Brief Summary of Minutes of Annual Meeting

W 4170 2022 Business Meeting Minutes

Location: UC Riverside, 301 Science Laboratories

Date: 06/05/2022, 4:00-5:40 pm

Participants: Maria Silveira (Chair), Patrick Dube, Guanglong Tian, Kang Xi, Ian Pepper. Gene Kester, Nicole Dennis, Andrew Gary, Jim Dunber, Sally Brown, Linda Lee, Jay Gan, Jon Judy, Hui Li, Kiranmayi Mangalgiri (virtual), Ganga Hettiarachchi (virtual), Nicolas Baste (virtual)

W4170 appreciates Greg Evanylo for his long-time involvement, service, contribution and leadership of W170, W1170, W2170, W3170 and W4170. Sally Brown will take a leadership role in the arrangement.

State reports

Currently, only five state reports have been received. Maria Silveira will send follow-up email reminders in the coming two weeks, or to individual state leader.

Research-based webinars

In the coming year, W 4170 will organize three quarterly webinars on the topics of (1) Urban environment, led by Sally Brown and Ganga Hettiarachchi, (2) PFAS, led by Linda Lee and Hui Li, and (3) Soil health, led by Jim Ippolito.

Extension/Outreach

The activities will include share of literature library, involvement of reginal biosolids associations, and communications with industrial stakeholders, farmers and PFAS-impacted communities. Sally Brown will take the lead in revising the letter to USDA administration on the issues of land application of biosolids.

W4170 shows interest in working with USDA LTAR Manureshed Working Group by adding the sites receiving biosolids.

W4170 2023 annual meeting will be held at Chicago from June 26 to 28, 2023. Guanglong Tian will host the annual meeting.

Objective #1-  Evaluate the short- and long-term fate, bioavailability and persistence of trace organic contaminants (TOrCs) with an emphasis on per- and polyfluoroalkyl substances (PFAS) 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 TOrCs in residuals, wastewaters and residuals- and wastewater-treated soils (e.g., agricultural, urban and brownfields); ii) Predict the long-term bioavailability, persistence and toxicity of TOrCs in residuals- and wastewater-amended soils; iii) Evaluate ecological effects of TOrCs 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 AZ, CA, FL, GA, IN, KS, MI, OH, PA, VA, WA.

       Per- and polyfluoroalkyl substances (PFAS)

       Researchers from numerous states (AZ, FL, IN, MI, FL, PA) performed laboratory and field studies quantifying the occurrence, persistence, fate and human health effects of PFAS. Studies to date also highlight the importance and magnitude of perfluoroalkyl acid (PFAA) precursors such as the polyfluoroalkyl phosphate esters (diPAPs) initially present in biosolids and their contribution to long term leaching of PFAAs from land-applied biosolids.

       Data from seven municipal water resource recovery facilities in IN indicated that fifty-four PFAS were quantified in biosolids with concentrations ranging from 323 ± 14.1 to 1100 ± 43.8 μg/kg (dry weight basis), of which > 75% of the fluorine moles from these PFAS were associated with precursors. Di-substituted polyfluorinated phosphate esters (diPAPs) were the most abundant PFAS precursors identified. The total oxidizable precursor assay on biosolids extracts generally failed to quantify the amount of precursors present, in large part due to the fact that diPAPS were not fully transformed during the TOP assay. Improved methods for PFAS determination in biosolids are also currently being evaluated by the IN team.

       In PA, researchers evaluated 20 PFAS compounds in wastewater influent, effluent, and in 13 groundwater monitoring wells at the Penn State “Living Filter”, which has been spray-irrigating treated wastewater at the site for 40 years. The most frequently detected PFAS in the effluent were short-chain PFCAs, including PFBA, PFHxA, and PFHpA. PFOA+PFOS levels in the groundwater monitoring wells did not exceed the EPA’s 70 ng/L health advisory levels, but 7 of the wells did have levels that exceeded the PA DEP’s proposed drinking water standards.

