W5170: Beneficial Use of Residuals to Improve Soil Health and Protect Public, and Ecosystem Health

(Multistate Research Project)

Status: Active

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SAES-422 Reports

Annual/Termination Reports:

[01/04/2025] [09/14/2026]

Date of Annual Report: 01/04/2025

Report Information

Annual Meeting Dates: 05/19/2025 - 05/20/2025
Period the Report Covers: 10/01/2024 - 09/30/2025

Participants

Brief Summary of Minutes

Accomplishments

Accomplishments <ol> <li>Objective #1-  Evaluate the short- and long-term fate, bioavailability and persistence of emerging contaminants with an emphasis on per- and polyfluoroalkyl substances (PFAS), microplastics, metals, and pathogens in residuals, reclaimed water, and amended soils to aid in assessing and minimizing environmental and human health risks from their application at a watershed scale.  Specific tasks: i) Quantify and evaluate the uptake, accumulation and transport of emerging contaminants in residuals, wasteways and residuals- and wastewater-treated soils (e.g., agricultural, urban and brownfields); ii) Predict the long-term bioavailability, persistence and toxicity of emerging contaminants in residuals- and wastewater-amended soils; iii) Evaluate ecological effects of emerging contaminants from soils amended with residuals and reclaimed wastewaters; and iv) Evaluate long-term effects of residuals and wastewater application on the emergence/spread of antibiotic resistance.  Research for this objective was conducted by members from CO, WA, GA, MN, FL, AZ, PA, HI, IN, OH, KS, and TX.</li> </ol> Per- and polyfluoroalkyl substances (PFAS) To answer the question: “Is land application of municipal biosolids a significant source of PFAS human exposure via groundwater?”, a national collaborative project through the University of Arizona was initiated to evaluate the incidence and mobility of PFAS through soil following land application of biosolids. The goal of PHASE 1 of the project was to sample soil and analyze for PFAS from land application sites across the U.S., with different soils, depths to groundwater, and variable climates. Additionally, measured PFAS concentrations in groundwater beneath the land application sites allow for paired data sets of soil and groundwater concentrations. Ultimately these field data allow for validation of a screening level risk assessment model to predict the risk of PFAS leaching and subsequent groundwater contamination. This approach will allow for site specific evaluation of land application sites nationally with respect to the issue of human PFAS exposure. Thus, both well managed land application sites, and any sites contributing to groundwater contamination can be identified. Overall, this project benefits wastewater utilities and farmers across the U.S. It also benefits the public at large by reducing the extent of a human PFAS exposure via groundwater contamination. To date, samples from 23 sites have been collected from 17 different states across the U.S., making the project truly national in scope. Samples of surface and subsurface soil samples, biosolids samples, and wherever possible, groundwater samples have been collected. All samples were analyzed for PFAS analytes. Data showed that mean and median values of soil PFAS analytes were less than or close to soil screening levels that are protective of groundwater contamination. These data will ultimately be used as inputs for modelling efforts to predict the risk of PFAS leaching to groundwater. The above work in AZ has been supported by several W5170 members, including those in Washington State.  Much of the focus of the WA work on PFAS in biosolids has been extension and outreach focus with multiple columns in Biocycle, a trade journal and an op ed piece in a national farming magazine.  The focus of these pieces was to put science and risk analysis surrounding the presence of PFAS in biosolids into non- scientific language.  These columns also discussed and analyzed a series of articles in the New York Times that presented a highly biased and alarmist perspective. The Pennsylvania State University (PSU) conducted a preliminary greenhouse study to identify the uptake of PFAS into hemp from soils that had been spray-irrigated by treated wastewater for more than 40 years. Five varieties of hemp were investigated, including two that were harvested for grains, two that were harvested for fiber, and one that was harvested for CBD oil. Results found that none of the varieties were good accumulators of the 5 PFAS currently regulated in drinking water, with uptake < 1% of the PFAS in wastewater-irrigated soil. However, hemp does show potential to be a good accumulator of PFPeA and PFBA, which will be assessed in a subsequent greenhouse study. Overall results appear to suggest that hemp can likely be grown safely in biosolids-amended fields, given the low uptake. PSU completed the data analysis from a greenhouse study to: (1) quantify the relative importance of root uptake versus foliar sorption of PFAS in corn and orchard grass; (2) assess any potential plant health effects of PFAS-impacted wastewater irrigation may have; and (3) determine the implications for bioaccumulation into the food chain. The greenhouse study was comprised of four treatments for each forage crop: (1) PFAS-containing agricultural soil watered with treated wastewater; (2) PFAS-containing agricultural soil watered with tap water; (3) control soil watered with treated wastewater; and (4) control soil watered with tap water. Results suggested that foliar sorption was an unlikely contributor to PFAS concentrations in crop tissue. Root uptake was identified as the predominant uptake pathway. PFAS were detected more frequently in orchard grass samples compared to corn silage samples. Additionally, corn exhibited a lower uptake of long-chain PFAS compared to grass. Overall, no plant health effects on growth attributable to PFAS concentrations were observed.  PSU continues to work on a site that has received biosolids for nearly 50 years, focused on quantifying PFAS concentrations within the field and in riparian buffers. PFAS concentrations appear to decrease across the buffer. Additional PSU work has focused on PFAS in living filters and a community science-based project of PFAS in private wells across PA. Studies in Florida have continued to focus on the retention-release behavior of PFAS in biosolids and, upon treatment with various sorbents including drinking water treatment residuals. Few effects on PFAS mobility were observed when amending biosolids with a suite of amendments at amendment rates below 10% wt/wt.  Experiments investigating the trophic transfer potential of PFAS in simulated terrestrial food chains are ongoing.  An experiment characterizing uptake and elimination of PFAS in earthworms from PFAS contaminated soil is nearing completion.  This work will also relate PFAS uptake in invertebrates to tissue lipid/protein content and compare results to another already published study that investigated the trophic transfer of PFAS from tomato to tobacco hornworm. Research in Colorado has aimed at combining targeted and non-targeted PFAS analysis to propose degradation pathways, and explore how these are affected by parameters such as biosolids composition and PFAS structure, and pyrolysis temperature when pyrolyzing biosolids. The PFAS content of biosolids before and after pyrolysis at 300-700°C, either unmodified or amended with a) distinct PFAS compounds that may shed light on differing transformation pathways or b) natural minerals that may catalyze PFAS transformation, were studied. To gain a better understanding of PFAS fate, targeted PFAS analysis was supplemented with non-targeted methods (QTOF analysis, extractable organic and inorganic fluorine analysis, TGA-GC-MS and TGA-FTIR analysis), as knowledge to date relies almost exclusively on targeted analysis. Finally, PFAS leaching from biosolids and biosolids-derived biochars was examined to compare the environmental exposure potential associated with land application of either substance. Results showed that at temperatures as low as 300°C, pyrolysis successfully removed >97% of the PFAS mass, which may allow the production of higher-quality biochar at lower energy investment and without compromising environmental safety. Studies at the University of Georgia have continued research on electrochemical oxidation of perfluoroalkyl substance (PFAS) using porous Magnéli phase titanium suboxide (TSO) anodes as an innovative technology to destroy PFAS in wastewater.  Specifically, University of Georgia participants have prepared TSO anodes doped by sintering that improved their service life as well as EO performance in terms of PFAS degradation. Their study revealed the mechanisms of the performance enhancement and provides understandings to guide further improvements of the TSO anodes via doping (Sui et al., 2025). The team has also systematically assessed the impact of anions commonly present in natural waters on EO performance in terms of PFAS degradation (Wang et al., 2024). In addition, they are in the process of evaluating an approach based on enzyme-catalyzed oxidative humification reactions (ECOHR) to remediate PFAS in biosolids.  University of Georgia W5170 members have also participated in studies to survey the occurrence, fate, and removal of PFAS in both the water streams and biosolids in municipal wastewater treatment plants via systematic sampling and analysis of wastewater and biosolid samples from multiple treatment plants of different scales and involving different treatment processes (Kim et al., 2024; Oza et al., 2024).  