La. Admin. Code tit. 56 § I-531

Current through Register Vol. 50, No. 11, November 20, 2024

Section I-531 - Methods and Standards for Plugging Abandoned Water Wells and Holes

A. The following methods and standards shall be used for the plugging of abandoned water wells and holes. If there is a need for variance from these regulations and/or clarification is required, departmental approval shall be obtained in writing, before the plugging operation is begun. For variance requests, refer to §513

B. Methods and Standards for Plugging Abandoned Water Wells. The following methods and standards shall apply to all abandoned water wells, regardless of use or type.

C. Removal of Obstructions from the Well. Before the plugging operation is begun, the drilling and construction records for the well should be obtained and studied (see §525). An investigation of the well shall be made to determine if there is any obstruction in the well that would interfere with the plugging operation. Any obstruction in the well shall be removed, using an acceptable method, before initiating the plugging operation.

D. Cutting off the Top of the Casing. In areas subject to subsidence and/or farming, the top of the casing shall be cut off a minimum of 3 feet below the surface of the ground before plugging operation begins. After filling the well with cement-bentonite slurry, the excavation above the top of the cement plug shall be filled with compacted soil to minimize future hazards to farming equipment, etc. In other areas, the top of the casing shall be cut off at or below the ground surface. Under no circumstances shall the top of the casing protrude above the surface of ground.

E. Plugging Material for the Screen. The screen or the area opposite the production aquifer (as in open hole construction) may be filled with filler materials specified in §529. B in lieu of cement-bentonite slurry.

F. Plugging Method. The entire well shall be plugged with cement-bentonite slurry from bottom of the well up to the ground surface using the pump-down method, preferably in one continuous operation. Placement of plugging material by pouring or dropping through the water shall not be permitted.

G. Annular Space. If the annular space of the abandoned well is not already sealed, the plugging material shall be brought up to the surface and allowed to spill over the top of the casing and into the annulus, sealing the annular space between the casing and the borehole. If the annular space is already sealed, the plugging material shall be brought up to the ground surface, unless specified otherwise.

H. Temporary Shut Down. When plugging of an abandoned water well or hole is temporarily suspended, such as overnight shut down or awaiting material, the well or hole shall be covered and the immediate area conspicuously marked to protect and warn the public. The cover shall be sufficiently strong and anchored to prevent easy or unintentional entry. The well or hole shall be sealed to prevent the seepage of surface water and foreign material into the well or hole.

I. Areas of Confirmed Contamination. In areas of confirmed ground water or soil contamination, the entire well shall be plugged with cement-bentonite slurry. The annular space of the well, if not already sealed, shall be sealed by perforating or ripping the casing and forcing cement-bentonite slurry under pressure into the annular space and surrounding formation to prevent the entry of contaminated fluids into an aquifer and to prevent the movement of water from one aquifer to another.

J. Areas of Potential Contamination. In areas of potential ground water or soil contamination, the entire well shall be plugged with cement-bentonite slurry. It is recommended that the annular space of the well, if not already sealed, be perforated or ripped and cement-bentonite slurry forced under pressure into the annular space and surrounding formation to safeguard against any possible entry of contaminated fluids into an aquifer and to prevent the movement of water from one aquifer to another.

K. Plugging of Abandoned Water Well from Which Some or All of the Casing Has Been Removed

1. If the casing remaining is in the upper part of the well, the well shall be sounded to determine the amount, if any, of "cave in." The part of the hole filled with "cave in" material shall be reamed or drilled out of the original depth of the well and then the entire hole shall be plugged with cement-bentonite slurry from the bottom, up to the ground surface, using the pump-down method.

2. If the casing (including the screen) remaining is in the lower part of the well, the well and hole shall be completely filled with cement-bentonite slurry from the bottom up to the ground surface, using the pump-down method.

3. If all the casing and screen is removed, the hole for the entire original depth of the well shall be plugged with cement-bentonite slurry from the bottom, up to the ground surface, using the pumpdown method.

L. Plugging of Abandoned Monitoring Wells. The entire well shall be plugged with cement-bentonite slurry from bottom of the well, up to the ground surface, using the pump-down method.

NOTE: Plugging of abandoned monitoring wells associated with facilities regulated by the Department of Environmental Quality (DEQ) require approval from DEQ prior to actual plugging.

M. Plugging of Abandoned Dug or Augered Wells. Domestic dug or augered wells shall be plugged from bottom of the well up to the ground surface with cement-bentonite slurry or with local fill material such as silt, sand, clay, native soil, or a mixture thereof. If local fill material is used, it should be allowed to settle, and then permanently capped with cement or compacted clay.

N. Plugging of Abandoned Holes. If the hole penetrates an aquifer containing saline water, the entire hole shall be plugged with cement-bentonite slurry from bottom of the hole, up to the ground surface using the pump-down method; otherwise, the hole shall be plugged in accordance with §531. O -R.2

O. Plugging of Abandoned Pilot Holes

1. The entire hole shall be plugged with cement-bentonite slurry from bottom of the hole, up to the ground surface, using the pumpdown method.

NOTE: If an aquifer (see §113. A for definitions) is not penetrated, the hole shall be plugged with either cement-bentonite slurry or bentonite slurry from bottom of the hole, up to a depth of 25 feet below the ground surface and then the upper 25 feet of the hole shall be plugged with cement-bentonite slurry, using the pump-down method.

P. Plugging of Abandoned Test Holes. An abandoned test hole shall be plugged with cement-bentonite slurry from bottom of the hole, up to the ground surface, using the pump-down method. If the casing cannot be removed, in addition to plugging the entire casing with cement-bentonite slurry, the annular space must also be cemented as per requirements of §527 or as approved by the department.

Q. Plugging of Abandoned Geotechnical Boreholes

1. The entire hole shall be plugged with cement-bentonite slurry from bottom of the hole, up to the ground surface, using the pumpdown method; or

2. The hole shall be plugged with bentonite slurry from bottom of the hole, up to a depth of 25 feet below the ground surface and then the upper 25 feet of the hole shall be plugged with cement-bentonite slurry, using the pump-down method.

3. For boreholes of 25 feet or less, drill cuttings from the original hole may be used to plug the hole in lieu of cement-bentonite slurry, provided that an aquifer is not penetrated and provided that a concrete cylinder is pushed into the hole to form a permanent seal at the ground surface.

NOTE: Plugging of geotechnical borehole associated with facilities regulated by the Department of Environmental Quality (DEQ) require approval from that department prior to actual plugging.

R. Plugging of Heat Pump Holes (Closed Loop System)

1. The entire hole shall be plugged with cement-bentonite slurry from bottom of the hole, up to the bottom of the horizontal trench, using the pump-down method; or

2. The hole shall be plugged with bentonite slurry from bottom of the hole, up to a depth of 25 feet below the bottom of the horizontal trench and then the upper 25 feet of the hole shall be plugged with cement-bentonite slurry, using the pump-down method.

La. Admin. Code tit. 56, § I-531

Promulgated by the Department of Transportation and Development, Office of Public Works, LR 1:249 (May 1975), amended LR 11:963 (October 1985), repromulgated by the Department of Transportation and Development, Office of Public Works, LR 31:942 (April 2005), amended by the Department of Natural Resources, Office of Conservation, LR 37:913 (March 2011).

AUTHORITY NOTE: Promulgated in accordance with R.S. 38:3091-R.S. 38:3097.