&EPA Office of United States Ground Water and Environmental Protection Agency Drinking Water CLASS V UIC STUDY FACT SHEET STORM WATER DRAINAGE WELLS What is a storm water Storm water drainage wells are Class V underground injection control (UIC) wells used to remove drainage well? storm water or urban runoff from impervious surfaces such as roadways, roofs, and paved surfaces to prevent flooding, infiltration into basements, etc. Hie primary types of storm water drainage wells are bored wells, dug wells, and improved sinkholes. In addition, "lake level control wells" are used to drain lakes to prevent overflow following heavy precipitation. What types of fluids are Primarily rain water and melted snow runoff, injected into storm water drainage wells? Do injectate constituents exceed drinking water standards at the point of injection? What are the characteristics of the injection zone of a storm water drainage well? Are there any contamination incidents associated with storm water drainage wells? Available sampling data indicate that concentrations of antimony, arsenic, beryllium, cadmium, chromium, cyanide, lead, mercury, nickel, nitrate, selenium, and certain organics in storm water runoff have exceeded primary drinking water standards. Available sampling data also show that concentrations of aluminum, chloride, copper, iron, manganese, total dissolved solids, zinc, and methyl tert-butyl ether have exceeded secondary drinking water standards or health advisory levels. Water quality data from FL indicate that lake level control well injectate has exceeded primary drinking water standards or health advisory levels for turbidity, arsenic, pentachlorophenol, and fecal colifonns, as well as secondary drinking water standards for iron, manganese, pH, and color. In general, the point of injection for most storm water drainage wells is into sandy, porous soils, a permeable coarse-grained unit, karst, or a fractured unit because these types of formations can readily accept large volumes of fluids. Contamination related to storm water drainage wells has been reported to various degrees in OH, KS, WI, CA, WA, AZ, OK, TN, NY, IN, FL, KY, and MD. Several studies, however, do not clearly distinguish contamination from storm water drainage wells versus more general, nonpoint source pollution. Lake level control wells have been associated with two documented contamination incidents in FL. Are storm water drainage Storm water drainage wells are generally vulnerable to spills or illicit discharges of hazardous wells vulnerable to spills or substances, as they are often located in close proximity to roadways, parking lots, and illicit discharges? commercial/industrial loading facilities where such substances are handled and potentially released. How many storm water There are approximately 71,000 documented storm water drainage wells and approximately 248,000 drainage wells exist in the storm water drainage wells estimated to exist in the United States. United States? Where are storm water About 81 percent of the documented wells are in seven western states: AZ (14,857), CA (3,743), WA drainage wells located (22,688), OR (4,148), ID (5,359), MT (4,000), and UT (2,890). Five other states contain within the United States? approximately 15 percent of the total wells: OH (3,036), FL (2,153), MI (1,301), MD (1,678), and HI (2,622). There are approximately 200-250 lake level control wells in FL. How are storm water Permit by rule: IL, IN, MI, OH, WI (<10 ft. deep and constructed prior to 1994), MT, WY, ND, SD, drainage wells regulated in UT, CO, ID (< 18 ft. deep), OR, WA, KS, TN, RI states with the largest number of this type of Individualpermit/registration system. AZ, CA, HI, ID (> 18 ft. deep), AL, FL, TX, NH, MD, NE, NY well? Banned: NC, GA, WI (any new well since 1994 and wells >10 ft. deep since the 1930's), MN (for "wells" that reach ground water) Where can I obtain For general information, contact the Safe Drinking Water Hotline, toll-free 800-426-4791. The Safe additional information on Drinking Water Hotline is open Monday through Friday, excluding federal holidays, from 9:00 a.m. storm water drainage to 5:30 p.m. Eastern Standard Time. For technical inquiries, contact Amber Moreen, Underground wells? Injection Control Program, Office of Ground Water and Drinking Water (mail code 4606), EPA, 401 M Street, SW, Washington, D.C., 20460. Phone: 202-260-4891. E-mail: moreen.amber(S?epa.gov. The complete Class V UIC Study (EPA/816-R-99-014, September 1999), which includes a volume addressing storm water drainage wells (Volume 3), can be found at http://www.epa.gov/OGWDW/uic/cl5study.html. ------- |