Brief Summary of Minutes of Annual Meeting

University of Maryland

Homeowner education = main focus; updating / revising coursework; new state regulations for inspectors so updated training (including field training component)

2 acre demonstration site being developed at University for hands-on training

Research project proposal from brewery/distillery/winery businesses: Mixed messaging on how to treat effluent from these types of business … characterize waste strength, flow and use info to educate regulators (state/county) and designers on best practices… avoid over- or under-engineered systems (and premature failures)

University of Georgia

Basic information/training for CoopExt agents to talk to people about septic systems to share trusted information with homeowners

Training for Department of Public Health for new employees + soil assessment for OWTS design (promotion within DPH)

Outreach with groups around state, soil & water conservation districts, RCCAP, MS4 in county – water festivals (add septic)

Research: Guar & Capps – “septic sitter” monitoring systems for flows in tank vs. trenches … and locate problems in landscape/water quality as related to septic systems

Michigan State University

• Grad student research; Lab-scale (50-gal drums) greenhouse ecosystem to treat craft beverage wastewater
  • Native Michigan plants treating brewery & cidery wastewater
  • Current running a non-plant control through system
  • Expect report in late December; Thesis report late November
  • Craft beverage wastewater can have high COD (>100k mg/L) from dumping “bad batches”
    • Wastewater moving through biological reactors (plants floating on surface, microbes + aeration) shows good COD removal – nearly 100% after first reactor (100k to 800mg/L) … HRT ~9 days
    • Also showed total N & P reduction (little ammonium/nitrate; most remaining N was in organic or nitrate form)
  • Grad student research: Meat processing wastewater characterization
    • 6 processing facilities (some with slaughter facility include) – documenting contaminants, planning to publish soon
    • Use statistics to explore differences among systems with / without slaughter, smoking, comingling human waste, etc.
      • Higher BOD, COD, Total N in systems with slaughter operations (from blood)
      • Higher Nitrates and BOD/COD in systems with smoking
      • Higher COD on systems with comingled human wastewater
      • Physical effluent screens/filters have improved BOD, COD, trace metals (Cu, Zn) removal
    • Facultative treatment lagoons – aeration improves total N treatment
    • Explore practices at facilities & impacts on treatment performance

North Carolina State University

Extension profs turned over …  Severson runs fee-for-service training – 19 classes with 891 participants for licensing/continuing Education… Annual state conference in October 2023 for 300 person. New extension position for onsite/soils planned in next few years

Research related to sea level rise / climate change impacts in coastal environments

• 2 million residents along coast; much of coast will be inundated by 2100…. Climate adaptation through soil management group (privately funded / donors). Look at coastal salinization research…
  • Functional groupings of soil types predicted to be underwater - 600k hectares of land
    • Drained wetland soils with very old septic systems, often surrounded by saltmarshes
  • Data availability for OWTS very patchy to match permitted system with soil parameters – some records lost (e.g. via fire)
  • Exploring rapid methods (geophysical measurements, remote sensing, drones, field kits for rapid tests) – salinization effects on system function & GHG & crop production & biogeochemistry
  • Mesocosm work: Mechanisms of biochemistry & microbial community responses to brackish (5-18ppt salinity) floods (GHG, microbiome, changes in biogeochemical processes, CEC, etc.) … mimicking nuisance floodings predicted by NOAA
    • After 6 floods, soil productivity for cropping destroyed – little resilience to chronic flooding
  • Costs of OWTS – extension article; some research featured on PBS on state of climate change (“Of salt and soil”)… bring attention to soil use

University of Tennessee

• RCAP funding – together with UMN – education collaboration
• State of TN funding – best management practices for large-scale drip systems (small community … 20-100kgal per day
  • Develop guidance doc of best management practices – with peer review from coopext programs across country; in lieu of TN state regulation
  • TN big construction boom; contractors & developers pressuring state to allow development of previously undeveloped/undevelopable land to meet demand; too fast for TN legislation to keep up
  • Some research included: why do large-scale systems fail; design/soil ID/OM reasons exploring large system failure…. Notices of violations
  • Explore how best practices (e.g. 2’ spacing of drip tubing) are backed up by performance / research
• J Buchanan role transition – from research to education; expect less research reporting in future

Purdue University

Nothing to report

University of Minnesota

EPA funding – NOWRA & RCAP Homeowner education curriculum – 4 modules + interactive online homeowner training on IDing system in yard + troubleshooting

