Dedicated to advancing the use of fabricated flexible geomembranes through education, research, and technology transfer.

Factory fabrication reduces field welding, reduces installation time and costs, allows modular construction and provides consistent seam and liner quality.

Geomembrane Test Method Videos Now Available

FGI has created FIELD AND FACTORY VIDEOS for the following
Test Methods:

ASTM D1239 Chemical Resistance, ASTM D1203 Volatile Loss, D5641 Vacuum Chamber, ASTM D4437 Air Lance Test,
ASTM D5994 Thickness (Textured), D5119 Procedure B Thickness (Smooth), ASTM D7408 Seam Peel Strength, ASTM D882 Tensile Properties & D7408 Seam Shear Strength, ASTM D1204 Dimensional Stability, ASTM D1790 Brittleness Temperature.


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Join Tim Stark (Professor of Civil Engineering and Technical Director of the FGI) and Jen Miller (Coordinator of the FGI) as they discuss the latest emerging geosythetics industry trends and news.


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View Our Latest Webinar: Geomembrane Damage During Oil and Gas Operations Part 1

Recorded March 30, 2023


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Design and Installation Detail Drawings Available

Details available for constructing a containment facility including pipe boots, concrete attachments, penetrations, and vent details.  Both PDF and DWG available.

View details

Garrison Dam National Fish Hatchery

Fish Rearing Ponds
Viaflex Dura-Skrim N45B 45 mil thick Reinforced LLDPE Geomembrane Propex 801 GEOTEX Geotextile, and factory fabricated Ballast Tubes
International Cover Systems (ICS) and Viaflex

The Garrison Dam National Fish Hatchery in North Dakota is a federal facility, which produces over 10 million native fish annually. Along with the role of providing fish for restoration stockings or balancing fish populations, the facility is also an attraction for tens of thousands of tourists annually. This project consists of lining five of their existing 66 fish rearing ponds with geosynthetics. The subgrade is a clay/sand mix which was graded, compacted, and cleared of any rocks, roots and other potential penetration hazards prior to arrival of International Cover Systems on-site to install the geosynthetics. Each of the five ponds were lined with six specifically factory fabricated panels for ease and speed of deployment. In addition, 205 factory fabricated ballast tubes ranging from 32 to 46 ft long were filled on-site with Peastone and placed on the deployed geomembrane panels after they were seamed and quality tested. The geomembrane was secured with battening to all of the associated concrete structures.


Originally, the designer for this project specified a 45mil thick reinforced polypropylene (45RPP) geomembrane due to its UV resistance in long-term exposures, high puncture resistance, tear strength, cold cracking resistance, and potable water qualities, which are compatible with fish rearing. Due to supply chain issues after the project was awarded, 45RPP geomembrane was not available for the duration of the specified project timeframe. As a result, project engineers substituted Viaflex Dura-Skrim N45 45 mil thick reinforced linear-low density polyethylene (LLDPE) geomembrane for the pond liner system. Not only was the LLDPE geomembrane available within the project timeframe scope, it also shares similar properties that originally attracted the designer to the 45RPP geomembrane.


The use of factory fabricated geomembranes and ballast tubes aided the project in a variety of ways. This project was originally scheduled for installation in August 2021,giving the installation crew many hours of weldable temperatures and weather. Due to the aforementioned supply chain issues of the originally specified geomembrane, the project was delayed until late October 2021. Temperatures in Riverdale, North Dakota during late October limited welding operations to only a few hours per day. As a result, it was important to minimize the amount of field geomembrane seaming, which was accomplished by factory fabricating large panels. Deploying the geotextile underlayment and large fabricated panels for the first part of the day allowed ICS to perform quality welding operations when ambient and sheet temperatures reached optimal levels. Limited field welding due to the use of large fabricated panels minimized the duration of welding each day and allowed the project to be completed with the highest quality even in late October.  

Another challenge that was mitigated by using fabricated geomembrane panels and ballast tubes is the strong North Dakota winds during late October. Ballasting was required as soon as the geomembrane panels were deployed to maintain control of the geomembrane in the windy conditions. Fabricated geomembrane panels reduced the time required to secure the geomembrane with ballast, saving valuable time, and keeping all crew members safe from what can be a dangerous situation with an unballasted geomembrane in a windy environment. All ballast tubes were factory fabricated, shipped to the site, and filled with Peastone in place.  


