40D-3.502. Construction Methods

(1) Water wells may be constructed by drilling, coring, boring, washing, jetting, driving or digging, but must be so constructed, cased, cemented, plugged, capped or sealed as to permanently prevent:

(a) The escape of water to waste, either at or above the land surface, or from a subsurface zone of higher hydrostatic head to a zone of lower hydrostatic head, or

(b) The degradation of water by poor quality water or other substances from surface or underground sources.

(2) For wells constructed using the combination method of drilling a borehole and then driving the casing, the borehole shall be equal to or smaller in diameter than the inside diameter of the casing and shall be sealed by adding dry bentonite to the casing string at land surface and allowing that material to be carried down the outside of the casing as the casing is driven to completion. Dry bentonite shall be applied to maintain a grout seal around the casing. The first length of water bearing casing, excluding the attached drive shoe, shall not exceed 21 feet in length and must be driven into the ground before any additional borehole is constructed.

During construction of a well in a delineated area, as defined in Rule 62-524.200, F.A.C., or a public supply well using the combination drilling method, the minimum acceptable grout seal shall be accomplished by undercutting or underreaming the last five feet of hole before sealing the casing. A minimum of one foot of such enlarged hole must be into the consolidated formation in which the casing is seated. The entire enlarged portion of the hole shall be filled with cement grout and then the casing shall be driven through the cement grout and seated into the enlarged portion of the consolidated formation. The top 20 feet of casing shall be sealed with no less than a 2-inch nominal thickness of cement grout. Except as described above, the use of a drilling tool, such as an eccentric bit or an underreamer bit, that is capable of drilling a hole larger than the inside diameter of the casing is prohibited when constructing a well by combination method.

(3) In the construction of a well, reasonable caution shall be taken to maintain the premises in sanitary condition and to minimize the entrance of contaminants into the water resource. Water and materials used in construction shall be reasonably free of contamination. If the well or water supply is a known source of contamination or is within a known area of contamination, it shall not be used to provide water to construct the well. For purposes of this rule, a known source or known area of contamination would be any water supply or well within the area specified by Chapter 62-524, F.A.C.

(4) Monitor wells for underground storage systems shall be constructed in accordance with Chapter 62-761, F.A.C., and this Chapter.

(5) Injection wells shall be constructed in accordance with Chapter 62-528, F.A.C., and this chapter.

(6) Wells permitted under Chapter 62-524, F.A.C., shall be constructed, repaired, modified or abandoned in a manner that meets the special criteria developed for each designated area.

(7) Wells being constructed, repaired, modified or abandoned as part of a water use permit, issued under Chapter 40D-2, F.A.C., must meet all special well construction conditions specified by that permit. When special well construction conditions have been specified on a water use permit, these conditions shall be attached to applicable well construction permits.

(8) The District may designate special well construction standards areas by emergency rule to prevent transport of surface contaminants to ground water or movement of introduced or natural contaminants from one aquifer or zone to another. Such standards will be the minimum necessary to prevent the movement of contaminants, and will be developed in cooperation with other state agencies, local jurisdictions, and the regulated public, in accordance with Chapter 120, F.S., provisions for emergency rulemaking.

Rulemaking Authority 373.044, 373.171, 373.309, 373.337 FS. Law Implemented 373.306, 373.308, 373.309 FS. History–New 7-1-90, Amended 9-30-91, 12-31-92, 2-19-04, 12-12-11.