Research: Evaluate septage characteristics from commercial properties

• Is rest-area wastewater different from household wastewater (high toilet flushing) … not that different from domestic/household wastewater. Fewer metals than domestic wastewater …
• Testing new additive for bioaugmentation (exists for municipal systems) – sludge was building up too quickly (low flow fixtures … too much sludge at the beginning of tank),
  • Additive seems to work – less scum & sludge production with no adverse down-stream effects… went from quarterly to annual pump-outs
  • Question whether it would be applicable to household systems – planning future studies
• CEC treatment from systems in rest areas – paper in progress

Lots of training ongoing in MN

University of Rhode Island

Changes in program – staff/professor retirements; state-level deregulation of wastewater professional licensing & continuing education requirements (which affects fee-for-service training aspects of the program)

Working with Town of Charlestown (RI) on research grant – assessing field / real-life performance of proprietary + non-proprietary experimental n-reducing technologies for domestic wastewater

• Evaluating performance of newly installed layered soil treatment areas (pressurized distribution of septic tank effluent onto 18” of C-33 sand overlying an 18” layer of C-33 sand mixed (50/50 by volume) with sawdust) for N-reducing performance: first 9 months of operation very promising (well below 19mg/L total N in effluent), BOD somewhat elevated – need another year of performance data and 6 more sites before progressing through RI regulatory approval process

Expanding our efforts to engage with more system “end users” – helping people better understand onsite wastewater treatment infrastructure and maintenance needs

• Training for realtors
• URI student field trips @ training center (>300 students / year) + new course on OWTS (21 students in spring 2023)
• Public-facing events and workshops
  • Developed a new “To flush or not to flush” game
  • Student intern built plexiglass septic tank to demonstrate function & processes
  • New factsheets

General discussion / Action items

Industry need/wishlist: National initiative to quantify/characterize different types of wastewater – domestic vs. commercial; tourism vs. day-to-day … craft beverage industry & other high-strength wastewater sources

Q for group: worth collaborating on workforce development initiatives in future?

Need to determine where to hold next meeting – S. Heger willing to coordinate/host meeting at NOWRA again in future

Project Objective 1 - Improve our understanding of the interactions among wastewater, soils, biogeochemical cycles and processes and treatment performance (contaminant removal) of existing and novel wastewater treatment technologies in different geographic regions and landscapes over time and considering climate change.

North Carolina State University (NCSU)

North Carolina State University conducted several laboratory experiments to evaluate the potential impacts of sea level rise and soil salinization on a common coastal soil series used for on-site wastewater treatment. We sampled Hydeland soil series materials (Fine-silty, mixed, semiactive, thermic Umbric Endoaqualfs) from a reference site with no saltwater intrusion and packed mesocosms to simulate field conditions in the upper 30 cm of soil. Brackish (mesohaline, mean 16 ppt salinity) water from the Pamlico Sound was collected and added to the mesocosms monthly for 10 months to simulate projected annual occurrence of nuisance flooding in the region by 2050. Water properties (pH, dissolved oxygen, electrical conductivity, Na, Ca, Mg, S, Fe, K, and dissolved organic carbon) were measured for all water samples and leachate collected from the bottom of the columns. Soils were destructively sampled and characterized for chemical properties (cation exchange capacity, base saturation, exchangeable sodium percent, sodium absorption ratio, electrical conductivity, pH, and base cation concentrations) at time zero, 2, 4, 6, 8, and 10 months after flooding began. Real-time greenhouse gas emissions (carbon dioxide, methane, nitrous oxide) were also measured during the experiment using a Picarro 2508 gas analyzer.

Initial results have shown that:

• Greenhouse gas emissions were initially high, but decreased over time as soils became saline-sodic. This suggests that the microbial community was degraded over time and biogeochemical cycling of soil nutrients was slowed.
• Soil became impaired for freshwater plant growth and microbial processes after just 2 floods of brackish water.
• After 4 flood events the entire soil was saturated with sodium, resulting in destruction of soil aggregation due to sodium dispersion and exchangeable sodium percentage was at 100%.
• At flood 5 significant amounts of dissolved organic carbon and other soluble cations were leached from the columns, suggesting that the soil no longer had capacity to absorb added elements. This finding has significant implications for effective treatment of on-site waste and needs to be explored further to understand how sodium additions affect effluent treatment.
• Overall findings suggest that common soils used for septic systems in the coastal regions of North Carolina will be significantly impacted by sea level rise over the next 80 years and effective microbial and biogeochemical treatment of wastewater will be impaired relatively quickly due to predicted increased nuisance flooding by 20250.
• Data from this study is being used to identify permitted septic systems that are likely already impacted by soil salinization and to create a framework for future field sampling of existing on-site systems.

