(1) All casing installed, other than plastic casing set forth in ARM 36.21.641 and 36.21.645, shall be of steel, in new or like new condition, being free of pits, breaks, or contamination, and shall meet minimum American society of testing materials (ASTM A-120) specifications for line pipe, for the following sizes: Minimum specifications for steel well casing

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Nominal Size� (inches	Outside Diameter (inches)	Wall Thickness (inches)�	Weight Per Foot (pounds)
2	2.375	.154	3.56
2	2.875	.203	5.79
3	3.500	.216	7.58
3	4.000	.226	9.11
4	4.500	.237	10.79
5	5.563	.244	13.70
6	6.625	.250	17.02
8	8.625	.250	22.36
10	10.750	.250	28.04
12	12.750	.312	41.45
14	14.000	.312	45.68
16	16.000	.312	52.27
18	18.000	.375	70.59
20	20.000	.375	78.60

(2) All casing having a diameter larger than 20 inches shall have a wall thickness of at least .375 inch.

(3) Well casing installed in a well greater than a nominal diameter of 10 inches, may have a wall thickness of .250 inch as long as it otherwise meets ASTM A-120 specifications and does not exceed the following depth limitations:

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Diameter�	Maximum Depth
12 inches	250 feet
14-16 inches	150 feet
18-20 inches�	100 feet

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(4) Casings of other specifications may be considered under the provisions of variances ARM 36.21.680.