Spatiotemporal patterns of PFAS in water and crop tissue at a beneficial wastewater reuse site in central Pennsylvania

Abstract

Per-and polyfluoroalkyl substances (PFAS) are a collective name for thousands of synthetic compounds produced to enhance consumer and industrial products since the 1940s. They do not easily degrade, and some are known to pose serious ecological and human health concerns at trace concentrations (ng L −1 levels). Per-and polyfluoroalkyl substances persist in treated wastewater and are inadvertently introduced into the environment when treated wastewater is reused as an irrigation source.The Pennsylvania State University (PSU) has been spray-irrigating its wastewater at a 2.45 km 2 mixed-use agricultural and forested site known as the "Living Filter" since the 1960s. To understand the spatiotemporal patterns of 20 PFAS at the Living Filter, water samples were collected bimonthly from fall 2019 through winter 2021 from the PSU's wastewater effluent and from each of the site's 13 monitoring wells. Crop tissue was collected at the time of harvest to assess PFAS presence in corn silage and tall fescue grown at the study site. Total measured PFAS concentrations in the monitoring wells ranged from nondectable to 155 ng L −1 , with concentrations increasing with the direction of groundwater flow. Concentrations within each well exhibited little temporal variability across sampling events, with mixed relationships between PFAS and groundwater elevation observed between wells. Further, >84% of the PFAS present

Storage, Transport, and Fate of Perfluoroalkyl Acids (PFAAs) in a Wastewater Reuse and Groundwater Recharge System

“…For PFOA, the mean reported K oc paired with data from eight soil samples results in eight estimates of equilibrium water PFOA concentration, with a mean of 1,557 ng L −1 and a range of 120-5,183 ng L −1 (Figure 4). For both PFOS and PFOA, the lowest values of these ranges are an order of magnitude higher than the 2019-2020 mean effluent concentrations (Mroczko et al, 2022) (Figure 4).…”

“…PFAA concentrations were measured by others in site effluent and groundwater between October 2019 and February 2021, with nearly ubiquitous occurrence of PFAAs across the Living Filter (Mroczko et al., 2022). Though groundwater concentrations showed little seasonal variability, a spatial pattern was observed, with concentrations generally increasing along the groundwater flow gradient to the northeast beneath the site (Mroczko et al., 2022). Four of the groundwater wells sampled were located near the soil core locations at the Astronomy Site (Figure 1), so PFAA concentrations in those wells were used as a constraint for our analyses.…”

Mitigating risks and maximizing sustainability of treated wastewater reuse for irrigation

“…PFAS includes thousands of highly persistent, bio-accumulative, and potentially toxic substances ( Cousins et al., 2020 ). PFAS concentrations in TWW vary by location, and data on their levels in irrigated soils and crops are limited and conflicting ( Mroczko et al., 2022 ; Shigei et al., 2020 ; Table 2 ), highlighting the need for further research and comprehensive evaluation on local scales.…”

“… Contaminant Country Did the contaminant persist in soil/crops after irrigation OR were levels higher in TWW than other sources? Reference Chemical contaminants PFAS ⁎ USA Yes - Persistence after irrigation Mroczko et al., 2022 PFAS Jordan No - No persistence Shigei et al., 2020 Carbamazepine, other epilepsy drugs Israel Yes - Persistence after irrigation Ben Mordechay et al., 2022a ; Paltiel et al., 2016 ; Schapira et al., 2020 Antimicrobials USA Yes - TWW higher than other irrigation sources, with exception of ciprofloxacin Panthi et al., 2019 Antimicrobials Germany Yes - Persistence after irrigation Kampouris et al., 2022 Bacterial and viral contaminants Enteric viruses Spain Yes - TWW higher than other irrigation sources López-Gálvez et al., 2016 E. coli Palestine TWW not consistently different than other irrigation water sources Craddock et al., 2020 Vibrio spp. USA TWW not consistently higher than other irrigation water sources Malayil et al., 2021 Salmonella enterica and Listeria monocytogenes USA No - Surface water had higher levels than TWW Acheamfour et al., 2021 ARGs ⁎⁎ USA Yes - TWW higher than other irrigation sources Malayil et al., 2022 Resistant Enterococcus USA No - TWW had no impact on ARB in sludge McLain and Williams, 2014 ARGs …”

Storage, transport, and fate of perfluoroalkyl acids (PFAAs) in a wastewater re-use and groundwater recharge system

“…PFAA concentrations were measured by others in site effluent and groundwater between October 2019 and February 2021 (Mroczko et al, 2022). Four of the groundwater wells sampled were located near the soil core locations at the Astronomy Site (Figure 1), so PFAA concentrations in those wells were used as a constraint on our models.…”