They also participated in a study to assess the bioaccumulation of PFAS in a model soil organism caenorhabditis elegans, and to evaluate the impact on their learning and memory by early life exposure to individual and mixture PFAS (Currie et al., 2024). Work in Minnesota focused on three wastewater treatment plants (WWTP) and on-farm trials to monitor the occurrence of PFAS in soil and crop plants.  Within each WWTP location, three grower fields were selected: Field 1, where there was no record of biosolids application biosolids, Field 2 where biosolids were applied at least two years prior to 2023 (historical) and Field 3 where biosolids were applied either the fall or spring prior to planting based on available N content (current season).  Biosolids applied varied with location, and included aerobically digested, class A dried biosolids; aerobically digested class A liquid biosolids, and anaerobically digested class B liquid biosolids.  Crops grown at each location were: Field 1 - rye, corn, or soybeans; Field 2 - soybeans; Field 3 - corn.  Within each location, soil were sampled from 0-1, 1-2, and 2-3 foot depths prior to planting.  Soils were collected again at the three depths in June, from the 0-1 and 1-2 foot depths in August, and all three depths after crop harvest.  Samples underwent PFAS analysis using EPA method 1633.  Crops were hand harvested from the three sites within each field near the areas where soil samples were collected.  Harvested tissue also underwent PFAS analysis using EPA method 1633 and to UMRAL for total elemental analysis.  Minnesota results indicated that PFAS concentrations in biosolids varied with WWTP and in general higher concentrations in biosolids resulted in higher concentrations in soil.   Soil PFOS was detected in all fields with biosolids applied in the current year.  Highest concentrations were found with anaerobically digested biosolids. Highest soil PFOS concentrations were at the surface (0-1 ft), ranging from less than 1 ng/g up to 12 ng/g.   PFOS concentrations decreased at lower soil depths and as the season progressed.   Low amounts of PFOS were detected in fields that had no record of biosolids application (0.04- 0.11 ng/g).   Like PFOS, PFOA was detected in all fields with biosolids applied in the current year with highest concentrations resulting from application of anaerobically digested biosolids.  Concentrations ranged from < 0.1 ng/g to 1.0 ng/g and they tended to decrease with depth and as the season progressed.  Like PFOS, PFOA concentrations were detected at low levels in fields that had no recorded biosolids application, and concentrations were less than 0.2 ng/g.  At concentrations less than 0.6 ng/g, PFBA was detected in fields that had no history of biosolids application and sometimes were higher than in fields that had received biosolids.   PFBS was detected in fields that had a history of biosolids use and in fields with biosolids applied in the current year.   Results of this study demonstrate that the fate of PFAS in the soil environment may be linked to biosolids application but that for some compounds, other pathways also need to be considered.  Analysis of corn grain, corn stover, and soybean grain tissues revealed no detectable PFAS in soybean or corn grain.  PFOS, PFBA, PFPeA, PFBS, were detected in corn stover primarily in plots applied with liquid biosolids.   These results suggest that further testing is needed if stover is used for animal feed.   Under the conditions of this study and the PFAS concentrations in the biosolids applied, animal consumption of corn and soybean grain does not appear to be a health risk when biosolids are applied at agronomic rates. Purdue University researchers finished and published our comparative PFAS in biosolids analytical methodology as well as our investigation on PFAS dynamics within the solids stream processes in treatment of wastewater, specifically anaerobic digestion (AD), thermal hydrolysis (THP), autothermal thermophilic aerobic digestion (ATAD) and storage nitrification-denitrification reactor (SNDR).  Ongoing field studies include both historically applied and first-time biosolids applications on the west coast, east coast and Midwest fields, to  evaluate the persistence and transport of PFAS. Biosolids contained 50 to 75% precursor PFAS for which almost all the fluorotelomer precursors degraded to PFCAs within one year after application and primarily ECF-precursors remaining. Overall, long-chain PFAS predominantly persist in the upper 60 cm likely due to primarily organic carbon (OC) content given the high OC levels in the 0-30 cm depth (~15%) and the 30-60 cm depth (~5%) from annual biosolids applications annually (for up to four decades). No PFAS reached the DLD groundwater monitoring well above EPA April 2024 MCLs except PFOA at 39 ppt. Transport modeling of the field site in collaboration with Kurt Pennell at Brown University has been completed and is being written up. Additional work from Purdue University has focused on a 1-year feed grass greenhouse study (closed pots – no leachate exited the pot) using PFAS-contaminated soils from Maine in which the effect of three different application rates of high carbon wood ash plus a no ash addition on PFAS uptake was evaluated over multiple harvests. PFAS uptake in all treatments decreased from the first to third harvest and then increased consistently through the next 5 harvests. Uptake was not directly correlated to potential evapotranspiration rates (estimated from temperature, growing degree days) indicating other factors such as increased root mass and root exudates facilitated PFAS uptake. PFAS translocation factors decreased in all high carbon treatments with the 6 wt% ash treatment performing the best. A soybean greenhouse study (closed pot - no leachate exited the pot) using PFAS-contaminated soils from Indiana was conducted using six soybean plant genetic varieties as well as one treatment involving 3 wt% high carbon wood ash to evaluate where PFAS translocate into the soybean plant and if sorbents will alter uptake. Three pairs of soybean genetic varieties were selected for their genetic variations contributing to drought tolerance mechanisms or final bean protein/oil ratio to better understand mechanisms that may drive or reduce PFAS uptake in plants. At senescence, the beans, pods, leaves, and stems of the soybean plants were extracted and analyzed for PFAS. PFAS uptake into the bean had negligible bioaccumulative PFOS and EtFOSAA which were present at several hundred ppb in the soil, nor was PFOA taken up into the bean whereas substantial concentrations of C4 and C5 perfluoroalkylcarboxylic acids. PFAS accumulation in soybean plant tissues was greatest in leaves, followed by stems, and bean pods. PFOS only appeared in plant tissues with stomata indicating that transpiration is the primary mechanism of uptake. The high carbon wood ash treatment also reduced PFAS accumulation into soybean seeds demonstrating their potential as a management strategy contaminated agricultural lands. The Ohio State University is studying the transport of PFAS from biosolids in 12 soils with a range of properties important to absorption of PFAS .  This is a laboratory study using packed columns and USEPA Method 1340 which requires collection of 9 eluates per soil/biosolid.  Most, but not all, of the column studies have been completed.  Additional studies are focused on various biosolids and rates, and their effects on PFAS concentrations in soils and uptake in barley and corn plant components (e.g., stalks, leaves, grain).  A subsequent study is focused on the ability of ~ 50 different biochars to sorb/desorb PFAS. Other unregulated organic contaminants The University of Florida developed a method for the extraction of microplastics from drinking water treatment residuals and used this method to extract and characterize the amount of microplastics in a small but representative number of drinking water treatment residual samples. Ca-DWTRs contained very little microplastics contamination compared to Al- and Fe-DWTRs. Purdue University completed and published work on comparative biosolids analytical methodology for other unregulated organic compounds (UOCs), e.g., personal care products, pharmaceuticals, etc.). They also finished our UOC comparative fate during AD and with addition of THP prior to AD. In addition, ongoing field studies include both historically applied and first-time biosolids applications on the west coast, east coast and Midwest fields, to  evaluate the persistence and transport of UOCs.  Only a handful of UOCs persisted after one year of being land-applied, which included the pharmaceuticals miconazole (antifungal), fluoxetine (antidepressant) and diphenhydramine (antihistamine), personal care product chemicals tonalide (perfume) and nonylphenol, and the opioid methadone. The University of Cincinnati wrote up a report on the prioritization scheme for identifying the highest priority organic compounds in biosolids amended to agricultural fields. Briefly, a total of 910 chemicals known to be present in biosolids were screened to 125 priority UOCs. These 125 UOCs were then prioritized as high and low priority based on mobility, persistence, bioaccumulation, and toxicity. The carcinogens, endocrine disruptors, and the top 50 compounds that appeared in five prioritization scenarios were categorized as high priority. This represented 47 of the total UOCs evaluated. The remaining 78 UOCs were categorized as low priority. The 125 priority UOCs from this evaluation were also compared to other biosolids priority lists (Higgins et al. prepared for the Water Environment Research Foundation; wca Environment Ltd. prepared for the Scottish EPA; ToxStrategies Inc. prepared for the Texas Commission for Environment Quality). Eight UOCs from this study were present in two of the three other priority lists. These compounds included BDE-47, BDE-207, BDE-99, Tonalide, Sulfanilamide, Ofloxacin, Triclocarban, and Triclosan.  