NE1545: Onsite Wastewater Treatment Systems: Assessing the Impact of Climate Variability and Climate Change

(Multistate Research Project)

Status: Active

NE1545: Onsite Wastewater Treatment Systems: Assessing the Impact of Climate Variability and Climate Change

Duration: 10/01/2015 to 09/30/2020

Administrative Advisor(s):

NIFA Reps:

Statement of Issues and Justification

The Need

Onsite wastewater treatment systems (OWTS) serve approximately 25% of households in the United States and are the technology of choice in rural and suburban areas where population density and cost preclude the use of centralized sewer collection and treatment systems. In unsewered watersheds they are the sole means of wastewater treatment. Onsite wastewater treatment systems are an integral part of the water infrastructure throughout the country, which are expected to protect ground and surface water quality from inputs of carbon, nutrients, pathogens, and pharmaceutical & personal care compounds, and to do so under a wide range of environmental conditions with little intervention.

Meeting these expectations requires an understanding of the processes on which OWTS rely to treat wastewater in order to engineer systems that function effectively under a wide variety of conditions. This is particularly challenging for OWTS, which rely on hydraulic, hydrologic, physical, chemical and biological processes – and their interactions – to treat wastewater. Despite their ubiquity and importance as part of the nation’s water infrastructure, our understanding of these processes in OWTS lags behind that for centralized sewage treatment systems.

The systematic study of OWTS has evolved considerably over the past five decades, leading to improvements in understanding of how contaminant removal takes place within components in the treatment train and the receiving soil. This has led to more effective contaminant removal from changes in system design, improved understanding of the biogeochemical processes that remove contaminants, improved selection of soils receiving wastewater, and better placement of systems within watersheds to maximize treatment and minimize impact. These improvements have come about, in large measure, from the efforts of scientists, engineers and outreach professionals in Land Grant and private universities across the U.S., funded by federal, state and local agencies, and through collaborations with regulators and private industry.

As many of the contaminant removal concerns associated with OWTS are being addressed, a number of new challenges have developed in different parts of the country, such as more stringent nutrient reduction regulations, and concerns with removal of pharmaceuticals and personal care products present in wastewater. In addition, a changing climate presents a continental-scale challenge to OWTS. Soil-based wastewater treatment systems are regulated, designed and built based on assumptions about the volume of wastewater applied, the magnitude and distribution of past precipitation events, the historical range of variations in depth to water table, and soil temperature over the long-term (decades). These assumptions are no longer valid in many parts of the country because of climate variability and climate change (CV/C). Climate variability refers to the variation from the long-term (30-year) average weather conditions. Climate change refers to a long-term (decades), continuous change in average weather conditions, such as temperature, or the range of weather events, such as more severe and frequent extreme storms (Michigan Sea Grant, 2015). Climate change is one of the drivers of climate variability, along with events such as El Nino and La Nina and volcanic eruptions.

Climate change and climate variability have altered, and will continue to alter, the temporal and spatial patterns of precipitation and temperature, with attendant consequences as sea levels rise and changes in groundwater levels develop. These changes will affect populations that rely on OWTS, through effects on soil moisture dynamics, surface and groundwater hydrology, changes in water use patterns and associated changes in wastewater composition and volume, and temperature effects on processes within treatment trains and soil-based treatment. Regulatory decision-makers that set codes and policies and other stakeholders need to understand the consequences of these changes and the options available to mitigate, adapt, and plan for climate change and its effects on OWTS. As in the past, they rely on scientists, engineers and outreach professionals to carry out the research and provide them the necessary information in an effective and timely manner.

Importance of the Work

Scientists and engineers have developed a reasonable understanding of many of the processes that underlie the functioning of soil-based wastewater treatment over the past 50 years, with work conducted recently by NE1045 members helping to provide deeper understanding. This understanding continues to develop, as does our understanding of the challenges that CV/C pose to OWTS function and longevity. These changes will affect our assumptions about the magnitude and frequency of precipitation events, inputs of freshwater to OWTS soil treatment areas (STA), depth to groundwater, and temporal variability of temperature at diurnal seasonal and decadal scales.

