TM 5-815-5/AFM 88-5, Chap 6/NAVFAC p-418
and N piezometers on a schedule similar to the above
bowl. With approval of the C.O.R., the pump bowl may
for his own check and evaluation purposes.
be lowered. In order to maintain maximum well effi-
(f) Records. The Contractor shall furnish copies
ciency, the deep-well system shall be operated by
of all piezometer and water level readings to the
pumping whatever number of wells are required to
C.O.R. within 24 hours of being taken. Copies of pie-
achieve the specified water level lowering in the deep
zometer, water level, and flow measurements made by
sand formation without pumping any well more than
the C.O.R. will be furnished to the Contractor within
1200 gallons per minute except in an emergency or if
24 hours.
required to achieve the specified water level lowering.
(3) Dewatering system flow.
(4) Responsibility. Dewatering the excavation in-
(a) Flow measurements. The flow from individ-
cludes the control of seepage and artesian pressure in
ual dewatering wells will be measured by means of a
the deep sand stratum underlying the site and the con-
pitometer installed in the discharge pipe from the
trol of seepage from the upper silts and silty sand for
well. As a check on the pitometer measurements and
the duration of this contract. Included are the opera-
on the performance of the well pump, the rate of flow
tion and maintenance of the deep-well, jet-eductor
being pumped will also be estimated from the pump
well, and surface water control systems.
characteristic curve, engine speed, static lift of the
(5) Repair and replacement. The specified number
water, and the pressure in the discharge pipe at the
of wells and pumps shall be available for use at all
top of the well. Flow from the entire dewatering sys-
times. All damaged or malfunctioning wells or well
tem will also be measured by means of a pitometer. All
components shall be repaired or renewed as expedi-
flow measurements will be made by the C.O.R. as-
tiously as possible while continuing to maintain the re-
sisted by the Contractor's "dewatering" engineer.
quired water levels. The Contractor shall be responsi-
ble for all replacement equipment and the repair and
from the dewatering system shall be measured once or
maintenance of all system components so as to main-
twice a week and the flow from individual wells week-
tain the system fully operational. Replacement equip-
ly or biweekly, as appears appropriate.
ment and materials shall conform to the requirements
(c) Records. All flow measurements will be re-
of these specifications.
corded by the C.O.R. and a copy of the data furnished
(6) Maintenance criteria. The Contractor shall
to the Contractor within 24 hours. The C.O.R. will be
maintain a regularly scheduled maintenance program
responsible for reading the river gage and recording
which shall conform with the equipment manufac-
the data; a copy of the river gage reading will be fur-
turer's recommendations and include all other work
nished to the Contractor each day.
necessary to maintain all components fully operation-
(4) Sanding. The flow from each dewatering well
al. The maintenance program shall include, but not be
will be monitored for sanding. The rate of sanding will
limited to, checking the flow rate and water elevation
be determined by taking a measured amount of water
in each well. All data and records shall be submitted to
being pumped from each well and the sand content de-
the C.O.R. at the completion of this contract. The Con-
termined. The maximum rate of sanding acceptable
tractor shall also maintain any nonoperating pumps
will be 5 parts per million. The rate of sanding will be
and engines. Maintenance shall include, but not be
checked once a week by the C.O.R. and the data re-
limited to, starting each nonoperating pump and en-
corded. A copy of the data will be furnished to the Con-
gine on a weekly basis and operating the pump for a
tractor within 24 hours.
minimum of 15 minutes. All pumps, both operating
and nonoperating, shall be tested for wear, independ-
i. Operation and maintenance of dewatering and
ently, on a monthly basis. The Contractor shall con-
surface water control systems.
duct a shutoff head test and a test to verify that the
(1) Supervision. Supervisory personnel shall be
pump is capable of operating at its rated head capac-
present onsite during normal working hours and shall
ity. The Contractor shall renew all pumps having a
be available on call 24 hours a day, 7 days per week, in-
test result less than 75 percent of the manufacturer's
cluding holidays.
rated shutoff head or rated capacity. The maintenance
(2) Operating personnel. Sufficient personnel
tests shall be conducted under the supervision of the
skilled in the operation, maintenance, and replace-
Contractor Quality Control representative and under
ment of the dewatering and surface water control sys-
the observation of the C.O.R.
tems, components, and equipment shall be onsite 24
hours a day, 7 days per week, including holidays, at all
j. Damages. The Contractor shall be responsible and
times when the systems are in operation.
shall repair without cost to the Government, any work
(3) Well pumping restriction. The pumping rate of
in place, another contractor's equipment, and any
any dewatering (deep) well shall be adjusted, if neces-
damage to the excavation, including damage to the
sary, by adjustment of engine speed or valving so that
bottom due to heave that may result from his negli-
the water level in no well is lowered below the pump
gence, improper operation and/or maintenance of the
G-22
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