Recipient Organization
STROUD WATER RESEARCH CENTER INC
970 SPENCER ROAD
AVONDALE,PA 193119514
Performing Department
(N/A)
Non Technical Summary
The goalof this projectis to studyhow the use of biosolidsmay contribute to the degradation ofwater quality in agroecosystems. Biosolids, derived from the solid organic waste removed at water treatment plants,are a very valuable soil amendment, however, they can be contaminated withPFAS (per- and polyfluoroalkyl substances), a class of emerging contaminants that can be harmful to humans and the environment. Therefore, their use in farmscan result in the contamination of soils,water and food. Over the next three years, we will study the transport and transformation of biosolid-derived PFAS in soils and rivers usingacombination of laboratory and field experiments. We will attempt to answer thefollowing specific questions: Q1. What are temporal dynamics driving concentration and fluxes of PFAS in biosolid-treated soils and the agro-fluvial systems draining them?, Q2. How are PFAS dynamics in fluvial systems related to organic matter concentration and chemical character?, and Q3. How do temperature regimes affect the export of PFAS from biosolid-treated soils to the hydrologic network?Our proposed research has broad relevance to agricultural producers and regulators; outcomes of our work will inform best management practice development to minimize risks to agroecosystem health and productivity. Effectively and safely managing biosolids as a soil amendment is vital to ensuring sustainable agricultural economies.
Animal Health Component
0%
Research Effort Categories
Basic
100%
Applied
0%
Developmental
0%
Goals / Objectives
Our overarching goal of this project is to provide unmatched process-based estimates of transport and transformation of biosolid-derived PFAS in agro-fluvial systems. The especific objectives are:O1: To examine changes in PFAS concentrations and species in biosolid-treated farm surface soils, focusing on periods after biosolid application and storm events.O2: To quantify species, concentrations and fluxes of dissolved and particulate (sediment-sorbed) PFAS at base- and stormflow conditions in a stream draining a farm with history of biosolid use.O3: To characterize the transport and transformation of PFAS from biosolid-treated soils to the hydrologic network during simulated storm conditions at different temperatures using a mesocosm approach.
Project Methods
Study sitesTreatment stream site: We will work with one of the PA farmers that was part of one of our previous studies. The proposed stream monitoring station would be located in his property. At the monitoring station, the stream is 1st order, perennial, and drains an area of ~5 km2. Total stream length of the network 2.0 km. It is important to highlight that over 90% of the agricultural land in this watershed is owned by the same farmer, and that most of his fields have received biosolids over the last 15+ years.Control stream site: We will leverage an already-established monitoring site of the Stroud Water Research Center located in a nearby State Park. At the proposed site, the stream is 1st order, perennial and drains an area of 4 km. The stream network's total length is 2.4 km. Land use in the watershed is 4% open space, <1% developed, 93% forest, <1% pasture/hay, 1% cultivated crops, and 1% wetlands. Mean annual precipitation in the region is 112 cm. Based on previous work at the Stroud Water Research Center, the stream has a Macroinvertebrate Aggregated Index for Streams (MAIS) score of 14.5 (average over the last 7 years). A MAIS score between 11-15 is considered good and indicates the water quality at the site is high. Both treatment and control sites have very similar surface geology andthe closeness between the treatment and control sites ensure climate and weather conditions will likely be very similar during the study period.Biosolid-treated field: the monitored biosolid-treated field will be the same we have sampled previously. The field is located in the watershed of the proposed treatment stream site.Soil samplingSoil samples will be collected monthly over 2.5 years, however targeted sampling will be conducted immediately (hours) before and after storm events and biosolid applications. At the biosolid-treated field, 90 transects perpendicular to the crop contour will be geospatially marked. During each soil sampling collection, three transects will be selected randomly to generate three field pseudo-replicates. The used transects will be marked to avoid resampling. Ten equally spaced cores (0-15 cm) will be collected from each transect using a slide-hammer corer and combined in a PFAS-free bag to generate enough soil volume for all the analyses. The soils will be transported to the laboratory where they will be homogenized and subsampled for analysis of PFAS concentrations (STRIDE laboratory) and general soil chemistry properties (Cornell Soil Health Laboratory, Basic Package).Stream monitoringSensor installation and maintenance: at each stream monitoring site, sensors for