6 CRR-NY 363-6.8NY-CRR
6 CRR-NY 363-6.8
6 CRR-NY 363-6.8
363-6.8 Geomembrane liners.
(a) Materials required.
The geomembrane base liner material must be constructed of HDPE polymer that is acceptable to the department. Geomembrane base liners constructed of other polymers may be approved by the department based on the equivalent design requirements of section 363-6.21 of this Subpart if demonstrated to have equivalent chemical resistance, construction durability, and service life expectancy.
(b) Construction requirements.
(1) The geomembrane in both the primary and secondary composite liner systems must be installed in direct and uniform contact with the underlying low-permeability soil layer or GCL in a manner that eliminates waves and creases and must be field seamed to control fluid migration from the landfill.
(2) Geomembranes must be installed at a minimum slope of two percent, except slopes parallel to the leachate collection pipe must have a minimum slope of one percent.
(3) The surface of the supporting soil upon which the geomembrane will be installed must be free of stones, organic matter, cracks, irregularities, protrusions, loose soil, and any abrupt changes in grade.
(4) The anchoring system must be constructed as shown on the approved engineering drawings to eliminate potential liquid leakage into the secondary leachate collection and removal system by, at a minimum:
(i) diverting surface water run-off away from the anchoring system; and
(ii) seaming the primary and secondary geomembranes together.
(5) Field seams must be constructed in accordance with the following:
(i) field seams must be oriented parallel to the line of maximum slope (i.e., oriented along, not across the slope). In corners and irregularly shaped locations, the number of field seams must be minimized. The number of horizontal seams must be minimized. Horizontal seams must be more than five feet from the toe of slope in either direction;
(ii) field seams must be primarily made by using a dual-track thermal fusion seaming method. Extrusion welding of field seams must be minimized to the extent practical;
(iii) the seam area must be free of moisture, dust, dirt, debris, and foreign material before seaming;
(iv) field seaming is prohibited when either ambient air or sheet temperature is below 32° F, when the sheet temperature exceeds 158° F, when the ambient air temperature is above 120° F, during periods of sustained winds in excess of 20 miles per hour, or during periods of precipitation; and
(v) the field crew foreman of the liner installer must have a documented minimum qualification of installing at least 50 acres of previous landfill or comparable geosynthetic systems, on a minimum of 5 different projects. Each welding machine must be operated by a welding technician who has been certified to operate the welder by a certification program acceptable to the department.
(c) Certification requirements.
(1) The project engineer must certify that the results of the quality control testing for all geomembranes meet the requirements of the approved engineering drawings, reports, and specifications before the installation of any geomembrane, including the following information:
(i) origin and identification of the raw materials used to manufacture the geosynthetic material;
(ii) copies of quality control certificates issued by the producer of the raw materials used to manufacture the geomembrane, which at a minimum must include the results of tests conducted to verify material quality, specific gravity, melt flow index, percent carbon black, and carbon black dispersion using test methods acceptable to the department;
(iii) results of tests conducted at the factory to verify the quality of the geomembrane, including thickness, density, single-point stress crack resistance, tensile strength, tear and puncture resistance, elongation, carbon black content, carbon black dispersion, oxidation induction time, oven aging and UV resistance using test methods acceptable to the department; and
(iv) documentation that the geomembrane was fully inspected for uniformity, damage, imperfections, holes, cracks, thin spots, foreign materials, tears, punctures, and blisters and that any imperfections were immediately repaired and reinspected.
(2) The project engineer must review the appropriate documentation to certify that the quality control testing of any fabricated factory seams of geomembrane sheets took place at the factory in accordance with the following requirements:
(i) the geomembrane was fully inspected for uniformity, damage, imperfections, holes, cracks, thin spots, foreign materials, tears, punctures, and blisters. Any imperfections must be immediately repaired and reinspected;
(ii) nondestructive seam testing was performed on all fabricated seams over their full length using a test method acceptable to the department; and
(iii) destructive seam testing was performed on a minimum of two samples per factory fabricated geomembrane sheet. The samples must be taken from extra material at the beginning or end of sheet seams, so that the geomembrane sheet is not damaged and the sheet geometry is not altered. A laboratory acceptable to the department must have performed the required testing on the samples taken. If a sample fails a destructive test, the entire seam length must be reconstructed or repaired using a method acceptable to the department, and retested in accordance with subparagraph (ii) of this paragraph.
(3) The project engineer must certify that quality assurance testing was performed in the field during liner installation demonstrating that the liner conforms to the approved engineering drawings, reports, and specifications and the following requirements:
(i) For each lot number of geomembrane material that arrives at the site, a sample must be collected and archived.
(ii) All geomembrane must be visually inspected for uniformity, damage, imperfections, holes, cracks, thin spots, foreign materials, tears, punctures, and blisters. Any imperfections must be immediately repaired and reinspected.
(iii) The project engineer must ensure that trial seams are constructed and destructive seam tests are performed:
(a) at the start of each shift for every piece of seaming equipment and for each seaming crew;
(b) after every four hours of continuous seaming;
(c) every time seaming equipment is changed;
(d) whenever the project engineer requires; and
(e) as additionally required in the approved specifications.
(iv) The entire length of all field seams must be nondestructively tested in accordance with the procedures listed in this subparagraph using a test method acceptable to the department. The project engineer or designated representative must:
(a) monitor all nondestructive testing;
(b) record the location, date, name of tester, and results of all testing;
(c) inform the installer of any required repairs; and
(d) overlay all seams which cannot be nondestructively tested with the same geomembrane. The seaming and patching operation must be inspected by the project engineer for uniformity and quality.
(v) Destructive testing must be performed on the geomembrane liner seams in accordance with the following requirements using test methods acceptable to the department:
(a) Seam samples must be taken at a rate of 1 sample per 1,000 feet of seam length or 1 sample for each seaming machine operating on a given day, whichever is more frequent. All sample locations must be documented.
(b) The project engineer must approve the sample size, which must be large enough to perform the required testing.
(c) An independent laboratory acceptable to the department must perform the required testing, which must include testing for seam strength and adjacent geomembrane elongation, and peel adhesion (and separation in-plane for high density polyethylene) using testing procedures acceptable to the department.
(d) If a sample fails destructive testing, the seam must be reconstructed in each direction between the location of the sample that failed and the location of the next acceptable sample; alternatively, the welding path may be retraced to intermediate locations at least 10 feet in each direction from the location of the sample which failed the test, in which case a second sample must be taken for an additional field test at each of those locations. If these second samples pass, the seam must be patched or reconstructed between the locations of the second samples. If a second sample fails, this process must be repeated.
(e) All acceptable seams must lie between two locations where samples passed the test procedures found in clause (d) of this subparagraph.
(vi) Upon completion of geomembrane seaming, patching, or reconstruction, post-construction care of the installed geomembrane must commence and, at a minimum, include timely covering and temporary weighting using sandbags, as necessary, to prevent damage from wind uplift, construction, or other sources.
(vii) After placement of the soil drainage layer, an electrical resistivity leak location evaluation, and/or other geomembrane liner integrity evaluation approved by the department, must be conducted on areas of both the primary and secondary liners with slopes of 10 percent or less by a person independent of the geomembrane installer. All discovered liner defects must be repaired, and a written report of the findings and verification of repairs must be submitted to the department with the construction certification report required in section 363-6.19 of this Subpart.
6 CRR-NY 363-6.8
Current through March 15, 2022
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