Conducting Subsurface Environmental Investigations in Urban Watersheds - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 123

Used oil underground
tank

Stained soil and
stressed vegetation

Pump

FIGURE 4.1
Recognized environmental condition. (Photo courtesy of Daniel T. Rogers.)

If a REC is discovered, further investigation will likely be recommended to evaluate its
potential significance. Many sites have more than one REC, and many of these RECs may
require further evaluation. An example of a REC with significant amounts of oil-stained
soil, stressed, and dead vegetation is presented in Figure 4.1.
RECs are intended to exclude de minimis conditions generally not presenting a threat
to human health or the environment and typically would not be the subject of an enforce-
ment action if brought to the attention of appropriate governmental agencies. However,
there may be impacts encountered whose perceived severity falls between a de minimis
condition and a REC. In these situations, the term environmental concern is applied.
Items listed as environmental concerns become RECs if left unattended or lead to a release.
Figure 4.2 is a photograph of a paved parking space with a residual amount of what
appears to be a petroleum product discharged from an automobile. In the opinion of the
environmental professional who conducted a Phase I ESA at this property, this condition
was not evaluated to be a REC and was characterized as de minimis.

Slight oil-like staining
on pavement

FIGURE 4.2
Example of a de minimis release. (Photo courtesy of Daniel T. Rogers.)