       A collaborative project in IN and FL indicated that mixing biosolids with sorbents such as aluminum chlorohydrate water treatment residuals or biochars or blending biosolids with other organic-rich low PFAS-containing material could mitigate PFAS in biosolids. Similarly, a collaborative study (IN and VA) evaluated PFAS leaching from biosolids and a biosolids-mulch blend applied to an artificially constructed land-reclamation site showed that dilution of PFAS loads in the biosolids-mulch blend generally translated to reduced PFAS concentrations in the leachate PFAS-specific trends are being evaluated in more detail, but data are consistent with the idea that blending biosolids to dilute PFAS loads may be a reasonable solution, at least in the short term, for mitigating potential impacts PFAS in biosolids on water quality. Wastewater treatment process has also been reported to correlate with PFAS portioning in biosolids. For instance, research in FL demonstrated that PFAS partition coefficients in biosolids were highly variable (~10 to 20,000 L kg^-1) and dependent on both PFAS and wastewater treatment process.

      Similar work focused on the impacts of exchangeable cations in soils on sorption of perfluoroalkyl acids (PFCA) is also currently being conducted in MI. A meta-analysis revealed that sorption of PFAS could not be described singularly as the partitioning in soil organic matter. Divalent cations such as Ca²⁺ in aqueous solution could enhance PFAS sorption. To test this hypothesis, the MI group evaluated the relative contributions of partitioning in SOM and cation-bridging interaction to sorption of PFCAs by soils. Results suggested that in natural soils, divalent cation Ca²⁺ is predominant at cation exchange sites in moderately weathered soils, and trivalent cations Fe³⁺ and Al³⁺ are abundant in highly weathered subtropical and tropical soils, the potential contributions of cation-bridging interaction to sorption of PFCAs could be substantial, which could influence PFCA fate and transport in the environment.

       A short-term (6 month) mesocosm study in IN showed sustained PFAS leaching during the experimental period. Perfluoroalkyl acid concentrations in leachate, when detected, typically ranged in the 10  to 100 ng/L; no diPAPs were detected in the leachate. The PFAA leaching from the biosolids exceeded the PFAA mass initially present in the biosolids due to precursor degradation.

       A new study was initiated in MN in cooperation with the Minnesota Pollution Control Agency and Texas Tech University to determine the fate and transport of PFAS and their breakdown products following land application of biosolids and food waste compost. PFAS concentrations and their breakdown products in soil, tissue, and water samples will be monitored.

       Multiple states are currently working on PFAS toxicity studies. For instance, researchers in IN are currently evaluating the effect of PFAS on ecotox and human health. Results showed that PFAS concentrations in biota are elevated above those measured in a nearby wetland receiving runoff and discharge from agricultural lands not receiving biosolids or wastewater. In FL, a study examining trophic transfer of PFAS within a simulated terrestrial food chain (tomato à tobacco hornworm) indicated that while patterns of uptake and elimination were similar between different PFAS, PFOS bioaccumulated in the hornworms to a higher concentration, featuring approximately 5-fold higher assimilation efficiency than other PFAS tested. Results suggest that although recently published work has demonstrated that shorter chain PFAS are more readily accumulated in plants, shorter-chain PFAS may also be more readily eliminated by higher trophic level consumers. 

      Research in PA showed that PFAS are entering livestock feed due to elevated levels of short-chain PFAS compounds in corn silage and fescue grown at a site where treated wastewater is spray-irrigated, and suggest that more research is needed to understand the impacts of wastewater irrigation activities on livestock feed quality, with potential implications for human health (meat and milk consumption).

      Research efforts have also been placed on evaluating PFAS presence in rural well water supplies. Research team from IN and PA team conducted a collaborative study involving nearly 70 homeowners. Results showed no wells contained PFOS+PFOA concentrations that exceeded EPA’s 70 ng/L health advisor levels, and one well exceeded the PA DEP’s proposed drinking water standards, suggesting that biosolids applications do not pose an elevated risk to groundwater used as a potable water to supply for homeowners in rural areas.

       Antibiotics

       Rainfall simulation studies were conducted in VA to evaluate the impact of manure application on the absolute abundance (CFU/mL/g) of antibiotic-resistant fecal coliform bacteria (ARFCB) and antibiotic resistance genes (ARGs) in surface runoff and soils. Data showed that when preferential flow represented less than 15% of the total water flow, solute transport to lysimeters was similar, regardless of antibiotic affinity for soil. When preferential flow exceeded 15%, however, concentrations were higher for compounds with relatively low affinity for soil. Natural spectrum preferential flow should be considered as an explanatory variable to gauge the influence of soil matrix-solute interactions and may improve parsimonious transport models for antibiotics in soils.

