Brief Summary of Minutes of Annual Meeting

1. The meeting began at approximately 1:00 pm. Ten individuals, representing six institutions, attended the NE1545 project meeting.  Each representative institution delivered a brief update of NE1545 related activities for the reporting year October 1, 2016 to September 30, 2017.  Accomplishments from these research and outreach activities are noted in the Accomplishment section of this report.
2.  presentation and tour of the University of South Florida/Hillsborough County Northwest Water Reclamation Facility (NWWRF) pilot plant was conducted by Sarina Ergas, Emma Lopez, and Kebreab Ghebremichael from USF.  Screened raw wastewater from the NWWRF flows to a septic tank that feeds two pilot scale Hybrid Adsorption Biological Treatment Systems (HABiTS).  Wastewater flow rates are controlled by pumps and timers and effluent is returned to the headworks of the NWWRF.  Both systems are considered “passive” treatment systems, where advanced treatment of onsite wastewater is provided without mechanical aeration or extensive use of pumping.  In Stage 1, a natural zeolite material, clinoptilolite, is used as an NH₄⁺ IX medium in aerobic nitrifying packed bed reactors (PBRs).  In Stage 2, saturated PBRs containing scrap tire chips as a NO₃^- IX medium are combined with sulfur pellets and crushed oyster shells to promote sulfur oxidizing denitrification.  One of the system incorporates effluent recirculation in Stage 1.  Visitors viewed a presentation on the research and review of current data followed by a tour of the facility with representatives from USF and Hillsborough County.
3. Mussie Habteselassie from University of Georgia informed the group that long-time colleague, David Radcliffe, has retired from UGA.  Mussie informed the group of three new publications and three outreach training classes UGA produced during the report period.
4. Sara Wigginton from the University of Rhode Island reported on her research investigating the microbial communities of three nitrogen removing advanced onsite wastewater treatment systems (OWTS) widely used in RI. Microorganisms containing nitrous oxide reductase (nosZ) genes were much more abundant than ammonia monooxygenase (amoA) genes within advanced OWTS microbial populations for all advanced N-reducing OWTS designs. The aerated zones within Septic-Tech systems had significantly higher populations of amoA containing microbes than the anaerobic zones of the same tank design. Advantex aerated zones contained significantly higher nosZ populations than FAST tank aerated zones. There were no differences in species diversity or composition between the three different advanced OWTS designs tested. The most prevalent amoA species was Nitrosomonas oligotropha and the most prevalent nosZ species was a Pseudomonas spp. URI’s role in testing layered STAs in collaboration with the Massachusetts Alternative Septic System Testing Center (MASSTC) was also discussed. We will be performing similar microbial analyses on layered STAs, as well as monitoring N removal efficiency and greenhouse gas emissions as a function of STA design.
5. Jennifer Cooper (currently at the University of Florida) reported on her continued research with the University of Rhode Island related to DNA sequencing methods to compare the microbial community composition in onsite wastewater treatment systems (OWTS) using intact soil mesocosms.
6. Alissa Cox from the University of Rhode Island reported on two current research projects related to OWTS and climate change – assessing the influence of sea level rise on groundwater tables adjacent to existing OWTS along the Southern RI Coast to assess influence of sea level rise, and evaluation of plant species that can be used with plant-based OWTS designs to help mitigate the impacts of climate change.
7. Sergio Abit from Oklahoma State University presented his output from cooperative extension projects related to OWTS. In addition to the usual stakeholders that were reached by the extension program, he expanded his extension activities to include home builders, realtors, 4H members and summer campers.  He also organized the 2^nd Oklahoma Onsite Wastewater Conference which was attended by 168 participants from various stakeholder groups across the State. He also reported the increasing utilization of the OWTS Training and Demonstration Facility for Tours, Training and classes.
8. Steven Safferman from Michigan State University reported on research associated with Objectives 2 and 3. Specifically, he provided an update on research on the appropriate organic and hydraulic loading associated with the land treatment of food processing waste.  The advantages relative to treatment cost and greenhouse gas emissions was estimated.  Additionally, a new finite element modeling effort using the HYDRUS Wetland Module was discussed.   Included was a comparison of model derived results and data from a laboratory experiment using larger-scale soil trenches. He also discussed progress relative to Objective 4.  The MSUE Comprehensive Onsite Wastewater Management Education Program.  The facilitated online program for designers and installers is now being offered for the third time and approximately 20 professionals have participated.  Completion of the classes results in 1.6 continuing education credits and/or 16 septage waste education credits.   The homeowner programs continues to be offered.  A new folder was developed that is distributed during workshops.  This resource defines onsite wastewater and provides important operational and maintenance procedures.  Also included are a grid to plot the location of structures, drives, and the onsite wastewater system and a maintenance log.  As part of this objective, a short public service announcement was produced for homeowners and policy makers (https://www.youtube.com/watch?v=ZtppgvPlOCU&feature=youtu.be).
9. Details of the efforts noted above are included under Objectives 2 and 4 in the Outputs Section of this report.
10. The meeting concluded at 4:00 pm.

