Reclaimed Water Irrigation: Plant Accumulation and Risks of Contaminants of Emerging Concern (CECs)EPA Grant Number: R835829
Title: Reclaimed Water Irrigation: Plant Accumulation and Risks of Contaminants of Emerging Concern (CECs)
Investigators: Gan, Jay , Trumble, John T.
Institution: University of California - Riverside
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2015 through August 31, 2018 (Extended to August 31, 2019)
Project Amount: $749,631
RFA: Human and Ecological Health Impacts Associated with Water Reuse and Conservation Practices (2014) RFA Text | Recipients Lists
Research Category: Water , Health
In arid and semi-arid regions such as the southwestern U.S., municipal treated wastewater (reclaimed water) is a valuable water resource that may be used for augmenting agricultural irrigation, thus alleviating water scarcity caused by urbanization and droughts. Use of treated wastewater for irrigation allows reallocation of high quality freshwater for more crucial uses (e.g., drinking water) and also helps replenish groundwater through percolation. A significant hurdle to this beneficial reuse, however, is the perceived uptake and risks of contaminants of emerging concern (CECs) from the treated wastewater via food crops. To addesses this concern and promote safe reuse of reclaimed water, we propose to measure levels of CECs in edible parts of common vegetables and other food crops irrigated with treated wastewater under field conditions, and to evaluate human dietary exposure and potential adverse effects on terrestrial organisms.
We will integrate greenhouse experiments with field studies to identify CECs with the greatest potential for plant accumulation, understand effects of soil types and plant species, and obtain direct measurements of occurrence of CECs in edible parts of common vegetables and other food crops, e.g., lettuce, cabbage, spinach, celery, tomato, pepper, cucumber, carrot, potato, onion, strawberry, cantuloupe, watermelon, that receive treated wastewater for irrigation. We will evaluate acute and sublethal effects of selected CECs on the herbivory insect beet armyworm (Spodoptera exigua) as an indicator terrestrial invertebrate. The derived endpoints and field-measured concentrations will be used to predict potential ecological effects and human exposures. We will further work with county-based extension advisors and USDA scientists to effectively disseminate research results to growers, water and sanitation districts, and the general public.
This project will provide the much needed field-based information on the occurrence and potential risks of CECs in food plants when treated wastewater is used for irrigation. The study findings will have immediate and broad implications for the scientific community and the society at-large in promoting the safe reuse of treated wastewater.