University of Minnesota (UMN)

The University of Minnesota has several research projects focused on gaining a better understanding of septic system performance.  

• A 10 year project has evaluated separation and groundwater mounding beneath septic systems.
• Removal of contaminants of emerging concern was monitored over 4 years at 3 rest area septic systems and one land application site, and a master's thesis was published documenting this work (peer review is underway). In addition, a greenhouse study was conducted to determine the potential breakdown and plant uptake of CECs with land application of domestic septage application. 
• A new project was started evaluating the characteristics of septage removed from commercial systems.
• Several sites were instrumented in the last year with temperature probes to gain a better understanding of soil temperatures concerning the local climate and the impacts of climate change.
• A study was designed to evaluate the effectiveness of various gravity distribution devices.
• A bioaugmentation project is being studied to determine if it can reduce the need for septic tank pumping at facilities receiving primarily toilet waste while maintaining typical wastewater characteristics.
• Biochar and iron-enhanced sand are being studied as enhancement materials to improve nutrient removal.

Rutgers University

Microbial Metabolomics and Genetics Associated with Biodegradation of Pharmaceuticals and Personal Care Products During Wastewater Treatment (A. Porter, L. Young)

Our work examines the removal of micropollutants to improve water quality and produce tools for monitoring water quality. Micropollutants are chemicals that are found at very low concentrations and include household chemicals like pharmaceuticals and personal care products. These chemicals are either washed down the drain or flushed down the toilet and end up as components in wastewater. If these chemicals are not fully degraded by the microorganisms in wastewater treatment systems, they may be released into the environment with unknown consequences.

We have studied pharmaceutical biodegradation activity in enrichment cultures to understand the biodegradation potential of household pollutants by anaerobic microorganisms.  Using naproxen as a model pharmaceutical compound, we explored the effects of different materials as surfaces for microbial attachment and biofilm formation. We have shown that the microbial community composition changes when there are surfaces for attachment, however, the function of the community appeared to be unaffected. We have started to  genetically characterize the microbial community that is responsible for pharmaceutical biotransformation. We have targeted genes to determine whether the presence of genetic markers can be used to trace the presence of the compounds and whether they indicate biogeochemical cycling of carbon by these organisms. We have successfully detected genes for both aromatic ring metabolism and acetogenesis, which is consistent with our previous culture-based results.

University of Rhode Island (URI)

Piloting N-reducing nonproprietary layered soil treatment areas. In FY 2022, we continued to partner with the Town of Charlestown, RI to gain regulatory approval to pilot a novel, non-proprietary advanced N-reducing OWTS drainfield option in RI, which presents an inexpensive alternative to currently approved proprietary technologies for N reduction. We monitored four pilot systems installed in 2021 to serve private residences in coastal Charlestown, RI. Our data (monthly sampling of each of the four installed systems) indicate that these systems are performing well in terms of N-reduction, and that if additional years’ of data collection continue to indicate good N-reduction performance, the RI Department of Environmental Management (RIDEM) could approve this technology for wider use in RI.

Monitoring the performance of proprietary advanced N-reduction technologies. Building on past research efforts to document the real-world performance of existing advances OWTS technologies installed and operated in private residences, we continue to conduct quarterly sampling of effluent leaving 20 advanced proprietary nitrogen-removing residential systems from a variety of manufacturers (including both media filter and aerobic treatment unit technologies approved in RI) with our municipal partners. Lab analyses indicate that many systems are capable of meeting the regulatory requirements and are discharging effluent concentrations at or below 19mg/L of Total N, but some systems do not. We continue to search for predictors of system performance that are easily assessed in the field to inform maintenance best practices for professionals in the industry.