The University of Cincinnati also continued progress on a risk calculator model for biosolids amendment to agricultural soils. Modeling code for plant uptake, beef and milk accumulation, and vadose zone leaching has been developed. Additional modeling for chicken and egg exposure, surface runoff and fish exposure, and groundwater transport with drinking water exposure are in the process of being developed. Also, effects data are being gathered (cancer and non-cancer) and preliminary risk calculations are planned for the highest priority UOCs over the summer of 2025.   <ol> <li>Objective #2-  Evaluate and optimize the uses and associated environmental benefits of residuals and wastewaters applied to various ecosystems (e.g., agricultural, urban, recreational, forest, rangeland, mine-impacted, other anthropogenic) on soil physical, chemical, and biological properties and plant nutrition, health, and yield. Specific tasks: i) Quantify the effects of biosolids and other municipal, industrial, and agricultural residuals on indicators of soil health; ii) Quantify the effects of biosolids and other residuals on pollutant (metals/metalloids) availability, assimilation, phytotoxicity and remediation; and iii) Develop and evaluate treatment strategies of residuals and wastewaters to reduce contaminant or pathogen loads. Research on this topic was conducted by members from CO, WA, GA, MN, FL, AZ, PA, HI, IN, OH, KS, and TX.</li> </ol>  Soil health and soil carbon benefits Work in Washington State has focused on the impacts of biosolids for dryland wheat production.  The emphasis of the research has been on understanding benefits associated with use of biosolids in lieu of conventional fertilizer.  Our work has shown that use of biosolids provides persistent benefits with increased soil carbon and yields observed seven years after biosolids applications ceased (Singh et al., 2024).  We have also considered biosolids as an example of a circular nutrient economy.  For the latter, we have quantified the economic benefits to participating farmers on a per ha basis, as a result of reduced fertilization costs and increased yields (Brown et al., in review). The University of Florida completed a series of column experiments investigating the impact of amending a high Ca, high P “legacy” ranchland soil with a suite of different a P-immobilizing agents, including waste residuals and commercially-available mixtures (Objective #2). This work was funded by the St. Johns River Water Management District. Experiments were conducted to simulate both a permeable reactive barrier approach (PRB; where a barrier layer is placed within the column) as well as an “Add/Mix” approach (i.e., adding an amendment to soil and homogenizing it).  Al-DWTRs outperformed even commercial reference formulations. This work, featured in various presentations during the project year as well as being published in a MS thesis late last year, is currently being prepared for publication in a peer-reviewed journal. Kansas State University researched simultaneous recovery of P (Ca-phosphate precipitation) and N (sorption using clays or struvite precipitation) from swine wastewater using a laboratory- and field-scale treatment train centered around anaerobic membrane bioreactor (AnMBR) to assess the efficiency of an innovative configuration of AnMBR technology in combination with constructed wetlands (CWs) systems, providing a sustainable and resilient management system for agricultural wastewaters. Water quality Texas A&M projects were conducted to examine the impacts of an extreme flooding event on surface water quality and the potential for photocatalytic disinfection of E. coli in water. The first study examined microbial fecal indicators in Houston, TX following Hurricane Harvey where some areas received >150 cm of rainfall within a few days. Surface water samples were collected at six locations in the southeastern Houston area immediately before and after the hurricane and then every 1 to 2 weeks thereafter over a 2-month period. Total E. coli numbers were determined and water samples were analyzed via quantitative real-time PCR (qPCR) for general and source-specific total Bacteroidales and human Bacteroidales markers, and digital PCR (dPCR) for antibiotic resistance genes (ARG) and a plasmid (pBI143) associated with human waste. SourceTracker2 was used to determine human source contributions based on metagenomic analysis of PCR-amplified 16S rRNA gene fragments. Samples collected immediately after the hurricane had elevated levels of E. coli, ranging from 488 to 1,733 CFU 100 ml−1. After 1 week, E. coli levels decreased to <100 MPN 100 ml−1. Total Bacteroidales numbers were elevated immediately following the hurricane and remained high for 12 days. Human-source contributions, as assessed by PCR methods and metagenomic analysis, peaked within 12 days after the hurricane consistently across all sampling sites. Multiple regression analysis of environmental parameters, copies of ARG and pBI143, and metagenomic data confirmed that human waste caused the dramatic, short-term, high levels of fecal contamination of floodwaters generated by Hurricane Harvey. Fecal indicators approached normal background levels approximately 3 weeks after the rainfall ended.  The second study evaluated the use of TiO2 nanowire porous foams for photocatalytic disinfection of water. Use of the foams led to a 2–3-log reduction of E. coli in a span of 180 min when ultraviolet-A (UV-A) light was employed for photoactivation. More importantly, the photocatalyst foams were easily recoverable from water via mechanical separation, which in this study led to a recovery of 98–99% of the TiO2 nanowire photocatalysts. This strategy allows for further optimization of both the process kinetics and the total amount of photocatalysts needed for water remediation through optimization of the porosities and the geometries of the foams and ensuring that all the photocatalyst surfaces remain accessible to both the pollutants and light. Biochar studies The University of Hawaii created a biochar made from invasive tree species, mainly leucaena (Leucaena leucocephala L.) at pyrolysis temperatures around 350 – 400 oC. Subsequently, two types of compost were prepared with and without 5% biocchar and were amended to a nutrient-poor weathered soil in Oahu, Hawaii. Sweet corn (Zea mays L.)  was grown as a test crop. Preliminary results showed that the  biochar-assisted compost had more microbial activities (higher CO2 production) and matured about 2 weeks faster than the compost without biochar. Importantly, corn grew much better, yielded larger ears than the no biochar treatment. This work helped control invasive trees, protect local environment and profit farming operations.  Urban soils Dr Brown (University of Washington) and Dr. Hettiarachchi (Kansas State University) co-authored a paper considering the benefits of green space in urban areas (Brown and Hettiarachchi, 2025).  Green space here included urban agriculture.  The potential risks associated with contaminants (Pb and PAH) in urban soils was discussed.  Use of municipal biosolids and residual based composts as tools to both reduce the concentration and bioaccessibility of contaminants as well as to enhance plant growth in urban soils was a focus of the work. Dr. Hettiarachchi (Kansas State University) collected data from child lead poisoning prevention programs in Kansas City, MO, and Kansas City, KS, as well as brownfields programs. The data indicated that a significant number of residential properties tested contain lead (Pb) above the EPA level for child play areas (400 mg/kg). In situ stabilization of common soil contaminants, such as Pb, using soil amendments primarily focuses on reducing human health and environmental risks by inducing biogeochemical reactions that convert soil contaminants into forms with low bioavailability. Kansas State University personnel have been conducting field-based research studies at seven vacant lot sites in Kansas City, MO residential neighborhoods, using phosphorus and other soil amendments, including locally available Class A biosolids, since the summer of 2022. Results have demonstrated that P fertilizers, such as ammonium polyphosphate, and Class A biosolids amendments help to reduce the bioaccessibility of Pb in soils (measured using both PBET at pH 2.5 and USEPA’s IVBA at pH 2.5 methods) with relatively higher Pb bioaccessibilities (> 15-20% of the total Pb was bioaccessible at the beginning). Results also showed that it was challenging to reduce bioaccessibility further when soils have inherently low bioaccessible Pb (i.e., only <10-15% of total Pb in the soil is bioaccessible). The team is also verifying these reductions by studying changes in soil Pb speciation using X-ray absorption spectroscopy and currently in the process of establishing field sites in Kansas City, Kansas.

