26.04.04.16

.16 Construction Standards — General.

A. Sanitary Protection During Well Construction.

(1) During well construction, the permittee shall protect against pollution of the well and any water-bearing geologic formations by any cause, including surface water drainage.

(2) Whenever construction ceases before the well is grouted, the open annular space shall be covered by the permittee and the well shall be capped.

B. Water for Well Construction.

(1) Only water from a source approved by the Approving Authority in accordance with this section may be used in the construction and development of a well.

(2) Water used for construction of a well shall be taken from the best source available to the well driller.

(3) The best source, in order of preference, shall be:

(a) A public water supply system meeting the requirements of COMAR 26.04.01 for water quality;

(b) Any other potable water supply;

(c) A nonpotable well;

(d) A temporary well, constructed specifically for the purposes of obtaining water for the construction of the well.

(4) Water used for the construction or development of a well shall:

(a) Have a turbidity of not more than 25 standard units, except when the turbidity is due to the oxidation of dissolved iron or manganese;

(b) Be transported, when necessary, in tank trucks used only for the purpose of transporting drilling or potable water;

(c) Be treated with chlorine in amounts indicated in §B(5) of this regulation;

(d) Have a color of not more than 25 standard units; and

(e) Contain no objectionable odor.

(5) Chlorine treatment required in §B(4)(c) of this regulation, shall be as follows:

(a) For water from a public supply approved under COMAR 26.04.01, a chlorine compound shall be added to the water to produce a free chlorine residual of at least 1.0 mg/l when delivered at the drilling site;

(b) For water from any other potable water supply, the free chlorine residual of at least 3.0 mg/l in the water delivered at the drilling site;

(c) Water from a nonpotable well shall be dosed with chlorine to produce a minimum free chlorine residual of 50 mg/l.

C. Screening in More Than One Aquifer Prohibited. A well may not be screened in more than one aquifer.

D. Sealing-Off Strata. In order to preserve the quality of ground water, the Approving Authority may include a special condition in a well construction permit requiring that aquifers and other strata be sealed off.

E. Well Development. All wells shall be developed according to the following requirements:

(1) Well development means the process whereby a well is pumped, surged, bailed, airlifted, swabbed or jetted to remove any material that may be blocking the well screen or fractures within the borehole;

(2) Development shall continue until formation cuttings, drilling fluids, and additives are removed from the well;

(3) For wells in Hydrogeologic Areas 1 and 2, well development shall remove the fine sand, silt, and clay from the water-bearing zone surrounding the well screen;

(4) Any hydrofracturing shall be performed in accordance with Regulation .28 of this chapter; and

(5) Every well shall be developed in order to obtain the full yield of the well and a water quality that meets all of the following requirements:

(a) Contains less than 5 milligrams sand or larger sized particles per liter of water, where particles with a diameter between 0.0625 and 2.0 mm are considered to be sand; and

(b) Has a turbidity of less than 10 NTU (nephelometric turbidity unit) as determined by methods designated in 40 CFR §141.74(a)(1), except if the turbidity is due to the oxidation of dissolved iron or manganese naturally occurring in the water.