Examining the prevalence of PFAS in onsite systems. With funding from the USGS, we investigated the presence and concentration of 24 per- and polyfluoroalkyl substance (PFAS) compounds in domestic wastewater from 19 households in Charlestown RI. Many regions, like our study area, that use septic systems also rely on groundwater for clean drinking water, so understanding occurrence of PFAS in septic systems is critical to protecting human health. Samples were collected from septic tanks (n=4), advanced nitrogen-removing technologies (n=14) and experimental layered nitrogen-removing drainfield leachate (n=4). Following a new EPA method (method 8372) for quantifying PFAS in water samples, we successfully detected the presence of 22 of the 24 PFAS compounds studied in our project. Total PFAS concentrations ranged from 100 to 450 ng/L with a median concentration of 312 ng/L. There was a wide variation in concentrations and in which compounds were present across individual systems. The most common potential sources of the PFAS compounds present in our wastewater were stain and water-resistant fabric coatings and food packaging. When considering the concentrations of compounds regulated in drinking water, it is clear that septic systems may be a source of harmful compounds to groundwater, a potential threat to people who draw well water from groundwater in regions where septic systems treat wastewater. These findings indicate the need for additional research of PFAS in septic systems and the mechanics governing concentrations in different types of septic systems. The concentrations we have found in this initial study should advise regulators and policy makers to test PFAS in drinking water supplies in regions where onsite wastewater treatment is common.

University of Tennessee Institute of Agriculture

New knowledge has been gained about the nitrification/denitrification that takes place as secondary-treated wastewater moves through the soil under a subsurface drip dispersal system.  Preliminary results seem to suggest that the dosing and resting cycles of a drip system promote the aerobic/anaerobic conditions that are needed to reduce nitrate to nitrogen gas.  If this trend continues, the implication is that criteria employed by the state of Tennessee for the design of community-scale drip dispersal system is protective of the groundwater.  Subsurface drip dispersal systems are seen as a potential solution for the land-based application of effluent in areas where the water table has become more shallow due to the effects of climate change.

Project Objective 2 - Examine watershed-level impacts of septic systems on water quality and other environmental parameters in suburban, rural and coastal areas.

University of Rhode Island (URI)

Modeling N-reducing OWTS technology performance at the watershed scale. Based on the performance data from nitrogen-reducing technologies (both proprietary and experimental) described in Objective 2, we coupled the total N concentration data with flow estimates from all septic systems in a small subwatershed in Charlestown, RI to model the impact of different OWTS upgrade scenarios. Based on the initial performance of the experimental layered N-removing drainfields, if existing conventional septic systems were upgraded to these experimental systems where feasible (based on lot size, horizontal setbacks to wells, and groundwater table depth constraints), the mass nitrogen load to our study watershed could be reduced by 78%, when compared to present conditions. This scenario is more favorable than upgrading all the existing systems to currently approved proprietary N-removing technologies we have been collecting N-removing performance data for, as they put out higher concentrations of total N in their effluent than the experimental system and are more costly to install. Nevertheless, upgrading existing conventional systems to either of the N-reducing technology options (proprietary vs. experimental) would significantly reduce the N load to the watershed at a fraction of the cost of connecting the watershed to a centralized wastewater treatment plant.

Project Objective 3 – Develop educational materials and tools to acquaint the public and practitioners about management, operation, maintenance and health issues related to OWTS in light of system performance, and the need for adaptation to climate change.

University of Arizona

As an Extension Specialist (outreach professional), I educate and train onsite wastewater treatment practitioners in the soil and site evaluation, design, installation, operation and management, and inspection of onsite wastewater treatment systems, and inform homeowners and users of onsite wastewater treatment systems how to better manage their systems to prolong their useful life while protecting human health and the environment. This is done through formal training classes (1 to 3 days each) and seminars for homeowners. Exit surveys are conducted to obtain knowledge gained for the homeowners. Exams are given in several of the training courses for practitioners.

The target audiences include homeowners, regulators, and onsite wastewater practitioners (including soil and site evaluators, designers, installers, and inspectors). Homeowners have a better understanding of their septic system and the management needed to extend the life of their system. Due to the nature of the regulatory sector, there is a turnover of regulators. Regulators new to the position often have not been exposed to onsite wastewater treatment systems and attending the training provides them with the knowledge and skills to be better at their jobs. In Arizona, there are two regulatory training courses required by law: inspection for the Transfer of Ownership Inspection program and soil and site evaluation. These courses allow professionals to either expand their business model or allow them to continue conducting their business.

