This article shall apply to water wells drilled within town
limits under New Mexico Statutes Annotated section 72-12-1, 72-12-3,
72-12-7, 72-12-22, 72-12-23, or 72-12-24, or any other applicable
statute.
(Ordinance 03-04, sec. 1, adopted 2003)
A. No
person shall construct, install, or use a new water well unless such
well is constructed and maintained in accordance with any rules or
regulations promulgated under this article.
B. The
location of the well on the site shall be at a point normally free
from flooding and hydrologically upgradient of all known sources of
pollution and contamination.
C. The
surface completion of the well shall be graded to drain away in all
directions and a concrete platform at least four inches (4") thick
and extending at least three feet (3') from the casing on all sides
shall be provided around the casing.
D. The
casing or piping shall be exposed at least twelve inches (12") above
the platform and capped with a secure cap and the surface of the platform
shall slope away from the casing to the edges.
E. The
water well pump and equipment shall be designed and installed to ensure
a pollution-proof and, where necessary, a frost-proof installation.
New and reconstructed water wells constructed after the effective
date hereof shall be constructed with a pitless adapter and the well
shall not be placed in a pit.
F. Every
water well must be maintained to prohibit entrance of pollution or
contaminants into the well or annular space.
G. Within
ten (10) days of completion of the well, the property owner or agent
shall submit to the town a copy of the well record/driller’s
log. The log shall contain all completion information required in
this article. No certificate of occupancy shall be issued until such
time as these requirements are fulfilled.
H. The
town may perform site inspections during construction of the system
and after completion of the well.
(Ordinance 03-04, sec. 1, adopted 2003)
Construction of wells defined under section
13.04.210 of this article shall comply with the following sealing and casing requirements:
A. Nonpublic
well.
Any person who proposes to drill a nonpublic well
within the town limits under a permit issued by the New Mexico office
of the state engineer under New Mexico Statutes Annotated section
72-12-1, 72-12-3, 72-12-7, 72-12-22, 72-12-23, or 72-12-24 and other
applicable statutes and by the town shall be required to complete
the well in a manner that will seal the annular space to prevent contaminated
surface and ground waters from entering the borehole, annular space
or well.
B. Annular
seal.
All proposed wells included in subsection
A of this section shall be completed with an annular seal or surface/conductor casing. Annular seals shall be placed above the filter pack or screened interval and shall consist of either a bentonite seal overlain by a neat cement grout, or by installation and grouting of surface or conductor casing. The bottom of the tremie tubing shall be no more than forty feet (40') above the top of the filter pack during placement. Annular seals shall be emplaced by one of the following methods:
1. Placing
of bentonite seal.
The bentonite seal material shall
be a minimum of ten feet (10') thick, be placed immediately above
the gravel pack, and consist of bentonite pellets or chips which will
not hydrate too rapidly or bridge off as they fall from the surface.
The neat cement grout seal shall be a minimum of eight feet (8') thick
and shall be placed in the annulus by tremie method above the bentonite
seal to within five feet (5') of ground surface, and shall have the
following properties:
Neat cement grout: Grout shall consist
of a mixture of Portland cement meeting the requirements of ASTM C150
type II, and water shall be approximately 15.6 lbs./gal. (117 lbs./ft.3).
A maximum of two (2) to five percent (5%) by weight of bentonite may
be added. If bentonite is added, mixing water shall be increased by
0.6 gallon per sack for each one percent (1%) by weight addition of
bentonite.
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2. Placing
of surface casing and grouting.
In the portion of the
well in which surface casing is to be installed, the pilot hole shall
be reamed to the confining layer above the principal water bearing
strata. The diameter of the boring shall be a minimum of four inches
(4") greater than the outside diameter of the casing. The conductor
casing then shall be cemented with neat cement grout, by tremie, the
Haliburton method or an approved equal. Regardless of the cementing
method used, the casing must be kept completely full of liquid at
all times until cement is set. The cementing of the conductor casing
shall be approved by the town. All drilling equipment and specialized
tools shall be operated by personnel thoroughly trained in the operation
and application of their equipment. The placing of the cement grout
shall be performed in a manner that shall seal the annulus against
infiltration of water. Upon completion of grouting, cement grout shall
set for a minimum period of twenty-four (24) hours. The time shall
not exceed seventy-two (72) hours.
C. Protection
of the well.
The open annulus shall be protected from
entry of unwanted material at all times. The contractor shall construct
and maintain drainage berms around the wellhead to prevent surface
runoff from reaching and entering the well during construction.
D. Certification
of work.
The applicant and/or well driller shall provide
its log and a certification to the town certifying that all work has
been performed as required under this chapter.
(Ordinance 03-04, sec. 1, adopted 2003)