Release detection groundwater monitoring

This is a method of external leak detection that involves the use
of one or more monitoring wells placed close to the UST that can
be monitored visually or by electronic sensors. The wells are
checked monthly for the presence of product that has leaked from
the UST and is floating on to the groundwater. If this method is
used, it is normally used for both the tank and the piping.
Also, there are a number of criteria that must be met to use this
as a leak detection option.