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W2170: Soil-Based Use of Residuals, Wastewater and Reclaimed Water

Annual/Termination Reports (SAES-422): [06/25/2010] [08/04/2011] [08/07/2012]

Date of Annual Report: 06/25/2010

Report Information:
  • Annual Meeting Dates: 06/06/10 to 06/08/10
  • Period the Report Covers: 10/2009 to 09/2010

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    1. New Project and Group Project Report - Greg Evanylo gave an update on the status of the new project. He reminded members to submit their 2009 project reports. He mentioned that instead of distributing hard copies, the reports and presentations will be posted on the NIMSS website. George OConnor mentioned that some reports and presentation that are not yet published should not be placed on the website for open distribution to the public.

    2. Communication - Greg Evanylo advised that if we need to send sensitive information to the W2170 members, it should not be sent to the listserv, since there are many non-members on the list. Information should be sent via email to Greg or Sally Brown for posting. Lakhwinder Hundal suggested that posting presentations to the web should be optional. Paul Schwab promised to develop a website at the 2009 annual meeting, but that has not yet been done.

    3. Update from Project Directors Lee Sommers  Lee gave an update on potential support under National Institute of Food and Agriculture (NIFA). One change in leadership is that Rajiv Shah is no longer the USDA Chief Scientist and will be replaced by NIFA Director Roger Beachy. Lee recommended New Biology for 21st Century as a publication to best describe NIFAs research emphasis, which focuses on climate change, bioenergy, food safety, nutrition, and global food security. Grants will be mostly multi-year and multi-discipline. W2170 members need to be creative to determine where their disciplines fit. George OConnor asked if the Land Grant institutions were given opportunity to contribute to the development of NIFA priorities. Lee Sommers stated that the approach, borrowed from NIH, included experiment station input.

    4. USEPAs Risk Assessment of 135 Pollutants - Bob Brobst suggested that the group should seek opportunities for collaborative research to get data to be used in the risk assessment model. EPA will need to fill data gaps and evaluate the risk assessment algorithms for accuracy. George OConnor said that these issues have been discussed several times and we need to look at the models critically to establish more confidence in any numeric standards. Bob Brobst confirmed that this is the opportune time for the group to be involved in the process.

    5. Current State and National Topics of Interest  Albert Cox reported on MWRD-Chicago together with Illinois Water Environment Association is working on an initiative to develop a state-wide biosolids network in Illinois. The goal of the biosolids network is to develop a forum for municipalities and other stakeholders to unify approaches to land application, improve communication of public relations issues, and develop a common approach to minimize and address public relations issues. A kickoff workshop will be held in August 2010.

    6. Future Meetings  Chip Elliott stated that Penn State will host the 2011 meeting. Most participants agreed that the best time for the meeting will be between the third week of May and mid June. Greg reminded that one of the reasons for moving the meeting to spring was to include field trips, and we need to advantage of those opportunities in the future. It was suggested that it will be best to plan field trips at the end of the technical meeting. Tentative venues for future meetings are Seattle (2012) and Denver (2013).

    Technical Meeting Agenda:

    Mon, June 7; MWRDGC Lawndale Avenue Solids Management Area (LASMA) 8:00 USEPA's rationale for how they plan to evaluate the most recent 135 inorganic and organic pollutants from the TNSSS: Overview, process, and drivers, Rick Stevens, EPA OST Biosolids Coordinator Data summaries for past and current biosolids surveys, Robert Brobst, EPA Biosolids Coordinator, Denver Core risk assessment discussion, data needs and usage, Steve Beaulieu, EPA's Contract Modeler 9:45 Break 10:00 Presentations (cont'd) and facilitated discussion between EPA and W2170 members 11:45 Lunch 12:45 pm Presentation of selected oral state reports dealing with emerging pollutants relevant to the EPA session: Risk assessment data gaps and resulting numerical standards, George O'Connor, Univ of Florida Organic compounds of emerging concern in biosolids and biosolids-amended soil, Kang Xia, Mississippi State Univ 2:15 Break 2:30 Pharmaceutical fate and transport following land application of biosolids, Ed Topp, Agriculture and Agri-Food Canada Steroid hormone runoff from an agricultural field applied with biosolids, Thomas Borch, Colorado State Univ 3:45 Discussion between W2170 and EPA, including leveraging resources with W2170 4:15 Wrap-up/summary Tue, June 8, MWRDGC LASMA 8:00 Further discussion between W2170 and EPA 8:45 Uptake of Pharmaceutical and Personal Care Products by Plants, Kuldip Kumar, MWRDGC 9:15 Foundry sand risk assessment, Rufus Chaney, USDA-ARS Background soil As concentrations and regulatory-mandated remediation, Nick Basta, Ohio State University State reports by W2170 members who would like to share data relevant to the EPA discussion on emerging organic and inorganic pollutants and/or other volunteered presentations on other aspects of biosolids and other residuals 10:00 Break 10:15 State reports by Kirk Scheckel, Carl Rosen, Maria Silveira and Greg Evanylo Noon Adjourn (Transportation to Midway will be provided by the MWRDGC)

    Following EPAs presentation and discussion on the risk assessment process, Greg Evanylo suggested that to collaborate with EPA on the process a committee be commissioned to review the risk assessment model. The individuals who volunteered for this committee were: " Bob Brobst " Chris Higgins " Drew McAvoy " Ed Topp " Ganga Hettiarachchi " George O'Connor " Greg Evanylo " Herschel Elliott " Kang Xia " Kuldip Kumar " Lakhwinder Hundal " Linda Lee " Nick Basta " Rufus Chaney " Tom Borch

    Funding opportunities and collaborations were discussed. Some members asked about EPAs financial assistance for research on emerging contaminants. Rick Stevens agreed to explore funding opportunities, but no concrete actions were promised. The posting/sharing of presentations was discussed. Greg said he would distribute pdfs of speakers modified presentations to those members who attended the meeting.

    Lee Jacobs, retiring Michigan State University participant, offered to any member of the group considerable amounts of a soil that had received rates of high metal-containing sewage sludges from various sources between 1977 and 1986. Lee is willing to fill and have shipped drums of the soil if members will pay the cost of the drums and shipping. A description of the sewage sludges and soils are described in Lee 2008 W1170 annual research summary and journal articles published by Berti and Jacobs in the Journal of Environmental Quality in 1996 and 1998.

    Accomplishments:
    Objective 1: Evaluate the risk-based effects of residual application to uncontaminated (e.g. baseline) soils on chemistry, bioavailability, and toxicity of nutrients and contaminants. University of Minnesota researchers characterized the chemical properties of anaerobically digested biosolids from the Western Lake Superior Sanitary District (WLSSD) in northeast Minnesota at different times during the year to evaluate the effects of freezing and thawing on nutrient composition of biosolids. Ammonium-nitrogen (N) and organic N were lower in May than in September or February. Organic N availability was probably similar at all three times, since C:N ratios did not differ significantly. Total phosphorus (P), soil test Bray P, and sulfate-sulfur (S) were highest in May, suggesting higher amounts of plant-available P and S. Seasonal variability in potassium, calcium, magnesium, and micronutrients was not large enough to have important effects on the nutrient value of the biosolids tested. Concentrations of cadmium, copper, lead, molybdenum, nickel, and zinc varied, but they were consistently below permitted concentrations for exceptional quality biosolids suitable for land application.

    A considerable number of studies have been conducted to assess the availability and chemistry of constituents in biosolids used for mineland reclamation. University of Minnesota researchers measured the release of N and P from WLSSD biosolids under controlled laboratory conditions during a 64-day incubation period. Treatments included a non-amended control, three rates of biosolids, and N+P fertilizer. The middle biosolids rate supplied comparable amounts of available N and P as the fertilizer-based Minnesota Pollution Control Agency (MPCA) guidelines for calculating biosolids rates in soils. Biosolids and fertilizer treatments were tested on two soil types (clay and sandy loam) and fine mine tailings from the taconite industry.

    A regression model was used to estimate potentially mineralizable N and calculate organic N availability from the biosolids. Release of N was similar for the two soils, but N availability was significantly lower from biosolids mixed with mine tailings. This may have been due to reduced biological activity in the mine tailings. The Availability Index for organic N in biosolids was about 27% in the two soils and 17% in the mine tailings. Under the optimum mineralization conditions of this experiment, availability of organic N from biosolids in native soil was greater than the 20% estimate currently used by the MPCA to calculate biosolids rates. Higher rates of biosolids application may be necessary in mine tailings until organic matter and biological activity are stabilized.

    Release of P from biosolids was evaluated by changes in soluble P and the Bray P and Olsen P soil tests. Increases in P measured by these tests in the two soils were generally greater and more rapid from P fertilizer than biosolids. The rate of biosolids applied had little effect on P levels in the clay soil, but changes tended to be greater as the biosolids rate increased in the sandy loam soil. Results suggest greater P fixation in the clay soil. Application of P to mine tailings had no effect on soluble P and Bray P, indicating a very high P fixation capacity in mine tailings. Increases in Olsen P from biosolids and fertilizer were as high in mine tailings as they were in the two soils. Olsen P also increased with increasing biosolids rate. The pH of the mine tailings was 8.5, which is a level where the Olsen P soil test would be recommended.

    University of Minnesota researchers evaluated the effects of WLSSD biosolids on plant growth and uptake of N and P in a greenhouse study. Reed canarygrass was grown for 121 days and harvested twice. Soils, mine tailings, and preplant applications of biosolids and fertilizer were the same as in the Incubation Study, except that an N fertilizer treatment without P was added. In addition, a second application of biosolids or fertilizer was made to one-half of the pots in each treatment after the first cutting. Plant growth increased in both soils and the mine tailings as the biosolids rate increased. Under the conditions of this experiment, the highest biosolids rate was required for maximum yield. This may have been due to different requirements for a greenhouse pot study than a field study, or it could indicate that current N recommendations for Reed canarygrass are too low. Growth for similar treatments was usually higher for the sandy loam soil than the clay soil and higher for the clay soil than for the mine tailings. There were also consistent responses to the additional applications of biosolids and fertilizer after the first cutting. Applying N fertilizer alone resulted in reduced yields in the clay soil and mine tailings, which had low soil test levels for P. Biosolids and P fertilizer were both effective in alleviating this apparent P deficiency. The biosolids rate required for plant growth equivalent to N+P fertilizer was higher for the clay soil than for the sandy loam soil and mine tailings, suggesting that the optimum biosolids rate may vary, depending on where they are applied.

    Tissue N concentrations were highest for plants grown in mine tailings, probably due to growth restriction from inadequate P. Nitrogen concentrations and N uptake for both soils increased as biosolids rates increased and they were higher for treatments receiving additional biosolids after the first cutting. These results are consistent with the growth increases from biosolids and indicate that N availability played a role in these responses. Under the optimum conditions of this study, recovery of plant-available, applied N was similar for N+P fertilizer and the comparable biosolids rate, which supports the validity of MPCA guidelines for calculating biosolids rates in soils. Cooler temperatures in northeast Minnesota may result in lower release rates, but this would have to be validated in field studies.

    The lowest P concentrations and P uptake were in the non-amended controls and the N fertilizer only treatments in the clay soil and mine tailings. These treatments also had the least plant growth, which was consistent with inadequate P being the limiting growth factor. Growth and P uptake generally increased as the biosolids application rate increased, but since the biosolids supplied both N and P this growth response may have been due to N or a combination of P and N. Recovery of the applied, plant-available P from biosolids was greater for plants growing on the sandy loam soil than on the clay soil and greater on the clay soil than on mine tailings. This was consistent with greater P fixation in the clay soil and mine tailings. Phosphorus recovery from fertilizer was less than or equal to P recovery from the comparable biosolids rate in the two soils, but greater from P fertilizer than biosolids in the mine tailings.

    Virginia Tech researchers completed the analysis of soil, water, and biosolids samples from the field study initiated in 2006 at the Iluka mineral sands mine reclamation site in Dinwiddie and Sussex Counties, Virginia to determine whether hybrid poplars (Populus deltoides L. OP367) can be used to assimilate high amounts of deep row incorporated biosolids-applied nutrients with environmentally insignificant N and P leaching during the reclamation of coarse-textured soils. The amount of N lost from the entrenched biosolids was 261803 kg N ha-1, while the fertilizer treatments were not different from 0 kg N ha-1 yr-1 control. Orthophosphate and TKP leached in negligible amounts. Hybrid poplars sequestered up to 3.20±0.54 Mg C ha-1, 71±12 kg N ha-1 and 11.0±1.8 kg P ha-1. Total N lost from the biosolids seams after ~30 months was 15.2 Mg ha-1 and 10.9 Mg ha-1 for lime stabilized (LS) and anaerobically digested (AD) biosolids, respectively, which was roughly 50% of the N applied. Most of the P was Al- and Fe-bound in the AD biosolids and Ca-bound in the LS biosolids. More N2O was produced in the biosolids than in the conventional fertilizer treatments, and N2O production was higher in AD than in LS. Expressed as global warming potentials, N2O emissions from AD (101.5 Mg C ha-1) were 4.6 times higher than from LS and 14.5-16.1 times higher than from the fertilizer treatments.

    In another Virginia Tech study, the prime farmland soil reconstruction experiment established in 2004 at the Iluka Mineral Sands mining site continued to be monitored. The four primary treatments (lime and N-P-K fertilizer only; 15 cm topsoil return over limed and P-fertilized tailings; 75 Mg ha-1 lime stabilized biosolids with conventional tillage; 75 Mg ha-1 lime stabilized biosolids with minimum/no-tillage) were cropped to cotton in 2009. Cotton lint yields in 2009 averaged 1176 kg/ha across the four soil reconstruction treatments, which comprised approximately 75% of adjacent unmined prime farmland control plots. Mine soils that received biosolids in 2004 were slightly higher in yield than unamended controls, but the difference was not statistically significant.

