Assessing the Environmental Risk of Emerging Organic Contaminants in Fields Receiving Reclaimed Wastewater Irrigation.

Reclaimed wastewater irrigation in agriculture and landscape becomes more popular due to scarcity of good quality water. One of the concerns of water reuse is the fate of effluent-associated contaminants, such as pharmaceuticals and personal care products (PPCPs) and endocrine disrupting compounds (EDCs) in the receiving soils. The objectives of our research were to develop analytical methods to quantify these compounds and to assess their environmental fates in soil and water. A simple and robust analytical method to measure these organic compounds in soils with the aid of sonication was developed in our laboratory. Representative PPCPs and EDCs in soil and water were assessed in three fields that received reclaimed wastewater irrigation: runoff water samples from a potato field, soil and leachate samples in a turfgrass field, and soil and groundwater samples from fields irrigated with treated municipal wastewater for 3, 8, and 20 years, respectively. Our results show that PPCPs (e.g., clofibric acid, ibuprofen, naproxen, ketoprofen, diclofenac), personal care products (e.g., triclosan), EDCs (e.g., bisphenol A, 4-n-nonylphenol, 4-t-octylphenol), and estrogenic compounds (e.g., estrone, 17b-estradiol, 17a-ethynylestradiol) were present in runoff at concentrations from below LOQ (limits of quantification) to sub µg/L levels. In the turfgrass field, some target chemicals including ibuprofen, naproxen, triclosan, bisphenol A, clofibric acid and estrone were detected in the surface 30 cm soil layers, but none of them were found in the leachates through an 89-cm soil column. Results from the screening model showed that under normal turf grass irrigation, clofibric acid and ibuprofen are most prone to cause the groundwater pollution. In the field receiving long-term wastewater irrigation (20 years), some PPCPs and EDCs were also detected in the soil profiles at the top 40-cm depth. Although the concentrations were low, their potential of adverse effects on the aquatic and terrestrial environment cannot be overlooked.