North Dakota Administrative Code
Title 33.1 - Department of Environmental Quality
Article 33.1-18 - Water Well Contractors
Chapter 33.1-18-02 - Ground Water Monitoring Well Construction Requirements
Section 33.1-18-02-10 - Borehole and monitoring well abandonment

Universal Citation: ND Admin Code ยง 33.1-18-02-10

Current through Supplement No. 394, October, 2024

1. The department may require by written notification an owner of the site of a borehole or monitoring well to decommission the borehole or monitoring well when necessary to:

a. Eliminate physical hazards on the surface;

b. Prevent contamination of ground water;

c. Prevent intermingling of desirable and undesirable waters; or

d. Eliminate unintended use.

2. Any monitoring well which is constructed and installed after March 1, 1997, and which does not meet the requirements of this chapter must be decommissioned within thirty days after written notification by the department.

3. A borehole must be decommissioned within three working days of discontinuance of use according to subsection 5.

4. A monitoring well must be decommissioned in accordance with the requirements of subsection 5 within one year of discontinuance of use unless it may be reasonably anticipated the well will be reused in the future. If the well is anticipated to be used in the future, the owner of the well is responsible to periodically inspect and maintain the well to ensure the well remains in compliance with the standards established in this chapter.

5. Decommissioned and plugged boreholes and monitoring wells must have equal or less permeability than the local environment resulting in no greater influence on the local environment than the original geologic formation. Factors, such as topography, hydrogeology, borehole or well construction, and contaminants, must be considered in a decommissioning operation.

a. Immediately prior to decommissioning a monitoring well, the water in the well must be disinfected, except water containing hydrocarbons should not be disinfected with a chlorine disinfectant or other reactive compounds.

b. Sealant materials cannot be native soil materials. An acceptable sealant for dry boreholes is concrete. Acceptable sealant materials for wet boreholes and monitoring wells include neat cement, bentonite grout, bentonite pellets, and bentonite chips. Sealant materials must:
(1) Be durable;

(2) Not adversely impact local geologic materials or ground water;

(3) Form a bond and seal with the sidewall; and

(4) Resist cracking or shrinkage.

c. Any settling of the sealant material must be topped off. Sealant material may be terminated two and one-half feet [0.761 meter] below the ground surface in agricultural areas, in which case a native soil plug must be placed on top of the sealant material.

d. When monitoring well construction and installation documentation is not available, the well has been damaged down hole or the well is located in a proposed future solid waste treatment or disposal area, all protective casing, riser, screen, seals, and filter pack must be removed by pulling or over drilling.

e. Monitoring wells known by available documentation to be constructed with an impermeable annular space seal may be decommissioned without removing the riser, screen, annular sealant, and filter pack provided:
(1) The remaining screen and riser are filled with sealant material;

(2) The ground surface seal and protective casing are removed; and

(3) The riser must be cut off at a depth to preclude interference with site-specific activities, but should be no less than two and one-half feet [0.761 meter] below the surface.

General Authority: NDCC 43-35-19.2; S.L.2017, ch.199, § 1

Law Implemented: NDCC 43-35-19.2; S.L.2017, ch. 199, § 47

Disclaimer: These regulations may not be the most recent version. North Dakota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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