Pharmaceuticals at Penn State living filter: from wasterwater to groundwater

Authors: AYERS, BRITTANY - Pennsylvania State University; Elkin, Kyle; KIBUYE, FAITH - Pennsylvania State University; GALL, HEATHER - Pennsylvania State University

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 7/18/2018
Publication Date: 7/18/2018
Citation: Ayers, B., Elkin, K.R., Kibuye, F., Gall, H. 2018. Pharmaceuticals at Penn State living filter: from wasterwater to groundwater. ASABE Annual International Meeting. doi: 10.1031/aim.201700255.
DOI: https://doi.org/10.13031/aim.201700255

Interpretive Summary: Daily human activities produce a group of chemicals known commonly as pharmaceuticals and personal care products (PPCPs). These chemicals make their way via wastewater streams into water treatment plants where their removal efficiency is largely unknown. The water leaving the treatment plant is returned to streams where it is then reused for activities such as irrigation. To understand the fate of these chemicals, we tracked several specific PPCPs for 6 months, through a wastewater treatment process and ultimately into the groundwater of irrigated fields. In general, the concentrations of chemicals at the outlet of the treatment plant were higher in colder months. Analysis of the groundwater showed trends of the chemicals, which were about 10 times lower than what was seen in the surface water indicating that the soil was effectively filtering a good portion of the chemicals that were not removed by the treatment plant.

Technical Abstract: Humans 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), thereby 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 5, 2016 to March 1, 2017, 24-hr composite samples were collected after each treatment process through the WWTP. Once a month, water samples were collected from 14 groundwater wells at irrigated and non-irrigated locations at the Living Filter. Each sample was 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: (i) understand the performance of the WWTP to remove these contaminants and (ii) to assess the ability of the soil profile at the Living Filter to provide further treatment of the compounds that persist in the effluent. In general, concentrations entering the wastewater treatment plant increased during the study period and the performance of the WWTP typically decreased as temperatures decreased. Concentrations in the groundwater were typically at least one order of magnitude lower than the concentrations in the WWTP effluent, suggesting that the soil is generally acting as an effective biogeochemical filter.