    Penn State researchers completed the fourth year of a field experiment investigating the potential for use of composted or fresh poultry layer manure for mine reclamation and bioenergy production. Reclamation treatments, including conventional lime+fertilizer, composted layer manure, and fresh manure plus paper mill sludge, were applied to an abandoned coal mine site. Switchgrass was established in the second year of the study, and three year stands of switchgrass produced much larger yields with the organic amendments than with the conventional reclamation amendments. Soil carbon accumulation and nitrate leaching was greatest in paper mill sludge plots. Two additional experiments involving similar amendments and 3 warm season grasses was initiated in 2008 on an active mine site.

    In Kansas, two contrasting metal-rich mine-spoil materials were characterized in an incubation study under anaerobic conditions and in the presence of organic C (OC) electron donor using wet chemistry and advanced spectroscopic methods. Solution samples were analyzed periodically for pH, Eh, and soluble constituents. Characterization and speciation of solids samples were performed using scanning electron microscopy-energy dispersive x-ray (SEM-EDX) analysis, ¼-x-ray fluorescence (¼-XRF) maps and ¼-x-ray absorption spectroscopy (¼-XAS). Although the Eh in reaction vessels with no added OC was higher than the vessels with OC added samples, none of the systems showed Eh values below -100 mV. SEM-EDXA analyses of samples submerged for about 110 d showed more C in metal-rich particles (appeared more like precipitates in SE and BSE images) in OC added systems. In contrast, S concentrations in metal rich particles were either non-detectable or very low. The researchers suspect that high carbonate in these geological materials and microbial respiration might have increased bicarbonate concentrations and the formation of metal carbonate solid solutions instead of sulfide solid solutions. Soluble Fe2+ concentrations in samples collected from systems with OC added were significantly higher (23 mmol/L-1) than the OC-unamended samples (~4 mmol/L-1) at 110 d of submergence. Soluble Mn, Pb and Zn concentrations in samples collected from systems with OC added were significantly lower than the OC-unamended samples indicating major differences in transformation products of these two (with and without OC) systems. Micro-x-ray absorption near edge structure (¼-XANES) spectra of selected Zn rich points located by µ- XRF maps, collected at Sector 13 BM (Advanced Photon Source (APS), Argonne National Laboratory, Argonne, IL), on samples submerged for 60 days, showed that OC added samples contained more Zn silicate- and Zn carbonate-like Zn phases as compared to no-OC added samples. Micro-XANES spectra of Pb collected from OC added samples showed varying amounts of Pb sulfide, Pb carbonate and Pb phosphates mixtures while no-OC added samples had Pb sulfide, Pb carbonate, leadhillite (Pb4(SO4)(CO3)2(OH)2). Moreover, m-XANES spectra of selected Fe rich points showed slight but apparent increases in Fe(II) in the C-added geomaterials that had been submerged for 60 days in comparison to the no-OC added samples that had been submerged the same number of days confirming that OC in these materials could be very critical in determining the rate of sample reduction. Moreover, soluble Fe2+ concentrations in samples collected from systems with OC added were significantly higher (~23 mmol/L-1) than the no-OC added samples (~4 mmol/L-1 ) both at 75 days and at 110 days of submergence and thereafter both systems consistently showed very low soluble Fe2+ concentrations. This could be due to formation of Fe(II) oxides, phosphates and/or sulfides in these samples. In contrast soluble Mn, Pb and Zn concentrations in samples collected from systems with OC added were significantly lower than the no-OC added samples. Preliminary data supports our argument that dissolved OC, in percolating water could have a significant impact on biogeochemical cycling of trace elements.

    Past use of arsenical pesticides has resulted in elevated levels of arsenic (As) in some Hawaii soils. Total As concentrations of 50 -100 mg/kg are not uncommon, and can exceed 1,000 mg/kg in some former sugarcane lands. Given the high content of amorphous aluminosilicates and iron oxides in many Hawaii soils, a high proportion of soil As seemed to associate with either these solid phases or with organic matter. Adding phosphate fertilizer or compost increases As bioaccessibility, whereas adding Fe(OH)3 decreases it. Brake fern (Pteris vittata L.) could be used to remove some soil As. Concentration of As in fern fronds varied from approximately 40 mg/kg when grown on a low-As Oxisol to 800 mg/kg when grown on a hih-As Andisol. The bioaccumulation ratio (plant As/soil As) appears nearly constant at 2:1 for this fern.

    A joint project between University of Florida and Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) personnel was conducted on the fate and transport of biosolids-borne TCS and TCC. Triclosan (TCS) and triclocarban (TCC) are antimicrobials chemicals commonly found in biosolids at concentrations (tens of parts per million) that can make biosolids a major source of the chemicals to the environment. Little is known about the fate, transport, and risk of the chemicals, particularly in biosolids-amended soils. The joint project investigated the sorption/desorption, degradation, mobility, plant and animal availability, and soil microorganism impact characteristics of the compounds to assess the risk of the chemicals (when biosolids-borne) to humans and the environment. Work on TCC was completed in 2009 and is summarized in a PhD dissertation by Elizabeth Hodges Snyder. Snyder found minimal risk of biosolids-borne TCC to humans and soil organisms, though earthworms can accumulate sufficient chemical to endanger certain predators. The predator pathway was the limiting pathway in a combined human health and environmental risk assessment and would dictate TCC concentrations below national biosolids mean concentrations. The risk assessment, however, identified several gaps in the understanding of TCC behavior and in databases used to assess risk, so the safe limit is best regarded as only a guide until additional work can be done. No biosolids TCC numerical limits nor any changes in current biosolids management practices are currently justified. Work on TCS has followed the same experimental approach as with TCC, including studies of TCS biodegradation, soil organism impacts, and sorption/desorption. Additionally, the researchers are examining the behavior of a major metabolite (Me-TCS), particularly its tendency to form non-extractable residues (aka. bound residues). Initial data suggest fairly rapid degradation of TCS (half-life ~ 9-10 weeks) to Me-TCS, which then seems to persist.

    The phytoavailability and persistence of endocrine disrupting compounds in biosolids amended and reclaimed water irrigated soils was investigated in two greenhouse studies conducted by University of Washington researchers. In the first trial, the degradation of 4- nonylphenol was measured in soils grown with and without wheat where biosolids had been applied at agronomic rates. The biosolids was a Class B anaerobically digested material with initial 4-NP concentration of 900 mg kg-1. Biosolids were incorporated into the top 4 cm of the columns. Half of the columns were planted with Triticum aestivum, L. with the other half maintained without any plants. Plant uptake as well as leachate concentrations of 4-NP were also measured. After 45 d, 15% of the initial biosolids-NP remained in the planted columns and approximately 30% remained in the unplanted columns. Half life of NP ranged from 16-23 d. While the 8 measured isomers degraded at different rates, there was no indication of persistence after 45 d. Movement of NP below the incorporated zone was minimal and there was no NP measured in plant tissues or leachates.

    A second study was conducted to measure degradation and plant uptake of estrogen (Estriol, 17²-estradiol, and Ethinylestradiol) and triclosan (TCS) in biosolids fertilized and reclaimed water irrigated turf grass. This study was conducted using a randomized complete block design in a greenhouse. Turf was irrigated for 6 months. At the end of the trial, all estrogen compounds were below detection limits in soil and plant samples. There was no estrogen detected in the leachate for any of the collection periods. There was also no detectible TCS in soils, plants or leachate for any of the reclaimed water irrigated treatments. In addition, the final concentration of TCS in the top 4 cm of the soil in the biosolids treatment (39 ±13 µg kg-1) was close to the soil detection limit. In the biosolids treatments, dried and ground biosolids were added to the surface of the turf grass. Turfgrass was cut several times during the study, but leaf tissue was not analyzed for any compounds until the final harvest and total plant removal of chemicals was not quantified. Thus, these results for soil concentrations of estrogens and TCS cannot be interpreted as proof of degradation of the added compounds. However, the collective data suggest minimal negative impacts of estrogen and TCS addition via land applied reclaimed water or biosolids on soil or water quality.

    In Ohio, research was published on the characterization of contaminants in spent foundry sand (SFS) and the potential environmental risk associated with soil application of these materials in residential gardens (Dayton et al., 2009). Spent molding sand is generated at about 2000 foundries in the U.S. when the sand can no longer be reclaimed within the foundry. Interest in beneficial use, rather than disposal of spent foundry sand (SFS), grew in recent years as the cost of landfilling increased and the potential benefit of using SFS in agriculture and horticulture became increasingly apparent. Thus, USDA-ARS, Ohio State University and the U.S. EPAs Office of Solid Waste cooperated to conduct a risk assessment for beneficial use of SFS, and to develop guidance for such use. The sample sets included 43 foundries which cast iron, steel, aluminum, or non-leaded brass, and generated SFSs which contained low levels of potentially toxic elements and xenobiotics, except for the brass SFS. Data from these 43 SFSs were evaluated and it was concluded that 40 of them could be used beneficially with no significant risk to humans or the environment. Iron, steel, and aluminum SFSs may be safely applied to land or used in manufacturing topsoils or potting media with only the limits set by the need of the users, as a small fraction of sand is used in their products.

    Ohio State University researchers also completed a research project on the characterization of feedstocks and candidate mulches for the development of a new mulch product for The Scotts Company (Basta, Dayton, and Myers, 2009). The Scotts Company generates 3.4 million cubic yards per year of mulch. Currently most mulch products are bark- or recycled wood-based, which are becoming scarce. This project provides preliminary data to support a future effort to develop new, renewable and sustainable sources of landscape mulches. This project evaluated a candidate feedstock (CF) from low-value by-products to develop new value-added product (i.e., mulch). The elemental content of the CF was low compared to soil. Concentrations of As, Be, Cd, Cr, Mo, Ni, Pb, Sb, Se, Tl, were within the normal range for uncontaminated natural soil. Elements regulated for land application of biosolids (As, Cd, Cu, Ni, Pb, Se, and Zn) are all below the CFR, Part 503 regulatory limit for exceptional quality biosolids. The CF contains other macro (Mg, K, P, S) and micro (Fe, Mn, Zn, Cu, and Mo) plant nutrients. These nutrients could be beneficial in the garden as the mulch decomposes over time. To identify the source and longevity of malodorous compounds, treatments were designed to track changes and relative intensity of VOCs over time at the constant moisture of the initial raw CF. Twenty-seven VOCs were isolated in the CF and characterized by their retention time and mass fragmentation spectra. Two persistent malororous compounds evaluated were dimethyl sulfide and dimethyl disulfide.

    Objective 2: Evaluate the ability of in situ treatment of contaminated soil with residuals to reduce chemical contaminant bioavailability and reduce toxicity.

    Application of drinking water treatment residuals (WTR) has been identified as a potential best management practice to reduce the loss of P from agricultural fields. In Ohio, two field simulated rainfall studies were used to investigate the efficacy of WTR in reducing P transport and soil test P with two different WTR application methods: incorporating WTR with soil with a range in soil test phosphorus (STP) levels and co-blending WTR with surface applied poultry litter. The objectives of this study were to determine if incorporating WTR into soil alters STP, reactive dissolved P (RDP), and the relationships between STP and DP. Phosphorus runoff and STP from a field amended with WTR co-blended with poultry litter was determined over a growing season. Results are reported in Jason Undercoffers M.S. thesis (Undercoffer, 2009). In the first field study, WTR was co-blended with poultry litter to achieve final Psat (Psaturation) of the blended materials of 600% (LWTR), 200% (MWTR) and 50% (HWTR), compared to the untreated litter which had a Psat of 1860% (0WTR). Co-blending treatments were broadcast at 11.3 Mg ha-1 on 2m x 2m plots and simulated rainfall was performed prior to, immediately following application and at 1 month intervals for 3 months. Immediately following treatment application RDP was reduced by 68% and 97% by MWTR and HWTR, respectively, when compared to the RDP of the 0WTR treatment (32.9 mg L-1). Three months after treatment application, the HWTR treatment maintained 33% more total P on plots than the 0WTR treatment suggesting a significant reduction of P transport from the co-blended WTR treatments over a growing season. Co-blending WTR with manure to achieve a final blended Psat < 100% may provide the best protection of water quality and provide a useful tool for WTR/manure co-blending calibration. In the second field simulated rainfall study, WTR (10 Mg ha-1) was incorporated into field plots (2m x 2m) with a wide STP range. The Ohio researchers observed positive linear relationships between Mehlich-3 P (M3P), Bray-1 P (B1P), water extractable P (WEP), and phosphorus saturation (Psat) with runoff dissolved phosphorus (RDP) for all runoff events. Relationships between M3P, B1P, or Psat and RDP were not significantly altered by soil incorporated WTR. Soil incorporated WTR significantly reduced STP for all methods following WEP (74.8%) > Psat (50.2%) > M3P (40.2%) > B1P (39.5%) and RDP (39.4%) one day after WTR application. Drinking water treatment residuals, applied as best management practices, substantially reduced P transport and would be a useful tool to reduce STP levels in agricultural fields above environmental threshold values.

    Florida researchers prepared summaries of their cumulative work with water treatment residues (WTRs) to control P solubility and off-site loss. Two extension publications (Agyin-Birikorang et al., 2009 a,b) were prepared, as well a chapter in a large report prepared for the South FL Water Management District aimed at suggesting means to control P mobility in the Northern Everglades.

