B. The area of review for each Class I non-hazardous waste injection well, or each Class III well or well field shall be an area which extends:

1. (1) two and one half (2 1/2) miles from the well, or well field; or
2. (2) one-quarter (1/4) mile from a well or well field where the area of review is calculated to be zero pursuant to Paragraph (3) of Subsection B below, or where the well field production at all times exceeds injection to produce a net withdrawal; or

3. (3) a suitable distance, not less than one-quarter (1/4) mile, proposed by the discharger and approved by the secretary, based upon a mathematical calculation to determine the area of review; computations to determine the area of review may be based upon the parameters listed below and should be calculated for an injection time period equal to the expected life of the Class I non-hazardous waste injection well, or Class III well or well field; the following modified Theis equation illustrates one form which the mathematical model may take to compute the area of review; the discharger must demonstrate that any equation or simulation used to compute the area of review applies to the hydrogeologic conditions in the area of review.

   Where:

   4BKH (H_w - H_bo)x S_pG_b

   r = Radius of the area of review for a Class I non-hazardous waste injection well or Class III well (length)

   K = Hydraulic conductivity of the injection zone (length/time)

   H = Thickness of the injection zone (length)

   t = Time of injection (time)

   S = Storage coefficient (dimensionless)

   Q = Injection rate (volume/time)

   H_bo = Observed original hydrostatic head of injection zone (length) measured from the base of the lowest aquifer containing ground water of 10,000 mg/l or less TDS

   H_w = Hydrostatic head of underground source of drinking water (length) measured from the base of the lowest aquifer containing ground water of 10,000 mg/l or less TDS

   S_pG_b = Specific gravity of fluid in the injection zone (dimensionless)

   B = 3.142 (dimensionless)

4. (4) The above equation is based on the following assumptions:

   1. (a) the injection zone is homogenous and isotropic;
   2. (b) the injection zone has infinite areal extent;
   3. (c) the Class I non-hazardous waste injection well or Class III well penetrates the entire thickness of the injection zone;
   4. (d) the well diameter is infinitesimal compared to "r" when injection time is longer than a few minutes; and
   5. (e) the emplacement of fluid into the injection zone creates an instantaneous increase in pressure.

C. The secretary shall require submittal by the discharger of information regarding the area of review including the information to be considered by the secretary in Subsection B of Section 20.6.2.5210 NMAC.

[9-20-82, 12-1-95; 20.6.2.5202 NMAC - Rn, 20 NMAC 6.2.V.5202, 1-15-01; A, 12-1-01; A, 12-21-18]