       Pathogens

       In KY, researchers are working on developing comprehensive methods to determine pathogen concentrations in biosolids. Reference Sequencing (RefSeq) is currently being evaluated as an alternative approach. Research efforts in GA are also focused on developing and evaluating treatment strategies of residuals and wastewaters to reduce contaminant and pathogen loads. Main emphasis has been placed on the development of novel technologies to address the few constituents limiting the beneficial reuse of biosolids, particularly electrochemical approaches and enzyme-based processes to remove hormones, antibiotics and per- and polyfluoroalkyl substances (PFASs). 

       Coronavirus, pharmaceuticals, and substance of abuse surveillance

       During the COVID-19 pandemic, evidence began to grow that the novel coronavirus, SARS-CoV-2, is shed through feces and therefore enters the wastewater stream. The PA team provided wastewater surveillance data to four wastewater treatment plants in the PA. Surveillance data were shared with facility operators within 48 hours of sample collection, enabling the communities to track increases and decreases, particularly of the virus, in near-real time. These data have been utilized, along with other indicators, to understand the prevalence of disease within the community over the past year. Further, the data have been particularly useful to the Department of Corrections in knowing when transmission has been high and low at their facility.  Surveillance efforts in PA are ongoing.

       Researchers in VA evaluated the occurrence of opioids in wastewater treatment plant influent, effluent, and biosolids. Results showed all 13 opioids were detectable in all samples. The team estimated that the average daily drug usage/1000 people in the communities ranged from 0.64 g/day/1000 people – 5.92 g/day/1000 people.

       Metals

       A recently completed study in FL examining how different soil nutrient tests correlate with various lead bioavailability tests in a variety of lead contaminated soils indicated that bioavailable lead (determined via a diverse suite of relatively inexpensive and accessible soil nutrient test methods) was correlated with bioaccessible Pb (determined via specific in vitro lead bioavailability tests).

       Research in KS continued to investigate the use of high-Fe biosolids amendments for in situ stabilization of Pb contaminated alkaline soils collected from El Paso neighborhoods. Results from this study demonstrated that high-Fe biosolids amendments help to reduce bioaccessibility of lead in alkaline soils that are not responding effectively to conventional phosphorus fertilizer treatments.

       In NE, researchers are evaluating the utility of ferrihydrite soil amendment to reduce plant uptake of arsenic and uranium. Soils that received ferrihydrite showed that greater plant dry biomass and less arsenic and uranium concentrations in plant tissue.

       Other unregulated organic contaminants

       The IN team is leading a new, collaborative field study recently initiated at 2 biosolids-field sites in California.  PFAS and other unregulated organic compounds are or will be assessed at these sites over time. Initial monitoring well, soil and biosolids samples have been taken and are currently being analyzed.

Objective 2: Objective 2 of the project: 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 (TOrCs and metals/metalloids) availability, assimilation, phytotoxicity, and remediations. Research on this topic was conducted by members from AZ, CO, FL, HI, KS, MS, NE, OH, PA, VA, WA.

       Soil health and soil carbon benefits

       Land application of biosolids has been associated with multiple agronomic and environmental benefits; however, the intimate association between biosolids use and soil health has not been adequately addressed. Research in CO continues to demonstrate soil health benefits associated with long-term land application of biosolids to agroecosystem. Results demonstrated that biosolids application at agronomic rates has greater, positive impact on soil health than inorganic fertilizer. These findings help assure that biosolids land application in the western US is a positive attribute for municipalities with land application programs (e.g., Denver Metro Wastewater; the South Platte Renew). The CO team has also partnered with the Soil Health Institute, and Washington State University to further evaluate soil health in long-term agroecosystem research plots. Results from this effort indicated that biosolids increases long-term soil C accumulation with subsequent positive impacts on soil health. Research is also focused on evaluating the potential impacts of biosolids on soil microbial community function and structure. Research in CO also demonstrated that biosolids application (rates of 10 Mg ha^-1) to overgrazed, western US rangelands improves soil health without negatively compromising above-ground plant community structure/function.