Outputs

Project Objective 2 – Develop new OWTS design criteria for the purposes of climate change adaptation and mitigation

University of Minnesota findings –  MnDOT Phase II

During previous research with the Minnesota Department of Transportation additional research areas arose which will be evaluated in this project.  The key aspects are:

1. Evaluating water tables and groundwater mounding at 20 existing systems with a combination of automated water level recorders and analog hand monitoring between early April through mid-November. Questions to answer - what level of vertical separation to a periodically saturated condition is maintained at each of these sites; and does the groundwater below these systems mound up either during high wastewater discharge times or wet climatic periods.
2. This project evaluated the how well varying toilet papers and related products break down in a septic tank. Twelve paper product samples were subjected to anaerobic digestion to identify their anaerobic biodegradability for methane yield using a standardized test. 

MnDOT Reuse

This project will evaluate the potential and effectiveness of wastewater reuse at MnDOT facilities.   This project will evaluate when reuse makes sense from a regulatory, environmental, economic and management perspective at truck washing/storage facilities and safety rest areas.  Sampling of various streams will be done to identify challenges related to various uses.  Recommendations will be provided on the most appropriate applications for reuse and the challenges with implementation. The possibility of reusing wastewater for anti-icing and pre-wetting after removal of sediment and oil will be evaluated along with options for domestic wastewater treatment

Optimizing Septic Tank Performance

A project was completed to develop an alternative (microbial electrochemical) septic tank configuration focusing on nutrient recuperation to mitigate the environmental footprint of septic systems. The one-liter bench scale tanks proved the phosphorus removal (between 20.7% and 98.3% of removal efficiency at 0.5 to 0.88 V voltage applications) and recovery from sewage via the improved phosphorus precipitation on electrodes and the improved phosphorus settling in sludge. Methane production in microbial electrochemical septic tank was boosted by electrode assistance, and the largest difference occurred at 0.88 V, increased from 180 mL by 107% at 25 °C, and from 15 mL by 360% at 15 °C, potentially serving as a bioenergy source if being utilized. The 20-L lab-scale prototypes treating real wastewater demonstrated that when operating the reactor at 15 ºC, the most appropriate Eap seems to be 1.7 V to achieve the best quality of the effluent (the lower phosphorous and the lower organic content). When operating reactors at 25 ºC, the most suitable Eap seems to be between 1.1-1.3 V. The quality of the effluent for the reactor operated at 15°C was on average 195 mg/L of total COD, 104 mg/L of soluble COD, 2.7 mg/L of total P, 1.7 mg/L of soluble P and 810 mg/L of total solids. The effluent quality of the reactor operated at 25°C was on average 102 mg/L of total COD, 61 mg/L of soluble COD, 2.5 mg/L of total P, 0.5 mg/L of soluble P and 1000 mg/L of total solids.  We tested this novel design with a 100-gal pilot-scale system at the Saint Paul Municipal Wastewater Treatment Plant of Metropolitan Council Environmental Services, and demonstrated the technology application in close-to-real operating conditions of typical septic tanks in Minnesota. Two treatment conditions, i.e., electrodes with a voltage application of 0.82 V and 1.13 V, respectively, achieved phosphorus removal efficiency of 28.2% and 41.6%. At 1.13 V, the treatment achieved 34.3% of soluble phosphorus removal and 56.3% of particulate phosphorus removal. There was a generally lower phosphorus removal efficiency in the pilot-scale tank than in bench scale experiments. The most possible explanations to the discrepancy can be the different patterns of feeding/sampling cycle, liquid flow and the decreased power consumption per volume of liquid being treated.

Ottertail Use and Pumping Evaluation

The Otter Tail Water Management District (OTWMD) in Minnesota provided a unique study opportunity for the analysis of household practices and maintenance needs of septic systems. This study looked for correlations between household practices and the functioning of individual OWTS in order to identify factors contributing to successful septic system performance. Homeowner surveys were coupled with septic tank inspection and monitoring records kept by the OTWMD since 1981. The frequency at which septic tank pumping occurred and the average length of time between septic pumping events were evaluated for both seasonal and full time residences. A Kruskal-Wallis Test was used to identify factors that had significant impact on septic tank pumping frequency. There were 28 household factors that were tested against the two pumping categories. Of the 56 factors tested, 17 were found to have an impact on sludge and scum accumulation. The septic tank pumping frequency and average time between septic tank pumping were both impacted by: the presence of a water softener, washing machine, hot tub, dishwasher, property use (i.e., seasonal/fulltime), and fixture leaks. The average time between septic tank pumping was impacted by:  having well water, the number of adults and children at the residence, having a sump pump, and the use of long-term prescription medications. The time range between pumping varied from an average of 4.9 years for full time residents to 8.9 years for those only using the property during the summer months.   An assessment every 2-4 years is still recommended to evaluate the need for pumping and to evaluate other system and use issues that can affect long-term system performance.

