Dedicated to advancing the use of fabricated 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.


Listen to our Geo-Engineering Podcast Series!

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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Cutting edge topics presented by industry experts & scholars.


View Our Latest Webinar:
An Introduction to Mechanically Stabilized Earth (MSE) Walls

Recorded October 21, 2021


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NEW! Spanish Webinars

Check out our latest Spanish webinar: Ingenio en el Diseño de Obras Geotécnicas con el Uso de Geosintéticos
Presented by Jorge G. Zornberg of the University of Texas, Austin

View details

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


Maerkle Reservoir Floating Cover Project

Floating cover and chafer for drinking water distribution reservoir
45mil, scrim reinforced CSPE geomembrane - beige material for floating cover , 45mil, scrim reinforced CSPE geomembrane - black material for chafer
Hilts Consulting Group and Raven Industries

The reservoir stores treated potable water as part of a water distribution system and provide a 10-day operation storage of 200 million gallons. The reservoir covers 17 acres and has a maximum depth of 60 ft.  Interior side slopes range from 2H:1V to 4.5H:1V.  The reservoir geometry is complex, consisting of eight curves and eight tangent sections.

The project components include removing the 20-year-old existing reinforced polypropylene floating cover and existing partial HDPE geomembrane chafer. The replacement floating cover system consists of a new 45-mil,scrim reinforced CSPE geomembrane, weight tensioned floating cover.  The floating cover features include access hatches, air/vacuum vents, remote water quality sampling capabilities, four submersible rainwater removal pumps, and walkaway access paths.  A new 45-mil, scrim reinforced, CSPE geomembrane chafer strip was installed covering approximately two-thirds of the reservoir side slopes.

The floating cover and chafer materials were prefabricated into large panels based on site specific geometry and location within the reservoir.  A total of 117 prefabricated panels were required for the floating cover system and 101 prefabricated panels for the chafer. The panels are approximately 34 feet wide with custom lengths up to over300 feet long.

Additional site improvements include new storm water discharge laterals for the floating cover, rainwater removal pumps, discharge points, new electrical power distribution system, replacement of three submerged valves at the outlet structures within the reservoir, and perimeter site fencing.


Floating cover designs are typically performed while a reservoir is in service. Accurate as-built drawings and underwater dive inspection photos and videos are essential to document and verify actual existing conditions for the design. One lesson learned is the information shown on as-built drawings may not always be accurate so underwater dive inspections during design are important. Existing conditions should be documented and reviewed by the design engineer once the reservoir is dewatered, and the existing floating cover is exposed before removal. Any unforeseen conditions revealed during this process should be addressed early in the design and construction phases to avoid potential project delays and costs.

Long lead-time components must be identified early to prevent project delays. On this project, the CSPE geomembrane for the floating cover and chafer, along with the outlet valves, actuators, and hydraulic power unit, were all identified as long lead-time items.  The CSPE geomembrane manufacturing supply chain for large quantities requires highly coordinated schedules and upfront time to facilitate.  This process guarantees the project-specific sized panels delivered to the job site on time and ready for installation.

Coordination with the valve manufacturer along with the actuator and hydraulic power unit manufacturer proved to be critical in the timing of this long lead-time item.  Manufacturing was performed in multiple locations both domestically and abroad.

During this project, lessons learned include the sheer-importance of preparation through the coordination of shop drawing submittals, fabrication schedules, different contracting entities, and subcontractors, which all proved to be essential components of success.  All of these components should be aggressively pursued right at the project onset.

On a complex project, such as this one, coordinating with vendors both domestically and abroad is essential for both the design, approval, and construction processes.  Sequence of construction required close collaboration with material suppliers, fabricators, and field installation crews.


Large panel fabrication for this project and appurtenances dramatically reduced the field installation time on this project with a tight schedule. This ensured no startup delays for the owners and the reservoir was back online per schedule.

More Project Spotlights
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Tim Stark, FGI Technical Director

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


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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 geomembranes. Read more

The FGI Pond Leakage Calculator
Geomembranes v. Compacted Clay Liners

Pond Leakage Calculator - Fabricated Geomembranes
Fresh water is a precious resource with demands rising daily and supply greatly fluctuating. Only two (2) percent of all water on Earth is fresh water with the other 98% being salt water.  This 2% of fresh water is comprised of: 87% ice, 12% groundwater, and 1% rivers and lakes.  Thus, only 13% of the available freshwater is readily accessible.  Therefore, it is imperative that we capture and hold these limited water resources for agriculture, domestic use, and industry and also protect valuable groundwater from surface or subsurface contamination.

