Background
Implementation
Annual Cost
Summary

As of December 31, 1997, the National Sanitation Foundation (NSF) of Ann Arbor, Michigan terminated its long standing geomembrane certification program. At that time, NSF also terminated the distribution of its NSF 54 specifications, which stipulated test methods and limiting values for a wide range of geomembranes. Both the certification program and the product specifications went from having widespread use in the early 1980's, to being greatly criticized as of late. While the NSF 54 specifications were often cited (and still are), the NSF product certification program ended with only the involvement of polyethylene geomembrane manufacturers. Reasons for this situation arising are many and, while subjective, the lack of internal support on the part of NSF was certainly a contributing factor.

In order to partially fill the void, the Geosynthetic Institute issued its GRI-GM13 specification for smooth and textured high density polyethylene (HDPE) geomembranes. This specification was presented in its entirety in the previous section. GM13 is a major upgrade of the NSF 54 specification and includes some new and updated tests, eliminates many outdated tests, and includes not only test methods and limiting values, but minimum testing frequencies as well. GRI-GM13 has been accepted by a number of HDPE geomembrane manufacturers and is regularly cited by design engineers and facility owners in their specifications.

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Within the overall structure of the Geosynthetic Institute (GSI), there are a number of related institutes. One of these is the Geosynthetic Certification Institute (GCI). See the flow chart that follows for these interrelationships and the activities of each of the specific institutes. Of importance here is the shaded box for product certification. (The laboratory accreditation program will be described in the next section of this report). Previously, the only activity within GCI was providing technical assistance to the National Institute of Certification of Engineering Technologists (NICET) with regard to its program for certification of CQA field inspectors. The certification of HDPE geomembranes is the second activity and is the focus of this section.

 The Geosynthetic Certification Institute's-Product Certification Program (GCI-PCP) can be viewed in the form of a flow chart; each step of which will be described in the text to follow:

Step 1 - Manufacturer's Request: The process is initiated by a manufacturer of HDPE geomembranes requesting information on the GCI-PCP program. Dr. George R. Koerner is in charge of the program and will represent the initial point of contact. (He will also follow through with the entire program including its long-term servicing.)

Step 2 - Manufacturer Document Submittal: If the outcome of the initial exchange is positive, the manufacturer submits the following information to GCI:

• The company's Quality Manual. It should be noted that this program is modeled after ISO 9002. Thus the manufacturer's quality manual should cover all, or most, of the 20-listed elements. While it is a good idea to follow the ordering, it is not strictly necessary.
• An example of statistical data for at least 60 months production of smooth and textured HDPE geomembranes at each of the manufacturing locations.
• The sample target specification, which for HDPE geomembranes is GRI-GM13, see previous section. Any modifications to this specification must be stated and justified accordingly.

Step 3 -An audit is arranged: Upon acceptance of the documentation of the previous step, Dr. George Koerner and the designated representative of the manufacturer will arrange for an audit of the production facilities. The manufacturer has the right to require secrecy agreements to be signed by the auditor.

Step 4 - The Site Audit: A number of specific items are undertaken during the site audit:

• The opening meeting among the auditor, the manufacturer's representative and at least one officer of the company has the purpose of describing the audit and testing processes and the possible outcomes. There are two tasks; one being the audit of the manufacturer's quality system and statistical control, and the other being the sampling of geomembranes for subsequent testing and comparison to the GRI-GM13 specification values. Of these two, the audit is particularly important since it attests to the manufacturer's ongoing control of production. While also important, the testing of products only gives a snapshot of quality for the particular samples selected.
• A quality systems audit of each operating line in the plant is undertaken. Both historic and on-going statistical data is reviewed and discussed. The auditor must have access to all operating systems which directly influence the finished geomembrane product. Of particular interest is the quality of the incoming resin and the master batch, which includes both carbon black and the processing/antioxidant package. The manufacturer's testing and/or required written certification of the incoming resin and master batch is critical to the success of this program. These "endurance" aspects of the formulation are arguably more important than physical/mechanical properties which are routinely measured by manufacturing quality assurance (MQA), construction quality assurance (CQA), and/or site-specific conformance testing.
• The manufacturer's quality control laboratory will be carefully scrutinized. The auditor will look for details of each applicable test procedure to the level of being audited for the Geosynthetic Accreditation Institute's - Laboratory Accreditation Program (GAI-LAP); see next section. Note that GAI-LAP approval is not necessary, per se, but that the equivalent level of care and accuracy must be met.
• The GCI-PCP auditor will sample the product being produced on-line and/or inventoried product. Three full width by 1 m (3 ft.) long samples are to be taken for each material to be tested. The samples are sent respectively to the testing laboratory, to GCI for possible corroboration testing, and to the manufacturer for archival purposes.
• Sampling of the different HDPE geomembranes made by the manufacturer for labeling as GRI-GM13 certified product will be done at a rate of 10% per 6-month audit. On this basis, all product will be sampled and tested every 5-years. Within this scheme, the following will be considered "different" product.