Reducing Chlorides from Water Softeners in Surface and Ground Water

This project is initiating evaluating options to reduce chloride loads from water softening salts often discharged from wastewater treatment plants to surface waters and also from private septic systems directly into adjacent soils. When water is softened to remove hardness, salt is used to regenerate the softener releasing chloride to septic systems and wastewater treatment plants (WWTPs). This project will quantify the current water softening salt loads in Minnesota, assess alternative softening materials and methods and quantify the transport of chloride from de-icing and softening through the soil. This project will enable us to minimize the long-term impacts of de-icing and softening salt on surface waters and groundwater across Minnesota.   The outcome of this project is to enhance strategies that improve water quality by providing methods to reduce the chloride load from water softening and developing tools that predict salt movement through the soil. The methods and tools developed during this project will inform state, municipal and private entities using de-icing salt, municipal wastewater treatment system operators, and thousands of rural communities and property owners with subsurface sewage treatment systems in Minnesota. 

University of Rhode Island

Groundwater Tables along Southern RI Coast.  During the reporting period, URI scientists collected/compiled groundwater table data from Onsite Wastewater Treatment Systems (OWTS) permit applications submitted to RI Department of Environmental Management for homes situated on sandy soils along the coastal zone.  Groundwater tables do appear to be rising, with an overall trend of 1.3 cm / year rise along southern RI coast.   To assess loss of vertical separation distance from OWTS drainfield bases to groundwater, six groundwater monitoring wells with water table capacitance loggers were installed in the study coastal study area to collect long-term data on groundwater table fluctuation.  Wells installed in barrier beach locations show a clear tidal influence on groundwater level, with plotted elevations showing sharp peaks.  Wells installed in back barrier locations show wider peaks in groundwater elevations, but not the same magnitude nor timing of tidal cycle.  Additional wells will be installed during the next report period.  In collaboration with USDA NRCS, Ground-Penetrating Radar (GPR) was conducted at two study sites (Dec. 2016 and Apr. 2017) to find OWTS drainfield components and their relation to groundwater tables at sites located on barrier beaches.  GPR proved to be an effective tool to determine OWTS component locations and groundwater elevation in sandy coastal soils.  Additional GPR evaluations will be conducted in the next report period. 

Plant-based Mitigation Experiments.  Greenhouse experiments with 5 species of plants were conducted to assess which plants can withstand being sub-surface irrigated with septic tank effluent and help attenuate nutrients in wastewater.  This type of plant-based soil treatment area is being evaluated as a potential climate change mitigation measure for at-risk coastal areas.  Plant candidates include: turfgrass mix (Poa spp.), phragmites (Phragmites australis; non-native), New England aster (Symphyotrichum novae-angliae), seaside goldenrod (Solidago sempervirens), and switchgrass (Panicum virgatum).  This research will continue in the next report period assessing nutrient attenuation and characterizing microbial communities in mesocosm-scale drainfield replicates.

Full Scale Assessment of Non-Proprietary Passive Nitrogen Removing Septic Systems. In collaboration with the Massachusetts Alternative Septic System Testing Center (MASSTC), the URI Laboratory of Soil Ecology and Microbiology (URI LSEM) is designing experiments to test the nitrogen removal potential of layered soil treatment areas (STA). Unlike typical STAs that are placed on sand or native soils meeting certain design requirements, layered STAs consist of an 18” layer of sawdust/sand under 18” of sand.  These low-profile leaching systems are designed to increase sequential nitrification (in a sand layer) and denitrification (in a sand layer mixed with sawdust) as septic tank effluent percolates through. The cellulosic amendment (sawdust) in the lower layer of the STA will provide organic C that serves as a carbon and energy source for heterotrophic denitrification.

Twelve onsite septic systems with different temporal use patterns and soil types within the watershed of Buzzards Bay, MA will be selected as sites for installation of experimental layered STAs. The main objectives of this project are to: (1) Monitor layered STA effectiveness using monthly effluent and environmental data collected by MASSTC personnel to determine differences in STA system performance as a result of system design, media specifications, water quality parameters, and environmental conditions (2) Survey STAs for microorganisms involved in N transformations (ammonia oxidation, nitrous oxide reduction, and anaerobic ammonia oxidizing) to elucidate the roles these organisms play in N removal from wastewater (3) Monitor STAs for greenhouse gas emissions to examine the sources of N₂O production, and elucidate the mechanisms of gaseous N removal as N₂ and N₂O using a ¹⁵N tracer experiment, (4) Relate microbial and greenhouse gas data to nitrogen efficiency data.