conductivity, temperature and depthwill be installed. Sensors will be cleaned, and data will be downloaded every time the sites are visited for sample collection. Discharge (Q) will be measured manually during regular site visits and also during targeted storm events to capture a wide range of hydrologic conditions necessary for the development of an appropriate depth-Q rating curve.Water sampling: Water samples will be collected manually at baseflow every two weeks at the treatment site and monthly at the control site. Battery-powered autosamplers will be used for the collection of water samples at higher-frequency during storm events (every 30 min to 2 hours, depending on the storm forecast). We will target three storms per year over 2.5 years for the stormflow sample collection.Sediment sampling: Sediment samples will be collected at baseflow every two weeks at the treatment site and monthly at the control site. In addition, sediment samples will be collected before and after targeted storm events. For this, 10 equally spaced cross sections in a 100 m stream transect will be geospatially marked at the onset of the project. Sediment samples will be collected from each cross section and combined to generate one composite sediment sample that will be representative of 100-m stream reach. For the collection of stream sediment, a 10-cm diameter coring probe and a spatula will be used to sample the streambed down to 3 cm.Mesocosm experimentWe will use custom-made pans to hold 20 x 20 cm, 15-cm deep, intact soil layers. The pans will be designed to allow the collection of infiltrated water and overland runoff (Figure 6). Treatments in triplicate will include a control (natural soil with no measurable PFAS content), natural soil amended with PFAS-contaminated biosolids (+b), and natural soil amended with PFAS-contaminated biosolids and two or more different isotopically labeled compounds(+b+i). Isotopically labeled compounds will be chosen to produce degradates or metabolites that are unique from each other and native PFAS that may be present. Each treatment will be incubated at two different environmentally relevant temperatures (0?, and 20?) for 72 hours before being exposed to a simulated rain event. The rain event will have an environmentally relevant rate (e.g., 1 in over two hours) for long enough to generate 150 mL of infiltrated water, collected in three timed increments of 50 mL. The bottom of the pan will then be closed, and the rain will continue until 200 mL of overland flow is generated, collected in three timed increments of 50 mL.Sample analysisSoil and sediment PFAS analysis: Samples will be dried to constant weight in a fume hood and then homogenized further in a glass mortar and pestle. An aliquot is then fortified with a mixture of stable-labeled isotopic internal standards and extracted with 2% (v/v) ammonium hydroxide in methanol. The extract is then treated with powdered activated carbon (PAC) and concentrated under a stream of nitrogen. The final sample is then analyzed using HPLC-MS/MS with negative ion electrospray.Water PFAS analysis: Water samples will be filtered using a 0.7 μm glass fiber filter to separate the suspended solids from the dissolved fraction. The filters will be treated as described above for soil and sediment samples. The dissolved fraction (250 mL) is fortified with a mixture of stable-labeled isotopic internal standards and concentrated using weak anion-exchange (WAX) solid-phase extraction (SPE) cartridges. The SPE cartridges are eluted with 2% ammonium hydroxide in methanol, and the eluate is reduced in volume under a stream of nitrogen. The final sample is then analyzed using HPLC-MS/MS with negative ion electrospray.HPLC-MS/MS analysis method: The HPLC-MS/MS method used will be consistent with the one specified in EPA Draft Method 1633. Multi-reaction monitoring (MRM) data is acquired for 40 native PFAS analytes, 25 extracted internal standards (stable labeled internal standards that are added prior to extraction to correct for minor recovery losses and signal suppression effects) and 7 non-extracted internal standards (stable labeled internal standards that are added at the end of sample preparation to assist in quantification of the extracted internal standards).Standard water chemistry analysis: Water samples will be filtered using a 0.2 μm filter and then analyzed for nitrate and chloride concentration using an Integrion ion chromatograph (DIONEX). A separate water aliquote will be filtered using a glass fiber filter (0.7 μm), the filtrate will be analyzed for dissolved organic carbon (DOC) concentration using a Sievers M510C carbon analyzer (Veolia), and optical properties of the dissolved organic matter (DOM) using an AQUALOG fluoro/spectrophotometer (HORIBA), the filter and particulate matter accumulated on the filter will be used for the quantification of particulate organic matter (POM) via loss on ignition.Soil and sediment chemistry analysis: Samples sent to the Cornell's Soil Health Laboratory will be analyzed for their Basic Soil Health Analysis Package.?