As a “green technology” (Lindbo, 2015), onsite wastewater treatment systems are relied upon by the majority of rural and a large proportion of suburban populations to also help protect public health and sensitive ecosystems. We do not know exactly how OWTS will be affected by climate change, but we can be certain that they will be affected. They rely on an intricate set of hydrologic, biogeochemical and physical processes to renovate wastewater. These are controlled, directly and indirectly, by precipitation, temperature, and depth to groundwater. Climate change will affect the quantity and quality of wastewater inputs as a result of changes in precipitation patterns (e.g. prolonged droughts or wetter conditions) as well as soil moisture dynamics and depth to saturation, from changes in precipitation patterns and associated fluctuations in water table levels, as well as sea level rise in coastal areas. Although these factors are likely to vary in magnitude geographically, climate change is expected to impact most the U.S. population, both in inland and coastal areas.

We are already familiar with the effects of malfunctioning and poorly functioning OWTS from previous experiences: contamination of ground and surface waters with human pathogens leading to the spread of enteric diseases, as well as increased inputs of N and P to aquatic ecosystems, resulting in eutrophication, anoxia and ecosystem collapse. In most instances, incidents of malfunctioning OWTS have had a modest impact on public health and ecosystem functioning, because they are generally limited in geographic scope to one or a few systems. Because climate change is experienced at regional and continental scales, the number of malfunctioning systems, and the magnitude of their impact, is expected to be at the regional and continental scales, affecting a much larger portion of the population, as well as regional aquifers and surface aquatic ecosystems. Ecosystem effects are expected to linger for decades, particularly for nutrients like P, for which removal pathways are physical, and for N - which relies on microbial processes, with severe constraints, for removal from ecosystems.

Because drinking water sources for large urban areas are often found in rural landscapes where OWTS are common, the impact will not be limited to rural areas alone. This is particularly true with respect to increased inputs of organic C and nutrients to surface and groundwater reservoirs from OWTS, which interfere with water disinfection processes and result in the production of trihalomethanes, known human carcinogens.

Letters from four regulatory agencies in the Northeast (MA, MD, RI, VT), speaking to the importance of this research, are included in the Attachments section.

The Technical Feasibility of the Research

The proposed research is technically feasible. The tools and techniques necessary to carry out the research have been developed, and include cutting-edge approaches from a variety of science and engineering fields, such as advanced computer modeling of hydrological and biogeochemical processes at a range of spatial and temporal scales, the use of stable isotopes to identify nutrient transformations, and application of the tools of molecular genetics to identify the microorganisms responsible for both water quality degradation and improvement. The research efforts of biological and environmental engineers, pedologists, hydrologists, soil physicists, soil microbiologist, computer modelers, and extension and outreach professionals at state and private universities have led to a better understanding of the challenges presented by climate change and the potential solutions.

Advantages for Doing the Work as a Multistate Effort

Addressing the research and outreach challenges presented by climate change requires the expertise of a broad spectrum of scientists, engineers and outreach professionals. The necessary breadth of expertise and perspectives is already found in Land Grant and private universities across the U.S. Researchers throughout the country are currently working on various aspects of the science and engineering of OWTS and the challenges presented by climate change. In some instances, the results of this research are broadly applicable, as is the case with studies focusing on fundamental processes. In other instances the research focuses on addressing problems that are local or regional in nature as a result of unique geological, geographical or regulatory issues. Similarly, outreach professionals develop materials that are tailored to national, regional and local issues, depending on the circumstances. In order to carry out and disseminate research that is responsive to the broad range of problems and constituencies in the U.S., the proposed work needs to be a comprehensive and collaborative effort done at a multistate level.

The Likely Impacts from Successfully Completing the Work

We anticipate that completion of the proposed work will lead to evidence-based solutions to OWTS problems associated with climate change. Specifically, we expect that results from examination of fundamental physical, chemical and biological processes – and their response to changes in hydrologic regime and temperature – will, in combination with studies focusing on local and regional aspects of OWTS and climate change, provide solutions to the challenges of climate change at appropriate spatial and temporal scales. Furthermore, we anticipate that these solutions will be shared among OWTS outreach professionals and made available to stakeholders in an effective and timely manner so that the expected impacts of climate change on OWTS – and associated large-scale public health and ecosystem effects – can be ameliorated or averted.

Related, Current and Previous Work

Building on NE 1045 Accomplishments

Our proposed project will build upon a number of research projects started under NE 1045, including:

• The NE 1045 team planned and successfully conducted a national OWTS research symposium under the auspices of SSSA in April 2014. Approximately 100 OWTS professionals attended and 53 papers and presentations were delivered. The event was a revenue generator for SSSA, and they have committed to sponsor future OWTS symposia. A keynote address related to the potential impacts of climate variability on OWTS was presented, bringing this issue to the forefront of discussion. Another national OWTS conference is currently being planned for 2016 by the NE1045 symposia committee and will be a continuing effort for our new proposal.