During the reporting period (first year of the project), URI LSEM prepared a Quality Assurance Project Plan (QAPP), which has been approved by the EPA (QA Tracking #: RFA 17077) that will ensure that quality data are collected, maintained, and reported. Additionally, we have developed and tested methods and established standard operating procedures for nucleic acid-based microbial community analyses, including DNA extraction, identification of primers, PCR, quantitative PCR, and sequencing of relevant genes. The data produced from this project will be used to develop guidelines and policies for the siting, design, installation, best practices, operation and maintenance of layered STA systems, with the overall goal of reducing nitrogen pollution in the Cape Cod and other N sensitive coastal watersheds. Because of their shallow placement, these layered STAs may prove to be a cost effective N mitigation option in coastal environments that are at risk for sea level / groundwater rise due to climate change.

Evaluation of Nitrogen Concentration in Final Effluent of Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems (OWTS)

Advanced nitrogen (N)-removal OWTS are installed in coastal areas throughout the USA to reduce N loading to groundwater and marine waters. However, final effluent total nitrogen (TN) concentration from these systems is not always routinely monitored, making it difficult to determine the extent to which they contribute to N loads. We monitored the final effluent TN concentration of 42 advanced N-removal OWTS within the Greater Narragansett Bay Watershed, RI between March 2015 and August 2016. The compliance rate with the State of RI final effluent standard (TN ≤ 19 mg N/L) was 64.3, 70.6, and 75.0% for MicroFAST, Advantex AX 20, and SeptiTech systems, respectively. The median (range) final effluent TN concentration (mg N/L) was 11.3 (0.1–41.6) for SeptiTech, 14.9 (0.6– 61.6) for Advantex, and 17.1 (0.6–104.9) for FAST systems. Variation in final effluent TN concentration was not driven by temperature; TN concentrations plotted against effluent temperature values resulted in R2 values of 0.001 for FAST, 0.007 for Advantex, and 0.040 for SeptiTech systems. The median effluent TN concentration for all the systems in our study (16.7 mg N/L) was greater than reported for Barnstable County, MA systems (13.3 mg N/L), where systems are monitored quarterly. Depending on technology type, ammonium, nitrate, alkalinity, forward flow, biochemical oxygen demand, and effluent temperature best predicted effluent TN concentrations. Service providers made adjustments to seven underperforming systems, but TN was reduced to 19 mg N/L in only two of the seven systems. Advanced N-removal OWTS can reduce TN to meet regulations, and monitoring of these systems can enable service providers to proactively manage systems. However, improvement of performance may require recursive adjustments and long-term monitoring.

Treatment Performance Optimization of Advanced Nitrogen Removal OWTS

OWTS can serve as a source of nitrogen (N) to coastal watersheds.  Because excessive N loads pose a serious eutrophication threat to coastal ecosystems, advanced OWTS technologies have been used to mitigate their impact on these ecosystems by reducing N inputs.  Advanced N-removal OWTS are designed to facilitate the processes of biological nitrification and denitrification before the effluent is applied to the soil treatment area and percolates to the groundwater.  In this study, we selected 50 existing advanced N-removal OWTS in the town of Charlestown, RI to determine the capacity of six different N-removal OWTS technologies – (Orenco Advantex AX20, Orenco Advantex RX30, BioMicrobics MicroFAST, and Norweco Singulair Models TNT, 960, and DN) to meet the Rhode Island Dept. of Environmental Management’s standard for final effluent total N concentration of 19 mg/L or less.  Twenty-four of the systems are for houses occupied year-round, while 26 are for seasonally-occupied houses.  The year-round systems are sampled quarterly and the seasonal systems are sampled four times over the summer occupancy period.

For all systems, field measurements are made of effluent pH, temperature, and concentration of dissolved oxygen (DO), ammonium (NH₄⁺), and nitrate (NO₃^-) in the final effluent.  Final effluent samples are also analyzed in the laboratory for pH, alkalinity, biochemical oxygen demand, NH₄⁺, NO₃^-, and total N.  Microbial analyses will also be performed targeting two genes that help facilitate nitrogen removal: ammonia monooxygenase (amoA) and nitrous oxide reductase (nosZ).  Samples from all systems will be analyzed both at the beginning and the end of the summer to investigate how home occupancy pattern influences microbial communities, as well as the role that those communities play in nitrogen removal.  Furthermore, greenhouse gas emissions from the advanced systems will be measured.  Because it is a byproduct of the nitrogen removal process, as well as a harmful greenhouse gas, these measurements will primarily target nitrous oxide (N₂O) emissions.

Overall, these data will allow us to quantify the rate of compliance with state effluent standards as a function of technology, seasonality/temperature, and home occupancy pattern, and help in identifying those conditions that may be adjusted within each technology to optimize N-removal treatment performance.  Optimizing performance of these technologies will be an important climate change mitigation tool for at-risk coastal zones.