      Collaborative research among CO, OH, and WA continues to evaluate biosolids land application in mine land contaminated with heavy metals, with a specific focus on soil health and plant health.  Results showed that although biosolids can improve mine land soil health and reduce plant-available heavy metals, above-ground plant tissue metal concentrations still may be greater than acceptable for browsing animals. The research team is working towards including soil heavy metal concentrations into an overall soil health program.

     Water quality

      In addition to the multiple agronomic benefits, biosolids offer several environmental advantages compared with inorganic fertilizers because nutrients are less soluble and, therefore less likely subject to losses. Research in FL demonstrated that long-term biosolids application reduced P leaching compared with control treatments, mainly due the addition of Fe and Al with biosolids and subsequent positive effects on soil P storage capacity. A field study in FL evaluating the impacts of new FL rule (62-640, Florida Administrative Code) on crop performance, soil health, and water quality responses demonstrated that reduced (P-based) biosolids rates were unable to supply adequate amounts of N and other essential nutrients to sustain adequate crop production. Land application of biosolids applied at P-based rates are practical or economically feasible for farmers, and will result in the loss of a valuable resource.

      A new research project in VA is evaluating physical and chemical properties of commercial biofiltration soil media currently utilized in stormwater BMPs and urban tree planter applications. Active work also includes preliminary column simulation studies of net elution vs. removal of N and P forms from simulated stormwater additions.

      Wastewater

      A study in TX evaluating the use of treated wastewater for irrigation of romaine lettuce indicated that AP205 bacteriophage (used as a pathogen surrogate) increased in foliage, leachate, and soil during lettuce cultivation. Although levels decreased during post-harvest storage, this suggests potential health risks from leafy greens grown with treated wastewater. A second project investigated use of photocatalytic disinfection for treatment of irrigation water. Ongoing work is further investigating the potential for enhancing recovery and reuse of nanomaterial catalysts in these systems. Furthermore, as part of a USDA-funded Research and Extension Experiences for Undergrads program on Reuse Water Quality, eleven undergraduate students from multiple universities were trained on advanced water treatment and reuse in summer 2022. A textbook on Principles and Applications of Soil Microbiology was also published.           

      Climate change mitigation

      Land application of biosolids can increase soil organic matter and help mitigate greenhouse gas emissions. Despite the vast literature on the agronomic value of biosolids, there is still limited information on its potential benefits on soil carbon sequestration potentials. Understanding the impact of biosolids end use on C emissions can help municipalities achieve C neutrality. A systematic literature review and meta-analysis was conducted in VA to quantify carbon sequestration potential of land-applied biosolids. The VA team reported growing evidence that biosolids may be used to restore mine soils in VA. The VA team continue to monitor an experiment on reconstructed Appalachian mine soils where biosolids were applied at rates of 22 to 224 Mg/ha in 1982. Over the past year, the team has improved a method to determine and eliminate the interference of both carbonates and trace coal fragments in these mine soils that will greatly enhance our ability to accurately calculate effects of the original treatments on long-term C-sequestration rates. They have also statistically confirmed >35-year positive effects of biosolids on mine soil CEC, plant available P, cations, essential micronutrients, and total C. However, overall net C-sequestration rates are much lower (e.g. ~0.25 Mg/ha/yr) than commonly reported in the coal mined land reclamation literature.

       Biochar studies

       Biochar is a solid material high in stable carbon, which is obtained from the thermochemical treatment (pyrolysis) of biomass (e.g., crop residue, discarded wood, animal waste) in an oxygen limited environment. Members of W4170 in CO, FL, HI, and NE continue to study land application biochar on heavy metal mitigation, soil health, carbon sequestration, nutrient availability, and crop productivity. Although biochar has been suggested as an approach to enhance carbon storage and to improve soil functioning, biochar characteristics and related improvements of soil functioning are variable depending on biochar production conditions. In a meta-analysis, the NE team reported that pyrolysis temperature and feedstock impacted biochar characteristics. Targeted production of biochar with specific characteristics can be facilitated by the selection of pyrolysis temperature and feedstock type.

       A field study conducted in Maui, Hawaii demonstrated biochar applied at 10 ton/ha increased crop production in nutrient-poor, highly weathered soils. Similar efforts are also being conducted in NE where researchers are evaluating the use of biochar in no-till corn-soybean cropping systems.