The FGI’s Pond Leakage Calculator is a Microsoft EXCEL spreadsheet based on Darcy's Law of Seepage and provides a comparison between leakage rates from a canal, pond, or reservoir constructed with compacted fine-grained soils and a geomembrane liner system. The Leakage Calculator allows the user to input the size of the containment basin (including length, width, depth, side slope angle and freeboard), the anticipated level of hydraulic conductivity of the compacted soil or geomembrane liner, and the relative cost of water in dollars per acre-foot of water.

The Calculator then calculates the volume of the basin in gallons, a comparison of leakage rates between the compacted soil and geomembrane liner systems in gallons, and the cost of the leakage based on the cost of water per acre-foot to replace it. This Calculator is designed to help consultants, engineers, architects, and end users decide how to line their canals, ponds, reservoirs, and basins to capture and/or protect valuable fresh water.  The Calculator does not consider variances in construction quality and operational techniques on the long-term effectiveness of the chosen liner system. The FGI has additional research and publications to help with other aspects of successful water containment applications.

Types of Geomembranes
Four (4) popular types of geomembranes are available for pond liner systems.  These four (4) geomembranes in ALPHABETICAL order are: (1) EPDM, (2) reinforced polyethylene (RPE), (3) Polypropylene (PP), and (4) Polyvinyl Chloride (PVC). EPDM (Ethylene Propylene Diene Monomer) geomembranes are unreinforced and have been used for the construction of ponds of varying kinds. EPDM geomembranes are made from rubber and can be welded together with tape and primer. EPDM can be reinforced or unreinforced.  RPE geomembranes have a high tensile strength and puncture resistance because they are reinforced. RPE geomembranes also can be welded with heat.  PP geomembranes can be unreinforced or reinforced depending on the application. Reinforced PP geomembranes also have a high tensile strength and puncture resistance because they are reinforced. PVC geomembranes are also unreinforced and have been used successfully for decades in water canals, ponds, and reservoirs. PVC geomembranes can be welded with heat and/or solvents.

Please click below to access FGI’s Pond Leakage Calculator.
Temporary Landfill Covers - Design & Construction

An Introduction to Mechanically Stabilized Earth (MSE) Walls
Professor Richard J. Bathurst, of the Geo-Engineering Centre at Queens-RMC, Royal Military College of Canada
Recorded on October 21, 2021

Earn PDH Credit for viewing this webinar!


FGI Fall 2021 Newsletter Now Available

Highlights Include:

New 3-Part Video Podcast Series on Reinforced Geomembranes

December Live Panel Webinar on Allowable Leakage Rates

New FGI Guideline for Desert Installation of Fabricated Geomembranes

Geomembrane Lab & Field Test Videos Library

Download Newsletter

FGI Welcomes GO2CQA

The Fabricated Geomembrane Institute (FGI) is pleased to welcome its newest Associate Member, GO2CQA.  GO2CQA was established in 2010 to assist design engineers and owners with third party geosynthetics construction quality assurance (CQA) specialty inspections, documentation, and reporting services. GO2CQA is an industry leader in inspection services with over 30 years of fabricated geomembrane liner system design experience with a focus on heavy civil, mechanical, and structural construction applications. GO2CQA specializes in both reinforced and non-reinforced geomembrane tension floating covers for a multitude of applications including: water storage reservoirs, wastewater treatment facilities, solid waste landfills, mining expansions and closures, agricultural lagoons, and anaerobic digesters (AD) biogas floating cover systems. Their FGI liaison is Shannon Goodrich, Founder and Principal, who can be reached at Please help us welcome GO2CQA to the FGI!!!!

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Pond Leakage Calculator

Use our Excel calculator to learn what measurements are needed to properly plan for your pond liner project.



Frequently asked questions from members, customers and industry professionals answered.


Specifications & Guides

FGI, ASTM and IAGI material specifications in one place for your reference and convenience


Geomembrane Guide

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