Design and Construction of Wells
A well is more than a hole in the ground that is used to produce
water or for monitoring water quality. Each well needs to be designed
and constructed to meet the unique aspects of the hydrogeologic
environment and the purpose for which it is intended. The purposes
range from obtaining thousands of gallons per minute from a
heterogeneous sand aquifer to monitoring for contaminants in a
fractured rock environment. What are the advantages and disadvantages
of air rotary vs. mud rotary or cable tool drilling techniques? How do
you select a drilling technique for a given site? How big should the
pump chamber casing be? Should a wire-wrapped well screen be used or
louvered casing? What interval should be screened for a monitoring
well? How do you avoid change orders and driller problems during well
construction? This course addresses these and other questions.
Both of the instructors for this course have a broad background in
the design and construction of wells for a variety of purposes. They
have well construction experience in drilling environments ranging from
unconsolidated glacial and alluvial sediments to a variety of fractured
rock settings including basalt, limestone, sandstone, granite, and
various metamorphic rocks. Water supply wells have ranged in depth to
2,000 feet and in yield to 3,000 gpm. The instructors have been
involved in designing and constructing monitoring wells in both
sedimentary and fractured rock environments.
Topics presented in this course include: (1) general aspects of well
design including meeting state and federal standards, (2) selection of
a drilling technology to meet site conditions and well objectives, (3)
design and construction of production wells, and (4) design and
construction of monitoring wells. Numerous case study examples will be
presented during the course. Attendees will work individually or in
small groups during the second day to do a detailed design of a
production well (morning session) and a monitoring well network
(afternoon session).