74:29:11:14Minimum requirements for monitor wells.

In determining the number, location, construction and frequency of sampling of monitor wells, the following shall be considered: (1) Whether or not any person is relying on the underground source of drinking water affected or potentially affected by the injection operation; (2) The proximity of the injection operation to points of withdrawal of drinking water; (3) The local geology and hydrology; (4) The operating pressures and whether a negative pressure gradient is being maintained; (5) The toxicity and volume of the injected fluid, the formation water, and the process by-products; and (6) The density of the injection wells.

Source: 33 SDR 160, effective April 17, 2007.