Definitions

ADEQ The Arizona Department of Environmental Quality is a state agency authorized by the Arizona legislature through the Arizona Environmental Quality Act.  A principal charge of the agency is to develop a comprehensive program to study, monitor, and regulate Arizona's water quality.
AZPDES Arizona Pollutant Discharge Elimination System. ADEQ has received status as a state from EPA to administer and regulate their own PDES program including stormwater.
BAT/BCT Best Available Technology/Best Control Technology. A level of technology based on the best (state of the art) control and treatment measures that have been developed and that are economically achievable.
BMPs Best Management Practices. Activities or structural improvements that help reduce the quantity and improve the quality of stormwater runoff. BMPs include treatment requirements, operating procedures, and practices to control runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage.
CWA Clean Water Act. Amendments made to the Federal Water Pollution Control Act in 1972 to establish water quality standards and to create the Nation Pollutant Discharge Elimination System to protect the waters of the U. S. by regulating the discharge of pollutants from point source discharges and municipal separate storm sewer systems (MS4s).
Ephemeral Stream A stream or reach of a stream that flows for short periods only in direct response to precipitation in the immediate watershed and whose channel is at all times above the water table. The term has also been defined as a stream or stream reach that does not flow continuously for periods of as much as one month.
FWPCA Federal Water Pollution Control Act. A 1948 act passed by Congress to address pollution impacts to the waters of the U. S. that were considered economically feasible and practical to correct.
Heavy Metals Metals such as zinc, copper, lead, mercury, chromium, cadmium, iron, manganese, nickel, molybdenum and silver that in low concentrations can be toxic or lethal to humans, animals and aquatic life.
Illicit Discharge The term refers to any discharge to an MS4 that is not composed entirely of stormwater unless authorized via an NPDES permit or otherwise excluded from regulation. Thus, not all illicit discharges are illegal or prohibited. See the illicit discharge link for a more complete discussion on exempted and regulated illicit discharges.
Intermittent Stream A stream or reach of a stream that flows only at certain times of the year, as when it receives water from springs, snowmelt or from some other surface source until water losses from evapotranspiration and seepage exceed the available streamflow. This term has also been defined as a stream or stream reach that flows continuously for a period of at least one month.
MS4s A Municipal Separate Storm Sewer System is a conveyance or a system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels and storm drains) that are not a combined sewer or part of a publically owned treatment system and are owned or operated and regulated by a municipality or authorized agency. MS4s may be small, medium or large with the medium or large MS4s being principally determined by population size.
NOI Notice of Intent. An application to notify the permitting authority (ADEQ) of a facility’s intention to be covered by a general permit. This exempts a facility form having to submit an individual or group application.
NOT Notice of Termination. An application to notify the permitting authority (ADEQ) that a facility no longer needs coverage under the general AZPDES for authorization to discharge stormwater runoff into the waters of the U.S.
NPDES The National Pollutant Discharge Elimination System is a provision of the 1987 Clean Water Act that prohibits the discharge of pollutants to waters of the U.S. unless a special permit is issued by the EPA, a state or local government. 
Nutrients The term typically refers to nitrogen and phosphorus or compounds containing free amounts of the two elements. These elements are essential for the growth of plant life, but can create problems in the form of algal blooms, depletion of dissolved oxygen and pH changes in streams and other water bodies when higher concentrations are allowed to enter drainage systems and lakes.
Ordinance A law based on state statutory authority developed and approved by a governmental agency to allow them to regulate the enforcement of criteria contained within the specific law and to invoke sanctions and other enforcement measures to ensure facilities comply with the criteria.
Perennial Stream A stream or reach of a stream that flows continuously throughout the year and whose upper surface generally stands lower than the water table in the region adjoining the stream.
Point Source Discharge Discharge from a single identifiable source such as a pond outfall, a pipe or a artificial drain channel.
SMS4s Small Municipal Separate Storm Sewer Systems. These are MS4s that are not merely determined by population, but are much broader in scope. SMS4s are land areas with conveyances that are designated because of one or more of the following criteria: 1) they discharge to sensitive waters; 2) they are experiencing high growth or have a high growth potential; 3) they are contiguous to urbanized areas and other SM4s; 4) they are a significant contributor of pollutants to the waters of the U. S.; and 5) they have ineffective protection of water quality through other programs.
Stormwater Runoff Stormwater runoff occurs when precipitation from rain or snowmelt flows over the ground. Impervious surfaces like driveways, sidewalks, and streets prevent stormwater runoff from naturally soaking into the ground.
SWMP Stormwater Management Program. A program whereby municipalities such as Coconino County plan, design, construct, maintain, finance and regulate both the constructed and natural facilities that collect, store, control and/or convey stormwater.
SWPPP Stormwater Pollution Prevention Plan. A plan developed by a facility or entity that thoroughly evaluates potential pollutant sources at a site and selects and implements appropriate best management practice measures designed to prevent or control the discharge of pollutants in stormwater runoff.
UA Urbanized Area. Is a land area consisting of one or more central places and the adjacent densely settled surrounding area (urban fringe) that together have a residential population of at least 50,000 and a minimum average population density of at least 1,000 people per square mile.
Waters of the U. S. These are surface waters defined as wetlands, lakes (including dry lakes), rivers, streams (including intermittent streams, ephemeral washes and arroyos), mudflats, sand flats, sloughs, wet meadows, playa lakes and natural ponds.