The impacts include:

1. 239 professionals know how to inspect an onsite wastewater treatment system for the Arizona Transfer of Ownership Inspection Program. Without taking this course, these professionals would not have been eligible to participate as an inspector for the statewide program. Thus, 239 professionals either expanded their business model or were able to continue conducting business in this area. A national exam is required to demonstrate knowledge.
2.  67 practitioners (both regulators and in-the-field professionals) know more about conducting soil and site evaluations for onsite wastewater treatment systems and can use the Arizona code to conduct the evaluations. Without attending this class, these practitioners would not be able to conduct these evaluations as part of their jobs. An exam, that includes both a written portion and a practicum, is required to demonstrate knowledge and the ability to texture and color a sample of soil.
3. 28 practitioners have increased knowledge for designing residential, gravity-distributed septic systems using Arizona rules. A homework assignment was used to provide practical application of material learned in the workshop. This class is not required by Arizona law, so those attending really want to learn best practices and/or earn continuing education hours.
4. 29 practitioners (both regulators and in-the-field professionals) have increased knowledge about designing systems using pressure distribution and pumps and overcoming site limitations. The course covered installation, inspection and operation and maintenance issues regarding pumps. Arizona law does not require this class, so those attending are interested in improving their life-long skills and/or earn continuing education hours.

University of Maryland (UMD)

Developed a new Inspection Course (14 hours) in collaboration with the state industry association.

Developed and taught new Septic 102 Septic Systems for Entry Level Professionals course (6 hours) .

Continued development of two acre onsite wastewater treatment demonstration facility.

University of Minnesota (UMN)

NE2045 project members from the University of Minnesota and the University of Tennessee worked together to secure U.S. EPA pass-through funding to develop a homeowner user guide to septic systems and a train-the-trainer program.  The PIs worked through the National Onsite Wastewater Recycling Association (NOWRA) to produce the curriculum for the train-the-trainer program and the publication titled Onsite Wastewater Treatment System User Manual.   In addition, an online version of the training program was developed These resources are available online at: https://www.nowra.org/library/homeowner-training-materials/

University of Rhode Island (URI)

Onsite wastewater professionals and regulators. Our program held 22 credit-bearing training workshops for wastewater professionals’ licensing requirements in RI, NH, VT, MA and NY, reaching a combined 323 professionals. We developed two new courses in conjunction with other OWTS experts in the region: one involved a tour of the Massachusetts Alternative Septic System Test Center (Barnstable County, MA) and a nearby demonstration project. Another workshop was co-developed with staff from Stonybrook University’s Center for Clean Water Technology on non-proprietary layered N-reducing bioreactors on Long Island. This year we also launched a 4-hour self-paced course centered on Nitrogen’s impact on the environment, and how N dynamics play out in different types of OWTS. The course has been well-received by professionals; 12 participants have completed the course as of September 2023, earning credits for regulatory licensing renewal. We are working to add additional self-paced and hybrid offerings for upcoming workshops in 2024. All of our workshops are continuously updated with the latest scientific and technical information, and are structured to be engaging while improving our attendees’ ability to implement science-based best practices in their professional work related to OWTS. We encourage wastewater professionals to design systems with greater separation distances from drainfield bases to groundwater tables, which results in better treatment of wastewater and also reduces the potential impacts of climate change, ultimately and helping to protect ground and surface receiving water quality for residents state-wide.

Realtors. We continued to offer a series of credit-bearing workshops for realtor audiences to help them disseminate accurate and factual information to their clients about conventional and advanced septic systems. The workshop series consists of two two-hour virtual trainings and a two-hour hands-on training session at our outdoor onsite wastewater training center. A total of 113 RI realtors attended our workshops, resulting in 120 training contact hours delivered on conventional septic systems, 66 training contact hours focused on advanced systems, and 40 field-based contact hours at the URI wastewater demonstration center.

Public audiences: OWTS owners. This year, we significantly ramped up our efforts to engage with members of the public who own properties with septic systems, answer their questions and share science-based information with them related to operation and maintenance of septic systems. Some of these efforts were the result of our ongoing grant-funded collaboration with local municipal and non-profit partners. Our staff attended and/or hosted 11 public-facing events, and engaged with about 450 members of the public. URI student volunteers supported many of these events (e.g. booths at the RI Home Show and Farmer’s Markets), contributing more than 50 volunteer hours and concurrently gaining important experience and skills related to effective public engagement and science communication. In response to frequently asked questions and community needs, we developed a series of new factsheets on (1) Conventional OWTS function, maintenance and best practices, (2) advanced N-removing OWTS function, operation and maintenance needs, (3) function and care of advanced pressurized drainfields, and (4) informed decision making for upgrading to an advanced N-removing OWTS. These factsheets have been well-received, and we have been distributing them during realtor trainings as well.