• A substantial University of Rhode Island research initiative relative to climate change impacts has emphasized the biogeochemistry of wastewater treatment in these systems and modeling of wastewater and contaminant movement beneath OWTS soil treatment areas (also referred to as drainfields). Work by Cooper et al. (2015) evaluated the extent and mechanisms of removal of BOD, N and P in conventional drainfields and shallow narrow drainfields. This information is useful in identifying drainfield types that may be more resilient to rising water tables. A study by Richard et al. (2014) examined the mechanism of N removal in intermittently aerated drainfields, which may provide an alternative in areas where sea level rise is a concern. Morales et al. (2014, 2015) have focused on modeling the transport of viruses and bacteria through drainfield soil, examining the impact of system properties including soil type, concentration of microorganisms and hydraulic loading rate, as well as climate related variables, such as temperature, moisture and rising water tables. New research initiatives in modeling, biogeochemistry, and hydropedology will likely build upon findings from earlier NE 1045 research.

• Pharmaceuticals and personal care products (PPCPs) can be difficult to remove from domestic wastewater. Knowledge is limited as to the fate and transport of most of these compounds as they pass through a conventional septic tank and soil treatment area. As soil resources become limited due to rising water tables as a result of climate change, advanced treatment technologies will be needed that can provide a high-level of treatment before the effluent is applied to a soil treatment area placed more shallow in the soil profile. Research is needed to better understand the fate of PPCPs in advanced onsite treatment systems. With funding from the Tennessee Water Resources Research Center, the NE1045 research team at the University of Tennessee has been evaluating the removal of three pharmaceuticals using commonly-used packed bed media filters. The compounds include an endocrine disrupting compound - triclosan and two non-steroidal anti-inflammatory drugs - ibuprofen and naproxen. Analysis of media filter influent and effluent water samples for the target compounds have been conducted using solid-phase extraction (SPE), derivatization, and gas-chromatography mass-spectrophotometry (GC-MS). The greatest removal rates were observed with ibuprofen and naproxen (>95%), along with moderate removal of triclosan (85-92%). The sorption of the PPCPs onto the media biofilm will be analyzed through separation, centrifugation, and reconstitution in acidified water, and then sent for SPE analysis. DNA extraction is also being performed on the biofilm to help identify any bacterial communities that could be attributed to PPCP degradation and/or inhibition. Preliminary results indicate that it is possible for small-scale treatment systems to provide comparable removal rates to that of large municipal wastewater treatment facilities. This work will continue under our proposed project.

• Michigan State University, working with a private industrial partner and with funding from USEPA and SBIR grants, has been researching an engineered nano-media with a large surface area and high porosity. The media is manufactured using an iron substrate that is coated with nano-iron. The media was tested on wastewater from 3 cluster onsite wastewater treatment systems and 4 municipal wastewater plants. These research activities cumulated with the operation of a 0.10 L/min demonstration unit at a cluster wastewater treatment system. The reactor had an empty bed contact time of 1.5 hours that reduced influent phosphorus from 7.2 mg/L to 0.4 mg/L for over 60 days, with no sign of breakthrough. Previous long-term laboratory column testing using actual wastewater indicates that the capacity of the media is approximately 70 mg P/g media. The media can be regenerated using a caustic solution and the phosphorus recovered as calcium phosphate. A preliminary analysis indicates that the greenhouse gas emissions associated with using the media are less than 25% of that from the equivalent amount of phosphorus removal by a chemical precipitation system. This research will continue under our new multi-state project.

• A research project – started under NE 1045 – which addresses the treatment performance of advanced N reduction technologies, identifies field parameters that best predict N removal, and evaluates the most efficient field tools that will aid operation and maintenance providers to evaluate treatment performance in the field, in real time, will be continued under the new multistate project. This will provide valuable information to system managers enabling them to optimize N removal within these systems. Because we will measure the response of system performance to temperature, this information will also help in assessing the impact of CV/C on advanced N removal OWTS.

• NE 1045 researchers have also evaluated different landscape positions and the impacts of land use on soil saturated hydraulic conductivity (Williamson et al., 2014) as well as the effects of various saturated hydraulic conductivity data sources hydrologic models (Williamson et al., 2014). This work has led to a new research project evaluating the impact of climate change on soil-water storage. This project will contribute to and expand the NE1045 team’s understanding of the ability of soil to disperse wastewater under different projected climate scenarios.

