Anything which is injurious to the public health or an obstruction to the free use of any waters of the state.

Particles in the air less than 2.5 micrometers in diameter. Often referred to as "fine" particles.  Also see PM10.

Facilities that emit 100 tons per year or more of any regulated air pollutant, or 10 tons per year or more of any single hazardous air pollutant (specifically listed in the Clean Air Act), or 25 tons [..]

A process or activity involving application of wastewater, surface water, or semi-liquid material to the land surface for the purpose of treatment, pollutant removal, or ground water recharge.  Also s [..]

An area that at least some of the time is saturated by surface or ground water.  Examples include swamps, bogs, and marshes. 

The upper surface of ground water; below this point, the soil is saturated with water.

A region or area drained by surface or ground water flows.  Watersheds are infinitely nested, and any large watershed is composed of smaller subwatersheds.

State-adopted and EPA-approved ambient standards for water bodies.  The standards prescribe the use of the water body and establish the water quality criteria that must be met to protect designated us [..]

A term for the combined biological, chemical, and physical characteristics of water with respect to its suitability for a beneficial use.

In the context of water quality, a narrative or numeric statement of water quality on which to base judgment of suitability of a beneficial use.