La. Admin. Code tit. 56 § I-323

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

Section I-323 - Drilling and Construction

A. Geologic conditions in Louisiana permit the use of two methods of drilling: the rotary method and reverse circulation method. Regardless of the method used, every precaution should be taken to prevent ground water contamination during drilling operations.

B. Water used in drilling operations shall be potable or chlorinated to prevent contamination of water-bearing formations.

C. When drilling a hole the contractor shall:

1. prior to the commencement of any construction on a new water well, the drilling contractor shall confirm that the office of conservation has received and responded to water well installation notification as required in LAC 43:VI.701.B;

2. record the hole diameter and any changes in size of hole;

3. record (driller's log) the depth and thickness of the formations penetrated;

4. record any unusual occurrences, such as loss of circulation, cave-ins, etc. (In the event the unusual occurrence is observable evidence of naturally occurring methane gas, natural gas or similar sub-surface gas, such as bubbling drilling mud or gas venting at the well bore or other nearby surface location or feature, the contractor shall report such event verbally to the Environmental Division of the Office of Conservation within 24 hours.); and

5. collect representative samples (drill cuttings) from each potential aquifer.

D. The contractor shall properly maintain all materials, tools, and drilling equipment and shall take all measures necessary to minimize health and safety hazards and to prevent movement of surface water and contaminants into the drilled hole or well.

E. An approved portable toilet shall be located at the drilling site if other restroom facilities are not available.

F. The mud pit shall be so constructed and maintained as to minimize the contamination of the drilling mud.

G. During a temporary shutdown for more than 24 hours, safeguards shall be taken to prevent possible contamination and damage. The well or hole shall be covered or capped to prevent entry by other than the contractor; it shall be clearly marked, and shall not be a safety hazard.

H. Alignment and Plumbness. The hole shall be drilled reasonably straight and plumb in order to:

a. avoid encroachment on neighboring property;

b. prevent intersection with other wells and holes;

c. prevent damage to screen while being set;

d. prevent damage to pumping equipment; and

e. allow for lowering the pump to the desired depth.

I. The contractor shall exercise reasonably straight and plumb. Testing for plumbness and alignment are described in Section 8 and Appendix C of the current American Water Works Association Standards for Water Wells (AWWA A-100), as well as in Article 51 of the United States Environmental Protection Agency's Manual of Water Well Construction Practices.

J. Drilling of Test Holes and Pilot Holes

1. A test hole is usually drilled to the base of the fresh water or to the bottom of the sand to be tested. Test holes are drilled primarily to:

a. determine the exact depth and thickness of the fresh-water bearing sands (aquifers);

b. collect drill cuttings for determining screen slot openings and the best location for the screen; and

c. collect quality and quantity of water data that can be used to design the well and select a pump and motor.

2. During the drilling operation, the contractor shall take the necessary precautions to prevent the contamination of any aquifer and the exchange of waters between aquifers.

3. When the drilling of a pilot hole or a test hole is temporarily suspended and the rig moves away from the drilling site, the hole shall be considered an abandoned hole unless drilling operations are resumed within 30 calendar days of the initial date of suspension of drilling or an extension, in writing, is granted by the department. During the "shut down" period, a mud column of sufficient weight and height shall be maintained in the hole at all times to prevent seepage of surface water and foreign materials into any aquifer and to prevent interaquifer movement of water. Additionally, the hole shall be capped and the immediate area shall be conspicuously marked to protect and warn the public. The cap shall be sufficiently strong and anchored to prevent easy and unintentional entry.

4. If the drilled test hole is deeper than the interval to be tested, the contractor shall use cement-bentonite slurry to set a plug extending from the bottom of the hole upward to a depth within 20 feet of the bottom of the proposed screen setting or to the top of clay or shale layer underlying the sand to be tested. A sufficient period of time shall be allotted for the cement to set before development begins. If sands were not penetrated below the bottom of the sand to be screened, heavy drilling mud or bentonite slurry may be used in lieu of cement-bentonite slurry to plug the bottom of the hole.

