TM 5-818-5/AFM 88-5, Chap 6/NAVFAC P-418
CHAPTER 7
CONTRACT SPECIFICATIONS
7-1. General. Good specifications are essential to
tor fully responsible for obtaining the required dewa-
ensure adequate dewatering and groundwater control.
tering and pressure relief as proven by a full-scale
Specifications must be clear, concise, and complete
pumping test(s) on the system prior to start of excava-
with respect to the desired results, special conditions,
tion, and for all maintenance, repairs, and operations.
inspection and control, payment, and responsibility.
(2) Type B-2. A specification that sets forth in
The extent to which specifications should specify pro-
detail the design and installation of a system that has
cedures and methods is largely dependent upon the
been designed to achieve the desired control of ground-
complexity and magnitude of the dewatering problem,
water wherein the Government or Owner assumes full
criticality of the dewatering with respect to schedule
responsibility for its initial performance, based on a
and damage to the work, and the experience of the
full-scale pumping test(s), but makes the Contractor
probable bidders. Regardless of the type of specifica-
responsible for maintenance and operation except for
tion selected, the dewatering system(s) should be de-
major repairs required over and beyond those appro-
signed, installed, operated, and monitored in accord-
priate to normal maintenance. (This type of specifica-
ance with the principles and criteria set forth in this
tion eliminates claims and contingencies commonly
manual.
added to bid prices for dewatering and also ensures
that the Government gets a dewatering system that it
7-2. Types of specifications.
has paid for and a properly dewatered excavation if
a. Type A. Where dewatering of an excavation does
the system has been designed and its installation su-
not involve unusual or complex features and failure or
pervised by qualified and experienced personnel.)
inadequacy of the system would not adversely affect
(3) Type B-3. A specification that sets forth the
the safety of personnel, the schedule, performance of
desired results making the Contractor solely responsi-
the work, foundation for the structure, or the com-
ble for design, equipment, installation procedures,
pleted work, the specifications should be one of the fol-
maintenance, and performance, but requires that the
lowing types:
Contractor employ or subcontract the dewatering and
(1) Type A-1. .A brief specification that requires
groundwater control to a recognized company with at
the Contractor to assume full responsibility for design,
least 5 years, and preferably 10 years, of experience in
installation, operation, and maintenance of an ade-
the management, design, installation, and operation of
quate system. (This type should not be used unless the
dewatering systems of equal complexity. The specifi-
issuing agency has considerable confidence in the Con-
cation should also state that the system(s) must be de-
tractor's dewatering qualifications and has the time
signed by a registered professional engineer recog-
and capability to check the Contractor's proposal and
nized as an expert in dewatering with a minimum of 5
work.)
to 10 years of responsible experience in the design and
(2) Type A-2. A specification that is more de-
installation of dewatering systems. This type of speci-
tailed than type A-1 but still requires the Contractor
fication should further require submittal of a brief but
to assume the responsibility for design, installation,
comprehensive report for review and approval includ-
operation, and maintenance. (This type conveys more
ing:
information regarding requirements of design and
(a) A description and profile of the geology, soil,
construction than type A- 1 while retaining the limita-
and groundwater conditions and characteristics at the
tions described in (1) above.)
site.
(b) Design values, analyses, and calculations.
b. Type B. Where dewatering or relief of artesian
(c) Drawings of the complete dewatering sys-
pressure is complex and of a considerable magnitude
tem(s) including a plan drawing, appropriate sections,
and is critical with respect to schedule and damage to
pump and pipe capacities and sizes, power system(s),
the work, the specifications should be of one of the fol-
standby power and pumps, grades, filter gradation,
lowing types:
surface water control, valving, and disposal of water.
(1) Type B-1. A specification that sets forth in
(d) A description of installation and operational
detail the design and installation of a "minimum" sys-
procedures.
tern that will ensure a basically adequate degree of wa-
(e) A layout of piezometers and flow measuring
tering and pressure relief but still makes the Contrac-
7-1
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