Publications

Impact Statements

The beneficial reuse of biosolids and municipal wastewater in agricultural activities is of growing importance to meet the need of increasing populations, but its acceptance is limited by some trace constituents in these materials, for example PFAS and other unregulated organic compounds (UOCs), e.g., personal care products, pharmaceuticals, etc.). The continued W5170 research is leading towards development of innovative technologies to mitigate heavy metal contamination, PFAS and other UOCs, including novel amendments, electrochemical approaches, enzyme-based processes, and pyrolysis techniques. The results provide a basis for design and optimization of the novel processes that can mitigate the constituents that limit the beneficial reuse of biosolids and wastewaters and thus reduce their environmental loads. These novel technologies are expected to have long-term impacts in beneficial reuse of biosolids and wastewater. In the meantime, we have conducted systematic research to investigate the occurrence of PFAS in water recovery facilities and assessed their toxicity potentials. The results provide useful information for knowledge-based environmental risk assessment and policy making in relation to PFAS contamination. WWTPs, farmers who receive biosolids, consultants, agricultural professionals, and the broader public will learn how biosolids application for crop production affects the fate of PFAS, UOCs, and metal compounds in soils, crops, and risk of groundwater contamination. The data generated will be used to help state agencies improve their PFAS transport and health risk models and develop policy on land application of biosolids.

Date of Annual Report: 09/14/2026

Report Information

Annual Meeting Dates: 07/12/2026 - 07/14/2026
Period the Report Covers: 10/01/2025 - 09/30/2026

Participants

Participants at Annual Meeting:

Jim Ippolito, The Ohio State University
Drew McAvoy, University of Cincinnati
Guanglong Tian, Metropolitan Water Reclamation District of Greater Chicago
Persephone Ma, Brown and Caldwell
Moss Birri, Biosolids Specialist, City of Columbus, OH
Ian Pepper, University of Arizona
Linda Lee, Purdue University
Carl Rosen, University of Minnesota
Vijay Chaganti, Virginia Tech
Qianqian Dong, Texas A&M University
Jim Dunbar, Lystek
Hui Li, Michigan State University
Nick Basta, The Ohio State University
Sally Brown, University of Washington
Maile Lono-Batura, California Association of Sanitation Agencies
Mary Baker, Mid-Atlantic Biosolids Association
John Uzupis, Synagro
Stefan Weaver, Denali Water
Kelly Kosiarski, Penn State University
Dallon Pannella, Penn State University

Brief Summary of Minutes

A list of presentations discussed at the annual meeting are attached. We also discussed location for the 2027 W5170 conference.

