The problem associated with leaking tanks,
whether they are above ground or below, are both serious and wide ranging. Deteriorating fuel and chemical tanks can threaten the public health and safety when they
leak or spill hazardous wastes into the environment. Billions of gallons of potable water, a precious resource, are lost each year from leaks that could be prevented.
Most of the problems can be traced to a common source. As a tank ages it can lose its structural integrity. In steel tanks, for example, seams can weaken
through expansion and contraction. Concrete surfaces become weakened through corrosion of the surface and erosion of the supporting soil foundations, and leakage is
accelerated by corrosion of metals from galvanic action, chemical or other sources. Even large natural structures can eventually lose their containment ability as a
result of soil shifting, settling, expansion and contraction and contamination of clay soils.
Polyethylene geomembranes can be used on ringwalls made from concrete to
provide a low permeability, high chemical and UV resistant flexible barrier to prevent contamination of the surrounding soil and conserve water. It can be placed directly on
the ground to prevent groundwater contamination in the event of a spill. The deterioration of concrete structures and steel tanks containing potentially environmentally
harmful products makes high density polyethylene the best choice as a secondary containment solution.