    Tens of thousands of brownfields (abandoned or underutilized properties where known or potential environmental issues are an obstacle to redevelopment) can be found in cities, towns, and rural areas across the USA. Kansas State University researchers investigated the conversion of brownfields to garden areas motivated by the increasing interest in locally produced foods. All the sites evaluated are located in urban or suburban environments. The most commonly found trace element contaminant in soils was Pb. It was apparent from the site history and previous land use that Pb-based paint and leaded gasoline could be the most probable sources of Pb in these environments. Out of those sites, the Washington Wheatley (WW) site in Kansas City was available for gardening in the summer 2009. This site had mildly elevated levels of lead (Pb), ranged from 60 to 352 mg/kg and and some detectable levels of dichlorodiphenyltrichloroethane/dichlorodiphenyldichloroethylene (DDT/DDE) (0.03mg/kg and 0.04 mg/kg, respectively). The soil pH ranged from 6.6 to 7.6 and Mehlich-3 extractable P concentrations ranged from 57 mg P/kg (high) to 154 mg P/kg (excessive). A variety of methods to reduce any potential risk associated with relatively immobile soil contaminants such as Pb (and DDT/DDE) was recommended to the WW community gardeners. Some of those were: root vegetables should be washed and peeled before consumption; all other vegetables should be thoroughly washed prior to consumption; removal of outer leaves of leafy crops before cleaning. Measures focused on reducing both direct (soil-human) and indirect (soil-plant-human) exposure of Pb (and DDT/DDE) to the gardeners and their children. In addition, field test plots were established within the community garden and three crop types with three very different growth and contaminant uptake patterns were planted. The three crop types planted were Swiss chard, sweet potato and tomato. At the end of the growing season, crops were harvested from test plots as well as from some randomly selected community gardening plots located on the site. Two cleaning methods was applied to the harvested crop material: One subset of plant materials was only washed once with deionized water (to mimic the kitchen style washing) while the second subset was thoroughly cleaned following the laboratory cleaning procedure described by Hettiarachchi et al. (2003). Initial soil Pb concentrations in field test plots were ranged from 82 to 123 mg/kg. Concentrations of Pb in all three types of vegetables were far below the maximum permissible concentration levels reported in the literature for vegetables (e.g., 2 mg/kg of Fresh Weight basis, Australian National Food Authority 1997). There were no consistent treatment effects (either compost addition or cleaning method) on plant Pb concentrations. Lead uptake by plants at these levels of soil Pb appears to be insignificant and, therefore, concentration differences among different produce samples were most probably due to other factors, for example dry matter yield and plant vigor.

    Objective 3: Predict the long-term bioavailability and toxicity of nutrients, trace elements, and organic constituents in residual-amended agricultural and contaminated soils.

    In Colorado, three water treatment residual (WTR) rates (5, 10, and 21 Mg ha-1) and a single biosolids rate (10 Mg ha-1) were co-applied to semi-arid rangeland soils in 1991 and again in 2002. Results for the top 8-cm of soil indicates co-application did not adversely affect nutrient or trace metal availability or microbial community structure.

    Colorado State University researchers determined the occurrence of steroid sex hormones in the Cache la Poudre River in Colorado, the potential for steroid sex hormone biodegradation and photodegradation under natural conditions, and the mobility of selected steroid sex hormones in agricultural fields using a rainfall simulator. Steroid sex hormones are present in the Cache la Poudre River, at concentrations ranging from 0.6 ng L-1 (epitestosterone) to 22.6 ng L-1 (estrone). Testosterone, progesterone, and 17²-estradiol can be degraded by manure-borne bacteria, and testosterone degradation is faster under aerobic conditions and at higher temperatures (i.e., 37C vs. 22C) but little affected by changes in pH (from 6 to 7.5) or glucose amendments. Direct photodegradation of testosterone and progesterone and indirect photodegradation of testosterone and 17²-estradiol occurred under ultraviolet light » > 340 nm in the presence of Elliot soil humic acid. Direct photodegradation of androstenedione was substantially faster than direct photodegradation of testosterone in ultraviolet light » > 310 nm, and no indirect photodegradation observed.

    In Pennsylvania, researchers continued to study the spatial and temporal distribution of soil phosphorus (P) in response to 26 years of continuous year-round irrigation with reclaimed municipal wastewater. The surface soil equilibrium P concentration at zero adsorption (EPCo) has increased markedly from <1 to 5.5 mg per L over 26 years of system operation. This has resulted in a biphasic behavior of Mehlich-3 P (M3P). During the initial buildup phase 12.4 kg P per ha was needed to increase M3P by 1 ppm. After 9 yr of building, the M3P has reached a quasi steady-state condition. With continuous crop removal, M3P has stabilized at about 110 mg/kg. The M3P depth profile data were used to determine a threshold M3P saturation ratio. Enrichment of a subsoil layer is expected if the saturation ratio of the overlying soil exceeds 0.065. Under existing management it appears that it takes about 16 years of irrigation to saturate the top 30 cm of soil with P.

    In Oregon, farmers seeking to improve nitrogen use efficiency employed the Organic Fertilizer Calculator developed by Oregon State University researchers. The Calculator assists organic farmers in choosing a fertilizer source and rate that supplies sufficient N, saving dollars and protecting groundwater quality.

    A study was conducted by University of Washington researchers to evaluate the long-term effects of biosolids and compost applications on soil carbon storage and soil physical properties including bulk density and water holding capacity. Soils sampled for the study included long-term replicated field trials and farmers fields. The sites were distributed across Washington State and include a range of land uses including turf, ornamental crops, highways, agronomic crops and high value orchard crops such as pears, cherries and hops.

    For all studies in this sampling addition of organic amendments resulted in significant increases in soil carbon storage. Rates of carbon storage per dry Mg of amendment ranged from 0.012 in a long- term study of turf grass to 0.54 in an organic pear orchard with a long history of compost use. In general, soils with the lowest carbon levels showed the highest levels of carbon storage. Carbon content in soils also increased with time, meaning that the organic matter added with the residuals application resulted in long term carbon increases in soils. Increases in soil carbon content were much greater when composts and biosolids were incorporated into the soils rather than surface applied.

    For all sites included in this study, total nitrogen in soils that received organic amendment addition was higher than conventionally fertilized or control soils for at least one of the rates of amendment tested. Soil physical properties generally improved as well. Bulk density decreased after amendment addition in many of the sites tested with the biggest decreases seen in the most compacted soils. In the site with the highest bulk density, incorporation of compost or biosolids reduced soil bulk density to half that of control soils. Soil water holding capacity was increased in 5 of the 9 sites sampled, with increases ranged from 10% to 50%. For both soil moisture tension levels tested, amendment or soil carbon was significantly positively correlated with water storage.

    Impact Statements:
    1. Amending natural or disturbed soils with organic residuals accelerates soil carbon accumulation while improving soil physical properties that enhances vegetation productivity and reduces pollutant transport. High application rates, however, may increase the generation and emission of nitrous oxide, a potent greenhouse gas.
    2. Gardening initiatives for brownfields via the amending of soils with organic amendments, including compost, are enhancing the capabilities of gardeners to produce crops locally without potentially adverse health effects to the grower or the end consumer while at the same time contributing to the meaningful revitalization of brownfields sites in a sustainable manner.
    3. Common computer models of biosolids-borne micro-constituents behavior, transport, and risk rely heavily on modeled data rather than empirical measurements and make assumptions that likely are inappropriate for biosolids systems. Our work has resulted in data that improve our understanding of biosolids-borne micro-constituent behavior and better estimates of risks to humans and the environment.
    4. Results of nonylphenol, estrogenic compounds and triclosan degradation in biosolids-amended soil complement the developing body of literature that suggest that these compounds have minimal impact on terrestrial systems and are not persistent.
    5. Using organic residuals to restore prime farmland following mineral sands mining decrease cost of mining, increase landowner royalty return and mineral production rates. Iluka Resources, Inc. was awarded the National Mined Land Reclamation Award by the Interstate Mining Compact Commission, and our research program was credited as the underpinning source of technology.
    6. Drinking water treatment residuals (WTR) can be used to reduce dissolved P loss from agricultural land. Co-blending WTR with manure to achieve a final blended P saturation < 100% may provide the best protection of water quality and a useful tool for WTR/manure co-blending calibration. Drinking WTRs, applied as best management practices, substantially reduced P transport and would be a useful tool to reduce soil test P levels in agricultural fields that are above environmental threshold values.
    7. Diverting 1 million tons of spent foundry sand (SFS) annually from landfills (at $30/ton) to beneficial use would realize annual savings of $30,000,000 by the foundry industry. Our research shows SFS has can be used as a component of manufactured soils. This would allow foundries to become more competitive and create start-up industries and jobs in Ohio focused on production and marketing of SFS soil blend materials to the public.
    Last Modified: 22-Jun-2012

    Date of Annual Report: 08/04/2011

    Report Information:
  • Annual Meeting Dates: 06/05/11 to 06/07/11
  • Period the Report Covers: 10/2010 to 09/2011

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    Sunday, June 5th, Business meeting

    Welcome and participant introductions - Greg Evanylo

    Update from Project Director Lee Sommers - Update on USDA and National Institute of Food and Agriculture (NIFA). Roger Beachy is no longer the NIFA director. Update on the Agricultural Experiment Station, including Roadmap for Food and Agriculture research (http://escop.ncsu.edu/docs/scienceroadmap.pdf), which includes 7 grand challenges.

    Greg Evanylo has received state reports from most of the participants on time and will be preparing the annual report due 60 days after the annual meeting.

    Venues for 2012-2014 annual meeting were finalized as: Seattle/Tacoma  2012, Denver  2013, Chicago - 2014. Sally Brown will host the Seattle/Tacoma meeting in 2012. (An email survey following the meeting identified June 24-26 as the dates for the 2012 meeting.) The group voted for the Metropolitan Water Reclamation District of Greater Chicago to host the annual meeting once every 2-3 years.

    Greg Evanylo provided the order of presentations for the technical presentations.

    Technical Meeting Agenda

    Monday June 6

    Selected oral presentations: The research-regulations nexus

    GDG-gypsum and spent foundry sand and the As and chromate problems at EPA, Chaney

    Hawaii soil As limit, Hue

    EPAs regulatory limits for emerging constituents- Brobst conference call

    Basis for wastewater application rate, Elliot

    Reclaimed water for ecological use and EDC activity assessment by YES, Brown

    Use of field capacity as basis for regulated recycled water application rate in Virginia, reduction of mine land restoration biosolids reclamation rate, P basis for biosolids application, Evanylo

    Lunch and bus tour of Penn States Living Filter

    Selected oral presentations: Urban soil remediation

    Use of soil amendments/residuals for restoration of urban land for "urban ag," Basta

    Field based evaluations of lead and arsenic transfer from contaminated urban soils to plants, Hettiarachchi

    Food waste residuals use, Thies and Morash

    Effects of residuals on urban soils, Sally Brown

    [The subgroup decided to write an outreach/extension bulletin on urban soil assessment and remediation. Nick Basta agreed to prepare an outline upon which individual chapters would be based.]

    Tuesday, June 7th

    Emerging contaminants

    Fate, transport and risk assessment of biosolids-borne triclosan, O'Connor

    The occurrence of carbamazepine in wastewater irrigated soils: Land use differences, Watson

    Transport of manure-borne hormones through tile-drained fields, Lee (remote Skype presentation)

    Climate change

    Use of biosolids for lignocellulosic-based energy crop production, Silveira

    Switchgrass and other warm season grass production on mined land reclaimed with manure and paper mill sludge, Stehouwer

    Spectroscopic techniques for assessing sequestered C stability, Jinling Li

    Noon: Adjourn Meeting

    Lunch and tour of Marcellus Shale hydraulic fracturing site

    Accomplishments:
    Objective 1: Evaluate the chemistry and bioavailability of trace elements, organic microconstituents and nutrients in residuals and residuals-amended soils to assess the environmental and health risks. The research performed to accomplish objective 1included a) direct chemical measurements of nitrogen, phosphorus, trace elements, and organic compounds in the applied residual and upon transformation and/or transport through the environment and b) bioassays to assess bioavailability.

    Researchers from Colorado State University (CSU), University of Florida (UF), Mississippi State University (MSU), Pennsylvania State University (PSU), Purdue University (PU), the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC), and Agriculture Canada (AgCan) performed research to measure the forms, amounts and effects (transport and/or bioavailability) of organic microconstituents in land applied residuals.

    A collaborative project between the UF (OConnor) and the MWRDGC (Cox and Hundal) was performed to investigate the fate and transport of biosolids-borne triclosan (TCS) and triclocarban (TCC), antimicrobial chemicals commonly found in biosolids at concentrations that can make biosolids a major source of the chemicals in the environment. The research focused on determining the sorption-desorption, degradation, mobility, plant and animal availability, and soil microorganism impact characteristics of the compounds to assess the risk of the chemicals to humans and the environment. Work on biosolids-borne TCC is now published in three 2010 journal articles by Snyder et al., and a final risk assessment paper is planned for 2011. Work on TCS has followed the same general experimental design as with TCC (batch sorption-desorption studies and column studies to assess TCS expected and observed mobility, greenhouse and field studies to assess phytoavailability to and accumulation by food-chain crops, earthworm accumulation studies, and biodegradation and extractability studies to assess persistence of the parent compound and metabolites. Work is detailed in the PhD dissertation of Manmeet Waria (2011), and summarized below.

