polyvinyl chloride (PVC) must have the following properties (Property - Test
(a) Thickness - ASTM D1593, Para
9.1.3, 30 mil, minimum
Gravity (minimum) - ASTM D792, Method A
Minimum Tensile Properties (each
direction) - ASTM D882:
(A) Breaking Factor
(pounds/inch width) - Method A or B (1 inch wide), 69
(B) Elongation at Break (percent) - Method A
or B, 300;
(C) Modulus (force) at
100% Elongation (pounds/inch width) - Method A or B, 27;
(d) Tear Resistance (pounds, minimum) - ASTM
D1004, Die C, 8
(e) Low Temperature
- ASTM D1790, -20° F
Dimensional Stability (each direction, percent change maximum) - ASTM D1204,
212° F;, 15 min., ± 5
(g) Water Extraction - ASTM D1239, 0.35%
(h) Volatile Loss - ASTM
D1203, Method A, 0.7% max;
Resistance to Soil Burial (percent change maximum in original value) - ASTM
(A) Breaking Factor, -5;
(B) Elongation at Break, -20;
(C) Modulus at 100% Elongation, ±
(j) Bonded Seam
Strength (factory seam, breaking factor, ppi width) - ASTM D3083,
(k) Hydrostatic Resistance -
ASTM D751, Method A, 82.
(a) Patches, repairs, and seams must have the
same physical properties as the parent material.
Site considerations and preparation.
(A) The supporting surface slopes and
foundation to accept the liner must be stable and structurally sound with
appropriate compaction. Particular attention must be paid to the potential of
sink-hole development and differential settlement.
(B) Soil stabilizers such as cementations or
chemical binding agents may not adversely affect the membrane; cementations and
chemical binding agents may be potentially abrasive agents.
(c) Only fully buried membrane
liner installation may be considered to avoid weathering.
(d) Unreinforced liners have high elongation
and can conform to irregular surfaces and follow settlements within limits.
Unreasonable strain reduces effective thickness and may reduce life expectancy
by lessening the chemical resistance of the thinner (stretched) material. Every
effort must be made to minimize the strain (or elongation) anywhere in the
flexible membrane liner.
Construction and installation.
(i) Preparation of earth subgrade.
The prepared subgrade must be of soil types no larger than Unified Soil
Classification System (USCS sand (SP) to a minimum of 4 inches below the
surface and free from loose earth, rock, fractured stone, debris, cobbles,
rubbish and roots. The surface of the completed subgrade must be properly
compacted, smooth, uniform, and free from sudden changes in grade. Importing
suitable soil may be required.
Maintenance of subgrade. The earth subgrade must be maintained in a smooth,
uniform, and compacted condition during installation of the lining.
(i) Temperature. Placing liner outside the
desirable temperature range must be avoided. The desirable temperature range
for membrane installation is 42° F. to 78° F. Lower or higher
temperatures may have an adverse effect on transportation, storage, field
handling, and placement, seaming, and backfilling; and attaching boots and
patches may be difficult.
Wind. Placing the liner in high wind must be avoided. Wind may have an adverse
effect on liner installation such as interfering with liner placement.
Mechanical damage may result. Cleanliness of areas for boot connection and
patching may not be possible. Alignment of seams and cleanliness may not be
Seaming, patching, and attaching "boots' must be done under dry conditions.
When field seaming is adversely affected by moisture, portable protective
structures and other methods must be used to maintain a dry sealing surface.
Proper surface preparation for bonding boots and patches may not be
Structures. Where penetrations are necessary, liners must be attached to pipes
with a mechanical type seal supplemented by a chemically compatible caulking or
adhesives to effect a liquid-tight seal. Maximum compaction must be provided in
the area adjacent to pipes to compensate for any settlement.
(i) Size. The final cut size of the liner
must be carefully determined and ordered to generously fit the container
geometry without field seaming or excess straining of the liner
handling, and storage. Transportation, handling, and storage procedures must be
planned to prevent material damage. Material must be stored in a secured area
and protected from adverse weather.
(iii) Site inspection. A site inspection must
be carried out by the agent and the installer before liner installation to
verify surface conditions and other conditions important to
Panels must be positioned to minimize handling. Seaming should not be
necessary. Bridging or stressed conditions must be avoided with proper slack
allowances for shrinkage. The liner must be secured to prevent movement and
trenches. The liner edges must be secured frequently in a backfilled
(vi) Field seaming. Field
seaming, if absolutely necessary, must be attempted only when weather
conditions are favorable. The contact surfaces of the materials must be clean
of dirt, dust, moisture, or other foreign materials. The contact surfaces must
be aligned with sufficient overlap and bonded in accordance with the suppliers
recommended procedures. Wrinkles must be smoothed out and seams must be
inspected by nondestructive testing techniques to verify their integrity. As
seaming occurs during installation, the field seams must be inspected
continuously, and any faulty area repaired immediately.
(vii) Field repairs. Traffic on the lined
area must be minimized. Any necessary repairs to the liner must be patched
using the same lining material and following the recommended procedure of the
and acceptance. Completed liner installations must be visually checked for
punctures, rips, tears, and seam discontinuities before placement of any
backfill. At this time the installer must also manually check all factory and
field seams with an appropriate tool. In lieu of or in addition to manual
checking seams, either of the following tests may be performed:
(I) Wet Test. The lined basin must be flooded
with water to the 1-foot level after inlets and outlets have been plugged.
There may not be any loss of water in a 24 hour test period.
Air Lance Test. All bonded seams must be
checked using a minimum 50 PSI (gauge) air supply directed through a 3/16 inch
(typical) nozzle held not more than 2 inches from the seam edge and directed at
the seam edge. Riffles indicate unbonded areas within the seam or other
undesirable seam construction.
[NOTE: Referenced publications are available from the