• The NE 1045 research team developed a new pressurized drainfield design guidance document that promotes shallow placement of drainfields in Rhode Island, Massachusetts, and Vermont. These new design guidelines create greater separation distances from drainfield bases to groundwater tables, result in dispersal of wastewater into more biochemically reactive soils, facilitate subsurface irrigation of residential lawns and landscapes, and, thereby, lessen the impacts of climate change on OWTS. Regulatory agencies in these states require designers and installers to take training classes before they can design or install these pressurized drainfields. The project outreach team will continue to offer training classes that help practitioners in these states, and other new ones, to incorporate these drainfields in their designs. This is the first time ever that state regulatory programs (in MA and VT) have required their regulated community to directly utilize a guidance document from a neighboring state (RI).

• The University of Minnesota NE 1045 team completed a research project evaluating 6 adult care facilities served with OWTS. These facilities have a challenging waste stream due to high flows, cleaning compounds and medicines. The results of this project provide design recommendations and guidance for similar facilities elsewhere in the US (Waak and Heger, 2014). The UMN is also evaluating 52 rest stop OWTS where findings of this research will assist similar facilities across Minnesota and the US relative to designing and managing systems in the future in the face of climate change.

• Education and outreach has always been a strong emphasis of the NE 1045 project technical committee, and in 2014 alone there were over 5,600 direct contacts made during nearly 135 workshops and classes, enabling over 2,670 OWTS practitioners to receive continuing education credits in order to renew their professional licenses, and helping nearly 350 new professionals to receive OWTS design training. About 335 professionals were directly reached in presentations specifically addressing climate change and OWTS. We expect these numbers to increase as we continue to prioritize this commitment to education and outreach in our new proposal.

• Building upon the success of outreach activities, the State of Oklahoma decided to establish for the first time a collaborative state-wide OWTS Professional Education Program to address training needs of all stakeholders in the OWTS industry. Future short-courses would include, among others, a topic on the Possible Effects of Climate Change on Performance of State-approved OWTS Designs –in response to drastic swings in environmental conditions that frequently happens in the State.

• With funding from the National Institute of Agriculture, the UMN NE 1045 team is developing a wastewater customizable Community System Owner’s Guide (CSOG). This includes a web-interface that allows an individual to produce an expert-driven and locally-customized manual (electronic or hard-copy) CSOG for any soil-based onsite wastewater treatment system in America. This tool will assist property owners across the US manage their OWTS in areas with extreme weather events including both draught and increased moisture.


  1. Improve our understanding of the interactions among wastewater, soils, and climate variables.
  2. Identify the biogeochemical processes that control contaminant removal from wastewater and how these are impacted by climate variables.
  3. Develop models that describe and predict how wastewater renovation processes are affected by climate variables at different spatial and temporal scales.
  4. Develop educational materials and tools to acquaint the public and practitioners to management, operation, maintenance and health issues related to OWTS in light of adaptation to climate variability and climate change.


The two main functions of the STA are (i) to allow for infiltration of wastewater in the subsurface, and (ii) to remove contaminants from wastewater. The main objective of the proposed work is to further our understanding about how climate variability and climate change affect the hydrologic and biogeochemical processes that govern the functioning of the STA. This will be based on data gathered from experimental, observational and modeling efforts at a variety of spatial (microcosm to watershed) and temporal (hours to decades) scales.

We recognize that hydrologic and biogeochemical processes do not take place in isolation from each other, but often interact in ways that can enhance or interfere with the functioning of OWTS. For example, removal of dissolved and particulate organic C by microorganisms in the STA can lead to the development of a biomat – a low-permeability layer of organic polymers, microorganisms and inert particles that forms at the STA-native soil interface that restricts the infiltration of wastewater and can result in hydraulic failure. On the other hand, the effectiveness of removal of bacteria and viruses in the STA is sensitive to water saturation in the soil, with less removal observed as the soil moisture content increases. Thus the proposed work will address these interactions within the context of climate.

We are also aware of the practical limitations presented by short-term experimental and observational studies in terms of predicting climate impacts on STA functions, particularly with respect to long-term effects of climate variables. To this end we will include a modeling component that incorporates climate variability and change in their description of hydrologic and biogeochemical processes in the STA.