    The typical concentration range for TCS in biosolids analyzed by Waria and reported in numerous published studies is 10-20 mg TCS/kg biosolids. The mean value of 18 mg/kg agrees with the mean value reported in the TNSSS (16 mg/kg). The water solubility of TCS depends on pH (pKa = 8.14), which is expected to affect TCS behavior in high pH soils and in lime-stabilized biosolids. The partitioning coefficient of TCS, normalized to OC content (log Koc= 4.7), is constant across soil, biosolids, and biosolids-amended soils. Desorption is strongly hysteretic; thus, biosolids TCS is expected to have limited mobility in soils. Column leaching studies confirm retention of TCS within the zone of biosolids incorporation. Greenhouse and field studies utilizing biosolids-borne TCS confirmed minimal phytoavailability. Biosolids-TCS was accumulated by, but was not toxic to, earthworms; a conservative estimate of the earthworm bioaccumulation factor was ~10. There was no effect of biosolids-borne TCS on microbial respiration and N-cycling. TCS degrades to methyl-TCS (Me-TCS) with a 50% disappearance time of ~100 days. Plants, soil, and earthworms from fields equilibrated with biosolids-borne TCS contained no detectable Me-TCS,which is more hydrophobic than TCS. A preliminary risk assessment identified the same predator-earthworm pathway as being potentially limiting for TCS as Snyder suggested for TCC. Accounting for TCS degradation significantly reduces estimated risk, and using realistic mean (95th percentile biosolids-TCS concentrations) practically eliminates estimated risk. Further refinement of the risk assessment, is necessary to confirm the initial estimates of risk.

    Mississippi State University researchers have also been studying the fate of TCS and TCC in biosolids-applied soils in terms of 1) developing cost-effective and reliable analytical methods for detection at trace levels in complex environmental matrixes and 2) understanding transformation kinetics and pathways. A cost-effective and reliable HPCL/UV analytical method for trace level detection of TCS and TCC in biosolids and biosolids-applied soils was developed and reported in the Journal of AOAC International. A molecularly imprinted polymer (MIP) able to selectively bind TCS and TCC was prepared using noncovalent molecular imprinting methods. The prepared MIP was evaluated as a selective sorbent in SPE for sample cleanup before HPLC-UV analysis of TCS and TCC in soil and biosolids samples. Compared to commercially available C18 SPE sorbent, the molecularly imprinted SPE (MISPE) developed in this study was more efficient for the cleanup of extracts of soil and biosolids samples prior to the analysis of TCC and TCS using HPLC-UV. Significant reduction of analytical cost was achieved because one MISPE can be reused up to 35 times and HPLC-UV instead of HPLC/MS can be used for instrumental analysis following sample cleanup by MISPE.

    The result of a laboratory microcosm study on TCS and TCC transformation in biosolids-applied Marietta fine loam and McLaurin coarse loam was reported in the Journal of Environmental Quality. Transformation of TCC in both soils was slower than that for TCS. After 100 d, 53 ± 1% and 71 ± 2% of the initially added TCC and only 2.8 ± 0.35% and 6.2 ± 0.80% of initially added TCS remained in Marietta fine loam and McLaurin coarse loam, respectively. The results suggest that abiotic processes have greater effect than biotic processes on TCC transformation. Addition of biosolids to the two soils slowed the transformation of both compounds, indicating interactions between both compounds and biosolids may adversely affect their transformation in soils, an important factor that must be included in models predicting environmental fate of biosolids-associated PPCPs.

    A laboratory soil column study to investigate the transport and transformation of TCS and TCC in a biosolids-surface applied soil was completed in 2010 and included in a manuscript submitted to the Environmental Toxicology and Chemistry. Significantly more TCS than TCC was transformed. Surface application of biosolids retarded their transformation. Downward movement of TCS and TCC occurred within 10-cm soil depth. Only small percentages of the transformed TCS and TCC appeared after 101-day column study, indicating that either the investigated transformation pathways were not significant or rapid transformation of the those products had occurred.

    Abiotic oxidative transformation of TCS by Fe(III)-modified montmorillonite was investigated in combination with computational modeling approach. Part of the result of this study was published in the Environmental Science and Technology. Significant TCS polymerization was observed when TCS was exposed to Fe(III)-modified montmorillonite in aqueous solution. Compared to TCS, the solubility of polymerized TCS products can be reduced more than 4000 times, resulting in significantly less bioavailability and movement in the environment. The result from this study has demonstrated the feasibility of utilizing Fe(III)-modified montmorillonite as in situ remediation material for other related PPCPs.

    Work in collaboration with MWRDGC on fate of selected PPCPS in long term land-applied biosolids was published in the Environmental Toxicology and Chemistry. The levels of TCC, TCS, 4-nonylphenol (4-NP), and polybrominated diphenyl ethers (PBDEs) in biosolids from 16 U.S wastewater treatment plants and in soils from field plots receiving annual applications of biosolids for 33 years were evaluated. Each of the four contaminants evaluated were detected in most of the biosolids at concentrations up to >1,000 mg/kg. They were detected at ¼g/kg levels in the biosolids-amended soil, but their concentrations decreased sharply with increasing soil depth, indicating limited soil leaching of those compounds. Most of the PBDEs and a small percentage of 4-NP, TCC, and TCS remained in the top 120-cm soil layer. These data suggest slow degradation of PBDEs but rapid transformation of 4-NP, TCC, and TCS in the biosolids-amended soils.

    Clotrimazole is a broad-spectrum antimycotic drug incompletely degraded during sewage treatment. It is a suspected endocrine disrupting chemical that could potentially reach agricultural land via the application of biosolids. In the absence of any environmental fate data, AgCan researchers evaluated the persistence and dissipation pathways of (3)H-clotrimazole during laboratory incubations of agricultural soils. Clotrimazole was removed from a loam, a sandy loam, and a clay loam, with formation of nonextractable residues being the major sink for (3)H. Their parent compound did not mineralize to any extent, and rate of dissipation was slower at a lower temperature.

    Diclofenac, 2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid, is a widely used non-steroidal anti-inflammatory drug whose consumption by carrion eaters has been responsible for the catastrophic decline in vulture populations in India and Pakistan. Diclofenac could potentially reach agricultural lands through the application of municipal biosolids. 14C-Diclofenac was rapidly mineralized when added to soils varying widely in texture. Over a range of temperature and moisture conditions, extractable 14C-diclofenac residues decreased with half lives <5days. No extractable transformation products were detectable by HPLC.

    Tenofovir (9-(R)-(2-phosphonylmethoxypropyl)-adenine) is an antiretroviral drug widely used for the treatment of human immunodeficiency virus and Hepatitis B virus infections. It is rapidly excreted in the urine and could potentially reach agricultural lands through the application of municipal biosolids or wastewater. The persistence of tenofovir in selected agricultural soils was evaluated because of the absence of any environmental fate data. Tenofovir was relatively persistent in soils, there were no extractable transformation products detected, and the response of mineralization to soil temperature and heat sterilization indicated that the molecule was biodegraded by aerobic microorganisms. Sorption isotherms with dewatered biosolids suggested that tenofovir residues could potentially partition into the particulate fraction during sewage treatment.

    Polybrominated diphenyl ethers (PBDEs), perfluorinated alkylated substances (PFAS), and metals were monitored in tile drainage and groundwater following liquid (LMB) and dewatered municipal biosolid (DMB) applications to silty-clay loam agricultural field plots. Key PBDE congeners (BDE-47, -99, -100, -153, -154, -183, -209) comprising 97% of total PBDE in LMB, had maximum tile effluent concentrations ranging from 6 to 320 ng/L during application-induced tile flow. Total PBDE loading to soil via LMB and DMB application was 0.0018 and 0.02 kg total PBDE ha/yr, respectively. Total PBDE concentration in soil (0-0.2m) 599 days after both applications was 115 ng/g dw. The only PFAS found above detectable limits in tile drainage from the application plots were PFOS (max conc = 17 ng/L) and PFOA (12 ng/L). Metals in tile for the LMB were significantly higher (p<0.05) than in control. Tilling the soil prior to surface application of LMB will reduce application-based PBDE and metal contamination to tile drainage and shallow groundwater.

    In Colorado, a field-scale study was conducted to assess the potential for runoff of seventeen hormones from an agricultural field applied with biosolids. Significantly higher concentrations of multiple estrogens (<0.8 to 25.02 ng L-1), androgens (<2 to 216.14 ng L-1), and progesterone (17.4 to 98.9 ng L-1) were observed in runoff samples taken 1, 8 and 35 days after biosolids application. Androgen runoff concentrations declined from day 1 to day 35 after biosolids application, but the concentrations observed 35 days after biosolids application were still higher than concentrations known to affect the endocrine system of aquatic organisms. Biosolids did not adversely affect earthworms (A. trapezoides) monitored in a biosolids-amended Colby (Aridic Ustorthents)-Adena (Ustic Paleargids) soil.

    The fate and transport of manure-borne hormones in agro-ecosystems remains poorly understood. Of particular environmental concern are the natural hormones 17²- and 17±-estradiol (E2), estrone (E1), estriol (E3), testosterone (TST), and androstenedione (AND) and the synthetic hormones 17²- and 17±-trenbolone (TB) and trendione (TND). Purdue University researchers assessed the hydro-chemo dynamics of natural and synthetic androgens and estrogens measured in tile drains and agricultural ditches and resulting hormone loads on a farm as a function of manure management practices. Animal wastes were land-applied through lagoon effluent pivot irrigation (beef, dairy, and poultry effluent), solids broadcasting (beef and dairy), and subsurface injection (swine). Hormone concentrations in the tile drains increased during effluent irrigation and storm events, whereas leaching of hormones in solid manure occurred due to rainfall or snow melt. Hormones persisted over the winter, with increased concentrations coinciding with early thaws and snow melt. Hormones were detected in greater than 80% of samples collected at each station, with estrone being detected the most frequently and estriol the least. Natural androgens were detected more frequently than synthetic androgens, which were detected in fewer than 10% of the samples. The highest concentrations of hormones in the ditch waters were observed in June, likely posing a threat to fish during their early developmental stages, with total estrogens exceeding 100 ng/L and total natural androgens approaching 40 ng/L. These concentrations were associated with dairy effluent irrigation; however, the frequency of detection of hormones was higher for fields that had received higher applications of dairy solids. Therefore, it is likely that dairy effluent irrigation may cause short-lived high concentrations, whereas the application of solid wastes may cause more chronic exposure to aquatic organisms.

    The PU researchers work with biosolids has been limited to identifying the PPCPs that exist in biosolids at a high enough concentration to allow good quantitation of release kinetics from the biosolids. Extraction of biosolids for total PPCPs was done as well as equilibration with water to estimate biosolid-water partition coefficients. Ciprofloxacin, ofloxacin, TCS and TCC were measured at high enough concentrations in the biosolids to initiate kinetic release studies. The first set of release experiments reflected the majority of the PPCPs are released within a few hours. Atorvastatin levels in the biosolids were relatively low (< 100 mg/kg dry biosolids).

    The distribution in carbamazepine in the soil profile beneath wastewater-irrigated forested land and cropped land was determined by PSU researchers. Based on the application time period, it is expected that carbamazepine has been applied in irrigation water for about 25 years. Results indicated approximately 15 years worth of carbamazepine accumulated in the surface 30 cm of both soils, with near surface concentrations being higher in the forested soil, consistent with organic carbon distributions.

    Researchers from Ohio State University (OSU), University of California-Riverside (UCR), University of Hawaii (UH), and PSU performed research to measure the types, forms, amounts, and effects (i.e. bioavailability) of inorganic elements in land-applied residuals.

    Deindustrialization of urban areas during the past two decades has resulted in a large amount of vacant land. Cities in Ohio and elsewhere have established stabilization projects to facilitate the redevelopment of vacant urban land for agriculture/gardening and creation of parks, playgrounds and other commons. Historical soil contamination presents the greatest challenge to urban vacant land reuse. In 2008, the Cuyahoga County (OH) Board of Health determined that 42% of children had elevated blood Pb levels. It is important to assess Pb lead content in these areas prior to reuse to prevent exposure to harmful levels of Pb. Most urban soils are not tested for Pb because of the high costs associated with sampling and analysis. Research conducted by OSU researchers with OSU Cuyahoga County Cooperative Extension on soil assessment of human health risk of Pb in soil from 60 vacant land sites was performed. The researchers discovered that several inexpensive agricultural laboratory methods provide accurate data to assess risk from soil Pb in urban soils. These data were presented at local, regional, and national meetings.

    At UCR, labile pools (E value) of Cd and Zn in ten soils were quantified using ICP-MS measurements of 114Cd and 111Cd and 68Zn and 66Zn that are needed for stable isotope dilution (SID). The ten soils contained from 130 to 19,600 mg/kg total Zn, and from 11 to 62 mg/kg total Cd. On average, the labile pools predicted by SID (E-values) represented 45% of the total Cd, but only 25% of the total Zn, a trend that was consistent across all soils and independent of soil pH, organic carbon, or clay content. The Cd extracted by 0.05 M EDTA, 1 M CaCl2, 0.05M Ca(NO3)2, and 0.01M Ca(NO3)2 were well-correlated with both total Cd and E-value for these 10 soils, suggesting that any f these chemical extractions could be used to predict bioavailability of Cd. UCR researchers completed the first set of experiments using the two earthworm species (E. fetida and L. terrestris) to assess bioavailability. In general, the Cd and Zn concentrations in the whole-body digests were highly correlated with E-values, but also with total metal concentrations in the soils. With this particular group of soils, these two parameters were sufficiently correlated (r = 0.93 for Cd; r = 0.88 for Zn) that it made it difficult to ascertain whether E-values are sufficiently superior predictors of metal accumulation in invertebrates to justify the extra effort required for their determination. The results are one of the first comprehensive studies of trace- metal bioavailability to soil invertebrates employing isotope dilution techniques.