Accomplishments

Objective 1: Evaluate the Short- and Long-Term Fate, Bioavailability, Persistence, and Risks of PFAS and Other Emerging Contaminants PFAS Occurrence and Environmental Monitoring <ol> <li>Researchers at the University of Hawaii investigated the occurrence of PFAS in recycled water and biosolids generated by wastewater treatment facilities throughout Hawaii. Results demonstrated detectable concentrations of PFAS in both treated effluent and biosolids, with total PFAS concentrations ranging from 17 to 663 ng L⁻¹ in effluent and from 23 to 68 ng g⁻¹ in biosolids. Application of the Total Oxidizable Precursor (TOP) assay revealed additional precursor PFAS compounds, emphasizing the importance of considering both targeted PFAS analytes and precursor compounds when evaluating environmental risks associated with biosolids reuse. These findings provide foundational information for future monitoring and regulatory efforts in tropical environments.</li> <li>Researchers at Pennsylvania State University expanded PFAS monitoring through innovative community-science approaches involving approximately 200 private well owners. Results were incorporated into a statewide extension tool that provides PFAS occurrence information for public and private drinking water sources throughout Pennsylvania. This effort significantly expanded public awareness and stakeholder engagement regarding PFAS contamination and groundwater management.</li> </ol>  PFAS Fate and Transport <ol> <li>Research conducted at The Ohio State University focused on PFAS transport through biosolids-amended soils representing a wide range of soil properties. Column studies demonstrated that PFAS leaching was strongly affected by biosolids composition, organic matter content, iron and aluminum oxide concentrations, and clay content. Multiple linear regression models explained between 74% and 92% of observed variability in PFAS transport, suggesting that integrated soil-property approaches provide useful predictive capability for PFAS movement following biosolids applications. Results further demonstrated that water-soluble PFAS fractions are often more informative predictors of environmental mobility than total PFAS concentrations.</li> <li>At Pennsylvania State University, researchers continued evaluating PFAS transport from biosolids-amended fields into riparian buffer systems and groundwater resources. Preliminary findings suggested that riparian buffer effectiveness was highly site-specific and dependent upon local hydrologic, soil, and management conditions. Concurrent groundwater investigations at the Living Filter beneficial reuse system demonstrated important relationships among groundwater elevation, PFAS concentrations, nitrate occurrence, and pharmaceutical transport dynamics. These findings provide valuable guidance for managing wastewater irrigation sites and biosolids application programs.</li> </ol>  PFAS Treatment and Mitigation Technologies <ol> <li>Research conducted by Qingguo Huang and colleagues at the University of Georgia advanced innovative PFAS destruction technologies utilizing electrochemical oxidation with titanium suboxide anodes. Researchers evaluated fluorine distribution among liquid, solid, and gaseous phases while tracking target and non-target PFAS transformation products. Findings improved understanding of PFAS mineralization mechanisms and established a foundation for integrated treatment systems utilizing ion-exchange resins followed by electrochemical oxidation.</li> <li>Georgia researchers also advanced enzyme-catalyzed oxidative humification reactions (ECOHRs) and demonstrated transformation of 6:2 fluorotelomer sulfonic acid using laccase-mediated systems. Collectively, these studies suggest that enzyme-based treatment systems may provide cost-effective alternatives for PFAS remediation in biosolids, wastewater, soils, and agricultural systems.</li> <li>Researchers at the University of Florida investigated amendment strategies intended to reduce PFAS mobility from biosolids. Findings indicated that sorbent amendment rates less than 10% by weight had limited impact on PFAS leachability, suggesting that substantially greater amendment rates may be required to achieve meaningful reductions in bioavailability and transport.</li> </ol>  Crop Uptake, Bioaccumulation, and Phytoremediation <ol> <li>Research at Pennsylvania State University evaluated PFAS uptake in hemp and orchard grass exposed to biosolids-amended soils. Across multiple greenhouse experiments, hemp consistently accumulated significantly greater PFAS concentrations than orchard grass, particularly for short-chain compounds. Results demonstrated that hemp effectively removed both short- and long-chain PFAS compounds and may serve as a practical phytoremediation crop for PFAS-impacted agricultural landscapes. Importantly, increasing biosolids application rates did not substantially increase PFAS accumulation in plant tissues, suggesting that soil fertility management and PFAS remediation objectives may be compatible.</li> <li>Researchers at the University of Minnesota investigated PFAS accumulation in biosolids-amended agricultural soils and crop systems. Their findings contributed to understanding crop uptake, dietary risk, and long-term behavior of PFAS in agricultural landscapes receiving biosolids applications.</li> </ol>  Other Emerging Contaminants <ol> <li>The University of Florida developed and applied methods for extracting and quantifying microplastics in drinking water treatment residuals. Results demonstrated substantially lower microplastic concentrations in calcium-based residuals relative to aluminum- and iron-based materials, supporting their beneficial reuse.</li> <li>Researchers from the University of Washington collaborated on studies evaluating pharmaceuticals and personal care products in biosolids and biosolids-amended soils. Findings indicated minimal ecosystem transfer potential for these compounds under the evaluated conditions.</li> </ol>   Objective 2: Evaluate and Optimize Beneficial Reuse, Soil Health, Nutrient Recovery, and Ecosystem Services Soil Carbon Sequestration and Climate Benefits <ol> <li>Research conducted by Guanglong Tian at the Metropolitan Water Reclamation District of Greater Chicago demonstrated remarkable long-term carbon sequestration associated with biosolids applications. Forty years after the final application, biosolids-treated soils maintained significantly greater soil organic carbon concentrations than conventionally fertilized soils. Net carbon sequestration averaged 37.1 Mg ha⁻¹, while greenhouse gas emission reductions averaged approximately 0.59 Mg CO₂-equivalent per Mg biosolids applied. These findings provide strong evidence supporting biosolids use as a climate mitigation strategy.</li> <li>Research conducted by Michael Kaiser and colleagues at the University of Nebraska demonstrated that biosolids-biochar co-application increased soil carbon storage by as much as 20 Mg ha⁻¹ while simultaneously improving nutrient retention. Results from one of the largest active field-scale biochar experiments in the United States emphasized the potential of biosolids-biochar systems to support smart soil management.</li> <li>Researchers at the University of Washington documented substantial improvements in soil health indicators following long-term biosolids application in dryland wheat systems. Enhanced soil function persisted years beyond application and contributed to improved crop performance and increased farm profitability.</li> </ol>  Nutrient Recovery and Circular Resource Management <ol> <li>Researchers at Kansas State University continued development of phosphorus and ammonium recovery technologies from livestock wastewater streams using anaerobic membrane bioreactor systems. Recovered nutrient products demonstrated potential as effective fertilizer alternatives while supporting circular nutrient economies.</li> <li>At the University of Florida, researchers demonstrated that aluminum-based drinking water treatment residuals effectively reduced phosphorus mobility in legacy biosolids-impacted soils and outperformed several commercially available alternatives. These findings support the beneficial reuse of residuals for nutrient management and water-quality protection.</li> </ol>  Urban Soil Remediation <ol> <li>Researchers at Kansas State University continued field-based studies evaluating biosolids, biochars, phosphorus amendments, and other residual-derived materials for mitigation of lead contamination in urban environments. Results confirmed the potential of residual-based amendments to reduce lead bioaccessibility and improve environmental quality in residential neighborhoods.</li> <li>At The Ohio State University, researchers advanced understanding of lead bioavailability, heavy metal remediation, ecological risk assessment, and remediation approaches utilizing compost and related amendments in contaminated soils. These studies contribute to improved management of urban and industrially impacted landscapes.</li> </ol>