Effective responses to climate variability and change require not only that we understand how existing systems work and interact with climate, but also how these may be modified or replaced to improve their effectiveness and adapt to new climate regimes. To this end, the proposed research will be conducted on both natural and engineered soils and treatment media, and on conventional and innovative STAs.

Our research and outreach efforts will focus on the following climate variables:

1. Precipitation: higher and lower than normal total precipitation, increased frequency of precipitation events, and extreme precipitation events.

2. Water table: short and long-term fluctuations.

3. Temperature: higher than normal temperatures, in the range of those expected in 50 and 100 years.

The different scenarios resulting from the independent and combined effects of these variables will be evaluated for their impact on the functioning of STAs through experimental, observational and modeling efforts.

Specific methods by objective:

Objective 1. Improve our understanding of the interactions among wastewater, soils, and climate variables.

We will examine relationships between soil properties, climate variables and movement of water in the STA and underlying vadose zone, with particular attention to the following scenarios:

1. Impact of (i) increased water inputs to surface soils and (ii) reduced wastewater inputs to the STA on (i) vadose zone hydraulic processes and (ii) surface and subsurface transport of contaminants.

2. Impact of rising water tables on water movement at the individual system and watershed scales.

3. Rising temperatures and effects on water dynamics, with emphasis on evapotranspiration.

4. Interactions among changes in water inputs, depth to water table and rising temperature in the context of water movement and contaminant transport.

Work will be conducted at scales from the individual STA to the watershed, and will include observational and experimental studies, as well as laboratory and field-scale studies. We will employ sampling schemes that capture spatial and temporal variability at scales relevant to the processes under study.

We will measure response of hydrologic variables to precipitation and temperature changes of differing magnitudes in different soil types and regions of the country. When possible, we will make measurements in existing conventional and innovative STAs receiving domestic wastewater. We will use intact core mesocosms (cm-m scale) to develop detailed understanding of hydraulic processes.

The information gathered will be used to develop conceptual and quantitative models of the relationship among soil properties, climate and water movement and their impact on hydraulic function of STAs and site suitability. In addition, our results will be used in combination with data from Objective 2 to modify existing models to predict impact on hydrology as well as transport of pollutants (Objective 3). Our results will be used to develop outreach materials for decision makers relative to siting, design, and regulation of OWTS (Objective 4).

Objective 2. Identify the biogeochemical and physical processes that control contaminant removal from wastewater and how these are impacted by climate variability and climate change.

We will focus our efforts on the biogeochemical and physical processes that result in (i) the removal/retention of dissolved contaminants, including organic C, N, P metals, and emerging organic contaminants, including medications and personal care products, and (ii) removal/inactivation of pathogenic viruses and bacteria. These are the main contaminants of concern across the country associated with OWTS contamination of ground and surface waters. Experimental and observational studies will be conducted at scales from microcosm to field, with emphasis on the impact of CV/C on these processes.

We will further our understanding of which biogeochemical processes contribute to removal/retention of dissolved contaminants using a variety of approaches, including:

1. Measurements of the concentration of contaminants in water inputs and outputs and as they move through the STA and their response to CV/C. This will allow us to determine whole-system removal rates and examine the role of soil depth and associated changes in soil physical and chemical properties.

2. Determination of variables thought to control the removal/retention of contaminants in the STA and their response to CV/C. These including changes in the concentration of (i) dissolved electron donors and acceptors, (ii) dissolved and gaseous reactants and products from redox reactions, (iii) redox potential, and (iv) pH. We will also determine soil properties (e.g. organic C, mineralogy, cation exchange capacity, buffering capacity). This information will help us identify the biogeochemical pathways by which contaminants are removed/retained, and the variables that control these processes.

3. Determination of the structure and function of microbial communities and groups of microorganisms in treatment processes and their responses to environmental challenges. This information will be used to test hypotheses on the microbial communities that carry out removal/retention of contaminants and their relationship to system variables. Emphasis will be placed on molecular genetics methods to analyze community structure and function, including metagenomic analysis of bacteria, archaea and fungi.

4. Developing mechanistic descriptions of biogeochemical removal/retention processes using analysis of stable isotopes (e.g. 13C-drugs, 15N-NH4, 34S-SO4) (enriched and natural abundance) in contaminants compounds and potential intermediates to track specific transformations.

Together, the information gathered in this objective will provide us with a more accurate picture of the biogeochemical processes that remove/retain dissolved contaminants from wastewater in the STA. These data will be useful for the development and testing of models predicting the impact of CV/C on fate and transport of dissolved contaminants (Objective 3). It will also help us address the challenges posed by CV/C through manipulation and/or modification of system variables in existing systems, and engineering and design of future systems to optimize water quality functions in the context of changing climate variables.

