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Land application of wastewater effluent is beneficial for recharging groundwater aquifers and avoiding direct pollutant discharges to surface waters. However, the fate of non-regulated organic wastewater pollutants, such as pharmaceuticals and personal care products (PPCPs), in such wastewater reuse systems is understudied. Here, a 14-month study (October 2016 through December 2017) was conducted to evaluate the fate and potential risks of seven commonly used PPCPs in a local wastewater treatment plant (WWTP) and from 13 groundwater monitoring wells at a spray-irrigation site where effluent has been spray-irrigated since the early 1980s. Acetaminophen and trimethoprim were the most frequently detected (93%) PPCPs in WWTP influent, while in the effluent, caffeine and trimethoprim were detected most frequently (70%). Wastewater treatment generally reduced concentrations of acetaminophen and caffeine by >88%; however, some compounds had low removal or were present at higher concentrations in the effluent compared with influent (e.g. naproxen, sulfamethoxazole, trimethoprim and ofloxacin). Seasonal trends were observed, with higher PPCP concentrations in the WWTP influent and effluent in the winter. Risk calculations conducted on the wastewater effluent suggest that the risk posed by PPCPs that persisted in the effluent are medium to high to aquatic organisms. Detection frequencies of PPCPs were lower in groundwater samples compared to the effluent, with sulfamethoxazole (40%) and caffeine (32%) as the most frequently detected compounds. Similarly, average concentrations of PPCPs in groundwater were found to be nearly two orders of magnitude lower than concentrations in the effluent. Minimal seasonal influence was observed for groundwater samples. Human health risk assessments indicate that concentrations in groundwater, which is used as a drinking water source, appear to pose minimal risk.

People use a large variety of chemicals in their everyday lives, including prescription drugs, over-the-counter medications, and personal care products. The chemicals in these products enter the wastewater stream and are not removed completely by wastewater treatment plants (WWTPs), causing these chemicals and their metabolites to persist in the treated effluent. The Pennsylvania State University has spray-irrigated all of its treated wastewater onto ~240 ha of agricultural and forested land known as the “Living Filter” since the early 1980s. Once a week from October 2016 to March 2017, 24-hr composite samples were collected after each treatment process through the WWTP. Water samples were collected monthly from 14 groundwater wells (20 – 100 m) at the Living Filter. Samples were analyzed for seven emerging contaminants: acetaminophen, ampicillin, caffeine, naproxen, ofloxacin, sulfamethoxazole, and trimethoprim. The goal was to track these compounds through the WWTP and ultimately to the wells at the Living Filter to assess: (i) the removal efficiency of the WWTP and (ii) the ability of the Living Filter‘s soil profile to provide further treatment of the compounds that persisted in the effluent. In general, the WWTP effectively removed acetaminophen and caffeine (>90%), and exhibited seasonal variability in the removal efficiency of the other compounds, with activated sludge as the most effective step for reducing contaminant concentrations. Concentrations in the groundwater were typically at least one order of magnitude lower than the concentrations in the WWTP effluent, suggesting that the soil generally acted as an effective biogeochemical filter, except during snowmelt events.