EP 1110-1-27
27 Jan 00
1-5. Safety
Personal safety is the top priority in any operations on HTRW sites. The guidance in this EP is provided
with safety in mind. However, users of this pamphlet are responsible for following the requirements of
EM 385-1-1 and ER 385-1-92.
1-6. Scope and Application
a. Scope. This EP is concerned with the operation and maintenance (O&M) of ground water
injection and extraction systems on HTRW sites; however, it does not address the rehabilitation of these
systems (that is, the actions taken to restore a well after substantial loss of performance), although
maintenance operations will have some similarities with rehabilitation. The scope also excludes the O&M
of the water treatment plant facility. Other pumping or injection wells besides those at HTRW sites (for
example, ground water monitoring wells or water supply and injection wells for purposes other than
HTRW cleanup) have performance and water quality problems associated with well deterioration. Also,
monitoring wells (for either HTRW or preventive monitoring) may become clogged and no longer
provide reliable samples for water quality analysis. While not specifically addressed to these applications,
many features of the diagnosis and maintenance treatments will also apply to these other wells.
(1) Performance. This EP will emphasize the role of preventive design and construction (based on
good quality data and practice) in preventing or delaying problems. It is assumed that wells on HTRW
sites will
operate under conditions that often promote rapid well performance deterioration.
need to be designed and operated in such a way that unavoidably promotes well performance
problems.
(2) Effects of past design and maintenance. The EP also addresses situations where installation
operators are required to maintain well systems that were not optimally designed in the first place. In
studying the operating challenges of such systems, it has become apparent that some O&M practices for
HTRW site well systems are ineffective, and obsolete processes are being followed that do not reflect
modern understanding of microbial and geochemical processes. This EP is intended to provide guidance
to update O&M processes, taking into consideration modern understandings to improve O&M
effectiveness.
b. Application. The specific application of and adherence to these guidelines must be tailored to
each project function, the contaminants of concern, the adopted treatment solution, local geohydrologic
properties, geotechnical judgment, available resources, applicable regulatory requirements, policy and
guidance, public concerns, and remediation goals.
1-7. Terminology
Communication between regulatory, oversight, owner, and contractor personnel involved in the remedi-
ation of an HTRW site is important both before and during remediation of the site. Communication is
complicated by the involvement of numerous technical disciplines and regulatory agencies, and it is
imperative that the descriptive language used during discussions be compatible. Likewise, the practices of
well design, construction, and maintenance and rehabilitation also have specific terminology and usages.
This EP promotes an interdisciplinary approach to well-system design and O&M that works to enhance
system performance. The reader is assumed to be a technically competent person who may not be familiar
with all specific terminology usages, but has a general but not thorough knowledge of ground water and
well-system construction. Therefore, a wide range of definitions will be supplied to promote clarity.
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