    University of Hawaii researchers used earthworms to assess As bioacccessibility in high-arsenic soils in a bench experiment. Eisenia fetida were raised in a soil mixture containing five levels of As: 20, 90, 160, 230, and 300 mg/kg as total As, or 1.27, 2.97, 5.40, 6.76, and 8.16 mg/kg as bioaccessible As. The worms were grown for 28 days in a thin layer of old lettuce and other vegetable discards, which were placed on top of the As-contaminated media. Worm growth rate peaked at the second lowest levels of soil As (90 mg/kg total As or approximately 3.0 mg/kg bioaccessible As); however, the growth started to decline when soil As exceeded 125 mg/kg (total) or 4.2 mg/kg (bioaccessible).

    A total phosphorus (TP) mass balance was performed by PSU researchers for cropped and forest sites that had been irrigated with secondary wastewater effluent for about 40 years. The mass balance indicates that 63% and 70% of net (applied minus harvested) TP could not be accounted for in the top 75 cm of soil in the field and forest, respectively. Because the cropped field was sampled at summit landscape positions, it is likely that surface runoff and subsurface lateral flow of effluent P is partially responsible for the deficit of P in the 0-75 cm soil layer. Moreover, changes in the P-retention ability of the soil and the high hydraulic loading rate has probably caused leaching of P below the 75 cm depth. The capacity of the soil to assimilate and renovate effluent-applied P has been reduced as a result of irrigation with wastewater. Leaching of P is generally not considered an environmental issue at most effluent irrigation sites; however, leaching of P could potentially impact groundwater where effluent is sprayed on forested soils of low P-sorbing capacity and overlying shallow groundwater. Copper, which forms strong complexes with soil organic matter, also appears to have leached to a greater extent from the surfaces layers in the wastewater-irrigated forest. One field day was held at the experiment site and was attended by 40 individuals from mining industry and state regulatory agency staff. Reports have been presented at mining and reclamation meetings.

    Objective 2: Evaluate the agronomic and environmental benefits/advantages of land applying residual by-products and/or substituting such materials for fertilizers.

    Studies have been conducted by researchers at CSU, UH, MWRDGC, Kansas State University (KSU), University of Minnesota (UM), PSU, Virginia Tech (VT), and University of Washington (UW) to assess the benefits of nutrients, organic matter and other constituents in biosolids and similar residuals on improving the properties of disturbed/poor/contaminated soils for enhancing vegetative growth, soil health, and water quality, and reducing greenhouse gas emissions.

    Improving N use efficiency of land-applied residuals is important to produce optimum crop yields and reduce water quality impairment risk. Researchers at CSU developed a three-dimensional predictive model for wheat yields and grain N removal from a 15-year study involving biosolids addition to a dryland agroecosystem. The model was superior (higher R2 and lower SE) to simple linear and quadratic models.

    University of Minnesota researchers completed laboratory and greenhouse experiments to characterize N and P availability from biosolids generated from the Western Lake Superior Sanitary District (WLSSD). A regression model developed for soil organic matter was used to estimate potentially mineralizable N and calculate N availability from the biosolids. Biosolids properties were examined using two soil types (clay and sandy loam) and fine mine tailings from the taconite iron industry. The N mineralization model was a good predictor of plant growth and N uptake in the greenhouse study. Results from incubation and greenhouse studies indicated that higher biosolids rates are required on mine tailings than on native soils. Results were disseminated at a full day biosolids workshop in Duluth, MN sponsored by WLSSD and in a biosolids session at the 2010 Minnesota Pollution Control Agency 73rd Annual Wastewater Operations Conference.

    The fifth year of field experiments investigating use of poultry layer manure for abandoned and active mine reclamation and biomass crop production was completed by PSU researchers. Reclamation treatments were lime+fertilizer, composted layer manure and fresh manure+papermill sludge. The yields of biomass crops (switchgrass, atlantic coastal panic grass and big bluestem) have been greater with the organic amendments (4.5-6 Mg/ha) than with the conventional reclamation amendments (1-2 Mg/ha) and are approaching those obtained on prime farmland.

    Virginia Tech researchers continued to monitor the prime farmland soil reconstruction experiment established in 2004 at the Iluka Mineral Sands mining site. The four primary treatments (lime and N-P-K fertilizer only; 15 cm topsoil return over limed and P-fertilized tailings; 75 Mg/ha lime stabilized biosolids with conventional tillage; 75 Mg/ha lime stabilized biosolids with no-tillage) were cropped to wheat and soybean in 2010. Crop yields in 2010 were approximately 75% of adjacent unmined prime farmland control plots. The findings and results were disseminated to local landowners, farmers, government representatives and regulators at two on-site field days and provide further justification for higher than agronomic N rates for reclamation of disturbed lands.

    Researchers from KSU, UW, USACE, and USEPA have collaboratively evaluated trace element chemistry, transformations, transfer from soil to plants, and toxicity amelioration by organic residuals in contaminated urban soils. The researchers evaluated the uptake of trace elements and other contaminants by food crops grown on unamended- and compost amended-mildly contaminated urban soils to develop recommendations for corrective actions to minimize potential contaminant transfer to food crops and gardeners. Evaluation of sites throughout the U.S. is on-going in this USEPA funded project. Sites in Kansas City, MO and Tacoma, WA have been amended with compost and/or a commercial biosolids-sawdust-sand mix (Tagro). Lead concentration in soils ranged from 60 to 385 mg/kg. Compost addition diluted soil Pb concentration by 59%. In compost-added plots, Pb uptake was 59% lower in Swiss chard and 20% lower in carrot compared to the control plots. Lead concentration in tomato was not affected by compost. Compost did not reduce bioaccessible Pb. At the Tacoma site plant, As and Pb concentrations in Tagro+lime added plots were significantly lower than that of the unamended control plots.

    Working in cooperation with Hetteraichchi at KSU, Chapell at USACE, and Scheckel at USEPA, Brown (UW) evaluated changes in Pb speciation following amendment of a high Fe biosolids compost to Pb contaminated soils. Philadelphia compost was added to a range of Pb/As contaminated soils. In vitro Pb was reduced, but the effects on As were mixed, by the addition of compost to several contaminated soils. Iron-rich composts added to co-contaminated As/Pb orchard soils did not reduce metal availability over 1 year, but the Philadelphia compost reduced Pb availability in this soil. UXAS showed conversion of Pb in the Philadelphia compost-amended soil altered the mineral form of Pb to favor adsorption onto Fe Oxides.

    Recycling of biosolids onto land may provide benefits beyond those as a source of nutrients and soil property enhancer. One such potential benefit of land-applied biosolids being investigated by members of the W2170 project is the effect on greenhouse gas (GHG) emissions and carbon budgeting. The GHG balance for different biosolids end use/disposal practices was evaluated by UW researchers as part of an effort sponsored by the Canadian Council of Ministers of the Environment. Different treatment processes, including anaerobic digestion, lime stabilization, dewatering and end use options including combustion with heat/energy recovery, composting and land application were included in this evaluation. A spreadsheet tool that includes default emissions and sequestration factors was developed. Data from a number of municipalities in California with different treatment processes were input to the model. Anaerobic digestion plus land application was the overall best practice for GHG emissions, resulting in net credits. Combustion, particularly at temperatures that commonly occur in multiple hearth furnaces or fluidized bed facilities, resulted in the most significant emissions as a result of the formation of N2O. Higher burn temperatures eliminate N2O formation but result in increased NOx emissions. The results from this study were published in Environmental Science and Technology.

    The model was used to calculate the GHG balance for the MWRDGC biosolids program using historical and new data. The MWRDGC biosolids are used as Class B cake on farmland and as landfill daily cover. The lagoon-aged air-dried biosolids are used on turf on urban areas and as landfill final cover. Unsuitable biosolids are disposed in landfills. The C credits and debits for each of MWRDs biosolids end uses were evaluated based on operations data for 2001 and 2008. Debits are due to fossil fuel use and fugitive gas emissions, and credits result from replacement of fertilizer by biosolids and soil carbon sequestration. The utilization of Class B biosolids in landfills showed a C debit due to the N2O and CH4 emissions. The beneficial use of biosolids as fertilizer on farmland and turf fertilizer, and landfill final cover resulted in C credits primarily through C sequestration and the offset of fertilizer use. The lagoon-aging of biosolids, which causes loss of C, was the major factor controlling the differences in credits among the beneficial use practices. Despite the higher consumption of fuel for transportation to farmland, the utilization of Class B centrifuge cake biosolids resulted in higher GHG credits than the use of lagoon-aged air-dried biosolids in urban areas. Overall, net GHG emissions were highest for landfill disposal, and were similar among the beneficial uses: farmland fertilizer, urban turf fertilizer, and landfill final cover. The study demonstrated, based on operations data, showed that land application of biosolids for primary benefit as a nutrient source, also contributes to mitigation of GHG emissions.

    The UW researchers conducted two surveys of long term biosolids and compost amended sites to quantify soil carbon storage and changes in soil physical properties including bulk density and water holding capacity. Sites sampled included coal mine sites restored with biosolids composts in PA and WA, gravel sites in New England and Canada, and a hard rock mining site in Canada. This sampling was done in parallel with sampling done by USEPA at biosolids amended mine sites. The sampling showed persistent increases in soil C sequestration in sites restored with organic amendments in comparison to conventional restoration practices. The other sampling was limited to WA, where similar and statistically significant C storage occurred at all sites that received organic amendments. A number of sites showed significant increases in plant available water.

    Another potential benefit from land-applied biosolids is their capability to increase plant drought tolerance due to the activity of humic acid-based biostimulants that act like plant hormones auxin and gibberllins. Field studies conducted by VTresearchers on coarse-textured soils in 2010 demonstrated the beneficial effects of biosolids on partial drought-amelioration in a corn (Zea mays L.)-soybean (Glycine max L.) rotation under both conventional and no-tillage practices. The calculated agronomic N rates of both lime-stabilized and anaerobically digested biosolids provided plant available N at levels intermediate to three rates of synthetic fertilizer N, according to soil (PSNT) and plant tissue (earleaf, corn stalk nitrate) indicators of N availability. However, both biosolids treatments increased corn grain yield above that from the fertilizer treatments during the drought-stricken 2010 season. The 1x and 1.5x N fertilizer rate and two biosolids treatments increased photochemical efficiency and plant indole acetic acid and t-Zeatine Riboside concentrations 20 days before and at silking. Yields of soybean grown in soil amended with the agronomic N rates of biosolids for corn planted on the same plots the preceding year were higher than those not previously receiving biosolids.

    Soil acidity is a serious constraint for crop production worldwide. Soil acidity is conventionally corrected by applications of limestone, but limestone may not be available or be too expensive in some areas. Replacement of lime with locally available organic materials to correct soil acidity was studied by UH researchers. A greenhouse study was performed to investigate the effects of approximately 15 Mg/ha (1% by weight) shredded pineapple (Ananas comosus) crowns and cowpea (Vigna unguiculata) vines on two acid soils of Hawaii. CaSO4, Ca(OH)2, and MgO at 4 cmolc/kg and an unamended control were employed for comparison. Results indicated that crop residues could be used as a partial substitute for lime in correcting soil acidity. The effectiveness of such soil organic amendments varied with residue type and mode of preparation (i.e., fresh or ashed). A combination of lime and organic materials is recommended for improving soil fertility, enhancing crop growth, and reducing cost.

    Work planned for 2010-2011:

    We plan to continue collaborative work on evaluating the chemistry, fate, transport, and bioavailability of PPCPs and EDCs in biosolids-amended and effluent-irrigated soils. These include refining the approach for assessing the release kinetics of selected PPCPs from biosolids. To predict the overall residence time of a PPCP in the upper horizon of soil during which it can be degraded aerobically, both release from the biosolids and sorption by soil will be considered. Computational chemistry will be combined with other investigative approaches to explore PPCP transformation pathways and environmental impacts of PPCP transformation products. We will continue our work on developing cost-effective and sensitive analytical methods for detecting PPCPs and their transformation products in complex matrices. Field research plots will be also established with the dual purpose of evaluating the uptake of perfluoronated compounds in biosolids-amended soil and to compare metal uptake from high metal and modern biosolids. Many of the data from the PPCP research will be translating into journal articles, especially risk assessment-based articles.

    Researchers have initiated work on coupling a source zone model, transport model, and management decision making model for predicting steroid hormone concentrations in an agricultural drainage network and subsequent transport and persistence of these loads into the watershed. The model will include effluent and solid manure as an input to the source zone and transport model, flexibility for mixed management practices, and incorporation of nutrient transport and tile drain size as a restriction to tile drain flow. These models can easily be adapted for biosolids application and other micropollutants if model parameters can be estimated with reasonable accuracy. Simulated rainfall/runoff studies will be performed to investigate the movement and carryover of hormones associated with surface application of biosolids. Manuscripts on hormone release from manure applied tile drained fields will be submitted to journals.

    Biosolids products from a variety of processes will continue to be assessed as sources of nutrients for vegetative growth in agricultural and non-agricultural eco-systems. Researchers will continue to investigate the beneficial effects of biosolids application on brownfield and other urban soil restoration, especially with regard to As, Pb and other trace inorganic element chemistry and bioavailability. In addition we will be investigating the potential to use biosolids composts, likely in combination with water treatment residuals for use in bioretention systems for Low Impact Development stormwater management projects.

