). During 2008, Dr. Buchanan presented new information at five national and local professional-society meetings. During these meetings, he presented some of the information gained by this project. On a local level, he toured agricultural Extension agents to a repaired septic system and explained the techniques used to restore the system functionality. Lastly, and equally important, Dr. Buchanan incorporated the gained knowledge into his teaching curriculum. During the Fall semesters of 2004, 2006, and 2008, Buchanan taught a graduate-level onsite wastewater treatment and dispersal engineering course. This project also provided an opportunity for five senior engineering students to research the potential for optimizing the nitrogen removal provided by a recirculating media filter - a device commonly used to provide secondary treatment at individual and small community wastewater treatment systems. This student team placed in the top-three in a campus-wide and in a national engineering competition. This project produced results that forced changes in Tennessee's rule regarding the installation of onsite wastewater renovation systems. It was determined that the regulations needed to provide a soil based loading rate rather than a product-based loading rate. As a result of this project, 20 specific recommendations were made as amendments to Tennessee's current subsurface sewage disposal regulations. Rule changes require public input, and thus these hearings provided an opportunity to disseminate new knowledge. The hearings took place January 22-25, 2008 at various locations across Tennessee. Based on the public comment, the proposed rule changes were modified and a second set of public hearings were held December 1-3, 2008. These new rules will go into effect on November 30, 2009. PARTICIPANTS: This project was partially funded by grants from the Tennessee Valley Authority (TVA), Tennessee Department of Agriculture's Nonpoint Source Program, Tennessee Department of Environment and Conservation Division of Ground Water Protection, Tennessee Onsite Wastewater Association, and the Tennessee Water Resources Research Center. TARGET AUDIENCES: The target audiences for this project were three-fold. First, the regulatory community was a target audience because they need the most up to date information on the science of soil-based wastewater renovation. The next audience was homeowners who depend on onsite wastewater renovation systems to protect themselves from becoming contaminated by their own (and their neighbor's) wastewater. And lastly, the professionals who install soil-based systems were a target audience as installers need to understand how they can influence the success or failure of an onsite wastewater system PROJECT MODIFICATIONS: The project was modified from the original proposal. Due to funding constraints, the actual wastewater trenches were not installed as planned. Instead, the P.I. used the research literature and previously-installed systems to do this investigation. Further, this projected added the study of Triclosan, an antimicrobial commonly found in hand soap. This project investigated the mobility of tricolsan in the soil environment. This was a pertinent addition to this project because triclosan is considered an emerging organic contaminant of concern.
Impacts
This research impacted how the regulatory community makes decisions about the appropriate use of conventional and alternative soil absorption systems that are used for the subsurface disposal of domestic wastewater. As a result of this project, Tennessee made 20 amendments to the rule that governs the installation and operation of onsite wastewater renovation systems. With the new knowledge gained by this research, onsite wastewater renovation systems have a greater potential to protect human health and maintain environmental quality. This project produced two graduates with Master of Science degrees. Each student completed a thesis based on the research conducted for this investigation.
Publications
- Buchanan, J.R. 2007. Sizing Soil Absorption Systems. A report to the Tennessee Department of Environment and Conservation Division of Ground Water Protection, 401 Church Street, Nashville, TN, 37243-1531
- Buchanan, J.R. 2007. The evolution of decentralized wastewater management regulations in Tennessee. Eleventh Individual and Small Community Sewage Systems Conference Proceedings, Warwick, Rhode Island, October 20-24, ASABE Publication Number 701P1107.
- Dobbs, P.A. 2007. Optimization of decentralized wastewater design flow rates based on risk analysis. An unpublished Master's thesis, the University of Tennessee, Department of Biosystems Engineering and Soil Science, Knoxville, Tennessee.
- Roach, A.L. 2006. Facilitated Transport of Triclosan in the Receiving Environment of an Onsite Wastewater Treatment System: Agent of Aquatic Concern. An unpublished master's thesis, The University of Tennessee, Department of Biosystems Engineering and Soil Science. Knoxville, Tennessee.
