Grantee Research Project Results
2024 Progress Report: Sustainable Nutrient Removal Opportunities for Small Communities with Lagoon Wastewater Systems
EPA Grant Number: R840468Title: Sustainable Nutrient Removal Opportunities for Small Communities with Lagoon Wastewater Systems
Investigators: Orner, Kevin , Leverenz, Harold , Lin, Lance , Cornejo, Pablo K
Institution: West Virginia University , California State University - Chico , University of California Davis
EPA Project Officer: Ludwig-Monty, Sarah
Project Period: January 1, 2023 through December 31, 2025
Project Period Covered by this Report: January 1, 2024 through December 31,2024
Project Amount: $1,000,000
RFA: Innovative Water Technologies for Lagoon Wastewater Systems in Small Communities Request for Applications (RFA) (2022) RFA Text | Recipients Lists
Research Category: Water Quality , Water
Objective:
(1) Identify the various technology options currently implemented at lagoon facilities serving less than 10,000 people that consistently remove ammonia, total nitrogen, and total phosphorus to low levels, (2) Determine the nutrient removal performance and contextual challenges of technologies that can efficiently and consistently remove nutrients in different types of lagoon systems in different climates, (3) Determine the economic performance of technologies that can efficiently and consistently remove nutrients in different types of lagoon systems in different climates, and (4) Determine the life-cycle environmental impacts of technologies that can efficiently and consistently remove nutrients in different types of lagoon systems in different climates.
Progress Summary:
Data analysis of additional publicly available data sources including the recently released Clean Water Needs Survey (CWNS) 2022 provided insights into the existing nutrient management infrastructure of lagoon systems in small communities. Common nutrient removal strategies identified include aeration, rock filters, and floating plants for nitrogen removal, while chemical precipitation was the primary method for phosphorus removal. Additionally, a systematic review of 1,003 peer-reviewed manuscripts identified trends in the application of nutrient management technologies applicable to lagoons over the last five decades. Findings from this effort will be used to put together a comprehensive compendium of nutrient management strategies suitable for lagoons in small communities. Additionally, this literature review informed the selection of viable nutrient management strategy scenarios to assess environmental and economic performance.
Nine nutrient management scenarios were selected for life cycle assessment (LCA) and life cycle cost analysis (LCCA). These scenarios ranged from baseline configurations, such as unlined and lined facultative lagoons, to advanced setups incorporating biodomes, packed-bed reactor, moving-bed biofilm reactor, constructed wetland, and algal-based system. A functional unit of 1 cubic meter was applied. Life cycle inventory data on infrastructure requirements, energy, use, chemical use, effluent quality, and air emissions were collected from case studies, vendors, and literature. Preliminary environmental impact analysis of the scenarios were conducted with a focus on carbon footprint and eutrophication potential. Scenario 5, which incorporated an iron-dosed upflow anaerobic reactor, achieved the lowest carbon footprint—81% lower than the baseline (unlined facultative lagoon)—due to its high removal efficiency of organics and nutrients (95% BOD₅, 98% TN, and 70% TP), significantly reducing greenhouse gas emissions. Scenario 6, featuring a packed-bed reactor, achieved the lowest eutrophication potential, reducing it by 79% compared to the baseline, owing to its high nutrient removal rates of 83% TN and 96% TP. On the other hand, Scenario 2, the lined facultative lagoon, had the highest carbon footprint (17% higher than baseline) and a modest reduction in eutrophication potential (12% lower than baseline), primarily due to limited nutrient removal efficiencies of 35% TN and 30% TP. The environmental impacts of the nine scenarios are still being finalized to publish in a peer-reviewed journal.
The LCCA quantified construction, operation, maintenance, upgrades, and decommissioning costs for the nine scenarios, capturing capital costs, annual operational expenses, and major replacement costs for components such as aeration systems, biodomes, and MBBRs. These outputs will be used to assess the economic viability of implementing these technologies in terms of the present worth of costs and affordability.
