must be approved by the CQA Consultant prior to use. The CQA Consultant has
the right to reject any vacuum box that he feels may not provide accurate
results.
C. Vacuum box testing shall be performed by applying a soap-and-water solution
to the seam and placing the box over the seam so a leak-tight seal is obtained,
applying a vacuum of 5 psi to the box. The seam shall be examined through the
viewing window for at least 10 seconds by the CQA Consultant for the presence
of soap bubbles. If soap bubbles are detected in the viewing window, the
location will be marked and repaired in accordance with these Specifications.
Vacuum testing shall be performed in accordance with ASTM D5641.
D. Air pressure testing shall be performed on double-fusion seams having an air
channel between the seams. Both ends of the seam shall be heat-sealed and a
hollow needle with a pressure gauge and valve attached shall be inserted into
the air channel. A pump shall be attached to the needle and an air pressure of
25 psi shall be applied to the air channel. The valve shall be closed and the
pressure shall be observed for a minimum of 5 minutes. If the pressure drops
more than 2 psi or doesn't stabilize, then the defective area shall be located,
marked, and repaired in accordance with these Specifications. After
completing the air pressure test, the needle shall be removed and the hole shall
be sealed and tested with the vacuum box. The CQA Consultant shall witness
the entire test, including the release of pressure or vacuum, to monitor for a
defective pressure or vacuum gauge. Air pressure testing shall be performed
in accordance with ASTM D5820.
E. Destructive testing of seam samples shall be performed at a minimum
frequency of one per 500 linear feet of seam. Seam sampling for destructive
testing shall be performed as work progresses to obtain test results before
seams are covered. The CQA Consultant will select the seam samples locations
and, at its discretion, may take samples more frequently than one per 500 feet.
If a lower testing sampling frequency is desired, the CQA Consultant will
prepare and submit proposed guidelines for selecting variable sampling
intervals based on a method of attributes to the New Hampshire Department of
Environmental Services Solid Waste Bureau for consideration.
F. The Installation Contractor shall cut seam samples at the locations designated
by the CQA Consultant. The seam samples shall be 12-inches wide and 48-
inches long with the seam centered lengthwise. Each test sample shall be
assigned an identification number and the locations shall be recorded on the
as-built drawings.
G. All holes resulting from seam sampling shall be repaired immediately and
tested with the vacuum box in accordance with these Specifications on the
same day the samples are taken.
File No. 3066.09.00 Geomembrane 02550 - 12 of 14 December 2017