Public audiences: URI students. As in past years, our program staff continued hosting 1-2 hour field trips at the URI onsite wastewater training center for students enrolled in natural resources science, landscape architecture, and geology courses. Last year, approximately 300 students spent at least an hour at the center learning about decentralized wastewater treatment mechanisms and best practices for protecting and enhancing wastewater treatment to protect local water quality. In addition Dr. Alissa Cox taught a new upper undergraduate/graduate course on the principles of onsite wastewater treatment to 21 students. The course was structured around the problem-based learning method of instruction, where students were assigned to stable teams which worked through a successive series of interconnected real-life problems related to environmental water quality and OWTS function, design and performance. At the end of the semester, three of the graduating seniors had applied to and accepted jobs in the wastewater industry. In addition, four URI civil engineering seniors participated in a 1-2 semester-long customized experiential learning project focused on the function, siting and design of OWTS.

Rutgers University

Continuing to develop curriculum materials that are used in two courses within the Environmental Sciences undergraduate major.  These students are frequently employed in the wastewater sector.

University of Tennessee Institute of Agriculture

NE2045 project members from the University of Minnesota and the University of Tennessee worked together to secure U.S. EPA pass-through funding to develop a homeowner users guide to septic systems and a train-the-trainer program.  The Rural Community Assistance Partnership (RCAP) is the EPA subcontractor for this effort and will conduct the homeowner training.  The PIs worked through the National Onsite Wastewater Recycling Association (NOWRA) to produce the curriculum for the train-the-trainer program and to produce a manuscript titled, Onsite Wastewater Treatment System User Manual.  

Inter-institutional collaborations

Heger, S. and J. Buchanan.   2023.   Onsite wastewater treatment system user guide.   National Onsite Wastewater Association and Rural Community Assistance Program.

Holodak, J., Stanley, Jacob K,M.S., PhD., Cox, Alissa H,M.S., PhD., Groves, T. W., Jantrania, Anish, MBA,PhD., P.E., Moeller, Jeffrey,M.S., P.E., Neset, Kris,M.S.M., P.E., Walker, C., M.S.E.H., Zhang, Harry,PhD., P.E., Ryan, Benjamin J, MPH,PhD., R.E.H.S., Heger, Sara F,M.S., PhD., & Brooks, Bryan W,M.S., PhD. (2023). Identifying Workforce Education, Training, and Outreach Needs in Decentralized Wastewater and Distributed Water Reuse. Journal of Environmental Health, 86(5), 20-28.

University of Minnesota (UMN).

Boor, Elizabeth.  2023.  Chemicals of Emerging Concern in Minnesota Subsurface Sewage Treatment Systems.  Masters Thesis.  University of Minnesota. 

University of Rhode Island (URI)

Alissa H. Cox, Owen Placido, Kristen Hemphill & Matthew Dowling (2023). “Notes from a Pilot Watershed: Protecting Water Quality in and Around Southern RI.” Poster presented at the 2023 SNEP Biennial Forum. June 13, 2023. Fall River, MA.

Placido, Owen, "Advanced septic systems contribute nitrogen and per and polyfluoroalkyl substances to coastal groundwater" (2023). Open Access Master's Theses. Paper 2346. https://digitalcommons.uri.edu/theses/2346

Owen Placido, Kristen Hemphill, Matthew Dowling, Alissa H. Cox (2023). “Nitrogen Reducing Septic System Upgrades Measurably Reduce Nitrogen Loading to Watersheds” Poster presented at the 2023 SNEP Biennial Forum. June 13, 2023. Fall River, MA.

URI Onsite Wastewater Resource Center (2023). “Informed Decision-Making: Advanced OWTS” University of Rhode Island, Kingston, RI.

URI Onsite Wastewater Resource Center (2023). “Factsheet: Advanced OWTS” University of Rhode Island, Kingston, RI.

URI Onsite Wastewater Resource Center (2023). “Factsheet: BSFs” University of Rhode Island, Kingston, RI.

URI Onsite Wastewater Resource Center (2023). “Factsheet: Conventional Septic Systems (OWTS)” University of Rhode Island, Kingston, RI.

URI Onsite Wastewater Resource Center (2023). “Factsheet: LSTAs” University of Rhode Island, Kingston, RI.