CHAPTER II. STANDARDS
Section 17. Special Provisions for Driven Wells ("Well Points").
- If the well is to be used as an individual domestic well, an oversize hole
with a diameter at least 3 inches greater than the diameter
of the pipe shall be constructed to a depth of 6 feet and the
annular space around the pipe shall be filled with neat cement, cement grout,
or bentonite mud.
- The minimum wall thickness of steel drive pipe shall not be less than
- Well points made of thermoplastic materials should not be driven but
jetted or washed into place.
Section 18. Rehabilitation, Repair, and Deepening of Wells.
- Rehabilitation is the treatment of a well by chemical or mechanical means
(or both) to recover lost production caused by incrustation or clogging of
screens or the formation immediately adjacent to the well. The following
methods used for rehabilitating a well when done with care are acceptable:
(1) introduction of chemicals designed for this purpose, (2) surging by use
of compressed air, (3) backwashing or surging by alternately starting or
stopping the pump, (4) jetting with water, (5) sonic cleaning, (6) vibratory
explosives, and (7) combinations of these. Methods which produce an
explosion (in addition to the use of vibratory explosives mentioned above)
are also acceptable provided, however, they are used with great care,
particularly where aquifers are separated by distinct barriers to the
movement of groundwater.
In those cases where chemicals or explosives have been used, the well shall
be pumped until all traces of them have been removed.
- In the repair of wells, material used for casing shall meet the
requirements of Section 12 "Casing" of these provisions. In addition, the
requirements of Section 11, Subsection A "Disinfection" and, when applicable,
Section 13 "Sealing-off Strata" shall be followed.
- Where wells are to be deepened, the requirements of Section 11, Section 12, Section 13,
Section 14, and Section 15 of these standards shall be followed.
Section 19. Temporary Cover.
Whenever there is an interruption in work on the well such as overnight
shutdown, during inclement weather, or waiting periods required for the
setting up of sealing materials, for tests, for installation of the pump,
etc., the well opening shall be closed with a cover to prevent the
introduction of undesirable material into the well and to insure the public
safety. The cover shall be held in place or "weighted-down" in such a manner
that it cannot be removed except with the aid of equipment or through the use
During prolonged interruptions (i.e., one week or more), a semipermanent
cover shall be installed. For wells cased with steel, a steel cover, tack-
welded to the top of the casing, is adequate.