Stormwater Glossary
Glossary
Adaptive Management: a system of implementing a plan that emphasizes modification as the plan progresses and more information is available
Aggradation: deposition of sediment on a portion of a stream channel
Benthic macroinvertebrates: aquatic life that lives beneath the surface of a natural water body, such as a marsh or stream; used for measuring stream health
Best Management Practice (BMP): a procedure or device designed to reduce or reverse the adverse effects of stormwater
Catch Basin: the part of a storm drain or sewer system designed to collect runoff from surface areas and trap debris
Chapter 500: Maine's Stormwater Management Law that provides standards for construction projects that include one acre or more of disturbed area and requires DEP approval for plans
Compensation Fee Utilization Plan (CFUP): DEP-approved plan using fees charged to developers required to obtain Chapter 500 permits for construction projects in impaired watersheds; to be used for approved off-site stormwater quality mitigation projects; CFUPs exist for the Penjajawoc, Birch Stream, and Arctic Brook
Conductivity: a measure of the ability of water to pass an electrical current; high conductivity generally indicates poor stream health
Degradation: scouring away of sediment on a portion of a stream channel
Diadromous: species of fish that use both marine and freshwater habitats during their life cycle; anadromous species live primarily at sea but migrating up rivers to spawn, and catadromous species live primarily in freshwater but spawn at sea
Dissolved Oxygen (DO): the amount of oxygen water holds, used by plants and organisms in the water; affected by temperature and other factors; used for measuring stream health
Effective Impervious Cover: an adjusted measure of impervious cover that takes into account techniques used to reduce pollutant runoff
Fluvial Geomorphology: the study of the processes that form rivers and streams
Hydrology: the science dealing with the occurrence, circulation, distribution, and properties of the waters of the earth
Impervious Cover (IC): pavement, roofs, and other ground cover that prevents stormwater from infiltrating into the ground
Macroinvertebrate: a small insect or insect larva that lives on rocks, logs, sediments, debris, and aquatic plants in a stream
Minimum Control Measures: six categories of stormwater mitigation measures required by an MS4 Permit
Municipal Separate Storm Sewer System (MS4): a system of piped and ditched channels that conveys stormwater; DEP requires a permit for its use in Bangor
Nonpoint Source Pollution: pollution in the form of stormwater runoff; originates from a surface area with various pollutant sources, as opposed to a point source such as a pipe
Pollutants: sediment, nutrients, toxins, heavy metals, temperature, and other parts of stormwater runoff that negatively impact a stream
Pollutant Load: the amount of a pollutant in a stream
Porous Pavement: pavement which allows precipitation to filter through it into the ground; this helps to reduce runoff, decreases the temperature of the water, filters out some pollutants, and may require less salt application than standard pavement in the winter
Retrofit: a structural best management practice installed in an already-developed site
Riparian: of or pertaining to a stream
Sediment Starved: lacking the amount of sediment appropriate for stream health
Stormwater Utility District: an area within which fees are charged to those contributing stormwater to a watershed or watersheds
Stressors: pollutants or conditions which are likely causes of stream impairment
SWMM Model: a hydrological and pollutant loading model used to quantify flow rates and pollutants generated on individual sites; a user-friendly model endorsed by the EPA
P8 Model: a hydrological and pollutant loading model, somewhat older than the SWMM Model
Total Maximum Daily Load (TMDL): theoretical maximum amount of pollutants a natural water body can absorb without reduced water quality; the State is required by the EPA to develop and implement TMDL reports
Urban Impaired Stream: a stream that does not meet state water quality standards and appears on the state 303(d) list; in Bangor, the Penjajawoc, Birch Stream, Arctic Brook, Shaw Brook, and an unnamed stream draining from Finson Road to the Kenduskeag
Watershed: the land area from which runoff flows to a particular stream; that area is considered the streams watershed
Watershed Management Plan (WMP): a community-developed plan designed to bring an urban impaired stream into attainment with state water quality requirements
303(d) List: a list of impaired streams put out by the Department of Environmental Protection; inclusion on this list means a Total Maximum Daily Load Report must be developed by the State and a watershed management plan created
319 Grant: State funding for projects focused on improving water quality
NB: These are simplified, general-purpose definitions, put together by staff with occasional reference to other sources; they may have additional or altered meaning in a particular context or to a particular organization, e.g. DEP or EPA.