Removal/inactivation of viruses and bacteria in the STA includes biogeochemical processes, as well as ecological and physical processes. We will examine the response of these processes to CV/V using a variety of approaches, including:

1. We will make measurements of the concentration of viruses and bacteria in water inputs and outputs and as they move through the STA and their response to CV/C. This will allow us to determine whole-system removal rates and examine the role of soil depth and associated changes in soil physical and chemical properties. When possible, these measurements will be made on bacteria and viruses already present in wastewater. In instances that human health risks associated with the use of pathogenic microorganisms in laboratory and field conditions are of concern, we will employ surrogates with physiological, chemical and physical properties similar to those of authentic pathogens. Both culture-dependent (e.g. plate counts) and culture-independent (e.g. molecular) methods will be used to characterize and quantify authentic pathogenic bacteria and viruses as well as surrogate organisms.

2. Determination of variables thought to control the removal/retention of microbial contaminants in the STA and their response to CV/C. These include the concentration of dissolved oxygen, potentially toxic compounds (e.g. H2S, dissolved metals) and pH. We will also determine soil physical properties (e.g. particle size distribution, porosity and pore size distribution, bulk density, infiltration rate) and soil chemical properties (e.g. organic C, clay mineralogy, cation exchange capacity) known to affect the fate of viruses and bacteria in the STA.

The data gathered on removal/inactivation of pathogens, in combination with information on controlling variables and data on interactions among wastewater, soils, and climate variables (Objective 1) will allow us to identify those processes most likely to be impacted by CV/C. These data will also be used in models (Objective 3) predicting the impact of CV/C on pathogen removal.

Objective 3. Develop models that describe and predict how wastewater renovation processes are affected by climate variables at different spatial and temporal scales.

Both simulation models and monitoring methods will be used to accomplish our objectives. Results of modeling efforts will be used to inform decisions on system siting and design.

Using simulation models, we will optimize the OWTS design by adjusting the design parameters and looking at the model output in terms of discharge capacity, chemical discharge, and pathogen fate. Once we have identified one or two optimal design criteria through simulation, we will test those designs in field-based pilot studies and collect data to show the workability of the new design criteria.

Two models will be used that represent different levels of complexity. As a relatively simple model, the STUMOD (Soil Treatment Unit Model; McCray et al., 2010) will be employed. STUMOD input parameters include effluent concentrations and hydraulic loading rates. The output is the expected steady-state performance (i.e., constituent concentration) at the center under the point of effluent application. STUMOD was developed for transport in the unsaturated zone, which is assumed to be predominantly vertical flow with contaminants transported mainly by advection and the effect of dispersion ignored. When the effluent application rate is constant, the infiltration reaches steady state and the pressure profile or soil moisture profile does not change with time. The effect of moisture content on nitrification and denitrification is calculated based on soil moisture profile. STUMOD accounts for the effect of temperature on nitrification and denitrification.

A more complex model, a modified version of HYDRUS(2D/3D) (Simunek et al., 2006), will also be used. HYDRUS is a numerical model that simulates water, solute, and heat transport in soil. We will use a 2D simulation that will be appropriate for STA trench, low pressure pipe (LPP), pressurized shallow narrow drainfield (PSND), and drip irrigation systems. The model will simulate the movement and transformations of different forms of N. HYDRUS does not assume steady state flow and will therefore respond to rapid changes in moisture and temperature, as well as the long- term changes in these variables. Also, the effect of modified systems such as low pressure pipe (LPP) drainfield will be tested. HYDRUS input parameters include soil hydraulic properties, daily weather, and concentrations of effluent from the septic tank or advanced treatment unit. Outputs are predicted concentrations of N and viruses moving below a given soil depth.

To determine the effect climate change may have on OWTS model simulations, weather scenarios, that are being developed using regional climate models (RCM) that downscale global climate model predictions to regions, will be used as they become available (Patz et al., 2005). These weather scenarios will be used to drive the STUMOD and HYDRUS models over a simulation period of one year and compared to a simulation using a year that represents the current climate.

Objective 4. Develop and deliver educational and outreach materials to inform practitioners and the public about the performance, management, operation, maintenance and health issues related to OWTS in light of climate variability and climate change.

