|KIBUYE, FAITH - Pennsylvania State University|
|GALL, HEATHER - Pennsylvania State University|
|AYERS, BRITTANY - Pennsylvania State University|
|Veith, Tameria - Tamie|
|MILLER, MEGAN - Pennsylvania State University|
|JACOB, SHANNON - Pennsylvania State University|
|HAYDEN, KATHRYN - Pennsylvania State University|
|WATSON, JOHN - Pennsylvania State University|
|ELLIOTT, HERSCHEL - Pennsylvania State University|
Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2018
Publication Date: 11/6/2018
Citation: Kibuye, F.A., Gall, H.E., Elkin, K.R., Ayers, B., Veith, T.L., Miller, M., Jacob, S., Hayden, K.R., Watson, J.E., Elliott, H.A. 2018. Fate of pharmaceuticals in a spray-irrigation system: From wastewater to groundwater. Science of the Total Environment. 654:197-208. https://doi.org/10.1016/j.scitotenv.2018.10.442.
Interpretive Summary: Spray-irrigation of treated wastewater is an increasingly common water reuse practice worldwide. However, since pharmaceuticals are not completely removed from the wastewater during normal treatment methods, spray-irrigation spreads these pharmaceuticals onto crop and forest fields where they can filter through the soils and into the groundwater. We monitored 7 human pharmaceuticals in a spray-irrigation system, including the wastewater influent, effluent, and monitoring wells, at a site in central Pennsylvania. The wastewater treatment plant and soil partially removed some of the pharmaceuticals of interest, and the untreated portions were found in the groundwater monitoring wells. However, the concentrations in the wells posed no human health risks, even after more than 35 years of the wastewater irrigation activities at the site. Therefore, these results suggest that wastewater reuse systems are effective at removing contaminants of emerging concern, such as pharmaceuticals, prior to reaching drinking water supplies.
Technical Abstract: Nutrients from treated wastewater are commonly recycled through spray-irrigation onto cropped and forested land. However, wastewater reuse poses potential environmental and human health challenges due to the presence of a large variety of pharmaceuticals and personal care products (PPCPs) that are not completely removed by wastewater treatment processes, causing them to persist in treated effluent. These compounds are then inadvertently introduced into the environment during spray-irrigation activities. Despite the increasing reuse of wastewater in this manner, few studies exist in which the entirety of such a coupled human-natural system can be monitored for PPCPs. Here, we collected water samples through a wastewater treatment plant (WWTP) and from 13 groundwater monitoring wells at the spray-irrigation fields where effluent has been spray-irrigated since the early 1980s. Samples were collected for a 14-month study period (October 2016 through December 2017). All samples were analyzed for seven pharmaceuticals that represent a wide range of environmentally relevant physicochemical parameters. Data revealed that the WWTP was able to effectively remove acetaminophen and caffeine (> 80%), but that some antibiotics were present in the effluent at higher concentrations than the influent. PPCP concentrations that persisted in the effluent were found to pose a medium risk to aquatic ecosystem health. However, PPCP concentrations in the groundwater were 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. Consequently, concentrations in the groundwater, which is used as a drinking water source, appear to pose a minimal risk to human health.