(a)
Standards for construction, repair or modification, destruction or inactivation of
wells as set forth in the Bulletins, are hereby adopted as part of this chapter, with
the following additional clarification and requirements for well construction:
(1)
The annular space between the casing and surrounding formation shall be a minimum
of three inches greater than the casing and shall be sealed to a minimum depth of
fifty feet below ground surface;
(2)
The sealing material shall be pumped into the annular space using a tremie pipe;
(3)
The minimum set up time allowed for annular seal materials shall be in accordance
with the Bulletins. When additives to shorten setting time are proposed to be used
with the sealing material, setup time may be reduced per the additive manufacturer's
specification. No additional construction or well development activity may resume
until the sealing material has sufficient time for proper set up;
(4)
Every well shall be equipped with an adequately sized opening by which disinfecting
agents may be conveniently introduced directly into the well casing. This opening
shall be protected against entrance of contaminants by use of a watertight cap or
plug;
(5)
Before being placed in service, every new, deepened, repaired or reconstructed individual
domestic or community water supply well shall be thoroughly disinfected utilizing
the procedures set forth in Appendix C of the Bulletins;
(6)
Upon completion of the drilling process, the well head shall be sealed in accordance
with the Bulletins, so as to prevent entry of contaminants into the casing;
(7)
Drilling waste shall be controlled and may not be discharged so as to create conditions
which violate water quality control board regulations, other state laws, federal regulations
or local ordinances;
(8)
Mud pits created to confine drilling mud shall be maintained during the well drilling
operation so as not to be a safety hazard. It shall be the well drilling contractor's
responsibility to properly earth fill the mud pit(s) upon completion of the job;
(9)
The location and design of all wells, including horizontal or lateral wells, shall
be approved by the administrative authority on a case-by-case basis prior to construction
or modification of such wells;
(10)
A concrete base or pad shall be constructed at ground surface around the top of the
well casing and contact the annular seal as per the Bulletins, except for cathodic
protection wells and monitoring wells which will follow California Well Standards
Bulletin 74-90 or its successors.
(A)
The soil under the pad must be thoroughly compacted and the pad shall have a minimum
thickness of four inches above grade, extend two feet laterally in all directions
and slope away from the exterior of the casing;
(B)
A minimum of forty-eight hours setting time shall be required on bentonite well seals
before a concrete base or pad is installed around the well casing;
(C)
The well pad for turbine pump installations shall be constructed to allow for additional
weight and soil bearing capacity as per the Bulletins;
(D)
The well casing shall extend a minimum of eighteen inches above the finished grade.
(b)
The administrative authority may approve requests for variances from the provisions
of this chapter if it is determined that complete compliance with the prescribed standards
is not possible or practical due to site characteristics and that the variance will
not endanger groundwater quality or jeopardize public health and safety.