Utilizing research knowledge gained from project Objectives 1 through 3, we will synthesize data, develop, and deliver stakeholder-appropriate education and outreach materials related to CV/C and: (i) interactions of soils, water, and wastewater relative to soil and site suitability for OWTS; (ii) wastewater biogeochemistry in advanced treatment OWTS, in soil treatment areas and underlying soils; and, (iii) modeling of wastewater movement and contaminant migration in soils underlying OWTS soil treatment areas.

To help OWTS practitioners, we will continue the outreach work started under NE 1045 by:

• Utilizing a technology matrix table that helps public and private decision makers to determine what OWTS technologies are best suited for nutrient and pathogen sensitive watersheds, and addresses various on-lot site constraints such as shallow groundwater tables, shallow bedrock, slowly and rapidly permeable soils and size restricted lots.

• Working with industry and regulatory stakeholders to develop and improve materials for design, operation, maintenance, installation, economics, planning, management, and analyzing and diagnosing malfunctions of conventional and advanced OWTS as it relates to adaptation to and mitigation of climate variability.

Using the education materials described above, we propose to train OWTS practitioners, decision makers and the public. Delivery of materials will be at outreach workshops conducted within the existing network of Land Grant and private institution OWTS training centers and programs across the United States. In addition, training materials will also be delivered at state, regional and national professional conferences and trade shows. Delivery methods may include lectures, e-Learning, distance learning venues and hands-on field exercises, fact sheets, demonstration systems and props, Power Point slides, videos and DVDs.

Measurement of Progress and Results


  • Refereed journal articles and publications for industry/ professional association conference proceedings related to OWTS and climate variability and climate change.
  • Training workshops and associated educational materials to transfer emerging information to onsite wastewater practitioners at state, regional and national venues.

Outcomes or Projected Impacts

  • Increased interaction, knowledge, and understanding among the members of the project technical committee, the OWTS industry and wastewater practitioners concerning siting, design, installation, operation and maintenance of conventional and advanced OWTS that meet the growing challenges posed by climate change, and the need to protect human and environmental health.
  • Improved or newly developed outreach demonstration education tools to help us communicate our research findings to our professional onsite wastewater practitioner communities.
  • Increase in knowledge of onsite wastewater stakeholders as a result of information developed from this project being delivered through outreach education and demonstration venues.
  • Increased use of advanced treatment technologies to help mitigate climate change impacts.


(2015): Distribute sponsored proposal to colleagues engaged in onsite wastewater research to raise awareness and to solicit participation. Develop and continue research efforts and strengthen multi-state research and outreach efforts. Convene the first project meeting. The purpose of this meeting will be to confirm leadership roles, assign duties to committee members to be completed during the tenure of the project and identify other scientists who may be interested in joining the project. Report on progress, expand development of methods to address objectives and development of outreach training materials.

(2016): Review progress made at the participating institutions under the different objectives, present committee reports, share and discuss common research interests and findings, and report on outreach efforts by members.

(2017): Present and discuss progress made in meeting project objectives. Review, identify, improve and augment ongoing research methods based upon peer review, and by utilizing evaluations, stakeholder feedback and comments, and experiences gained from training events. Develop, improve and enhance outreach education materials, deliver them at forums and assess the effectiveness of training efforts.

(2018): Review and assess progress made on research. Collect information to assess the numbers of practitioners being exposed to new research findings at training forums. Assess to what extent the practitioners being trained are utilizing the research-based outreach training they have received to change their behaviors, or to effect change in their practices.

(2019): Present and discuss progress made in meeting project objectives. Identify, improve and augment ongoing research based upon peer review and by utilizing evaluations, stakeholder feedback and comments, and experiences gained from training events. Develop, improve and enhance outreach education materials, deliver them at forums and assess the effectiveness of training efforts.

(2020):Convene the final project meeting to discuss and evaluate prioritized research efforts, effectiveness of associated outreach forums. Present all completed standards of practice, developed publications, and final committee reports.

Projected Participation

View Appendix E: Participation

Outreach Plan

The results of this proposed multistate project will be published as project reports on the project web site, as peer-reviewed publications, presentations at scientific meetings, presentations at industry conferences, and publications in industry journals, magazines and newsletters. Our project will sponsor a 2016 onsite wastewater symposium which will feature research findings from our new project. In addition, summaries of the completed work will be posted on participating members’ own web pages. Participating members involved in undergraduate teaching, graduate student advisement, and extension activities at Land Grant Universities will disseminate knowledge developed from the proposed project activities in these respective forums. Project participants manage an established network of onsite wastewater training centers/programs where project information will be disseminated at local, regional and national stakeholder training workshops and classes that reach regulatory officials, professional engineers, land surveyors, environmental health specialist, soil scientists, registered sanitarians, OWTS installers, designers and maintenance service providers.