Performance data was collected from the ECHO EPA database for all lagoon facilities that utilize an NPDES permit. The analysis of over 4,239 lagoon facilities found ammonia to be the most regulated nutrient constituent by far with 1,564 facilities having permit limits. Total phosphorus, while monitored by 1,572 facilities, only had 254 facilities with a permit. Total nitrogen and nitrate are not yet permitted widely, with less than 100 facilities having permits for each. Despite the geometric mean of monthly average ammonia concentrations being below 2 mg/L, the overall compliance rate for ammonia was 89% between July 2020 and July 2024. Lagoons especially struggle in winter months due to cold weather and the seasonal drop in performance; this is clear in both reported and compliance data. The data from two technologies (MBBR and attached growth reactors) were examined and found to greatly improve nutrient removal performance, especially during cold winter months. Satellite spectral data was found to be useful in predicting lagoon ammonium concentrations based on measurements at a local California lagoon facility. The spectral data could potentially be used at other facultative (non-mechanically aerated) systems to estimate ammonia performance or overloaded cells for facilities with little or no ammonia data. Ammonia and total nitrogen data were collected from the Esparto WWTP and are currently being used to calibrate a wastewater model in the software package SUMO. After calibration, future activity will include adding additional treatment to the digital model to gauge improvements in nutrient performance.
Iron-dosed UASB and iron-medium packed bed anoxic bioreactors are designed to promote lagoon sustainability. These bioreactors treat the lagoon effluent and compare the nutrient (nitrogen and phosphorus) removal as well as recovery efficiency. The UASB functions through several steps – inoculation, biomass enrichment, bioreactor monitoring (HRT, redox potential), maintenance and relevant water quality parameters analyses. The simultaneous inflow of synthetic wastewater (imitating lagoon effluent) and iron solution results in gradual biomass production in the bioreactor. The water quality parameters (pH, TOC, TSS, VSS, NH3-N, and NOX, PO4) are examined to be in the expected range. The microscopic analyses and the metagenomics studies of the sludge flocs are also being performed to understand the functional microbial community in the bioreactors. Furthermore, the iron-dosed packed bed bioreactor fabrication is also completed hence; the reactor operation will be initiated soon.
Future Activities:
In Year 3, the focus will shift to enhancing tools and frameworks for lagoon system evaluation and decision-making. This includes updating a web map with the latest lagoon system data, developing a "suitability index" to assess lagoon technologies, and compiling a comprehensive compendium of nutrient management strategies, detailing their performance, operational needs, advantages and drawbacks. A GIS- based deep learning model will also be developed and tested to help remotely identify non-discharging lagoons from satellite images, iteratively refining its performance based on discrepancies between predictions and ground truth data. Once validated, the model will be applied to target regions, enabling remote lagoon detection and comprehensive mapping.
Additionally, we will finalize the Life Cycle Assessments (LCA) and Life Cycle Cost Analysis (LCCA) of the baseline scenarios, evaluating environmental impacts (e.g., carbon footprint, eutrophication potential) and economic metrics such as net present value (NPV) and affordability within community financial capacities. This work will be finalized and submitted for peer-review to a reputable journal. Lastly, we will produce a Multi-Criteria Decision Analysis (MCDA) Tool that will allow users to assess LCA, LCCA, and social performance, while also evaluating factors like automation, maintenance, and resilience to incorporate modules for varying unit processes. A single-score impact framework will be developed, tested with stakeholders, and tailored for practical use, providing a robust framework to guide informed decision-making on lagoon system upgrades for improved nutrient management in small communities.
In Year 3, the focus will also be on finishing the calibration of the SUMO model and applying hypothetical upgrades to gauge the change in performance. While sufficient data has likely been collected, several additional months of data will be analyzed. Additionally, a bench-scale experiment will be performed to assess the impact of benthic release and potential seepage on nutrient performance. The model will also be applied to other systems to determine what is the minimum level of input information required to produce a useful model. The probability distribution analysis will be completed and updated based on the most recent Clean Watershed Needs Survey. Correlations between temperature and solar irradiance will also be created for systems within the NPDES system. The usage of satellite imagery to predict ammonia performance will be tested at other facilities to gauge its reliability.
Future activities for the pilot study include utilizing real lagoon wastewater effluent as the bioreactor influent, a metagenomics study of the microbial community of the UASB, sludge characterization, and initiating the operation of iron-dosed packed bed reactor.
Journal Articles:
No journal articles submitted with this report: View all 6 publications for this projectSupplemental Keywords:
Nutrient Management, Wastewater Lagoons, Life Cycle Assessment, Life Cycle Cost AnalysisRelevant Websites:
https://experience.arcgis.com/experience/5034936ab97c40ee975ee4977ad32c70/ Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.