Underground sources of drinking water

Fluid movement conditions are such that the injected fluids will not migrate within 10,000 years vertically upward out of the injection zone or laterally within the injection zone to a point of discharge or interface with an Underground Source of Drinking Water (USDW). 

Water with a salinity of less than 10,000 mg/L is considered to be a potential underground source of drinking water. By regulatory definition, deep-well injection of hazardous waste can occur only in very saline waters or brines. Actual salinities of waters in currently used deep-well injection zones vary greatly.70 Normally, the term brine is used to refer to the natural waters in deep-well injection zones. As noted above, however, this term is not technically correct if TDS levels are less than 35,000 mg/L. 

Part C—Protection of Underground Sources of Drinking Water... 

Underground source of drinking water (USDW)—As defined by 40 CFR 144.3, a USDW is an aquifer or its portion ... 

USEPA. (2004). The Central Appalachian Coal Basin—Attachment 6 Evaluation of Impacts to Underground Sources of Drinking Water by Hydraulic Fracturing of Coalbed Methane Reserves, ERA 816-R-04-003. U.S. Environmental Protection Agency, Washington, DC, 26 pp. 

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