Assessment of Residential Rain Barrel Water Quality and Use in Cincinnati, Ohio1

The collection, storage, and reuse of rainwater collected in rain barrels from urban rooftop areas assists municipalities in achieving stormwater management objectives and in some areas also serves as an adjunct resource for domestic water supplies. In this study, rainwater reuse and levels of select microbial indicators were monitored for six residential rain barrels located in the Shepherd Creek watershed of Cincinnati, Ohio. Water from rain barrels typically had poor microbial quality and was used for watering indoor and outdoor plants. Rain barrel water chemistry was slightly acidic, exhibited wide ranges in conductivity, turbidity, and total organic carbon (TOC) concentrations and gave no evidence of the presence of cyanobacterial microcystin toxins. Selected microbial water-quality indicators indicated that counts of total coliform and enterococci were consistently above U.S. Environmental Protection Agency standards for secondary recreational contact water-quality standards. Residential rain barrels can provide water appropriate for low-contact reuses (such as plant watering), although there may be transient periods of high levels of indicator bacteria in the collected water.