62-528.420. Monitoring Well Construction Standards for Class I and III Wells

(1) General Design Considerations.

(a) For Class I wells, associated on-site, cluster, multihorizon, or annular monitoring wells shall not penetrate the injection zone or final confining bed.

(b) For satellite and regional monitor wells associated with Class I wells, cluster or multihorizon monitoring wells shall be allowed to penetrate the injection zone or final confining bed only if the applicant demonstrates that the underground sources of drinking water and confining strata will be protected, the integrity of the monitoring and injection well system will be protected, and the well is designed in such a way that it can be easily repaired.

(c) All monitoring wells constructed for Class III injection operations shall be constructed in accordance with Chapter 62-532, F.A.C.

(d) Department approval by permit modification is required prior to any remedial procedures that alter the basic design specifications.

(2) Exploratory Pilot Hole.

For Class I wells, the Department shall require an exploratory pilot hole and shall require that the hole be drilled in stages. The Department shall waive the requirements of this subsection if the applicant can demonstrate that they are not needed to protect underground sources of drinking water and that waiving the requirements will not adversely affect the successful construction or operation of the monitor well.

(3) Drilling.

The Department shall require that a step-by-step drilling plan be submitted with the design specifications.

(4) Casings and Tubing.

(a) The casings or tubing used in the construction of each newly drilled well shall be designed for the life expectancy of the well.

(b) The number, thickness, type of material, and length of casing or tubing shall be sufficient to protect the quality of drinking water resources and the integrity of the well and confining strata. The type of materials used in the monitoring well shall not bias the sampling parameters used in the monitoring program.

(c) Exact setting depths for all casings or monitor tubing shall be determined from field data, based on all available information. Department approval shall be obtained prior to installation of the monitor casing. In order to obtain approval, the permittee shall submit a request to the Department. The Department shall approve the request if the proposed setting depth of the casing or tubing meets the monitoring requirements of this chapter and will not adversely affect the operation of the injection well.

(5) Cementing.

(a) The applicant shall submit the proposed cementing program with the design specifications. The cement used in the construction of each newly drilled well shall be designed for the life expectancy of the well. The applicant shall submit a list of proposed additives with the construction permit application.

(b) Cement must be compatible with the native fluids and the formation, but in no case less than the quality of American Society for Testing and Materials Type 2 or its equivalent (Standard Specification for Portland Cement, American National Standards Institute/American Society for Testing and Materials C 150-94, 1994).

(c) Cement placement shall be in such a manner that the purposes and characteristics of the cement are retained, and shall be in accordance with “AWWA Standard for Water Wells”, American Water Works Association A100-90, 1990.

(d) The applicant shall submit his cement testing program with the permit application for Department approval.

(e) For Class I monitor wells other than annular monitor wells, a nominal thickness of 2.5 inches of cement surrounding the casings with not less than five inches of overdrill is required, except for the annulus being used for monitoring in wells with open annulus monitoring.

(f) All casings and tubing shall be centralized where possible to ensure uniform cementing.

(g) All outer surfaces of casing or tubing which are uncemented shall be protected from corrosion for a minimum of thirty feet above and below the uncemented portion.

(6) Testing of Monitoring Well Construction.

Test to be considered by the applicant shall include:

(a) Cement evaluation survey.

(b) Temperature survey.

(c) Oxygen activation log.

(d) Noise log.

(e) Pressure test to at least 1.5 times the expected ultimate monitoring pressure but not less than 50 pounds per square inch for one hour.

(f) A pumping test to determine if the monitor well has sufficient capacity to yield a representative ground water sample.

(g) Chemical analyses of water from strata tapped by well.

(h) Water level measurement referenced to National Geodetic Vertical Datum (NGVD) of 1929.

Specific Authority 403.061, 403.087 FS. Law Implemented 403.021, 403.061, 403.062, 403.087, 403.161 FS. History–New 4-1-82, Amended 5-8-85, Formerly 17-28.24, 17-28.240, 62-28.240, Amended 8-10-95.