The FGI is proud to highlight our members' projects utilizing fabricated flexible geosynthetics. Check out some
of the creative projects, understand why certain products were selected, and read the project descriptions
as well as the important lessons learned.

VIEW Project Spotlights
We are a non-profit organization providing education, research, and support for the flexible and fabricated geomembrane industry.

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Ask the expert...
Tim Stark, FGI Technical Director

Tim Stark, Ph.D., P.E., D.GE., F.ASCE


Review our FAQs and you still have a question, please CONTACT US & Tim will get back to you as soon as possible...

Geomembrane Guide

An interactive list of geomembrane products for various applications. Read more

The FGI Equipment Guide

An interactive list of welding equipment and products for
fabricated flexible geomembranes. Read more

Temporary Landfill Covers - Design & Construction

Geomembrane Damage During Oil and Gas Operations Part 1
Presented by Timothy D. Stark, Ph.D., P.E.
Recorded on March 30, 2023

Earn PDH Credit for viewing this webinar!


Dr. Stark Visits El Toro Water Reservoir Project in Mission Viejo, California

On March 2, 2023, Tim Stark visited the replacement liner and floating cover system for the El Toro Reservoir in Mission Viejo, California. This is a joint reservoir project between three water districts that is providing emergency water supply, storage, and cost savings to south Orange County water customers. The reservoir holds 275 million gallons (1.04 billion liters) of potable water.  The reservoir was originally constructed in the 1960’s as an open reservoir.  The first geomembrane floating cover was installed in the early 1980’s. In 2001 a composite geosynthetic liner and reinforced polypropylene floating cover was installed.  After 20 years, the existing liner is being augmented with a new 60 mil (1.5 mm) CSPE geomembrane that is being placed on top of the existing 70 mil (1.8 mm) reinforced polypropylene (rPP) geomembrane, which is still in intimate contact with the underlying subgrade (see Figure1). The resulting bottom liner system is shown in Figure 2.  

The main impetus for the project is replacing the 45 mil (1.1 mm) rPP floating cover system, which had exceeded its service life. The old cover system is being discarded and replaced with a 45 mil (1.1 mm) CSPE geomembrane based floating cover based on a requirement for an extended 30 year weathering warranty and long term material history. The project involves installing about1.1 million square feet (102,000 square meters) of geomembrane for the bottom liner system and about 1.15 million square feet (107,000 square meters) for the floating cover system as well as updating the reservoir interior valves, site drainage piping, and electrical upgrades. Douglas Hilts of Hilts Consulting Group is the design engineer, and the Layfield Group is the fabricator and installer of the liner and floating cover system geosynthetics. This project illustrates the advantages of factory fabricated panels because one panel extends from the top of the reservoir to the floor down slope over 325 feet where it is seamed with floor panels.

Dr. Stark hopes to visit the facilities of all FGI members to better understand each member’s business and how the FGI can provide additional benefit to them. The FGI is an exciting advancement in the geomembrane industry and allows the Institute to focus on all geomembranes that can be factory fabricated.

FGI Elects New Board of Directors

New Board to Serve 2023-2025 Term

Congratulations to the following seven individuals for being elected to the FGI's Board of Directors for the 2023-2025 term:

President – Patrick Elliott (Viaflex/Colorado Lining International)

Treasurer – Ray Peebles (Cooley Group)

Secretary – Brian Fraser (Layfield Geosynthetics)

Board Member - Todd Harman (Hallaton)

Board Member - Doug Hilts (Hilts Consulting Group)

Board Member - Maya Innis (International Cover Systems)

Board Member - Duff Simbeck (Simbeck and Associates)

The FGI is dedicated to advancing the use of fabricated flexible geomembranes through education, research, and technology transfer. The FGI is a consortium of manufacturers, fabricators, installers, designers, regulators, and material suppliers of fabricated flexible geomembranes.

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Geomembrane Guide

A comprehensive guide to industry and our member material offerings for fabricated geomembranes.