Publications

Peer-Reviewed Publications Ahmad, A., Radovich, T., Hue, N., Meaney, S., Rodriguez, G., and Zhang, Y. 2026. Evaluating the Effects of Three Seaweed Extracts on the Growth and Yield of Three Crops. Sustainability, 18:8420. Brown, S., and G. Hettiarachchi. 2025. Considering Risks and Benefits Associated with Urban Green Space Through the Lens of Environmental Justice. Soil & Environmental Health. Brown, S., M. Vernik, D. Butman, D. Griffin-LaHue, J. Finlinson. 2026. Quantifying the Environmental and Economic Impact of Municipal Biosolids Use in Dryland Wheat in Washington State. Urban Agriculture & Regional Food Systems. Desjardins, M., J.A. Ippolito, A.I. Bary, S.B. Cappellazzi, D. Liptzin, D. Griffin-LaHue. 2025. Long-Term Biosolids Applications Improve Key Soil Health Functions for Semi-Arid Dryland Systems. Science of the Total Environment. Ghaznavi, S.M., M. Choudhary, M. Hannan, G. Hettiarachchi, O.G. Apul. 2025. A Critical Review of Per- and Polyfluoroalkyl Substances Adsorption by Soil. Journal of Hazardous Materials: Organics. Gamage, K.H.H., G. Hettiarachchi, E. Heronemus, P. Parameswaran. 2026. Recovered Calcium-Based Phosphorus Products from Synthetic Swine Wastewater: Fate and Behavior in Soils. Environmental Science & Technology. Hettiarachchi, G.M., L. Lake, A.D.E. Mudiyanselage, N. Basta, K. Scheckel. 2026. Bioavailability of Lead and Exposure Pathways to Humans. In S. Hayes, C. Alpers, T. Sowers, D. Brabander, R. Root (Eds.) Lead in the Environment: Mineralogy, Geochemistry, Sources, and Remediation. Reviews in Mineralogy and Geochemistry. Judy, J.D., C. Gravesen, P.C. Wilson, A. Wilkie, J. Sarchapone, F. Hinz, X. Yang, N. Renwick. 2026. Uptake and Elimination of 7 Selected PFAS in Eisenia Fetida Exposed in Artificial Soil. Bulletin of Environmental Contamination and Toxicology, 116(5), 92. Kosiarski, K., T.L. Veith, F.A. Kibuye, P.J. Drohan, O.G. Apul, H.E. Preisendanz. 2026. Hydrogeologic Drivers and Management Implications of PFAS, Nitrate, and Pharmaceuticals in Groundwater at a Karst Beneficial Reuse System. ACS ES&T Water. Kosiarski, K., H.E. Preisendanz, F.A. Kibuye. 2025. County-Level Summary of PFAS in Pennsylvania Drinking Water Sources. Penn State Extension. Kosiarski, K., H.E. Preisendanz, F.A. Kibuye. 2025. PFAS in Pennsylvania Groundwater and Factors Influencing Occurrence. Penn State Extension. Lai, Y.R., N.T. Basta. 2025. Beneficial Use of Byproducts to Reduce Phosphorus Loss from Agricultural Land. Journal of Environmental Management, 396:128090. Lai, Y.R., N.T. Basta, K. Xia, A. Wang, J.A. Ippolito. 2026. Predicting Per- and Poly-Fluoroalkyl Substances Leaching Potential from Biosolids-Amended Soils Based on Soil Properties. Journal of Hazardous Materials Advances. Lopez, A.R., J.D. Judy. 2025. Extraction and Quantification of Microplastics Contained Within Al, Fe and Ca Drinking Water Treatment Residuals. Bulletin of Environmental Contamination and Toxicology, 115(2), 30. Mudiyanselage, N., G. Hettiarachchi. 2026. Comparative Assessment of Mobility, Potential Availability, and Speciation of Reclaimed Struvite and Conventional Phosphorus Fertilizers in Mildly Calcareous, Neutral, and Acidic Soils. Journal of Environmental Quality. Munir, U., Y. Wang, X. Zhu, Y. Ji, M.Y. Habteselassie, A. Squartini, Q. Huang. 2026. Transformation of 6:2 Fluorotelomer Sulfonic Acid in Laccase-Mediator Systems. Frontiers in Environmental Engineering. National Academy of Sciences, Engineering, and Medicine. 2026. PFAS in agricultural systems: Guidance for conservation programs at USDA. Committee on assistance to the U.S. Department of Agriculture in building a framework for addressing PFAS on agricultural land. Ippolito, J.A. (committee chair), T.W. Christensen, J.M. Gibson, B.M. Gramig, J.L. Guelfo, L.S. Lee, H. Li, E.B. Mallory, and T. Rosen. National Academies Press, Washington, DC. Available on-line at: <a href="https://www.nationalacademies.org/publications/29272">https://www.nationalacademies.org/publications/29272</a>. Ngoetjana, M.P., E.H. Tesfamariam, S. Brown, M. Wooding. 2025. Occurrence, Distribution, and Risk Assessment of Selected Pharmaceuticals in Municipal Biosolids from the Four Wastewater Treatment Plants in Gauteng Province, South Africa. Scientific Reports, 15:45232. Ngoetjana, M.P., E.H. Tesfamariam, S. Brown, M. Wooding, M.A. Dippenaar. 2025. Occurrence, Concentration, and Risk Assessment of Selected Pharmaceuticals in Representative Cropland Soils and Their Underlying Groundwater in Gauteng Province, South Africa. Environmental Monitoring and Assessment, 197:986. Qiu, Z., K. Zhang, Y. Han, X. Wang, B. Song, H. Shi, H. Shi, G. Hou, B. Wang, H. Wang, S. Gao, Q. Huang. 2026. Electrochemical Activation of Peracetic Acid for Efficient Sulfamethoxazole Degradation: Transformation of Hydroxyl Radical into Organic Radical. Separation and Purification Technology. Reid, M.T., N.T. Basta, A.P. Dacres, M.S. Gonzalez-Serrano, A.M. Zearly. 2026. An Approach to More Accurately Estimate Soil Lead Bioavailability for Ecological Risk Assessment by Incorporating Diet into a Novel Avian In Vitro Gastrointestinal Assay. Environmental Toxicology and Chemistry. Renwick, N., Y. Katsenovich, Y. Lin, V. Nair, T. Osborne, J.D. Judy. 2026. Drinking Water Treatment Residuals, Biochar and Commercial Sorbent Blends as Soil Amendments to Reduce Phosphorus Leaching at a Legacy Biosolids Application Site. Revision submitted to JEQ. Streets, S., E. Souza, M. McNearney, S. Jedinak, A.D. Manzur, J.L. Guelfo, C. Rosen. 2026. Per- and Polyfluoroalkyl Substances in Land-Applied Biosolids: Accumulation in Soils, Crop Uptake, and Potential Dietary Risk. Journal of Environmental Quality. Tian, G., O. Oladeji, B. Morgan, E. El-Naggar, A. Cox, H. Zhang, E. Podczerwinski. 2025. Intracellular Carbon Storage of Microorganisms and Resulting C Sequestration in Biosolids-Amended Agricultural Soil. Soil Biology and Biochemistry, 207, 109836. Umar, M., Y. Wang, Q. Huang. 2025. Enzyme Catalyzed Oxidative Humification Reactions (ECOHRs): PFAS Remediation and Thatch Management. Frontiers in Environmental Engineering, 4, 1673461. Umeobi, E.C., T.F. Ducey, N.T. Basta, J.A. Ippolito. 2026. Bioaccessibility-Based Human Health Exposure Assessment of Compost-Amended Heavy Metal-Contaminated Soil. Soil Systems. Umeobi, E.C., T.F. Ducey, N.T. Basta, M.G. Johnson, J.A. Ippolito. 