Liner Systems: Single-Liner Systems, Composite-Liner Systems, Double-Liner Systems, Leachate Collection Systems and Well Collection Systems

Watch - HDPE Geomembrane Liner Install Process - Watch

Liner Components: Geomembranes (HDPE/LLDPE), Geosynthetic Clay Liners (GCL), Geotextiles, Geocomposites, Geonet and Clay

Types of Lining Projects

Wastewater Ponds, Lagoons, Evaporation Ponds, Secondary Containment, Settling Basins, Reservoir Liners & Covers, Irrigation Ponds & Ditches, Canals, Settling Basins, Landfill Liners & Caps, Oil & Gas Activity Containment, Golf Course Ponds, Remote Fire Ponds and Decorative Water Features

Mining Leach Ponds, Heap Leach Piles, Uranium Mill Tailings Impoundment Liners, Tailing Impoundments and Solution Storage Ponds

WHAT IS A LANDFILL?

A secure landfill is a carefully engineered depression in the ground (or built on top of the ground, resembling a stadium) into which wastes are placed. The aim is to avoid any hydraulic [water-related] connection between the wastes and the surrounding environment, particularly groundwater. Basically, a landfill is a pool in the ground; a double-lined landfill is one pool inside another. Pools leak two ways: out of the bottom or over the top.  

WHAT IS THE COMPOSITION OF A LANDFILL?

There are four critical elements in a secure landfill: bottom liner(s), a leachate collection system, a cover and the natural hydro-geologic setting. The natural setting can be selected to minimize the possibility of wastes escaping into groundwater beneath a landfill. The three other elements must be engineered. Each of these elements are critical to success.

THE NATURAL HYDRO-GEOLOGIC SETTING:

You want the geology to do two contradictory things for you. To prevent the wastes from escaping, you want rocks as tight as possible (waterproof). Yet if leakage occurs, you want the geology to be as simple as possible so you can easily predict where the wastes will go. Then you can install wells and capture the escaped wastes by pumping. Fractured bedrock is highly undesirable beneath a landfill because the wastes cannot be located if they escape. Mines and quarries should be avoided because they frequently contact groundwater.

WHAT IS A BOTTOM LINER?

It may be one or more layers of clay or a synthetic flexible membrane (or a combination of these). The liner effectively creates a bathtub in the ground. If the bottom liner fails, wastes will migrate directly into the environment. There are three types of liners: clay, plastic, and composite.

WHAT IS A LEACHATE COLLECTION SYSTEM?

Leachate is water that gets badly contaminated by contacting wastes. It seeps to the bottom of a landfill and is collected by a system of pipes. The bottom of the landfill is sloped; pipes laid along the bottom capture contaminated water and other fluid (leachate) as they accumulate. The pumped leachate is treated at a wastewater treatment plant (and the solids removed from the leachate during this step are returned to the landfill, or are sent to some other landfill). If leachate collection pipes clog up and leachate remains in the landfill, fluids can build up in the bathtub. The resulting liquid pressure becomes the main force driving waste out the bottom of the landfill when the bottom liner fails.

WHAT IS A COVER?

A cover or cap is an umbrella over the landfill to keep water out (to prevent leachate formation). It will generally consist of several sloped layers: clay or membrane liner (to prevent rain from intruding), overlain by a very permeable layer of sandy or gravelly soil (to promote rain runoff), overlain by topsoil in which vegetation can root (to stabilize the underlying layers of the cover). If the cover (cap) is not maintained, rain will enter the landfill resulting in buildup of leachate to the point where the bathtub overflows its sides and wastes enter the environment.