than or equal to 5 NTUs) after development. If the
local EPA Region enforces this criteria, it may be
necessary to include a requirement that the well be
developed until a turbidity of less than or equal to
5 NTUs is achieved.
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A well development record shall be maintained in accordance with paragraph
Well Development Records. Development is complete when all of the
following criteria are met:
a.
Well water is clear to the unaided eye [,and turbidity less than
or equal to [5] [____] Nephelometric Turbidity Units (NTUs)],
b.
Sediment thickness in the well is less than [1 percent of the
screen length] [30 mm 0.1 foot],
c.
A minimum of three times the standing water volume in the well is
removed plus three times the volume of all added water and
drilling fluid lost during drilling and installation of the well
is removed, and
d.
[Temperature, specific conductivity, pH,oxidation-reduction
potential (ORP), dissolved oxygen (DO), and turbidity readings,
measured before, twice during and after development operations,
have stabilized. Stabilization shall mean [variation of less than
0.2 pH units, variation of plus or minus + 0.5 degree Celsius, 1
degree Fahrenheit,;+ 3 percent change in specific conductance; and
less than a + 10mV for ORP; and + 10 percent for DO, and
turbidity, measured between three consecutive readings with one
casing volume of water removed between each reading] [_____].
ORP shall be determined in accordance with AWWA EWW. Temperature,
specific conductance, DO, turbidity, and pH readings shall be
conducted in accordance with EPA 600/4-79/020. At completion of
well development, approximately 0.5 liter 1 pint of well water
shall be collected in a clear glass jar. The jar shall be labeled
with project name, well number and date; and photographed using 35
mm color print film. The photograph (minimally 125 x 174 mm 5 x 7
inch) shall be a suitably backlit close-up which shows the clarity
of the water and any suspended sediment. The photograph and
negative shall become a part of the well development record.
Water removed during development and testing operations shall be
[contained in D.O.T. approved drums, containers or vessels and
disposed of by [_____], in accordance with paragraphs
CONTAINERIZATION OF DEVELOPMENT WATER, AND DRILL CUTTINGS, and
Drilling Waste Disposal] [discharged to the ground surface at
least [_____] meters feet from the well in a down gradient area].]
3.5
TESTS
After the wells have been developed, the Contractor shall notify the
Government and shall make the necessary arrangements for conducting the
capacity tests. If the capacity test indicates that the required capacity
can be obtained, the tests for quality of water shall be made. If the
capacity and quality tests indicate that the required capacity and quality
can be obtained, the permanent well, as specified, shall be completed at
that depth. Prior to making quality tests, drilling equipment, tools and
pumps contacting well water shall be cleaned with live steam.
SECTION 02521
Page 30
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