Microbial Community Composition in OWTS.  We used high throughput DNA sequencing methods to compare the 16S (bacterial and archaeal) and 18S (eukaryotic) microbial community composition in OWTS using intact soil mesocosms from Kingston, RI.  We compared microbial communities between three different technologies: conventional pipe and stone (P&S), and alternative systems pressurized shallow narrow drainfield (SND) and Geomat ® (GEO).  We evaluated microbial communities under four different soil conditions:  native soil (no wastewater introduction), present climate and water tables (at current regulation levels and 20°C soil temperatures), climate change conditions (30 cm elevation in water table and 25°C  soil temperature), and a storm surge event (samples taken 48h after saturation with ocean water from the top of the columns).  Additionally, we sampled at various depths below the infiltrative surface (5 to 75 cm below) to quantify differences in microbial treatment at scales relevant to OWTS.

Sterile soil samples were taken at each sample depth/technology/climate and stored at -80°C until analysis.  We performed DNA extraction using Mo-Bio Power Soil DNA kits, we amplified the DNA using polymerase chain reaction (PCR) using either 16S or 18S primers to amplify our selected region, and we performed gel electrophoresis to ensure proper amplification or our DNA fragment. Samples were sequenced using an Illumina MiSeq at the University of Rhode Island Genomics Sequencing Center in Kingston, RI.  To date, we have processed our sequencing data using the Qiime2 platform and are currently preparing the results for publication.

University of Tennessee at Knoxville

Using Advanced Oxidation Processes to Remove Trace Organic Compounds from Reclaimed Water

A reliable source of safe, clean water is a prerequisite for the production of fresh fruits and vegetables.  Fresh produce is particularly susceptible to being contaminated by poor-quality water because it receives very little post-harvest processing and is often consumed raw.  A potential source of safe irrigation water is reclaimed water, or the use of highly-treated domestic wastewater.  The assumption is that the wastewater would be free of suspended solids, have a very low oxygen demand, have no odors, and have pathogens (tertiary treatment).  A particular concern with this level of treatment is that many pharmaceutical compounds, such as hormones and antibiotics, are recalcitrant to the biological treatment process (oxygen demand reduction).  Because of this concern, an additional level of wastewater treatment must be devised – quaternary treatment – the removal of trace organics to ensure the safe use of reclaimed water.

Methods for trace organic compound removal include chemical oxidation (chlorine) and photo-oxidation (ultraviolet light).  The objective of this project is to gain new knowledge about using a combination of oxidizers to remove certain trace organic compounds.  Peroxyacetic acid (PAA) is a strong oxidizer commonly used in Europe as a disinfectant.  Ultraviolet light is gaining in popularity in the U.S. for providing disinfection.  Each of this methods have advantages and disadvantages; by using these two methods in tandem there may be a symbiotic effect that improves the performance of both.  The combination of chemical oxidizers and UV light is called Advanced Oxidation Processes (AOP).  Most AOP research has been conducted on the H₂O₂/UV combination.  This project proposes to use PAA as the chemical oxidizer.  Commonly called peracetic acid (or ethaneperoxoic acid), this compound is the peroxide of acetic acid and is typically purchased as a quaternary equilibrium mixture containing acetic acid, hydrogen peroxide, peracetic acid and water.  The peracetic acid solution has two peroxides – hydrogen peroxide and peracetic acid.  Peroxides are compounds that include a pair of oxygen atoms that are attached by a single covalent bond or O₂^-2.  This is different from molecular oxygen that is a pair of double bonded oxygen atoms (O₂). Peroxides are relatively unstable.  The single-bonded oxygen pair is a higher energy state and so there is a strong tendency to revert to molecular oxygen.  This process makes peroxides strong oxidizers.  Operating a UV source downstream from PAA injection can potentially break the chemical bond between the two oxygen atoms in PAA, and sequentially forms additional hydroxyl radicals.  Hydroxyl radicals are strong oxidizers. 

A bench-scale, continuous-flow treatment system was constructed to simulate point-of-use water treatment for the purpose of irrigation.   A solution with 1 ppm of triclosan was used to evaluate the treatment system performance.  The PAA injection rates were 1 ppm and 5 ppm, and the UV exposures were approximately 35,000 and 50,000 µW s cm^-2.

The AOP process seems to increase the overall remove efficiency and the removal rates as compared to PAA alone and UV alone.

Non-Steady State Operation of Subsurface Drip Dispersal Systems

For more than 20 years, manufacturers of irrigation equipment have been modifying drip irrigation tubing for use as an effluent dispersal system.  Depending on the brand, the tubing has been modified to resist the buildup of biofilm, prevent the clogging of emitters, and provide uniform distribution with pressure-compensating emitters.  However, many onsite wastewater regulatory jurisdictions are still hesitant to allow this method to be used to distribute.  A particular concern is how the distribution system responds during pressurization and de-pressurization, and if the non-steady state conditions will significantly affect distribution uniformity.  While under pressure, the emitter production rate is very predictable and dependable; however, little is known about rate of drainage from the tubing once the water pressure is released.  As a means of compensating for this lack of knowledge, many regulators require that the tubing must be placed on contour with very little variance.  Certainly, the tubing should be placed on or near contour, but the question remains as what is a reasonable tolerance?

