Introduction to Geosynthetic Certification Institute-Inspectors Certification Program

Geosynthetic Institute

Introduction to Geosynthetic Certification Institute-Inspectors Certification Program for “Geosynthetic and Compacted Clay Liner Materials”

(GCI-ICP)

The Geosynthetic Certification Institute-Inspectors Certification Program (GCI-ICP) for “Geosynthetics Materials and/or Compacted Clay Liners” is administered by the Geosynthetic Certification Institute which is a branch of the Geosynthetic Institute. It is located in Folsom, Pennsylvania about four-miles from the Philadelphia International Airport. Dr. George R. Koerner (Program Director), and Dr. Robert M. Koerner (Oversight) and Ms. Jamie Koerner (Administrator) are the principals involved.

Definition of CQA (as opposed to CQC)

Construction quality assurance (CQA) and construction quality control (CQC) are widely recognized as critically important factors in overall quality management for waste containment facilities of all types. This includes geosynthetic materials as well as natural soil materials. The best of designs and regulatory requirements will not necessarily translate to facilities that are protective of human health and environment unless they are properly constructed. Additionally, for geosynthetics, both manufacturing quality assurance (MQA) and manufacturing quality control (MQC) are equally important. Geosynthetics refer to factory fabricated polymeric materials like geomembranes, geotextiles, geonets, geogrids, geosynthetic clay liners, etc. The natural soils involved are compacted clay liners and drainage soils of various types. In this context, the definitions of CQA as contrasted to CQC are as follows:

Construction Quality Assurance (CQA): A planned system of activities that provides the owner and permitting agency assurance that the facility was constructed as specified in the design. Construction quality assurance includes inspectors, verifications, audits, and evaluations of materials and workmanship necessary to determine and document the quality of the constructed facility. Construction quality assurance (CQA) refers to measures taken by the CQA organization to assess if the installer or contractor is in compliance with the plans and specifications for the project.
Construction Quality Control (CQC): A planned system of inspections that is used to directly monitor and control the quality of a construction project. Construction quality control is normally performed by the geosynthetics installer, or for natural soil materials by the earthwork contractor, and is necessary to achieve quality in the constructed or installed system. Construction quality control (CQC) refers to measures taken by the installer or contractor to determine compliance with the requirements for materials and workmanship as stated in the plans and specifications for the project.

The certification program to be described herein focuses on CQA but can (and should) pertain to CQC as well. Two different programs are offered; one is focused on geosynthetic materials and the other on compacted clay liners. A candidate can take both programs if desired.

The following flow chart describes the interactions of MQA/CQA and MQC/CQC as they apply to a particular project so as to produce an appropriate level of quality.

Figure 1 - Organizational Structure of Quality Control and Quality Assurance Activities

*Note that this certification program focuses on both geosynthetic and compacted clay liner construction quality assurance (CQA) and only indirectly on manufacturing quality assurance (MQA).

The Value of CQA

The electrical leak location survey (ELLS) method was developed in 1984 and was slow to initially be implemented but for the past 10-years provided a wealth of data on leaks of geomembranes placed in the field; both uncovered, and after soil covering. For uncovered geomembranes the water puddle technique (ASTM D6747 and D7002) is used and for soil covered geomembrane the dipole technique (ASTM D6747 and D7007) is used. The following photographs (compliments of A. Rollin) show each technique being used.

(a) Water Puddle Technique (b) Dipole Technique

Figure 2 - Electric Leak Location Survey Techniques

In a paper by Forget, Jacquelin and Rollin (2005) a comparison of exposed geomembrane leakage without CQA and with CQA has been generated. Figure 3 shows the incidence of holes for these two situations. The result is that an average of 22 leaks/ha (9.0 leaks/acre) occurred in 14 projects without CQA; whereas an average of 4 leaks/ha (1.6 leaks acre) occurred in 43 projects with CQA.

Figure 3 - Exposed Geomembrane Leakage Without and With CQA

The situation for covered geomembranes [usually with 300 mm (or 12 in.) of sand or gravel] is even more dramatic. The result from 42-projects is that an average of 16 leaks/ha (6.5 leaks/acre) occurred without CQA; whereas an average of only 0.5 leaks/ha (0.20 leaks/acre) occurred with CQA.

This reference, and others, indicate that there is a direct relationship between leak occurrence and the presence or absence of a credible CQA program. Of course, the tacit assumption is that a “credible” CQA program is being offered and it is this program being described that will hopefully fill this need.