A. The following special requirements for specific types of wells based on the intended use of the well are as follows:
(1) Irrigation Wells.
- (a) Wells in unconfined aquifers in Hydrogeologic Areas 1 and 2 used solely for irrigation shall have an annular space grouted to a minimum depth of 20 feet below land surface.
- (b) All other irrigation wells shall meet the grouting requirements of Regulation .19 of this chapter.
(2) Monitoring Wells.
- (a) The well driller shall submit to the Approving Authority the construction specifications that are proposed for a monitoring well as an attachment to the permit application.
- (b) The Approving Authority may approve, as a special condition of a permit, special construction standards for wells installed for the purpose of monitoring ground water.
- (c) If the Approving Authority does not approve special construction standards, then well construction shall comply with the provisions of this chapter.
- (d) For an at-grade or below-grade well terminal, the well terminal shall be water tight and enclosed in a well vault.
(3) Injection Wells.
- (a) The well driller for an injection well shall submit to the Approving Authority the construction specifications that are proposed as an attachment to the permit application.
- (b) The Approving Authority may not issue a permit to construct an injection well unless a State Discharge Permit has been issued by the Department.
(4) Geothermal Wells — Closed Loop.
- (a) The pipe material, jointing, pressure testing, and anti-freeze solutions for a closed loop geothermal well shall conform to the standards of COMAR 09.15.05.
- (b) The anti-freeze solution shall be environmentally safe.
- (c) The borehole of a closed-loop geothermal well shall be grouted from the bottom of the borehole to the ground surface.
(d) The upper terminal of a closed-loop geothermal well may terminate below grade if:
- (i) The well location is marked by a metal plate so that the location can be found by a metal detector; or
- (ii) The manifold and horizontal lines are marked with detection tape.
- (e) When the closed-loop geothermal well is terminated below grade, the well tag shall be attached to the flow center.
- (f) If using copper as an exchange medium a maintenance agreement must be recorded in the County land records.
(5) Cathodic Protection Wells.
- (a) The borehole of a cathodic protection well shall be grouted from the bottom of the borehole to the ground surface.
- (b) The well driller shall submit to the Approving Authority the construction specifications that are proposed for a cathodic protection well as an attachment to the permit application.
- (6) Dewatering Wells. The annular space of a dewatering shall be grouted to a depth of 5 feet below the static water level.
B. The following specific construction standards for specific wells, based on construction method, are as follows:
(1) Driven Wells.
- (a) Driven wells may not be used for a potable water supply.
- (b) In a driven well an oversize hole for grout, at least 4 inches greater in diameter than the casing, shall be constructed to a depth of at least 10 feet, and the annular space between this hole and the casing shall be grouted to land surface.
- (c) The upper terminal of a driven well and pitless adapter or pitless unit installation shall be in accordance with this chapter.
(2) Bored, Augered, and Dug Wells Cased with Concrete Pipe.
- (a) Bored, augered, and dug wells shall have a borehole with a minimum diameter of 6 inches larger than the outside diameter of the casing.
- (b) The annular space shall be filled with grout to a depth of at least 30 feet below land surface, unless otherwise approved by the Approving Authority.
- (c) The annular space below the grout shall be filled with a sand or gravel pack.
- (d) Joints in the concrete casing shall be sealed with an impervious seal, such as cement and o-rings, to a depth of at least 20 feet.
- (e) The casing shall extend to a depth of at least 2 feet below the lowest seasonal water table.
- (f) The minimum depth of the casing shall be 20 feet.
(g) The well shall be protected with either:
- (i) A precast, overlapping, steel-reinforced concrete cover; or
- (ii) A metal cover at least 3/16 of an inch thick and fitted with a watertight gasket; and
- (iii) Be at least 8 inches above grade.
(3) Jetted and Jetted-Driven Wells.
- (a) Jetted and jetted-driven wells shall be grouted to a minimum depth of 20 feet. This will necessitate construction of an oversize hole for grout to this depth.
- (b) Jetted and jetted-driven wells may not be used for potable water supplies.
- (4) Horizontal Wells. The well driller shall submit plans with the Application for a Permit to Drill that provide details on how the horizontal well is to be constructed and identify the materials to be used.
Authority: Environment Article, §§9-1305 and 9-1305.1, Annotated Code of Maryland
Effective date: November 28, 1980 (7:24 Md. R. 2257)
Regulations .02J and .07B, C, D, G, J, and N amended effective March 1, 1982 (9:4 Md. R. 331)
Regulations .07Q and .09D adopted effective August 31, 1981 (8:17 Md. R. 1420)
Regulation .09C and D amended as an emergency provision effective May 26, 1983 (10:12 Md. R. 1070), emergency status expired September 26, 1983
Regulation .09C and D amended and E adopted effective December 5, 1983 (10:24 Md. R. 2189)
Map recodified as Regulation .13
Chapter recodified from COMAR 10.17.13 to COMAR 26.04.04
Regulation .07D amended as an emergency provision effective November 5, 2007 (34:26 Md. R. 2260); emergency status expired May 3, 2008
Regulation .09B amended effective September 2, 2002 (29:17 Md. R. 1382)
Regulation .09B-1, F, and G adopted effective November 25, 1991 (18:23 Md. R. 2493)
Regulation .12D amended effective October 26, 1992 (19:21 Md. R. 1894)
Regulation .12F amended effective November 25, 1991 (18:23 Md. R. 2493)
Regulations .01—.13 repealed and new Regulations .01—.39 adopted effective January 19, 2015 (42:01 Md. R. 19)