Using two common brands of drip tubing, we conducted a study that evaluated how the residual water remaining in the tubing after cessation of pumping discharges from the emitters.  Ninety-two meters (300 ft) of tubing was mounted above the ground on various slopes (no slope to 10% slope) and buckets were placed under the emitters.  The results are dependent on the brand of tubing - one brand would allow all the residual water to drain from the tubing, while the second brand will stop discharging when the head pressure on the emitter is reduced to approximately 20 cm.  These results are still being evaluated and will be published during 2018.

Senior Capstone Project

John Buchanan provided a capstone experience to three senior civil engineering students using a common small-community wastewater treatment problem.  A rural school in a neighboring county has a packaged activated sludge plant used to provide wastewater treatment.  The school is the single wastewater source and is the entity responsible for the NPDES permit.  This site is in perpetual violation of the BOD and ammonia limits stated in their permit.  This project is ongoing, but preliminary results suggest that the packaged plant is under-loaded and cannot maintain a sufficient mixed liquor suspended solids concentration needed to provide treatment.

Ohio State University (OSU)

Reuse of reclaimed wastewater through onsite spray irrigation  

Research on winter reuse of reclaimed wastewater was conducted in Ohio.  Issues evaluated were impact on plants, equipment protection, pathogen control, and pollutant runoff potential from cold soil.

Treatment of high salt content wastewater

Salt levels in wastewater become an issue from water treatment systems that use salt, food processing that involves curing or pickling and with fresh water scarcity, the use of high salt-content waste for toilet flushing.  Research is looking at the impact of salt on wastewater treatment using sand bioreactors.

Lab scale unsaturated sand/gravel columns were intermittently dosed, treating the high-strength wastewater in a single pass. Turkey processing wastewater served as the control, and 3 g/L and 6 g/L of table salt were added to wastewater for treatments in duplicate laboratory columns. BOD₅ and NH₃-N removal was measured during the 74-day experiment. The BOD₅ removal was achieved and maintained over 99% after day 21 at all salt levels. Over 99% NH₃-N removal was achieved after day 32. It was concluded from this study that sand/gravel bioreactors were able to treat high-strength, high salinity up to 0.6%.  Research is continuing at higher salt levels.

Michigan State University (MSU) findings – Land treatment of food processing wastewater can irrigate a crop, provide nutrients, recharge aquifers, reduce energy use, reduce greenhouse gas emissions, and save resources.  However, when excessive carbon is land applied, the soil becomes anaerobic and several metals become mobile when reduced.  Although aerobic conditions prevent metal mobilization, denitrification is inhibited under this condition.  Critical for land application is pretreatment and strategic organic and hydraulic loadings to maximize efficient waste management and minimize environmental impacts.  A long-term field study is ongoing that includes direct soil oxygen and moisture monitoring using remote sensors and site visits to make visual observations.  Results show that the control of hydraulic and organic loadings prevent metal mobilization. However, with higher levels of oxygen in the soil, nitrate release may have occurred as denitrification is inhibited. Studies using wastewater pretreatment and cropping strategies are being investigated. Modeling efforts are also underway. The outcome is a change in action and condition in that careful operations and design allow food processors to continue using this land application.  Additionally, using onsite application of wastewater, as compared to treatment in a traditional activated sludge process, reduces greenhouse gas emissions.  Reductions are achieved by not using energy for wastewater aeration, carbon dioxide uptake by the plants grown when using the wastewater, and reduced production of industrial nutrients.

The use of finite element modeling using the Hydrus Wetland Module is demonstrating the potential to simulate land application of wastewater under numerous scenarios.   Results to date show good agreement between the model output and experimental data on the fate of carbon and nitrogen.

University of South Florida (USF) findings - A combination of ion exchange (IX) and biological treatment has the potential to provide enhanced treatment under the variable N loading conditions observed in OWTs (Hirst et al., 2013; Krayzelova et al., 2014).  During periods of high loading, cation (NH₄⁺) or anion (NO₃^-) loads in excess of the system biodegradation capacity are adsorbed by the medium.  During low loading periods, the ions are desorbed and utilized by the microbial population.  IX materials, such as natural zeolites (e.g. chabazite and clinoptilolite), have the ability to adsorb NH₄⁺ (Wen et al., 2006).  Hirst et al. (2013) showed that addition of clinoptilolite in the nitrification stage of a passive N removal OWTs resulted in 94% removal of TKN.  The use of the combined IX/nitrification process coupled with sulfur oxidizing denitrification resulted in average effluent TN < 3 mg/L (Hirst et al., 2013).  In a similar manner, scrap tires have a high IX capacity for NO₃^- (Lisi et al., 2004), and can be bioregenerated by denitrification (Krayzelova et al., 2014). 