2026. Compost Applications Alter Heavy Metal Speciation and Bioavailability in a Natural and Remediated Contaminated Superfund Soil. Environmental Pollution. Wang, Y., N. Hue, Z.Y. Du, J. Chen, Q.X. Li. 2026. A Sensitive and Simple Method for Trace Analysis of Pesticide Residues in Plant Guttation. Wang, Y., Y. Ji, U. Ghimire, B. Rao, D. Reible, Y. Chen, Q. Huang. 2026. An Analysis on the Fate of PFAS in Still Bottoms During Electrochemical Oxidation with a Ti4O7 Anode. Frontiers in Environmental Engineering. Wekumbura, C., G. Hettiarachchi, W. Hargrove, Q. Ma, M. Newville, A. Lanzirotti, C. Sobin. 2025. Mitigating Lead Bioaccessibility in Metal(loid)-Contaminated Alkaline Soils Using Soil Amendments: Evaluating Efficacy Using In Vitro Bioaccessibility, Sequential Extraction, and Synchrotron Techniques. Journal of Hazardous Materials. Yang, X., F. Hinz, P.C. Wilson, C. Gravesen, J.D. Judy. 2025. Effects of Drinking Water Treatment Residual Amendment to Biosolids on Per- and Polyfluoroalkyl Substances Leachability. JEQ 54(6):1888-1898.   Presentations Florida <ul> <li>Judy, J.D. 2026. PFAS Concentrations and Partitioning Trends in Wastewater and Drinking Water Treatment Wastes. University of Florida Water Institute Symposium, Gainesville, Florida, February 24.</li> </ul> Kansas <ul> <li>Wekumbura, C., G.M. Hettiarachchi1, E. Gutierrez, A.D.E. Mudiyanselage. 2026. Stabilizing Urban Soil Lead: Long-Term Effects of Soil Amendments on Bioaccessibility and Speciation. 23rd World Congress of Soil Science, Nanjing, China. June 7-12.</li> <li>Gutierrez, E.E.B., G.M. Hettiarachchi, A.D.E. Mudiyanselage, J. Murphy, C. Wekumbura. 2025. From Lab to Field: A Comparative Study of Biochar and Phosphorus Amendments for Lead Immobilization in Urban Soils. CANVAS 2025. Salt Lake City, UT. Nov. 9-11.</li> <li>Hettiarachchi, G.M. 2025. Reducing the Risk: Strategies for Minimizing Toxic Trace Element Uptake in Vegetables Grown in Contaminated Urban Soils. CANVAS 2025. Salt Lake City, UT. Nov. 9-11.</li> <li>Mudiyanselage, A.D.E., G.M. Hettiarachchi, C. Wekumbura, R. Kumarasinghe, E. Gutierrez Britto, J. Murphy. 2025. Mitigating lead poisoning in urban residential soils through reducing bioaccessibility. CANVAS 2025. Salt Lake City, UT. Nov. 9-11.</li> <li>Wekumbura, C., G.M. Hettiarachchi, E.E. Gutierrez Brito, A.D.E. Mudiyanselage. 2025. Efficacy of phosphorus amendments on reducing soil lead risk: A comparison of routine vs. bioaccessibility assays. CANVAS 2025. Salt Lake City, UT. Nov. 9-11.</li> <li>Hettiarachchi, G.M., N. Basta, J. Ippolito. 2025. Mitigation of human health risk in urban neighborhoods through bioavailability-based approaches. International Conference on Biogeochemistry of Trace Elements/ International Conference on Heavy Metals in the Environment. Busan, South Korea, Sep. 22-26.</li> <li>Hettiarachchi, G.M. 2026. Strategies for Minimizing Toxic Trace Element Uptake in Vegetables Grown in Contaminated Urban Soils. School of the Environment, Henan University of Technology. Presented online from the Institute of Soil Science, Chinese Academy of Sciences, June 10.</li> </ul> Nebraska <ul> <li>Fossum, B., A. Malakar, M. Kaiser. 2025 Soil Carbon Dynamics Following Application of Biochar to a No-till Corn-Cover Crop-Soybean System Assessed Using Physico-Chemical Fractionation and Stable Isotope Ratios. CANVAS 2025, Salt Lake City, Utah.</li> <li>Fossum, B., A. Malakar, M. Kaiser. 2025. Acre-Scale Application of Biochar and Biosolids and Impacts on Nutrient Dynamics. CANVAS 2025, Salt Lake City, Utah.</li> <li>Kaiser, M., B. Fossum, K. Koehler-Cole, A. Malakar. 2026. Effect of biochar and cover crops on soil carbon sequestration revealed by the amount and isotopic signature of particulate and mineral-associated organic matter fractions. 10th International Symposium on Soil Organic Matter, Sao Paulo, Brazil. May 25-29.</li> <li>Fossum, B., A. Malakar, M. Kaiser. 2026. Enhanced nutrient retention following biochar application linked to biochar surface functionalization through a common mechanism across management conditions. 10th International Symposium on Soil Organic Matter, Sao Paulo, Brazil. May 25-29.</li> </ul> Ohio <ul> <li>Reid, M.T., N.T. Basta, A.P. Dacres, M.S. Gonzalez-Serrano, A.M. Zearly. 2026. An approach to incorporate soil Pb bioavailability in ERA by including diet in a novel avian in vitro gastrointestinal assay. SETAC Europe 36th Annual Meeting, Maastricht, The Netherlands, May 17–21.</li> <li>Ippolito, J. 2026. PFAS in agricultural systems. Wisconsin Department of Natural Resources PFAS External Advisory Group meeting. Virtual. August 21.</li> <li>Hu., X., J. Ippolito. 2026. Connections between biosolids land application, PFAS soil and plant accumulation, and soil health. W5170 National Workgroup Annual Meeting. Albany, NY. July 12-14.</li> <li>Hu, X., C.M. Buchanan, S.W. Blecker, A. Wang, K. Xia, S. Hao, J.A. Ippolito. 2026. The nexus between biosolids land application, PFAS soil accumulation, and plant uptake from a soil health perspective. Midwest Biosolids Association’s 3rd Annual Conference. Milwaukee, WI. June 8-10.</li> <li>Hu, X., C.M. Buchanan, S.W. Blecker, A. Wang, K. Xia, S. Hao, J.A. Ippolito. 2026. Tracking PFAS in soil and plants following short and long-term biosolids land application. Midwest Biosolids Association’s 3rd Annual Conference. Milwaukee, WI. June 8-10.</li> <li>Hu, X., C.M. Buchanan, S.W. Blecker, A. Wang, K. Xiz, S. Hao, J.A. Ippolito. 2026. The nexus between biosolids land application, PFAS soil accumulation, and plant uptake from a soil health perspective. OSU College of Food, Agriculture, and Environmental Sciences. April 9.</li> <li>Ippolito, J. 2026 PFAS in agricultural soils. 2026 Ohio Certified Crop Advisor Virtual Meeting. February 11.</li> <li>Chou, E., Y. Wang, L. Li, H. Li, J.A. Ippolito. 2025. Quantifying and comparing PFAS transport within short-term biosolids application containing varying levels of PFAS concentrations. CANVAS conference. Salt Lake City, UT. November 9-12.</li> </ul> Pennsylvania <ul> <li>Kosiarski, K. 2026. Evaluating Riparian Buffer Zone Effectiveness on Mitigating PFAS from Biosolids-Amended Fields. W5170 National Workgroup Meeting, Albany Marriott, Albany, NY. July 12-14.</li> <li>Pannella, D. 2026. "PFAS Uptake in Hemp and Orchard Grass: Effects of Biosolids and Variable Contamination Levels," W5170 National Workgroup Meeting, Albany Marriott, Albany, NY. July 12-14.