Heavy Duty Poly Storage Tanks - Bailiff Enterprises
Secondary Containment
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Secondary
Containment refers to the ability to catch or contain a
spill from a storage tank. In most cases, secondary
containment is used when the liquid being stored in the
tank is either a hazardous chemical or a liquid that
could pollute the local ground water supply. Our
Double Wall Chemical Storage Tanks have built in
secondary containment.
Most
municipalities, states and the federal government
require or stongly urge the use of secondary
containment. Depending on the type of containment there
are usually requirements that the containment have a
capacity of at least 120% of the largest tank within the
containment. The percentage of required capacity over
the largest tank can vary by agency. The EPA currently
urges operators to have containment capacity that is
equal to the volume of the largest tank plus the amount
of rain that could accumulate using the 25 year average
24 hour rainfall event. In areas that get much rain,
that could mean 150% secondary containment capacity or
more. In most areas the use of a Double Wall Tank with
closed containment exempts you from the need to have
containment that is over the capapcity of the primary
storage tank.
There are
several forms of Secondary Containment including open
containments like plastic containment basins, open
containments made from concrete, steel or earth berms
that have non-permeable membranes covering the interior
space.
Double wall plastic storage tanks have their own
secondary containment. The outer tank provides the
secondary containment to the primary inner tank.
When
using open containments, you have to deal with leaves,
dirt and debris which will enter the containment. You
must also account for the accumulation of rain and snow
that will affect the actual containment space you have
available in case of a spill. An open containment that
is half full of water may overflow if a tank spills its
contents into the containment.
A double
wall tank is a form of Secondary Containment that has a
small footprint and is sealed to keep dirt, debris and
rain out of the containment area.