A regional technical committee will be organized upon project approval. Operational procedures to be followed will be according to those outlined in the NIFA Manual for Cooperative Regional Research. The voting members of the regional technical committee will include one representative from each cooperating agricultural experiment station or institution appointed by the director. The administrative advisor and the NIFA representative will be considered nonvoting members. All voting members of the technical committee will be eligible for office. The offices of the regional technical committee will be the chair, vice-chair, and secretary and will serve as the executive committee. These officers for the first year will be elected at the organizational meeting for the technical committee. In subsequent years, the officers will be elected annually and may succeed themselves. The chair, in consultation with the executive committee, will appoint subcommittees to facilitate the accomplishment of the various research and administrative tasks involving the cooperating institutional representatives. Such tasks may include, but are not limited to, research planning and coordination, development of specific cooperative research procedures, assimilation and analysis of data from contributing scientists, and publication of regional bulletins. The duties of the technical committee will be to coordinate work activities related to the project. The chair, in accord with the administrative advisor, will notify the technical committee of the time and place of meetings, prepare meeting agendas, and preside at meetings of the technical committee and the executive committee. The chair is responsible for preparing the annual progress report and coordinating the preparation of regional reports. The vice-chair assists the chair in all functions. The secretary records the minutes and performs other duties assigned by the technical committee or the administrative advisor. Annual meetings will be held by the technical committee for the purpose of conducting business related to the project. During each annual technical committee meeting, the subcommittees will report on their progress and identified needs to the entire committee. Considerable time will be devoted to the discussion of these reports.

Literature Cited

Cooper, J. A., G. W. Loomis, D. V. Kalen, and J. A. Amador. 2015. Evaluation of water quality functions of conventional and advanced soil-based onsite wastewater treatment systems. Journal of Environmental Quality doi: 10.2134/jeq2014.06.0277

Lindbo, D. 2015. Septic Systems as a ‘Green’ Technology. Soil Horizons doi:10.2136/sh2015-56-3-gc

McCray, J., M Geza, K. Lowe, M. Tucholke, A. Wunsch, S. Roberts, J. Drewes, J. Amador, J. Atoyan, D. Kalen, G. Loomis, T. Boving, and D. Radcliffe. 2010. Quantitative Tools to Determine the Expected Performance of Wastewater Soil Treatment Units – Guidance Manual. Water Environment Research Foundation, Alexandria, VA.

Michigan Sea Grant. 2015. Climate variability and climate change: What is the difference? Available online at: Variability-and-Climate-Change.pdf (verified 4 May 2015)

Morales, I., J.A. Amador, and T. Boving. 2015. Transport of Escherichia coli in a soil- based wastewater treatment system under simulated climate change conditions. Journal of Environmental Quality (In revision).

Morales, I., T. B. Boving, J. A. Atoyan, and J. A. Amador. 2014. Transport of pathogen surrogates in soil treatment units: Numerical modeling. Water 6: 818-838.

Patz, J.A., D. Campbell-Lendrum, T. Holloway, and J.A. Foley. 2005. Impact of regional climate change on human health. Nature. 438:310-317.

Richard, J. T., D. A. Potts, and J. A. Amador. 2014. Mechanisms of ammonium transformation and loss in intermittently aerated leachfield soil. Journal of Environmental Quality 43: 2130–2136.

Šim?nek, J., M.T. van Genuchten, and M. Sejna, 2006. The HYDRUS Software Package for Simulating the Two-and Three-Dimensional Movement of Water, Heat, and Multiple Solutes in Variably-Saturated Media; Technical Manual, PC Progress: Prague, Czech Republic.

Waak, M. and S. Heger. 2014. Adult care facility septic system evaluation. In proceeding of NOWRA 23rd Annual Conference. Alexandria, VA.

Williamson, T.N., B.D. Lee, P.J. Schoeneberger, W.M. McCauley, S.J. Indorante, and P.R. Owens. 2014. Simulating soil-water movement through loess veneered landscapes using non-consilient Ksat measurements. doi:10.2136/sssaj2014.01.0045


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Non Land Grant Participating States/Institutions

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