|
Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Information gained by this project has been shared with several stakeholder groups within the onsite wastewater management industry. Stakeholders include citizens, who depend on onsite systems to renovate and disperse residential wastewater; practitioners who install and maintain residential and commercial onsite wastewater systems; and regulators who need the latest science-based information. The most significant output was a series of public hearings. Based on the findings of this project, the state of Tennessee proposed sweeping changes in the rules that govern residential septic systems. Rule changes require public input, and thus these hearings provided an opportunity to disseminate new knowledge. The hearings took place January 22-25, 2008 at various locations across Tennessee. Based on the public comment, the proposed rule changes were modified and a new series of public hearings were scheduled for December 1-3, 2008. During 2008, the project leader, Dr. John Buchanan, used community events, professional meetings, educational workshops, and for-credit college classes to inform people about some project results. Two small communities invited Dr. Buchanan to make presentations about how soil-based onsite wastewater treatment systems operate and how they should be maintained. The community of Huntland, Tennessee is not sewered and many individual septic systems have failed. On May 12, Buchanan met with the Mayor and city council to discuss options for improving the town's wastewater infrastructure. During 2008, Dr. Buchanan presented new information at five national and local professional-society meetings. During these meetings, he presented some of the information gained by this project. On a local level, he led a tour of agricultural Extension agents to a repaired septic system and explained the techniques used to restore the system functionality. Lastly, and equally important, Dr. Buchanan incorporated the knowledge gained into his teaching curriculum. During Fall Semester 2008, Buchanan taught a graduate-level onsite wastewater treatment and dispersal engineering course. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Tennessee has enacted new rules for the design, installation, and operation of onsite wastewater management systems. Largely based on the literature review produced by this project, these rule changes will allow modern materials to be utilized in the dispersal of septic tank effluent into subsurface soil. Further, specification of traditional materials was modified to reflect the better understanding that has been developed by recent scientific investigations.
Publications
- Buchanan, J. R. 2008. Wastewater Strength. Onsite Advocate, 6(1): 4-5.
- Buchanan, J. R. 2008. Wastewater management options for growing communities. Onsite Advocate, 6(2):9-10.
|
Progress 01/01/07 to 12/31/07
Outputs
An extensive review of Tennessee's subsurface sewage disposal rules found many inconsistencies in the loading rates assigned to various disposal field products. Historically, domestic sewage has been managed by septic tanks and soil absorption fields. Septic tank effluent was dispersed into the subsurface soil using a layer of mineral aggregate in the bottom of trenches. The aggregate provided in-trench porosity that allowed effluent exposure to the trench bottom and sidewalls. More recently, aggregate-replacement products are available that can potentially improve in-trench effluent infiltration. As these products entered the market, regulations for their use were written. The end result was piecemeal rules that provided inconsistent loading rates among products. Using the example of a septic system installed on 60 minute per inch (mpi) soil, the following list indicates how a sample of various systems would be sized by Tennessee regulation in units of gallon per day per square foot of trench bottom (gpd/sq ft). 1. 36-inch mineral aggregate: 0.45 gpd/sq ft 2. 36-inch wide chamber systems: 0.65 gpd/ sq ft 3. 8-inch large diameter gravelless pipe: 0.61 gpd/sq ft 4. 10-inch large diameter gravelless pipe: 0.91 gpd/sq ft. This list demonstrates the large range of loading rates that are allowed on a given soil. While the products do provide some enhancement to effluent infiltration, the soil is the ultimate limiting factor. The regulations need to provide a soil-based loading rate rather than a product-based loading rate. As a result of this review, 20 specific recommendations were made as amendments to Tennessee's current subsurface sewage disposal regulations.
Impacts
On December 7, 2007, the Tennessee Department of Environment and Conservation's Division of Ground Water Protection announced a series of public hearings that are to be conducted in January, 2008. The public hearings concern rule-change for subsurface sewage disposal. Most of the recommendations produced by this project have been incorporated into the proposed rule changes. The proposed rules can be found at http://state.tn.us/environment/gwp/ppo/.
Publications
- Buchanan, J. R. 2007. Sizing Soil Absorption Systems. A report to the Tennessee Department of Environment and Conservation Division of Ground Water Protection, 401 Church Street, Nashville, TN, 37243-1531
- Buchanan, J. R. 2007. The evolution of decentralized wastewater management regulations in Tennessee. Eleventh Individual and Small Community Sewage Systems Conference Proceedings, Warwick, Rhode Island, October 20-24, ASABE Publication Number 701P1107.