    The benefits of biosolids use with respect to nutrient cycling and C sequestration will be studied in natural and disturbed soils and between various tillage systems. We have submitted a collaborative, multi-agency grant proposal to USDA to quantify soil carbon storage on farm fields with a history of biosolids application as well as to attempt to quantify N2O emissions from biosolids application sites. Research on the effects of biostimulants in land-applied biosolids on amelioration of drought tolerance will continue.

    Impact Statements:
    1. Few measurements of biosolids-borne trace organics fate and transport exist, and risk assessment is primarily model-based. Data accumulated to date show that actual systems are more complicated than most models assume. Thus, we expect that data like those being generated will encourage regulators to cautiously consider model-generated fate and transport predictions and to modify the resulting risk assessments accordingly. Most of the data generated to date suggest minimal human or environmental risk of biosolids-borne PPCPs.
    2. Hormones applied to soils in biosolids and manures can be transported to and impair surface and ground waters, especially where soils are tile drained. Pre-tilling soil prior to surface application of liquid biosolids (and, presumably, manures) should reduce transport of many organic micro-constituents (and metals) to tile drainage and shallow groundwater. Such management practices should be considered by regulatory agencies where land application poses a threat to aquatic ecosystems.
    3. The bioavailability of arsenic and lead in soils, particularly brownfields and other urban sites, is a potential health risk to humans. Research conducted by members of the W2170 group provided accurate tests to evaluate and practical means to ameliorate such hazards. These tools are being shared with communities and state regulatory agencies. In addition, the W2170 group will write an extension/outreach publication on evaluating and remediating contaminated urban soils.
    4. The application of organic residuals to alleviate soil acidity has been adopted successfully by some organic farming communities, and such findings are applicable to solving soil acidity problem that plague many regions in the developing world.
    5. Models developed and tested by W2170 researchers to predict relationship between crop yields and grain N removal and between organic matter C and N fractions and plant available N, respectively, for biosolids-amended soil were superior to existing models and may improve N-based biosolids application recommendations. A model developed by Colorado State University may have application to soils covering 2.3 million ha in 10 U.S. states.
    6. Based on long-term research by Virginia Tech, Iluka Resources was able to petition their state regulatory agency (VDMME) for a waiver of requirements to save and return topsoil on their mineral sands mines in eastern Virginia. The topsoil substitute recipe that was used as the basis for this waiver included the use of lime stabilized biosolids at 78 Mg/ha. This permit amendment will add millions of dollars to the company, landowners via royalty return, local counties via severance tax, and the Commonwealth via increased corporate tax base.
    7. The first use of nutrient trading credits to pay for poultry manure transport from farm to mine reclamation site occurred in Pennsylvania as a result of the research on the use of manure for mineland reclamation.
    8. Virginia Tech researchers gained acceptance from the Virginia DEQ for a novel sediment quality screening protocol for identifying sediments and geologic materials that are suitable for upland placement and beneficial use. This system is unique to the USA and should lead to a major expansion of beneficial use of dredge sediments, which will simultaneously decrease the cost of sediment management for the public taxpayer and lead to substantial income streams and improved soil productivity for receiving landowners.
    9. The research demonstrating that biosolids can alter plant biostimulant content and improve plant drought tolerance during seasons when rainfall is below average provides evidence that soil nutrients may be better utilized with lower potential for water impairment during droughty years where biosolids are used as the source of nitrogen.
    10. Research focusing on green house gas benefits associated with the use of biosolids may potentially result in recognition of these materials as a tool for both land managers and municipal managers when carbon accounting becomes a generally accepted practice.
    Last Modified: 22-Jun-2012

    Date of Annual Report: 08/07/2012

    Report Information:
  • Annual Meeting Dates: 06/24/12 to 06/26/12
  • Period the Report Covers: 10/2010 to 09/2011

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    1. Welcome and participant introductions - Greg Evanylo

    2. Project Director, Lee Sommers, report  Update on National Institute of Food and Agriculture (NIFA) leadership. One of the significant changes is Sony Ramasamy replaced Roger Beachy as the Director of NIFA. Updates on farm bill were also given. Presentation will be posted on the project website. Lee announced his planned retirement in May 2013.

    3. Greg Evanylo has received state reports from most of the participants on time and will be preparing the annual report due 60 days after the annual meeting. W2170 is in Year 3. Renewal proposal is due January 15, 2015 and review will be in March 2015. It was suggested that the renewal proposal include supporting letters from USEPA and USDA stakeholders. The W2170 group will apply for the Multi-state Research award next year. The next award application is due March 1, 2013. This is $10,000 award with one nomination per region. Such an award would be valuable for helping to fund a 2014 decentennial State of the Science meeting in conjunction with our annual meeting.

    4. Venues for future annual meetings were finalized as: Denver/Ft. Collins, CO - 2013, Chicago, IL - 2014. Bob Brobst (USEPA) and Colorado State University members will host the Denver/Ft. Collins meeting. (An email survey following the meeting identified June 9-11as the preferred date for the 2013 meeting.) An urban focus was selected as a theme for the 2014 decentennial meeting in Chicago. Collaboration with USDA, USEPA, WEF, WERF, and other such organizations was recommended for the 2014 meeting.

    5. Urban soils issues - Greg Evanylo reported a desire by Ann Caroll, USEPA Brownfields Program, in bringing together interested W2170 members and USEPA Brownfield staff for a collaborative information-exchange meeting. It was agreed that the 2012 annual Soil Science Society of America meeting in Cincinnati, OH would be the best venue for such a meeting. The W2170 membership also discussed details necessary for developing an urban soil remediation handbook. Several W2170 members who have been working in this arena volunteered to participate. Pertinent chapter topics were further discussed during the Monday Urban Soils session. Members volunteering for this committee included: Rufus Chaney, Sally Brown, Greg Evanylo, Ganga Hettiarachchi, and Nick Basta.

    6. W2170 leadership discussions - Greg Evanylo explained a transition plan for the W2170 leadership. In-coming chair, Albert Cox will assume duty as chair during the 2013 annual meeting. Greg also encouraged members to contact future potential candidates for the W2170 group leadership positions. Albert Cox gave an update on Chicago municipal water treatment department and this included abandoning of their long-term test plots. Additional updates on state biosolids programs were provided by members.

    Technical Meeting Agenda

    Monday June 25

    8:00-11:45 AM

    Product development and soil pollutant assessment & remediation Bioretention mixes with organic residuals - Brown, UW

    EQ biosolids products - Cox, MRWD

    Environmental screening tool for incorporation of wastes into soil - Halbach, UMN

    Inexpensive risk-based screening of the usual suspects (i.e., contaminants) in soils from urban vacant lots - Basta, OSU

    Short paper fiber use - Bonhotal, CWMI

    Effects of soil amendments on Pb, As, and PAHs bioavailability in Urban soils - Hettiarchchi, KSU

    Cd and Zn bioavailability to earthworms - Parker, UC-R

    Using composts to remediate superfund sites and to reduce DDX uptake by earthworms - Chaney, USDA

    Facilitated discussion: urban soil remediation handbook, W2170-USEPA urban soil remediation collaboration

    Noon-2:00 PM Lunch and tour of Tacoma Community Gardens for remediation research-demos

    2:30-5:00 PM

    Climate change

    Effects of long term application of organic residuals on soil carbon sequestration - Evanylo, VT

    Carbon sequestration in mine soil reclaimed with manure based amendments  Stehouwer, PSU

    Carbon Sequestration in Appalachian Coal Mine Soils - Daniels, VT

    Carbon storage in reclaimed mine soils, life cycle analysis of biosolids reclamation, and ecosystem services with reforestation - Brown, UW

    Continuous automated measurements of soil N2O and CO2 Emissions with the portable IRGA system in the static chamber microplot study - Kostyanovsky, WSU

    Tuesday, June 25

    8:15-10:15 AM

    Fate and transport of emerging organic contaminants

    Fate of emerging trace organic contaminants during anaerobic digestion - McAvoy, UC

    Hormone chemodynamics in soils, sediments, ditches and streams associated with agricultural fields receiving animal waste applications - Lee, PU

    Bioaccumulation of biosolids-borne triclosan in terrestrial organisms - Waria, UW

    Tetracycline speciation controls the expression of bacterial antibiotic resistance - Li, MSU

    EDC activity by YES in irrigated recycled water leachate - Singer, UW 4-nonylphenol in biosolids-applied soils: where is it from? - Evanylo, VT

    10:30-11:30 AM

    Other State Reports and Volunteered Presentations

    Long term biosolids use in dryland wheat & struvite P availability - Cogger, WSU

    Threats to US crop exports to the EU based on EU lower Cd limits than Codex - Chaney, USDA

    11:30 AM Discussion and wrap-up

    Noon: Adjourn Meeting

    Accomplishments:
    Objective 1: Evaluate the chemistry and bioavailability of trace elements, organic microconstituents and nutrients in residuals and residuals-amended soils to assess the environmental and health risks. The research performed to accomplish objective 1included a) direct chemical measurements of nitrogen, phosphorus, trace elements, and organic compounds in the applied residual and upon transformation and/or transport through the environment and b) bioassays to assess bioavailability.

    Inorganic Trace Elements/Heavy Metals

    Use of urban land for agriculture can involve significant exposure to soil. However, most urban soils are not tested for Pb because of the high costs associated with sampling and analysis. Soil testing for plant nutrients is inexpensive and routinely performed for agricultural soils. Researchers from Ohio State University determined total and bioaccessible Pb in soil from 65 vacant lots being considered for food production in Cleveland, OH. Extractable Pb was determined using common agricultural soil test methods including Mehlich 3 extraction, Morgans extraction, and a 1M HNO3 extraction. Both the median and mean total Pb were above the Ohio EPA soil screening level of 400 mg/kg of Pb. Median bioaccessible Pb was 75.8% at a gastric pH of 1.5 and 42.6% at a gastric pH of 2.5. Significant linear regressions between total Pb and Mehlich 3 (r2=0.83), 1M HNO3 (r2=0.92), and Modified Morgan (r2=0.77) were found. Most commercial and university soil testing labs use Mehlich 3, which could be implemented as a screening tool for soil Pb, Cu, and Zn. The Mehlich 3 soil test is widely used and is inexpensive (< $15). Total Pb can be conservatively estimated by the equation: Total Pb (mg kg-1) = Mehlich 3 Pb (mg kg-1) x 2. In addition to accessing plant nutrition, the Mehlich 3 soil test can be expanded to be used as a screening tool to access Pb, and other select inorganic contaminants, and determine suitability of urban soil for food production.

    As part of an ongoing investigation of the bioavailability of trace metals (Cd and Zn) in soils contaminated by various sources (including biosolids and geogenic), researchers from the University of California-Riverside conducted a study of the uptake and elimination kinetics of Cd and Zn in two physiological contrasting earthworm species (Eisenia fetida and Lumbricus terrestris). A subset of three of the soils used previously was employed, and these were not isotopically labeled. Both earthworm species were reared in the three soils, and a subset was destructively sacrificed after 1, 2, 4, 7, 10, 15, 20, 25, and 30 days of exposure. Additional metal-loaded earthworms were transferred to an uncontaminated soil and reared for another 30 days (with periodic sub-sampling) to allow for monitoring of elimination. Uptake and elimination rates were each calculated using a first-order, one-compartment, toxico-kinetic model. This allowed evaluation of the element- and species-specific physiology of trace-metal accumulation. The three selected soils contained 130-1170 mg/kg total Zn and 11-19 mg/kg total Cd. Soils were also characterized for textural class, organic matter content, and pH. The labile pools by isotope dilution (E-values) represented 45% of the total Cd but only 25% of the total Zn, a trend that was consistent across all the soils under study. Pronounced differences were found on the earthworms' uptake and elimination kinetics between Zn and Cd. For the essential element Zn, initial uptake was rapid, and steady-state body burdens were observed after just 4-7 days of exposure. Uptake rates were slightly lower in L. terrestris than in E. fetida. The rapid attainment of steady-state body burdens could be explained by rapid elimination kinetics that, in turn, accounted for the rapid decline in Zn levels during the 30 d of cultivation in clean soil. Greater than 90% of the accumulated Zn was eliminated by the earthworms after the transfer to the clean soil. In contrast, initial Cd uptake was much slower and nearly linear, and a steady-state plateau in Cd body-burden was not reached after 25 days of exposure. Uptake rates were again lower in L. terrestris than in E. fetida. The fitted rate coefficients for the elimination of Cd were some 10-fold lower than for Zn and were greater in L. terrestris than in E. fetida. Moreover, less than 70% of internal Cd was eliminated by both species during the subsequent 30 d spent in clean soil.

    Colorado State University researchers found no adverse effects on earthworms (A. trapezoides) in a biosolids-amended Colby (Aridic Ustorthents)/Adena (Ustic Paleargids) soil. CSU researchers compared the long term application of biosolids and synthetic fertilizer N to dryland no-till wheat (Triticum aestivum, L.)-fallow (WF) and wheat-corn (Zea mays, L.)-fallow (WCF) agroecosystems to determine the effects of biosolids on grain Ba concentrations and soil P, Zn, Ba, and nitrate-N migration. Biosolids resulted in lower wheat grain Ba concentrations due to the soil formation of barium sulfate, and greater soil nitrate-N concentrations than N fertilizer in the 30-90 cm depth for the WF rotation and the 10-120 cm depth for the WCF rotation.