      Biochar has also been suggested as an effective remediation strategy. Research in PA evaluated the effectiveness of biochar to remove four pharmaceuticals from aqueous solution. Biochar produced from cotton gin waste was able to effectively remove docusate, whereas the walnut shell biochar removed acetaminophen and sulfapyridine better than the cotton gin biochar. Both biochars removed ibuprofen at similar efficiencies. The PA team is currently evaluating three pre-treatment options to improve performance of the biochar.

      Collaborative research in KS focused on improving the recovery Ca-P products from simulated swine wastewater indicated that anaerobic membrane bioreactors and associated technologies are viable strategies to generate secondary Ca-based P fertilizer sources that can be reused in agriculture.

Beneficial reuse of manure and other organic residuals

      A newly funded research and extension project in NE is evaluating the impact of integrated manure and inorganic fertilizer management on nitrogen use efficiency, water quality, and soil health. In PA, a manureshed-based approach using the Soil and Water Assessment Tool (SWAT) evaluated manure management strategies in the Susquehanna River Basin. Results from this effort showed lower N and P loads in the major sub-basins of the Susquehanna River Basin compared to crop N-demand baseline scenarios.

       In MN, a three-year study evaluated the effectiveness of sewage sludge incinerator ash has been completed.  The findings support SSA as a potential slow-release P fertilizer source for crop production. Landfill costs could be eliminated, and area farmers would be able to use the ash as a renewable source of P in addition to other residuals such as biosolids and struvite. As a result of this research, the Metropolitan Council has developed the “Smart Ash” project to explore regulatory issues with the Minnesota Pollution Control Agency related to land application of the ash as a P fertilizer source. 

      Urban soils

      Urban agriculture in general and community gardens in particular, have the potential to provide a wide range of direct and indirect benefits including improved diets and increased physical activity for direct participants.  Indirect benefits include reduced crime and increased real estate values in neighborhoods around the gardens.  These gardens also provide an excellent opportunity for use of residuals- based soil amendments.

      Soil health has recently been a focus of research in agronomic systems. However, with the growth of urban agriculture and the ready availability of a range of residuals -based soils and soil amendments in urban areas, it is pertinent to consider soil health in an urban context.  Research in WA evaluated the impact of two biosolids-based products and a vermicompost from food scraps in both field trials and a greenhouse study. Yield and nutrient uptake of a range of vegetable crops (including carrots, broccoli, kale and swiss chard) were evaluated.  In the most disturbed urban soil, fertilizer alone was only able to support minimal growth for some of the crops. All organic amendments showed high yield with increases over the control for certain nutrients. Soil properties (e.g., total C and N, active C, bulk density, water infiltration rates and Mehlich III available nutrients) also improved as a result of amendment addition.  For highly fertile, non- disturbed soils, the amendments generally performed slightly worse than synthetic fertilizer for plant yield.  However, improvements in soil characteristics including increased C and N and water infiltration were observed.

      An investigation of soil from vacant lots in Cleveland found 25% exceeded the 400 mg/kg Pb regulatory soil screening level. In older cities with longer industrial histories, Pb pollution tends to be more widespread and severe. Exposure to soil Pb results in health risks to human and ecological receptors. Human health risks are highest in children, who have high rates of incidental soil ingestion and can develop permanent neurological impairment from Pb exposure. In many communities, prohibitory expensive remediation costs have resulted in inaction and exposure of another generation of children to legacy Pb.  To address this concern, research in OH was focused on using inexpensive biosolids incinerator ash as an inexpensive Soil amendment to improve urban soil. An interdisciplinary project was initiated in 2021 with the goal of establishing demonstration plots on vacant land in Slavic village in Cleveland, OH, which was one of the hardest hit areas during the 2008 economy collapse. The soil was contaminated with lead and a four soil blends made from local byproducts (Lake Erie Dredge, high Fe biosolids incinerator ash and biosolids compost) were applied to vacant lots. Plots were seeded with a native plant blend designed for pollinators. Researchers will be evaluating the success of these treatments in Summer 2022. The OH research team is hoping this novel approach will be used a prototype for other urban areas. This project is also expected to break the exposure to legacy soil Pb that has damaged the population, especially children, in the Cleveland area. Similar work is ongoing in Kansas City vacant and residential lots in residential neighborhoods, using P and other soil amendments, including class A biosolids, to reduce bioaccessible Pb in urban soils.