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Glossary of technical terms
    that appear in the LaMPs

Acronyms | Words and definitions

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33/50 Program

A pollution prevention program sponsored by U.S. EPA in voluntary partnerships with industry. The program's goals are to reduce targeted chemicals by 33 percent by 1992 and 50 percent by 1995.

Part 70 Permit

A federal regulation that defines the requirements for permitting facilities for air emissions. States with federally-approved permit programs administer the permitting of facilities within their state.


Very small separate particles composed of organic or inorganic matter.


Very small separate particles composed of organic or inorganic matter.

Parts per Billion (ppb)

The number of parts of a substance per billion parts of another substance into which it is combined. Often expressed as micrograms per liter for water and micrograms per kilogram for fish and sediments.

Parts per Million (ppm)

The number of parts of a substance per million parts of another substance into which it is combined. Often expressed as milligrams per liter water or milligrams per kilogram for fish tissue and sediments.

Parts per Thousand (ppt)

The number of parts of a substance per thousands parts of another substance into which it is combined. Often expressed as grams per liter of water or grams per kilogram for fish tissue and sediments.

PCB Substitute Compounds

PCB substitute compounds are emerging pollutants addressed in the LaMP. They include: mineral and silicone oils; bis(2-ethylhexyl)phthalate (DEHP); isopropylbiphenyls; diphenylmethanes; butylbiphenyls; dichlorobenzyldichlorotoluene; diisopropylnaphthalene; and phenylxylyl ethane. Information on most of these compounds is currently limited. Also see "Polychlorinated biphenyls (PCBs)."


Biological community existing in the open waters. Includes organisms floating in the water column or at the surface, as well as free-swimming organism.


Related to or living in the open lake, rather than waters adjacent to the land.


Algae that grow attached to surfaces such as rocks or larger plants.

Permit Compliance System (PCS)

The PCS is a national management information system that tracks surface water discharges under the NPDES program. It contains data on permit issuance, permit limits, monitoring data, and other data pertaining to facilities that discharge into navigable waters of the U.S.

Persistent Bioaccumulative Toxic (PBT) chemicals

Chemicals that persist in the environment, do not break down easily, and bioaccumulate in plant, animal and human tissues.

Persistent Toxic Substance

Any toxic substance with a half-life, the time required for the concentration of a substance to diminish to one-half of its original value, in any medium -- water, air, sediment, soil, or biota -- of greater than eight weeks, as well as those toxic substances that bioaccumulate in the tissue of living organisms. A toxic pollutant that remains in the environment for a substantial period of time, potentially causing injury to ecosystem health.


A numeric value that indicates relative acidity and alkalinity on a scale of 1 to 14. A pH of 7.0 is neutral, higher values indicate increasing alkalinity; lower values indicate increasing acidity.


Microscopic forms of aquatic plants. Plant microorganisms that float in the water, such as certain algae. Algae that grow suspended in the water column or open waters of a lake.


Fish-eating fish.


Plankton-feeding fish.


A term used to describe bacteria, tiny plants (phytoplankton), and animals (zooplankton) that live in the water column of lakes.

Point Source Pollution

Pollution from a distinct, identifiable source, such as a pipe, smokestack, or exhaust.


Chemicals or refuse material released into the atmosphere, water, or onto the land.

Pollutant of Concern

Toxic substances that are associated with local or regional use impairments or those for which there is evidence that loadings to or ambient concentrations in the Great Lakes watershed are increasing. Pollutants of concern include arsenic, cadmium, chromium, copper, cyanide, lead, zinc, hexachlorobenzene, toxaphene, and polycyclic aromatic hydrocarbons (PAHs).

Pollutant of Interest

Nutrients and radionuclides are classified as pollutants of interst because they may cause use impairments of the Great Lakes.

Pollution Prevention (P2)

This is defined in the Minnesota Toxic Pollution Prevention Act as eliminating or reducing at the source the use, generation, or release of toxic pollutants. Methods of reducing pollution include, but are not limited to, industrial process modification, inventory control measures, feedstock substitutions, various housekeeping and management practices, and improved efficiency of machinery. The federal version of this term is source reduction.

Pollution Prevention Act of 1990

A federal law that establishes a national policy of pollution prevention, and requires the EPA to develop and implement a strategy to promote source reduction. This act declares as national policy that pollution prevention is the preferred approach to environmental protection.

Polychlorinated biphenyls (PCBs)

A group of toxic, highly persistent and bioaccumulative chemicals used in transformers and capacitors. One of the six critical pollutants, PCBs are a group of over 200 nonflammable compounds formerly used in heating and cooling equipment, electrical insulation, hydraulic and lubricating fluids, and various inks, adhesives, and paints. These compounds are highly toxic to aquatic life, persist in the environment for long periods of time, and are bioaccumulative. PCBs are suspected carcinogens, and are linked to infant development problems. Fish from some lakes and streams contain measurable amounts of PCBs. See also "Fish Consumption Advisory" and "Remedial Action Plans."

Polycyclic Aromatic Hydrocarbons (PAHs)

PAHs are identified as pollutants of concern. They are the result of incomplete combustion of organic compounds due to insufficient oxygen and are associated with oil, grease, and other components derived from petroleum products that can end up in sediments. Examples of compounds in the PAH group include benzo(a)anthracene, benzo(b)fluoranthene, benzo(a)pyrene, chrysene, phenanthrene and pyrene.

Polynuclear aromatic hydrocarbon

A petroleum or coal combustion by-product often associated with elevated levels of tumors in fish (PAH).

Pressure-State-Response Approach

The pressure-state-response approach involves linking environmental indicators to stressors that impact the environment and to program activities. The use of this approach should promote consistency in the development and application of environmental indicators. It is an organizing framework used by U.S. EPA Region 5 in its Guide for Developing Environmental Goals, Milestones and Indicators.


Partial wastewater treatment required for some industries. Pretreatment removes some types of industrial pollutants before the wastewater is discharged to a municipal wastewater treatment plant.

Primary Productivity

The amount of production of living organic material through photosynthesis by plants, including algae, measured over a period of time.

Primary Treatment

The first step in wastewater treatment in which most of the debris and solids are removed mechanically.

Priority Pollutants

Pollutants identified in certain federal and state regulations. Priority pollutants have different definitions in air, water, and waste programs.

Protected Waters

Minnesota waters of the state identified as public waters or wetlands under Minnesota statutes.

Public Waters

Generally, public waters are water bodies determined by statutes to have significant public value and are controlled by the state.

Public Waters Wetlands

A class of wetlands defined by the state of Minnesota as public waters deserving of a certain level of protection under the Wetland Conservation Act. These include all Types 3, 4, and 5 wetlands, as defined in U.S. Fish and Wildlife Service Circular No. 39 (1971 edition), that are ten or more acres in size in unincorporated areas, or 2-1/2 or more acres in size in incorporated areas.

Publicly-owned Treatment Works (POTW)

A system that treats (which can include recycling and reclamation) municipal sewage or industrial wastes of a liquid nature. Large facilities are generally owned and operated by local governments. Any device or system that is used in treatment, including recycling and reclamation, of municipal sewage.

Purple Loosestrife

A wetland plant from Eurasia that quickly invades water bodies, including the Great Lakes, forming dense stands unsuitable as cover, food, or nesting sites for fish, amphibians, waterfowl, and wildlife. Imported as an ornamental plant, it spread quickly across North America along roads, canals, and drainage ditches. Research on the use of European beetles that attack only purple loosestrife shows promise for biological control in North America.

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