5. If another aquifer at a shallower depth is to be tested, the contractor shall use cement-bentonite slurry to set a plug extending upward from the top of the plug, previously placed in the bottom of the hole, to within 20 feet of the depth where the bottom of the test screen is to be set in the shallower aquifer, or to the top of the clay or shale layer underlying the shallower sand to be tested.

6. Abandoned pilot holes and test holes shall be plugged in accordance with requirements of §531, respectively.

K. Drilling of Heat Pump Holes (Closed Loop-System)

1. Heat pump holes shall be constructed in accordance with the pertinent provisions of this Chapter in order to protect freshwater aquifers from surface contamination and to prevent movement of water of objectionable quality from one aquifer to another.

2. Piping, casing or tubing materials shall conform to the applicable ASTM standards for polyvinyl chloride (PVC), polyethylene (PE), or polybutylene (PB) plastics and shall be installed and joined according to manufacturer's recommendations.

3. If used, antifreeze compounds shall be nontoxic and approved for use by the U.S. Environmental Protection Agency.

4. The entire depth of the closed loop heat pump holes shall be sealed in accordance with requirements of §531 within 30 calendar days after completion of drilling operations.

5. Service manifold should be protected from external forces as recommended by the manufacturer, designer and/or local building codes.

L. Drilling of Monitoring Wells

1. Monitoring wells shall be constructed in accordance with the pertinent provisions of this Chapter in order to protect freshwater aquifers from surface contamination and to prevent movement of water of objectionable quality from one aquifer to another.

2. To prevent the introduction of extraneous compounds into the formation water, the use of drilling mud in the monitoring wells is discouraged.

3. Monitoring wells shall be cased and the casing shall be strong enough to resist the forces imposed during and after installation, including reaction upon the casing by natural or foreign constituents or contamination.

4. The entire annular space of the monitoring wells shall be sealed with cement-bentonite slurry, unless specified otherwise by the Department of Environmental Quality (DEQ). Prior to cementing, flushing of the annular space with water will be necessary when obstructions are present or suspected. Coarse ground bentonite or bentonite pellets shall be placed between and the sand pack and the cement-bentonite slurry. The ground surface around the well shall be covered with a concrete slab at least 4 inches thick, extending at least 2 1/2 feet from the well in all directions. The surface of the slab shall be sloped to drain away from the well.

5. Monitoring wells shall be covered with a protective cover or cap.

6. Abandoned monitoring wells shall be plugged in accordance with requirements of §531

Note: Construction of Monitoring Wells for facilities regulated by the department of Environmental Quality (DEQ) require approval from DEQ prior to construction.

M. Drilling of Geotechnical Boreholes

1. Boreholes shall be drilled in accordance with pertinent provisions of this Chapter in order to protect the fresh-water aquifers from surface contamination and to prevent movement of water of objectionable quality from one aquifer to another.

2. Geotechnical boreholes shall be plugged in accordance with requirements of §531 within 30 calendar days after the termination of drilling and sampling operations.

NOTE: Drilling of geotechnical boreholes for facilities regulated by the Department of Environmental Quality (DEQ) require special consideration by that department.

N. Reworking of Water Wells

1. Rehabilitation or modification of water wells shall be accomplished in accordance with the provisions of this Chapter of the rules, regulations and standards for water well drilling in order to protect the fresh-water aquifers from contamination.

O. The following operations shall be considered as reworking water wells and shall require a water well contractor's license.

1. removing and replacing screen;

2. replacing gravel pack around screen;

3. placing a new screen within the old screen;

4. placing a liner pipe within the old casing;

5. redeveloping a well by surging, adicizing, jetting, etc.

P. When a well is reworked or the sanitary seal is removed, the drop pipe, jet line or column pipe, pump/motor, etc., shall be cleaned and the well shall be disinfected in accordance with Chapter XII of the State Sanitary Code.

La. Admin. Code tit. 56, § I-323

Promulgated by the Department of Transportation and Development, Office of Public Works, LR 1:249 (May 1975), amended LR 11:954 (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 37:910 (March 2011), amended by the Department of Natural Resources, Office of Conservation, LR 37:910 (March 2011), LR 37:3528 (December 2011), LR 38:2932 (November 2012).

AUTHORITY NOTE: Promulgated in accordance with R.S. 38:3091-38:309.8.