General Glossary

Concentrations of chemicals or defined mixtures of chemicals
emitted to air that are unlikely to pose a significant risk of
harmful effects when humans are exposed to those concentrations
over a specified time.

Rain with a higher than normal
acid range. Caused when polluted
air mixes with cloud moisture.
The "acid" in acid rain comes from
sulfur oxides and nitrogen oxides,
products of burning coal and other
fuels and from certain industrial
processes. Acid rain can make
lakes devoid of fish and damage
human health and property.

A special carbon in powdered or
grainy form that attracts and
holds organic molecules. It is
often used to remove dissolved
contaminants.

The health based standards for ozone and fine particles are based
on 8- and 24-hour average concentrations, respectively. During
rapidly changing air quality conditions, the use of these
averaging times creates a lag in the AQI; underestimating
pollution levels on the front end of a poor air quality event and
overestimating levels on the tail end. To better reflect
real-time conditions, the surrogate method places greater weight
on the most recent hourly data when calculating the AQI. See

The list of Unpermitted Dump Sites was created in the 1980's and
was originally called the Open Dump Inventory (ODI). Sites
maintained in this list were later referred to as Outstate Dump
Inventory (ODI) and Metro Dump Inventory (MDI) sites. Because
these sites are no longer open the name has been changed to
Unpermitted Dump Sites and contains dump sites for the entire
state. Included in the list are abandoned dumps, demolition
sites, tree disposal sites, industrial dumps and other dumps.

Delisted State Superfund Sites, or Delisted PLP (DPLP), sites
are those that have been removed from the state Superfund
priority list because they have been cleaned up, pose no further
risk to public health or the environment, or have been
transferred to a more appropriate cleanup program. For more
information, visit the <a
href="http://www.pca.state.mn.us/programs/superf_p.html">MPCA

Federal Superfund sites, also referred to as National Priority
List (NPL) sites, are those considered high priority for cleanup
under the federal Superfund Program. These are sites where known
or suspected environmental contamination threatens public health
or the environment. The <a href="http://www.epa.gov">U.S.
Environmental Protection Agency</a> updates the NPL once a
year. For more information, visit the <a

NFRAP, or &quot;No Further Remedial Action Planned&quot; sites,
are the
sites that have been removed from the CERCLIS list by the U.S.
Environmental Protection Agency. These sites are no longer
considered a federal concern, and most are also a low priority
for the state. For more information, contact the MPCA at 651-
757-2509, or toll-free at 800-657-3864.

Suspected hazardous waste sites throughout the United States are
listed in the Comprehensive Environmental Response, Compensation
and Liability Information System, or CERCLIS. This federal
database contains information on preliminary assessments,
potential and actual hazardous waste sites, site inspections,
and cleanup activities.

The Voluntary Investigation and Cleanup (VIC) Program allows
buyers, sellers, developers or local governments to voluntarily
investigate and, if necessary, clean up contaminated land to
facilitate its sale, financing or redevelopment. Voluntary
parties that complete investigation and/or cleanup activities
under MPCA oversight can receive liability assurances that
protect them from future Superfund liability. In some cases,
the MPCA may use Institutional Controls as part of the overall