The goal of this research is to improve N removal performance and decrease reactor size requirements in OWTs using Hybrid Adsorption Biological Treatment Systems (HABiTS). Bench, pilot scale and modeling studies of a two stage HABiTS process are being conducted at the University of South Florida as part of the EPA Center for Reinventing Aging Infrastructure for Nutrient Management.  In Stage 1, a natural zeolite material, clinoptilolite, is used as an NH₄⁺ IX medium in aerobic nitrifying packed bed reactors (PBRs).  In Stage 2, saturated PBRs containing scrap tire chips as a NO₃^- IX medium are combined with sulfur pellets and crushed oyster shells to promote sulfur oxidizing denitrification.

Activities 

Project Objective 4 – OWTS Training and Outreach Education

University of Minnesota – UMN trained over 2,000 septic professionals in Minnesota in over 50 training events and also delivered training in numerous other states.  Staff planned and organized the educational program for 2016 annual Minnesota Onsite Wastewater Association conference.  In addition, staff assisted in organizing and delivering the National Onsite Wastewater Recycling Association annual conference in 2016.  Three online courses were developed with NOWRA to provide additional opportunities for education.  UMN is working with MnDOT on additional educational activities to raise public awareness about keeping solid waste from entering the septic systems at rest stops, and the complexities of water management systems.  In the next report period, the H2OandM.com (developed through past NIFA grant) will be used to develop customized septic system owner’s guides to deal with the complexity of the 52 MnDOT systems and sites.

University of Georgia – In Mar. 2017 UGA staff held a Level II soils workshop for 19 new Georgia Department of Health (DPH) employees, including a test at the end.  In May 2017 UGA staff held a second Level II soils workshop for 25 new GADPH employees.  Thirty-four new GADPH employees attended a required Level II soils course and examination, providing them with essential training needed for their professional advancement.

University of Tennessee at Knoxville - J. Buchanan was involved with 6 educational sessions during 2017 and spoke to 688 people about septic system installation, operation, and maintenance.   The scope of these events ranged from meeting with individuals seeking knowledge about their systems, community-level discussions about high septic system failure rates, state-level meetings with regulators, engineers and soil scientists, to presentations at national meetings.

Ohio State University –The updated version of the OSU Soil Treatment System bulletin was presented at the Dec.2016 Green & Sustainable Wastewater Treatment conference – 80 installers and local regulators attended.  A new 6-hour online soils course has been developed, is being tested, and ofered in 2018.  The course is the first segment in an eight-segment curriculum that is under development.  It will be offered both as Extension courses and an OSU 3-credit course for students.

Oklahoma State University – OSU organized its 2nd Oklahoma Onsite Wastewater Treatment Conference on November 10, 2016. The 168 participants who attended the Conference were composed of Regulators, Sanitarians, Soil Profilers, Certified Installers, Extension Educators and representatives from various Native American Nations. OSU also started developing 5-minute informational videos about OWTS that were used for extension activities and by the Oklahoma Water Resources Center. OSU also collaborated with the Department of Environmental Quality in conducting two soil profiler certification courses that served 6 participants. The OWTS specialist also delivered two seminars at conferences. A total of five OWTS-related talks were presented to various stakeholders including: realtors, home builders, 4-H members, summer campers, and extension educators. A total of 84 people were given tours at the Oklahoma Onsite Wastewater Training and Demonstration Facility.

Michigan State University – The Michigan State University Extension Onsite Wastewater Education Program continues.  The program includes homeowner and professional education events and the production of a public service announcement (https://www.youtube.com/watch?v=ZtppgvPlOCU&feature=youtu.be).  The 16 hour online training module for designers and installers currently has ten  students enrolled.

University of Rhode Island – The URI project team delivered 14 talks (2 of which were invited) and 7 posters to academic and professional audiences relative to OWTS and climate change at conferences in RI, CT, MA, CA, AZ, FL; reaching scientists, wastewater practitioners, board of health officials, regulatory decision makers and coastal resource managers.  In addition, we published 3 peer-reviewed papers, and one MS thesis, delivered a total of 31 workshops/ classes in 3 states in the region, reaching a total of nearly 750 practitioners, decision makers and students. These classes provided continuing education credits needed by over 540 licensed professionals to renew their professional licenses.  Three of the classes had qualifying exams.  We provided direct OWTS technical assistance to: Suffolk County Health Dept., NY and RI Department of Environmental Management.

University of Arizona - UAZ is working with practitioners to develop need-to-know statements for septic tank technicians (pumpers), installers, designers, operation and maintenance providers, and inspectors.  A one-day workshop and four two-hour webinars have been used to obtain statewide and industry wide participation.  Fifty-eight contacts in UA Extension, Arizona County Health Departments, and ADEQ received timely educational materials from ACE Onsite Wastewater Education Program and are more aware of the services that the program can and do provide.

University of South Florida -  USF conducted a tour of the USF/Hillsborough County Northwest Water Reclamation Facility (NWWRF) pilot plant on November 6, 2016.  The participants included Hillsborough County staff, USF students and faculty, faculty and students from other universities (Michigan State, University of Central Florida), local consulting engineers, and regulatory agency staff.