    Arsenic contaminated soils from past use as herbicides on former sugarcane fields present human health risks in Hawaii. A survey of soil As levels, using soil map units and GPS geographic coordinates, by University of Hawaii researchers concluded that: (1) As levels in Hawaiian soils range from 12 to 950 mg/kg; (2) the soil order of As concentration is Andisols (mean = 161 mg/kg), Oxisols (64 mg/kg), Ultisols (42 mg/kg), Inceptisols (36 mg/kg), and Mollisols (33 mg/kg). High contents of Fe and Al oxides in Andisols and Oxisols strongly retain As.

    Nutrients

    Penn State University researchers compared the accumulation of phosphorus (P) in forested and cropland soils continuously irrigated for 26 yr with secondary wastewater effluent. Whereas crop harvesting withdraws P from the cropped system, the lack of forest biomass removal suggests greater P accumulation in the surface horizons of the forest soils. However, both Mehlich-3 P (M3P) and total P (TP) were lower (alpha=0.05) in the 0-15 and 15-30 cm soil horizons in the forest than in the cropped areas. Mehlich-3 Fe and Al were lower in most horizons of the forest soil profile, suggesting soil P retention capacity of the soils has been depleted faster by podzolization in the forest than the cropped fields. Although total organic matter content in profiles were not statistically different, it is speculated that the increased management intensity of the cropped soils caused the soluble organic matter to be less conducive to formation of organo-metal complexes than in the forest soils. This phenomenon is supported by lower Mehlich-extractable Cu, known for its tendency to form strong organic complexes, in the forest soil profile. Greater displacement of P in forest soils appears to be confined to the upper soil horizons, and M3P and TP were statistically similar in the 30-45 and 45-60 cm horizons of the forest and arable soils.

    Pharmaceuticals and Personal Care Products/Hormones/Emerging Organics

    Wastewater treatment plants have been identified as a major source of trace organic compounds (TOrCs) to the environment. Since a significant amount of biosolids are land applied in the U.S., it is important to understand the fate of TOrCs during sludge digestion. University of Cincinnati researchers assessed the fate and removal of selected TOrCs during anaerobic digestion by monitoring TOrCs at a full-scale wastewater treatment plant and conducting laboratory fate experiments. Based on observed removal efficiencies in anaerobic sludge digestion, the TOrCs are categorized into three general groups. The first group comprises compounds with significant attenuation (> 90%) and includes atenolol, caffeine, and trimethoprim. These compounds also correspond to those compounds with the most rapid biotransformation rates (> 0.1 d-1) measured under laboratory conditions. The second group consists of compounds with moderate attenuation during anaerobic sludge digestion (removals between 15 and 90%) and includes DEET, meprobamate and triclocarban. Results for these compounds are not consistent with measured laboratory biotransformation rate constants (< 0.01 d-1). The third group of compounds are refractory during anaerobic sludge digestion (removals < 15%) and includes bisphenol A, carbamazepine, fluoxetine, and gemfibrozil. All of these compounds have laboratory biotransformation rate constants < 0.01 d-1. In general, compounds with the highest sorption potential (log Kd > 3) are expected to have the highest sludge concentrations. However, some of the compounds with low sorption potential (log Kd < 2) such as bisphenol A, caffeine, DEET, and trimethoprim have measureable quantities in sludge and biosolids. This observation occurs for high usage and biodegradable TOrCs like caffeine, as well as recalcitrant TOrCs like bisphenol A, carbamazepine, and trimethoprim.

    A collaborative project between researchers from the University of Florida and the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) entitled Fate and Transport of Biosolids-borne TCS and TCC was completed in 2011. Knowledge about the fate, transport, and risk of TCS (Triclosan) and TCC (triclocarban), antimicrobial chemicals commonly found in biosolids at concentrations on the order of 10-20 mg/kg, respectively, is incomplete, particularly in biosolids-amended soils. Work on biosolids-borne-TCC culminated in a recent submission of Snyder and OConnor (Risk assessment of land-applied biosolids-borne triclocarban (TCC), Sci. Total Environ.). The researchers integrated human and ecological risk assessment parameters measured in previous studies with recent data to perform a two-tiered human health and ecological risk assessment of land-applied biosolids-borne TCC. The 14 exposure pathways identified in the Part 503 Biosolids Rule were expanded, and conservative screening-level hazard quotients (HQ values) were first calculated to estimate risk to humans and a variety of terrestrial and aquatic organisms (Tier 1). The majority of biosolids-borne TCC exposure pathways resulted in no screening-level HQ values indicative of significant risks to exposed organisms (including humans), even under worst-case land-application scenarios. The two pathways for which the conservative screening-level HQ values exceeded one (i.e. Pathway 10: biosolids->soil->soil organism->predator, and Pathway 16: biosolids->soil->surface water->aquatic organism) were then reexamined using modified parameters and scenarios (Tier 2). Adjusted HQ values remained greater than one for Exposure Pathway 10, with the exception of the final adjusted HQ values under a one-time 5 Mg ha-1 (agronomic) biosolids loading rate scenario for the American woodcock (Scolopax minor) and short-tailed shrew (Blarina brevicauda). Results were used to prioritize recommendations for future biosolids-borne TCC research, which include additional measurements of toxicological effects and TCC concentrations in environmental matrices at the field level. Work on biosolids-borne-TCS reported in the 2010 report was described in three journal articles authored by Waria Pannu and OConnor. A nearly complete risk assessment paper reports that TCS is more strongly retained (log Koc = 4.26 ± 0.31) than TCS (log Koc = 3.82 ± 0.16), but both are essentially immobile in most soil conditions. The major difference between the compounds is in estimated half-lives: TCS t 1/2 ~100 d and TCC t 1/2 ~20 y, which significantly impacted ecological risk assessment. Omitting degradation identified pathway 10 as critical for TCS. Including degradation, however, eliminated pathway 10 (HI value <1) for most biosolids containing TCS. Major conclusions are: 1) ecological risk assessments remain incomplete because of critical data gaps, 2) theoretically modeled/estimated parameters should be viewed with caution as they frequently differ significantly from measured values, and 3) long-term field studies are needed to validate risk assessment parameters and estimates and to accurately derive regulatory standards.

    A laboratory soil column study performed by Virginia Tech researchers to investigate the transport and transformation of TCS and TCC in a biosolids-surface applied soil was published online by the Environmental Toxicology and Chemistry in 2011. During this study, the column leachates and soil samples were analyzed for TCS, TCC, and their transformation products. Significantly more TCS was transformed compared to TCC. Surface application of biosolids significantly retarded their transformation. Downward movement of TCS and TCC occurred within 10-cm soil depth. Methyl-TCS was not detectable in the leachates but was detected in the top 5-cm soil layer, and higher in the biosolids-applied soil. At the end of the column study, carbanilide (CBA) was the only detectable TCC reductive dechlorination products in the soil. None of the TCC reductive dechlorination products were detectable in the leachates. Detection of 3,4-dichloroaniline (3,4-DCA) and 4-chloroaniline (4-CA) suggested the occurrence of TCC hydrolysis. Rapid leaching of 4-CA through the soil column was observed. The 3,4-DCA was detected throughout the entire 20-cm depth of the soil column but not in the leachates. The fact that only small percentages of the transformed TCS and TCC appeared, after 101-day column study, in the forms of the products analyzed suggested that either the investigated transformation pathways were not significant or rapid transformation of the those products had occurred.

    Researchers from Michigan State University developed an analytical method to quantitatively determine pharmaceuticals in biosolids. Following freeze drying and grinding, biosolids samples were subjected to accelerated solvent extraction. The optimal operation parameters, including extraction solvent, temperature, pressure, extraction time and cycles, were identified to be acetonitrile/water mixture (v/v 7:3) as extraction solvent with 3 extraction cycles (15 minutes for each cycle) at 100 °C and 100 bars. The extracts were purified using solid-phase extraction followed by determination by liquid chromatography coupled with tandem mass spectrometer. For the fifteen target pharmaceuticals commonly found in the environment, the overall method recoveries ranged from 49% to 68% for tetracyclines, 64% to 95% for sulfonamides, and 77% to 88% for other pharmaceuticals (i.e. acetaminophen, caffeine, carbamazepine, erythromycin, lincomycin and tylosin). The method limit of quantification attained mg pharmaceuticals per kg of dry biosolids level. The method was successfully validated and applied to the biosolids samples collected from WWTPs in six Michigan cities. Fourteen or the 15 targeted pharmaceuticals were detected in the biosolids samples, with mean concentrations ranging from 2.6 g/kg for lincomycin to 744 g/kg for oxytetracycline. Cation exchange is the primary mechanism driving lincomycin for sorption by soils. Lincomycin is more competitive for cation exchange sites occupied by K+ than those by Ca2+. The presence of K+ and Ca2+ in aqueous solution (0.02 M) significantly suppressed lincomycin sorption, with more suppression observed for the soils with lower cation exchange capacity. CaCl2 solution manifested a more suppressive effect on lincomycin sorption than KCl, plausibly because the acidic functional groups in soil organic matter such as carboxylate form relative stable complexes with Ca2+ leading to the reduced interactions with lincomycin. Lincomycin sorption increased as soil solution pH increased from 5.8 to 7.8, and then decreased significantly at pH 8.9. The maximum sorption occurred at pH values between 7.3 and 7.8, near the pKa of lincomycin (7.6).

    Experiments were conducted by Penn State University researchers to determine the optimal conditions for sample storage of soils spiked with estrogens (17-beta-estradiol, estrone, 17-alpha-ethinylestradiol). Soil samples (Ap horizon of the silt loam Hublersburg series) were collected from a wastewater irrigated site in central Pennsylvania. Spiked soils were used to evaluate sample storage stability from samples stored at 4C versus -18C across three storage times (2 days, 7 days, 30 days). With respect to storage, -18C was found to provide better stability for storage of 17-²-estradiol compared with storage at 4C, but similar storage stability occurred for estrone and 17-±-ethinylestradiol whether samples were stored at -18C or 4C. Moreover, storage in the refrigerator and freezer showed similar recovery rates for time frames of 2 days and one week; however, recovery rates dropped ~ 20% after one month of storage for both the freezer and refrigerator.

    Purdue University researchers conducted or completed research focused on the fate of natural and veterinary hormones associated with animal manures. They quantified trenbolone (TB) and E2 isomers and their metabolites in manure collection pits and lagoon effluent from beef cattle implanted with the commercial anabolic preparation Ravoler-S (containing 140 mg 17²-trenbolone acetate and 28 mg 17b-E2). 17±-TB was the most abundant androgen with the highest concentration observed 2 weeks post implant. 17²-TB and trendione peaked at the end of week 2 and 4, respectively. For the estrogens, the highest concentrations for estrone (E1), estriol (E3), and 17a-E2 were observed after week 4, 6, and 8, respectively. 17b-E2 concentrations were the lowest of the estrogens and erratic over time. In lagoon water, which is used for irrigation, 17±-TB and E1 had the highest detected hormone concentrations (1.53 and 1.72 µg L-1, respectively). Assuming a 1 to 2 order dilution during transport to surface water, these hormone levels could lead to concentrations in receiving waters that exceed some of the lowest observable effect levels (LOELs) reported for hormones (e.g., 0.01-0.03 µg L-1). The Purdue researchers developed and validated a hydro-biogeochemical model, Hormone Export and Restoration Dynamics (HERD) to determine the relative roles of macropore and matrix flow on hormone transport, hormone persistence, and effect of management practices to reduce downstream export of hormones. HERD simulation results confirmed that retardation and degradation play a minor role in macro-pore transport given the short travel times, exporting hormone loads directly to tile drains and receiving ditches. For matrix flow with longer travel times, retardation and fast hormone degradation rates leads to limited contributions to hormone loads. Additionally, preliminary HERD simulations suggest that hormones build up in the source zone over time as a result of repeated animal effluent irrigations, suggesting the development of legacy sources. Findings imply that hydrologic variability rather than biogeochemical processes serve as the dominant control of hormone export from agricultural fields. Trends observed in HERD simulations are consistent with field-scale observations measured in an earlier EPA STAR funded project. Model and field-scale monitoring results show that long-term, repeated animal waste applications can lead to chronic exposure of aquatic organisms to hormones at low concentrations and intermittent, short durations of high concentrations closely related to application times and hydrologic variability. The preliminary model simulation results also suggest a short lag time (~5 years) between the ceasing of animal waste application and subsequent depletion of the accumulated legacy sources, suggesting that the extent of legacy hormone sources is much less than that of nutrients, which can have lag times on the order of decades. Furthermore, the positive correlation between hormone loads and hydrologic variability leads to the majority of hormone export occurring during high-flow events. Considerable research has focused on the fate of 17²-estradiol (17²-E2) given its high estrogenic potency and frequency of detection in the environment; however, little is known about the fate and transport behavior of 17±-estradiol (17±-E2) although it often dominates in some animal feces such as dairy, beef cattle, and sheep, and recently has been shown to have similar impacts as the ²-isomer. Purdue researchers quantified the degradation and metabolite trends for both isomers using two agricultural soils under aerobic conditions and sediments under nitrate- and sulfate-reducing conditions. In laboratory-based aerobic surface soils, 17²-estradiol (E2) and 17a-E2 half-lives were similar for a given soil and ranged between 4-12 h with estrone (E1) as the primary metabolite and E2 degradation retarding after 1-2 days. Under both reducing conditions, the half-lives of 17²E2 < 17±E2 and half-lives were greater under sulfate-reducing conditions. Interconversion between 17²E2 and 17±E2 was observed under both reducing conditions, presumably with E1 serving as the intermediate. Under both reducing conditions, E1 was transformed back to its precursors, with a preference for 17²-E2 formation. Initial conversion to ²E2 was rapid, especially under sulfate-reducing conditions where ~30% E1 (% mole) was transformed to ²E2 within 3 days and ~2.5% under nitrate-reducing conditions within hours. E1 was more persistent under nitrate-reducing conditions; however, transformation back to the precursors was greater under sulfate-reducing conditions with a higher accumulation of the precursors under sulfate-reducing conditions. Therefore, while sediments may serve as a sink for estrogenic compounds, anaerobic conditions provide a unique environment where metabolites may transform back to the parent estrogens, which are often the more potent contaminants of concern. Controls performed in autoclaved-sterilized soils and sediments indicate that E2 degradation is dominated by microbial processes.