  • plant location
  • formulation
  • type of process
  • type of surface
  • thickness

• Thus, for 1-plant location, 1-resin formulation, 2-processes (e.g., blown film and flat die), 2-surfaces (smooth and textured) and 3-thickness (40, 60 and 80-mil); there are 12-products. At 10%/audit, one product would be tested for 8 audits and two products would be tested for 2 audits in the 5-year (10 audit) cycle.
• There will be an exit meeting to discuss audit findings in light of the manufacturer's quality manual vis-a-vis actual production. If deficiencies are observed, the manufacturer will have to implement corrective action and supply GCI with written documentation that the root cause of the deficiencies has been identified and corrected. An explanation of the results of sample testing in light of the GRI-GM13 specification will also be discussed, along with the possible outcomes of this activity.

Step 5 - The Testing Process: The GCI-PCP auditor will send the sampled product to the GAI-LAP laboratory of the manufacturer's choice. A description and listing of the current GAI-LAP laboratories is given in the next section. Note that manufacturers' MQC laboratories are not candidates for this testing program. The tests to be conducted at each audit are all of those listed in GRI GM13 with the exception of oven aging and UV resistance. These two long-term aging procedures are to be conducted every other audit, i.e., once per year. Note that the purchase order or contract between the testing laboratory and manufacturer is not to be disclosed to the auditor. The financial contract for testing services is between the manufacturer and the selected testing laboratory. No added percentage, fixed-fee billing, or incremental charges are to be added to the testing laboratory's bill by GCI under this certification program.

Step 6 - Testing Laboratory Results: Upon completion of the sampled material's test results, the data are sent to the GCI-PCP auditor and a copy to the manufacturer. The auditor reviews the test results in the context of the on-site audit findings and reports to the manufacturer one of three outcomes;

• acceptable, see Step 6(a),
• minor deficiency, see Step 6(b), or
• major deficiency, see Step 6(c).

Step 6(a) - Acceptable Outcome: This comes about via an acceptable on-site audit as to the manufacturer's quality system and acceptable laboratory test results insofar as meeting the requirements of the GRI-GM13 specification. In this case, the procedure follows according to Steps 7 and 8.

Step 7 - GCI-PCP Approval: With an acceptable outcome per Step 6(a), the manufacturer's HDPE geomembranes are approved and the following actions are allowed:

• The manufacturer can list and advertise the approved geomembranes as being GCI certified per GRI-GM13.
• The following identification should be placed on all product labels.

• Product labels should appear at both ends of the roll and in 3 locations: outside of the outer wrap, inside of the outer wrap and inside the inner core. Thus a minimum of 6-labels are necessary.
• Inquiries as to the approval process can be referred to GCI for discussion, clarification and/or elaboration.

Step 8 - Ongoing Actions by GCI between 6-month audits. The GCI will provide the following services:

• The manufacturer's products will be listed in a special section of the Home Page of the Geosynthetic Institute.
• Ongoing dialogue with potential customers of the manufacturer will be maintained for the 6-month period until the next audit cycle.
• A continuous tracking mechanism of noncompliance product by independent testing laboratories will be maintained. Trouble shooting and dispute resolution will be ongoing activities.
• Dispute resolution requiring additional testing will be engaged by GCI.
• If ongoing complaints as to a manufacturer's certified product are expressed and deemed substantive, GCI-PCP reserves the right to conduct an interim audit (on an unannounced basis) and/or product sampling at any time within the 6-month interval until the next scheduled audit.

Step 6(b) - Minor Deficiency Outcome: In the event of a minor deficiency during the on-site audit that is not explainable at the time of the audit, the manufacturer can respond in writing and (if acceptable to the auditor) can be approved insofar as production is concerned. Minor deficiencies in test results require additional testing as described in Step 9 following.