Abit, S.M. and E. Hollarn. Basic Septic System Rules for Oklahoma. PSS-2918.

Amador, J.A., G. Loomis, B. Lancellotti, K. Hoyt, E. Avizinis, and S. Wigginton. 2017. Reducing nitrogen inputs to Narragansett Bay: Optimizing the performance of existing onsite wastewater treatment technologies. Final Report to the Narragansett Bay Estuary Program and the New England Interstate Water Pollution Control Commission, Lowell, MA.

 
Brannon, E., S. Moseman-Valtierra, B. Lancellotti, S. Wigginton, J. A. Amador, J. McCaughey, and G. Loomis. 2017. Comparison of N₂O emissions and gene abundances between wastewater nitrogen removal systems. J. Environmental Quality 46:931-938. 

Chen, Feng. 2016. Evaluating the performance of sand/gravel bioreactors in treatment of high strength, high salinity wastewater. Master’s Thesis, The Ohio State University. https://etd.ohiolink.edu/pg_10?7071194303911::NO:10:P10_ETD_SUBID:114155

Dong, Y., Safferman, S. I., Ostahowski J., Herold, T., Panter, R. 2016. Enzyme Pretreatment of Fats, Oil, and Grease from Restaurant Waste to Prolong Drain Filed Effectiveness.  Journal of Environmental Science and Health, Part A, 52(1)55-63.

Hoghooghi, N., Radcliffe, D., Habteselassie, M.Y., Clarke, J. 2016. Confirmation of the impact of onsite wastewater treatment systems on stream base-flow nitrogen concentrations in urban watersheds of metropolitan Atlanta, GA. J. Environmental Quality 45:1740-1748.

Hoghooghi, N., Radcliffe, D., Habteselassie, M.Y., Jeong, J. 2017. Modeling the effects of onsite wastewater treatment systems on nitrate loads using SWAT in an urban watershed of metropolitan Atlanta, GA. J. Environmental Quality 46:632-640.

Lancellotti, B.V. 2016. Performance evaluation of advanced nitrogen removal onsite wastewater treatment systems. M.S. Thesis, University of Rhode Island, 95 pages.

Lancellotti, B.V., G. Loomis, K. Hoyt, E. Avizinis, and J.A. Amador. 2017. Evaluation of Nitrogen Concentration in Final Effluent of Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems (OWTS). Water, Air & Soil Pollution 228:383-298.

Mancl, K. 2016. Gray Water Recycling in Ohio. Ohio State University Fact Sheet. AEX-GW1.

Mancl, K. 2016. Simple Gray Water Systems: Type 1. Ohio State University Fact Sheet. AEX-GW2.

Mancl, K. 2017. Septic Tank- Soil Treatment Systems. Ohio State University Extension Bulletin 939.

Nelson, Taylor. 2016. Water Use at Minnesota Rest Areas. Retrieved from the University of Minnesota Digital Conservancy, http://hdl.handle.net/11299/185075.

Nelson, T.  and S. Heger. 2017. Impacts of water use practices in the home on septic tank pumping. National Onsite Wastewater Recycling Association Annual Conference Proceedings, Dover, Delaware.

Park, E., K. Mancl, O. Tuovinen, M. Bisesi and J. Lee. 2016. Ensuring safe reuse of residential wastewater: Reduction of microbes and genes using peat biofilter and batch chlorine in an on-site treatment system. Journal of Applied Microbiology. 121:1777-1788.doi:10.1111/jam.13288

Perez, B. N., J. R. Buchanan, J. N. DeBruyn, K. Colbaugh, and W. E. Hart.  2017.  Removal of trace organic compounds in domestic wastewater using recirculating packed-bed media filters.   Transactions of the ASABE. 60(5): 1593-1605. (doi: 10.13031/trans.12176)

Rodriguez-Gonzalez, L., K. Payne, M. Trotz, D. Anderson, and S.J. Ergas. 2017. Hybrid Adsorption Biological Treatment Systems for enhanced onsite N removal. WEF Nutrient Symposium, June 12-14, 2017, Ft. Lauderdale FL.

Rodriguez-Gonzalez, L., K. Payne, M. Trotz, D. Anderson, and S.J. Ergas. 2016. Hybrid Adsorption and Biological Treatment System (HABiTS) for enhanced nitrogen removal in onsite wastewater treatment systems.13th IWA Specialized Conference on Small Water & Wastewater Systems, Athens, Greece. September 14-16, 2016.

Sowah, R., Habteselassie, M.Y., Radcliffe, D., Bauske, E., Risse, M. 2017. Isolating the impact of septic systems on fecal pollution in streams of suburban watersheds in Georgia, United States. Water Research 108:330-338.

Zamalloa, C. and Heger., S. 2017. Biodegradability analysis of toilet paper under anaerobic conditions. National Onsite Wastewater Recycling Association Annual Conference Proceedings, Dover, Delaware.