- Dobbs, P.A. 2007. Optimization of decentralized wastewater design flow rates based on risk analysis. An unpublished Master's thesis, the University of Tennessee, Department of Biosystems Engineering and Soil Science, Knoxville, Tennessee.
|
Progress 01/01/06 to 12/31/06
Outputs
Progress has been made in better understanding the fate and transport of triclosan in onsite wastewater renovation systems. Triclosan is an antimicrobial that is found in a host of consumer products, but mostly in antibacterial handsoaps. Adrienne Roach completed her graduate research that focused on whether dissolved organic compounds (found in domestic wastewater) facilitate the transport of triclosan through a soil column. Based on batch sorption and column transport studies, dissolved organic matter reduces the triclosan mass that would otherwise attach to soil particles, thus increasing the mobility of triclosan in the soil environment. This is a significant finding because triclosan is a strong antimicrobial and is found in many consumer products. Dissolved organic compounds are pervasive in septic systems and in the soil environment. If triclosan is not captured by soil particles or degraded by biological activity, then there is a risk that triclosan can enter
the ground water. In many locations where onsite septic systems are used for domestic wastewater disposal, groundwater is frequently the primary source of drinking water. Progress has been made in the overall funding of this project. Tennessee's Division of Ground Water Protection has provided funding to conduct laboratory and field analyses of various in-trench architectures used for the subsurface dispersal of domestic wastewater. The specific task is to investigate the effluent storage capacity of non-mineral trench media. The Southern Region Water Program awarded a subcontract to this project. This program is a partnership of USDA CSREES and Land Grant Colleges and Universities. The grant is for the development of a protocol to measure the long-term acceptance rate of mature drainfields.
Impacts
This research will impact how the regulatory community makes decisions about the appropriate use of conventional and alternative soil absorption systems that are used for the subsurface disposal of domestic wastewater. The current definition of a failed system is one that allows wastewater to come to the soil surface or forces wastewater to be backed up into the house. Failure needs to also include whether the wastewater has been appropriately renovated before re-entering the hydrologic cycle. This project is investigating the quality of the soil-water beneath the absorption trenches to determine if there are differences in how conventional and alternative absorption systems provide wastewater renovation.
Publications
- Roach, A. L. 2006. Facilitated Transport of Triclosan in the Receiving Environment of an Onsite Wastewater Treatment System: Agent of Aquatic Concern. An unpublished masters thesis, The University of Tennessee, Department of Biosystems Engineering and Soil Science. Knoxville, Tennessee.
|
Progress 01/01/05 to 12/31/05
Outputs
Triclosan is an antibacterial found in a host of consumer products ranging from toothpaste to textiles. The most common application of this product is in antimicrobial handsoaps. Little is known about the fate of triclosan in onsite domestic wastewater renovation systems. As part of the theme of this project, a graduate student has been assigned the task of determining whether the dissolved organic matter found in wastewater will facilitate the transport of triclosan through onsite wastewater renovation systems. Triclosan is hydrophobic and preliminary results demonstrate that dissolved organic matter increases triclosan solubility in wastewater. These results suggest that dissolved organic matter may facilitate triclosan transport through the septic tank and into the drainfield. The Tennessee Department of Agriculture Nonpoint Source Program has provided additional funding to this project. This program uses U. S. EPA 319-H dollars to support nonpoint source research
and education. The new funding is being used to explore alternative solutions for failed systems. A failed drainfield at a home in North Knox County, Tennessee is currently being converted from a rock and pipe system to a low pressure pipe system. The primary question at this site is whether the soil at the failed location can be made to start taking water again with the low pressure pipe system.
Impacts
This research will impact how the regulatory community makes decisions about the appropriate use of conventional and alternative soil absorption systems that are used for the subsurface disposal of domestic wastewater. The current definition of a failed system is one that allows wastewater to come to the soil surface or forces wastewater to be backed up into the house. Failure needs to also include whether the wastewater has been appropriately renovated before re-entering the hydrologic cycle. This project is investigating the quality of the soil-water beneath the absorption trenches to determine if there are differences in how conventional and alternative absorption systems provide wastewater renovation.
Publications
- No publications reported this period
|
Progress 01/01/04 to 12/31/04
Outputs
This project is still in its infancy. The Middle Tennessee Experiment Station has designated three homes (located on the station) to serve as wastewater sources for this project. To complete the objectives, approximately 360 gallons of septic tank effluent will be required each day. These three homes are in close proximity to one another and will have their wastewater systems connected to a common collection system.
Impacts
This research will impact how the regulatory community makes decisions about the appropriate use of conventional and alternative soil absorption systems that are used for the subsurface disposal of domestic wastewater. The current definition of a failed system is one that allows wastewater to come to the soil surface or forces wastewater to be backed up into the house. The definition of failure needs to also include whether the wastewater has been appropriately renovated before re-entering the hydrologic cycle. This project is investigating the quality of the soil-water beneath the absorption trenches to determine if there are differences in how conventional and alternative absorption systems provide wastewater renovation.
Publications
- No publications reported this period
|
|