    Objective 2: Evaluate the agronomic and environmental benefits/advantages of land applying residual by-products and/or substituting such materials for fertilizers.

    Use of biosolids as a beneficial fertilizer in agricultural ecosystems

    Colorado State University researchers determined that the long term application of biosolids to dryland, no-till wheat (Triticum aestivum, L.)-fallow (WF) and wheat-corn (Zea mays, L.)-fallow (WCF) agroecosystems at a site approximately 40 km east of Byers, CO improved soil moisture retention and vegetative cover that reduced erosion. Biosolids and N fertilizer produced similar wheat and corn yields.

    University of Minnesota researchers conducted studies for the Southern Minnesota Beet Sugar Cooperative (SMBSC) on soil byproducts derived from sugar beet tare soils. Experiments have been completed to evaluate the germination of corn, oats, and soybeans in soil byproducts relative to field soils and the stable aggregate size distributions of a field soil amended with varying amounts of a soil byproduct. The soil byproduct reduced germination rate and increased time to germination of corn, oats, and soybeans planted in a clay loam and a sandy soil. Variations among growth media in crop germination percentage and time to germination could not be explained by any of 19 measured soil characteristics (pH, salts, etc.). The byproduct amended soils had a significantly greater percentage of their mass in moderately large particles (1-2 mm and 2-4 mm in diameter) and a significantly smaller percentage in small particles (< 0.25 mm) than the untreated soil.

    Field studies conducted by Virginia Tech researchers on coarse-textured soils from 2009-2011 demonstrated the beneficial effects of biosolids on drought-amelioration, carbon (C) sequestration and nitrogen (N) availability in a corn (Zea mays L.)-soybean (Glycine max L.) rotation under both conventional and no-tillage practices. The estimated agronomic N rate of both lime-stabilized and anaerobically digested biosolids increased soil inorganic (plant-available) N immediately prior to the high N uptake period by corn, plant tissue N at silking, and soil organic C and N by the end of the growing season compared to similar synthetic fertilizer nitrogen rates supplemented with needed P and potassium. The same combination of mineralization and volatilization factors used to calculate plant available N for soil-incorporated biosolids can be used on biosolids applied to no-till systems in coarse-textured soils of the mid Atlantic Coastal Plain. There was no effect of amendment type on soil C concentration, but both biosolids types increased plant available water holding capacity above that attained with the fertilizer treatment by the end of the study. Biosolids applied at agronomic rates have been shown to improve hormone metabolism and drought tolerance in greenhouse trials, but no research has demonstrated such effects in the field. Application of lime stabilized and anaerobically digested biosolids increased leaf photochemical efficiency (PE), auxin, cytokinin, proline, protein, and superoxide dismutase (SOD) activity in corn throughout the season. The soybean grown in the plots previously amended with the biosolids exhibited greater PE, auxin, trans-zeatin riboside, protein content and SOD activity when compared to those without biosolids. The lime stabilized and anaerobically digested biosolids increased corn grain yield by 87% and 77%, respectively, and soybean grain yield by 15% and 18%, respectively, compared to the fertilizer control. The results of this study indicated that biosolids application could improve PE, growth hormones, proline, protein, and antioxidant metabolism, and increase grain yields, especially under drought stress environment.

    Large-scale sampling of long term field plots and farm fields were conducted in WA and CA by University of Washington researchers and in Virginia by Virginia Tech researchers to determine the value of agronomic rates of biosolids and composts on soil carbon and nitrogen concentrations and stocks. Changes in water holding capacity and bulk density were also measured in CA and WA. For the majority of the sites, using organic residuals resulted in increased soil carbon storage, persistent increases in total nitrogen and improved soil physical properties. These results suggest that land application of such residuals may be useful for sequestering carbon and for maintaining or enhancing soil quality attributes.

    Land Reclamation with Residuals

    Penn State University researchers determined that substantial production of switchgrass and Atlantic coastal panic grass is possible with the use of manure and paper mill sludge amendments for reclaiming mined land.

    As a result of historic mining activities conducted in the Tri-State Mining District, the Spring River and its tributaries in the far southeast part of the Neosho Basin in southeast Kansas are contaminated with lead, zinc, and cadmium. It has been hypothesized that under reducing conditions, metals in these materials can be transformed back in to their sulfide forms, greatly limiting their mobility. Kansas State University researchers showed that, upon stimulation of reduction, metals were effectively immobilized within ninety days of submergence. Scanning electron microscopy and energy dispersive x-ray analysis conducted on micro- and nano-size colloids in the effluent water provided evidence of bacterial associated and freely dispersed colloidal-bound contaminant transportation.

    Virginia Tech researchers continued their long-term evaluation of the effects of higher than agronomic (78 Mg/ha) loadings of biosolids on soil productivity of lands reclaimed at a mineral sands mining site in 2001. Consistent with previous results, significant improvements in soil productivity were noted, and reclaimed mined lands continue to exceed local county average crop yields by 25% to 35%.

    Virginia Tech researchers installed a new experiment in April 2011to evaluate potential nitrate-N leaching following use of biosolids to reclaim mineral sands mined lands in Dinwiddie County. The overall objective is to determine the effectiveness of high rates of biosolids (21Mg/ha) vs. agronomic rates (4Mg/ha) of biosolids for soil reconstruction as compared with standard fertilization practices. First year vegetation establishment was hindered by hot dry conditions, but a wide array of weed species that invaded the plots was more abundant on the two biosolids treatments. The plots were over-seeded again in the fall of 2011 and vegetation establishment and production to date is still substantially higher on the biosolids treated plots. Large leaching losses of fertilizer N have been noted below the conventionally fertilized plots while a minor loss of N has also been noted for the high rate of biosolids. A surprising pulse of ortho-P was also noted in leachates in the late summer of 2011 following several very large rain events.

    Use of biosolids as a beneficial soil amendment for urban/brownfield soils

    Kansas State University researchers evaluated the uptake of contaminants by food crops grown on residual unamended- and amended-mildly contaminated urban soils (formerly brownfields), the effects of residual amendments on bioaccessibility of contaminants, and developed recommendations for corrective/protective actions to minimize direct (ingestion) and indirect (food chain transfer) exposure pathways of contaminants. Contaminants were: As and Pb (Tacoma, WA); Pb (Seattle WA); Pb, As, and PAHs (Indianapolis, IN); Pb (Pomona, CA); Pb (Philadelphia, PA); and Pb and As (Toledo, OH). Treatments at the Indianapolis site were 28 kg/m2 of leaf and mushroom compost and biosolids (composted and uncomposted). Three types of crops were planted: a leafy vegetable (collard green); a root crop (carrot), and a fruit crop (tomato). Two cleaning procedures used were kitchen style washing and thorough laboratory cleaning. Results to-date show soil pH and residuals additions reduce plant uptake of contaminants. Thorough cleaning of vegetables significantly reduces potential for food-chain transfer of soil contaminants. Although soil Pb concentration was as high as 2000 mg/kg and soil As was as high as 146 mg/kg, concentrations in laboratory cleaned leafy vegetables and fruit crops were low. Uptake of Pb from some mildly Pb contaminated soils (~200 to 250 mg/kg) by root crops was high. Bioaccessibility of Pb in most urban soils appeared to be low (< 15-20% of total Pb in soil).

    University of Washington researchers investigated the ability of high Fe biosolids composts to reduce Pb and As bioaccessibility in situ. In many municipalities, Fe is added to the wastewater treatment process to reduce P concentrations in effluent. Fe oxides are also commonly used to treat potable water and spent water treatment residuals (WTR) are commonly landfilled. The UW researchers tested a high-Fe compost from Philadelphia and two composts created by adding Fe as iron chloride or an iron grit powder to feedstocks prior to composting. Composts were evaluated in a field trial as well as in laboratory incubations. Bioaccessibility was measured using an in vitro extract. Pb and As speciation were determined using u-XAFS. Results indicate that not all Fe is created equal. Reductions in absolute bioaccessibilty, as well as changes in mineral form of Pb and As, were only observed for the compost where spent Fe WTR were added to the compost. These results suggest a potential specialized compost blend could be produced for homeowners concerned about potential Pb and As contamination in home gardens.

    Composting and compost use

    Researchers from the Cornell Waste Management Institute continued surveying uncharacterized organic residuals from New York state industries and began a multi-tiered analysis protocol to evaluate them for use as soil amendments. Residuals included short-fiber paper mill residuals, residues from the grape industry, residuals from manufacture of composite board, and limed and unlimed short-fiber paper residuals (PR) as a byproduct of paper manufacturing. Currently, these residuals are landfilled, with issues arising due to leachate runoff, methane emissions and cost. Alternatives being testing include composting, pyrolysis, and direct soil incorporation. Organic residuals with no current beneficial end use determinations continue to be surveyed. Only the PR and unlimed PR with no additional feedstocks did not compost well, likely due to their high C:N ratios. Metal concentrations in PR and unlimed PR were within the USEPA Part 503 Ceiling Concentrations. The ranges of the composition of the composts were pH: 8.3 - 8.4, soluble salts (dS m-1): 0.05 - 0.06, bulk density (g cm-3): 0.82 - 0.98; moisture (g kg-1): 430-460, organic matter (g kg-1): 340-420, total N (g kg-1): 17.4-26.5, organic N (g kg-1): 16.7-25.7, C:N: 16-18, P (g kg-1): 6.3-6.8, K (g kg-1): 8.5-8.6, Cu (mg kg-1): 46  69, Zn (mg kg-1): 97  111; and indicated very good organic amendments for soil. Use of these residuals as a compost feedstock is proving thus far to be an environmentally-friendly alternative to disposing of them in a dedicated landfill.

    The process of producing Class A, air-dried biosolids at the MWRDGC includes lagoon-aging followed by air-drying, which often produce odors during storage because it is not well stabilized. MRWDGC researchers composted various blends of aged and unaged biosolids and high carbon materials (tree leaves, wood chips and landscaping waste mixture) to determine the effect on biological stability and odor potential of the final air-dried product. Each type of biosolids was mixed with a high carbon material at the ratio of 2:1 (w/w) biosolids:high carbon waste. Maximum temperature in windrows was higher in the unaged than aged, with landscaping waste mixture than with leaves and wood, and with the higher carbon:biosolids ratio. All blends with high carbon materials reduced final basal respiration, odor and nitrogen loss. These preliminary results show that the addition of low rates of high carbon materials could improve the stability of the MWRDGCs air-dried biosolids.

    University of Hawaii researchers investigated the effects of vermicompost tea (aqueous extract) on yield and chemical quality of pak choi (Brassica rapa cv Bonsai, Chinensis group) grown in three media (two soils and a peat-perlite medium) under two fertilizer regimes (compost and synthetic fertilizer). Application of vermicompost tea increased plant production, total carotenoids and total glucosinolates in plant tissue. This effect was most prominent under compost fertilization. Total phenolics concentration was lower in vermicompost tea treated plants compared to those treated with only mineral nutrient solution and the water control. Vermicompost tea improved mineral nutrient status of plants and media, and enhanced the biological activity of the media. Variability in yield and chemical quality of plants across treatments was explained largely by variability in tissue N uptake and dry matter accumulation. Dehydrogenase activity and soil respiration of vermicompost tea-treated growth media were approximately 50% higher than untreated media. This study confirmed that vermicompost tea can positively influence plant yield and quality and increase soil biological activity in multiple soil types.

    Penn State University and Virginia Tech faculty conducted basic and advanced composting training to commercial composters from across the mid-Atlantic region. Course participants indicated a strong intent to add food and other residuals to their composting operations.

    Impact Statements:
    1. Addition of earthworms (A. trapezoides) to biosolids-amended dryland agroecosystems improves water movement and storage in soils.
    2. Anaerobic sludge digestion reduces many trace organic compounds.
    3. Risk assessments performed for most exposure pathways suggest minimal risk from the land application of biosolids-borne TCC and TCS.
    4. Biosolids partially composted with high C materials and minimal modifications to biosolids processing operations result in a stable, odor-free product that will have greater public acceptance for urban use.
    5. Commonly used, inexpensive, and widely available agricultural soil tests can serve as an excellent screening tool to assess the suitability of Pb-enriched urban soil for gardening.
    6. Anaerobic conditions in field ditch sediments can transform estrogenic metabolites to their parent compounds, which are often the more potent contaminants of concern.
    7. Land-applied biosolids can increase crop yields above that attained with synthetic fertilizer by their promotion of plant biostimulants that ameliorate drought stress.
    8. Use of high rates or regular applications of agronomic loading rates of organic residuals is the most effective option for increasing soil C storage and improving the physical properties of soils, which can aid in ameliorating the detrimental effects of climate change.
    9. Use of high rates of biosolids in post-mining soil reconstruction provides optimal soil productivity restoration for row-crops with minimal risks of nitrate-N leaching to groundwater, which results in highest post-mining land values and considerable cost savings.
    10. Mixing high Fe water treatment residuals into compost can produce amendments that will reduce the bioaccessibiltiy of soil lead.
    Last Modified: 08-Aug-2012
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