</li> <li>Kosiarski, K., H. Preisendanz. 2026. Evaluating Riparian Buffer Zone Effectiveness on Mitigating PFAS Transport from Biosolids-Amended Fields. Chesapeake Community Research Symposium, Annapolis, MD. June 1-3.</li> <li>Pannella, D., H.E. Preisendanz, P.J. Drohan. 2026. PFAS Occurrence in Pennsylvania Urban Farm Soils. Pennsylvania Groundwater Symposium, Penn State Extension, Harrisburg, PA. May 5.</li> <li>Kosiarksi, K., T.L. Veith, F.A. Kibuye, J. Fetter, S. Boser, J.P. Vanden Heuvel, C.L. Thompson, H.E. Preisendanz. 2026. Environmental and Socioeconomic Factors of PFAS Contamination in Private Drinking Water Wells: Insights for Monitoring and Management.” Emerging Contaminants in the Environment Conference (ECEC26), University of Illinois Champaign-Urbana, Champaign, IL. April 27-30.</li> <li>Pannella, D., H.E. Preisendanz, P.J. Drohan. 2026. PFAS Occurrence in Pennsylvania Urban Farm Soils. PFAS Workshop, Penn State Extension, University Park, PA. April 1.</li> <li>Pannella, D. 2025. Assessing PFAS Dynamics and Phytoremediation Capacity of Hemp and Orchard Grass, Student Presentations of Research Projects: SOILS 590, Department of Ecosystem Science and Management: Penn State University, University Park, PA. December 17.</li> <li>Preisendanz, H.E. 2025. PFAS occurrence, transport, and impact in agroecosystems. Water Quality Insights Webinar Series, Penn State Extension, Virtual Webinar. November 21.</li> <li>Preisendanz, H.E. 2025. PFAS occurrence, transport, and impact in agroecosystems. Mid-Atlantic Crop Management School, University of Maryland Extension, Ocean City, MD. November 18.</li> <li>Kosiarski, K., H.E. Preisendanz. 2025. Evaluating riparian buffer zone effectiveness on mitigating PFAS from surface runoff. CANVAS Conference, Soil Science Society of America, Agronomy Society of America, and Crop Science Society of American, Salt Lake City, UT. November 17.</li> <li>Pannella, D. 2025. PFAS Uptake and Allocation in Orchard Grass and Hemp – Phytoremediation Assessment. CANVAS conference (ASA, CSSA, SSSA International Annual Meeting), Salt Lake City, UT. November 17.</li> </ul>  Theses and Dissertations Florida <ul> <li>Amber Lopez, Undergraduate Honors Thesis, Microplastics Detection in Drinking Water Treatment Residuals. </li> <li>Xinya Yang, M.S. Research on PFAS Retention-Release in Biosolids. </li> <li>Neveah Renwick, M.S. Thesis on Phosphorus Mobility and Soil Amendments. </li> </ul> Kansas <ul> <li>Murphy. Lead in Kansas City Soils: Lead Source Tracking and Assessment of Wastewater-Derived Phosphate for Fertilization and Lead Remediation.</li> <li>Gutierrez Brito. Geochemical Mechanisms of Lead Stabilization in Phosphate-Amended Urban Soils and Prediction of Physicochemical Properties Using Proximal Soil Sensors.</li> </ul> Nebraska <ul> <li>Britt Fossum. Combining Biochar Application with Sustainable Agricultural Management Practices to Increase Soil Carbon Retention and Resource Efficiency in Agro-Ecosystems.</li> </ul> Ohio <ul> <li>Adriana Dacres. Soil Carbon Dynamics Shaped by Ecological Gradients, Biochar-Based Lead Remediation and Forest Restoration.</li> <li>Ying-Ren Lai. Soil-Amendment Controls on Phosphorus Retention, PFAS Mobility, and Arsenic Remediation Under Varying Redox Conditions.</li> </ul>  Technical Reports, New Releases, and Others <ul> <li>Brown, S. 2025. We Can Fix What We've Broken. <a href="https://www.biocycle.net/connections-we-can-fix-what-weve-broken/">https://www.biocycle.net/connections-we-can-fix-what-weve-broken/</a></li> <li>Brown, S. 2025. User's Guide to Risk Analysis. <a href="https://www.biocycle.net/connections-users-guide-to-risk-analysis/">https://www.biocycle.net/connections-users-guide-to-risk-analysis/</a></li> <li>Brown, S. 2025. Failing Grade. <a href="https://www.biocycle.net/connections-failing-grade/">https://www.biocycle.net/connections-failing-grade/</a></li> <li>Brown, S. 2026. Can Worms Destroy Pathogens During Composting? <a href="https://www.biocycle.net/can-worms-destroy-pathogens-during-composting/">https://www.biocycle.net/can-worms-destroy-pathogens-during-composting/</a></li> <li>Brown, S. 2026. More Nutrient Cycling, Less Footloose. <a href="https://www.biocycle.net/more-nutrient-cycling-less-footloose/">https://www.biocycle.net/more-nutrient-cycling-less-footloose/</a></li> <li>Brown, S. 2025. How to Measure Soil Carbon Storage. <a href="https://www.biocycle.net/how-to-guide-to-measure-soil-carbon-storage/">https://www.biocycle.net/how-to-guide-to-measure-soil-carbon-storage/</a></li> <li>Brown, S. 2025. How Much Nitrogen is on the Compost Menu? <a href="https://www.biocycle.net/connections-how-much-nitrogen-is-on-the-compost-menu/">https://www.biocycle.net/connections-how-much-nitrogen-is-on-the-compost-menu/</a></li> <li>Brown, S. 2025. Compost and Crime. <a href="https://www.biocycle.net/connections-compost-and-crime/">https://www.biocycle.net/connections-compost-and-crime/</a></li> <li>Brown, S. 2026. Soil and Compost Matching. <a href="https://www.biocycle.net/soil-and-compost-matching/">https://www.biocycle.net/soil-and-compost-matching/</a></li> <li>Brown, S. 2026. Compost Testing vs. Soil Testing Comparison. <a href="https://www.biocycle.net/compost-testing-vs-soil-testing-comparison/">https://www.biocycle.net/compost-testing-vs-soil-testing-comparison/</a></li> <li>Brown, S. 2026. Methane Yield from Anaerobic Digestion of Food Waste. <a href="https://www.biocycle.net/methane-yield-anaerobic-digestion-food-waste/">https://www.biocycle.net/methane-yield-anaerobic-digestion-food-waste/</a></li> </ul>

Impact Statements

The collective accomplishments of W5170 generated significant impacts: Improved understanding of PFAS occurrence, transport, bioavailability, and remediation; Expanded scientific foundations for PFAS risk assessment and policy development; Demonstrated long-term carbon sequestration benefits from biosolids application; Advanced nutrient recovery technologies supporting circular resource management; Improved soil health, crop productivity, and farm profitability; Reduced environmental risks associated with urban contaminants and heavy metals; and Expanded stakeholder engagement through extension, outreach, workshops, and community-science initiatives.