Step 9 - Resolution via Additional Testing: The GCI will take the unused half sample of material (recall Step 4) and evaluate it for the test result(s) that were inadequate. The two possible outcomes of this process are either product approval (which proceeds through the previously described Steps 7 and 8), or disapproval (which proceeds through Steps 10 to 13) to be discussed next.

Step 6(c) - Major Deficiency Outcome: In the event that a major deficiency is identified at the on-site audit, the manufacturer must respond in writing and (at the discretion of the auditor) schedule another on-site audit. The process follows the outline of the original audit. For a major deficiency in test results, re-sampling of the product in question is required. Steps 10 through 13 are subsequently followed.

Step 10 - Resolution via Re-Audit and/or Re-Testing: If the manufacturer's process is deficient, a re-audit is scheduled and the entire process is repeated. If the findings of this re-audit are not acceptable, the product(s) are not acceptable and the entire process concludes with a non-certification decision. If the re-audit is acceptable, product re-sampling and re-testing may be required. This decision is made at the discretion of the auditor.

If the results of the laboratory testing are not acceptable (either for a number of tests, or for a particular value that is confirmed as being seriously deficient), the manufacturer can request the testing laboratory to re-test a new sample. Confirmation testing by GCI will generally be necessary. If the re-testing is acceptable, the manufacturer's products are approved and Steps 7 and 8 are followed. If the retesting is unacceptable, Steps 11 and 12 are followed.

Step 11 - Product Deficient: If the product is deficient on the basis of either the audit (e.g., quality systems control) or the re-testing (e.g., major variations from the listed values in the GRI-GM13 specification), a non-acceptable situation results. The manufacturer's product(s) is not approved, or, if previously approved, it is de-listed.

Step 12 - Re-Approval Process: If a manufacturer's product(s) is not approved, or if it is de-listed, a minimum waiting period of 6-months is required before reinitiating the entire GCI-PCP process.

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*Independent laboratory testing costs are not included in above total. They include all GRI-GM13 tests after the annual audit, and all except oven aging and UV resistance after the midyear audit.

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The Geosynthetic Certification Institute announces the availability of a Product Certification Program (GCI-PCP) for high density polyethylene (HDPE) geomembranes, both smooth and textured, in all product thicknesses. The program consists of two distinct, but clearly related, tasks:

• Manufacturer's conformance to their quality system with acceptable statistical control during manufacturing.
• Product conformance to the GRI-GM13 specification for HDPE geomembranes.

The first aspect is verified by past product control data supplied by the manufacturer and verification via an on-site visit by an auditor. The auditor will be Dr. George R. Koerner. The program will have the benefit of an advisory committee (to be guided by the GSI Board of Directors) to discuss operational details and for particularly sensitive issues, e.g., delisting of a manufacturer's products.

At the time of the audit, product sample(s) will be taken for the purpose of verifying physical, mechanical and endurance properties versus the GRI-GM13 HDPE geomembrane specification. These tests are to be conducted by a GAI-LAP accredited testing laboratory of the manufacturer's selection. The next section describes this program and lists the currently accredited laboratories. The actual contract for this work is between the manufacturer and the testing laboratory. GCI-PCP is not involved in the testing process except for assessing and critiquing the test results.

Three possible outcomes of the on-site audit and testing results are possible: acceptance, minor deficiency and major deficiency. When acceptance is reached, the manufacturer's HDPE geomembranes are certifiable. When a minor deficiency is reached, the situation can be resolved by written communication and/or by additional limited testing. When a major deficiency is reached, either re-audit, re-testing or both must be undertaken. There are two audits per year spaced at approximately 6-month intervals.

For HDPE geomembranes that are certified under this program, the manufacturer can advertise such and can stamp product GRI-GM13 Certified. Inquires, questions, challenges, etc., are handled by the program's manager Dr. George R. Koerner and may involve the settling of disputes if such occasions arise. Oversight of the program by the GSI Director, Dr. Robert M. Koerner, will be ongoing throughout the program. Quality assurance for the program will be maintained by Dr. Y. (Grace) Hsuan. For inquires into this product certification program contact Dr. George R. Koerner, whose resume follows the next section of this report.

Dr. George R. Koerner, PE & CQA
Geosynthetic Institute
475 Kedron Avenue
Folsom, PA 19033-1208
Phone: (610) 522-8440
Fax: (610) 522-8441

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