Definitions. As used in this section, the following terms shall have
the meanings indicated:
BEST MANAGEMENT PRACTICES (BMPs)
Methods and means that have been determined to be the most
effective, practical approaches for preventing or reducing pollution
and detrimental impacts from stormwater runoff.
BIORETENTION
A water quality practice that utilizes vegetation and soils
to treat urban stormwater runoff by collecting it in shallow depressions,
before filtering through an engineered bioretention planting soil
media.
BUFFER
For purposes of these regulations, a special type of preserved
area along a watercourse or wetland where development is restricted
or prohibited.
DEVELOPMENT
Any man-made change to improved or unimproved real estate,
including but not limited to buildings or other structures, mining,
dredging, road construction, filling, grading, paving, excavation,
clearing or drilling operations.
DISCONNECTED IMPERVIOUS COVER
The sum of the proposed areas of impervious cover and pavement
that receives runoff and that, by means of implementing BMPs and LID
strategies, are designed to capture and infiltrate the precipitation
from a one-inch twenty-four-hour rain event.
DISTURBANCE
Any activity that alters the characteristics of the terrain
in such a manner as to impede or alter the hydrology or natural runoff
pattern or that creates an unnatural runoff.
DISTURBED AREA
An area in which the natural vegetative soil cover has been
removed or altered.
FILTRATION
The process of physically or chemically removing pollutants
from runoff. Practices that capture and store stormwater runoff and
pass it through a filtering media such as sand, organic material,
or the native soil for pollutant removal. Stormwater filters are primarily
water quality control devices designed to remove particulate pollutants
and, to a lesser degree, bacteria and nutrients.
GROUNDWATER RECHARGE
The process by which water seeps into the ground, eventually
replenishing groundwater aquifers and surface waters, such as lakes,
streams, and the oceans. This process helps maintain water flow in
streams and wetlands and preserves water table levels that support
drinking water supplies.
GROUNDWATER RECHARGE VOLUME
The post-development design recharge volume (e.g., on a storm-event
basis) required to minimize the loss of annual predevelopment groundwater
recharge. The groundwater recharge volume is determined as a function
of annual predevelopment recharge for site-specific soils or surficial
materials, average annual rainfall volume, and amount of impervious
cover on a site. See Table 1.
IMPAIRED WATERS
Those waterbodies not meeting water quality standards. Pursuant
to Section 303(d) of the Federal Clean Water Act, each state prepares
a list of impaired waters [known as the "303(d) list"] which is presented
in the state's Integrated Water Report as Category 5 waters.
IMPERVIOUS SURFACE
Any modified surface that cannot effectively absorb or infiltrate
water. Examples of impervious sources include, but are not limited
to, roofs, and unless designed to effectively absorb or infiltrate
water, decks, patios, and paved, gravel, or crushed stone driveways,
parking areas, and walkways.
INFILTRATION
The process of runoff percolating into the ground (subsurface
materials). Stormwater treatment practices designed to capture stormwater
runoff and infiltrate it into the ground over a period of days.
LOW-IMPACT DEVELOPMENT (LID)
A site planning and design strategy intended to maintain
or replicate predevelopment hydrology with site planning, source control,
and small-scale practices integrated throughout the site to prevent,
infiltrate and manage runoff as close to its source as possible. Examples
of LID strategies are pervious pavement, rain gardens, green roofs,
bioretention basins and swales, filtration trenches, and other functionally
similar BMPs located near the runoff source.
MAXIMUM EXTENT PRACTICABLE (MEP)
To show that a proposed development has met a standard to
the maximum extent practicable, the applicant must demonstrate the
following:
(1)
All reasonable efforts have been made to meet the standard;
(2)
A complete evaluation of all possible management measures has
been performed; and
(3)
If full compliance cannot be achieved, the highest practicable
level of management is being implemented.
MITIGATION
Activities, strategies, policies, programs, actions that,
over time, will serve to avoid, minimize, or compensate for (by treating
or removing pollution sources) the impacts to or disruption of water
quality and water resources.
NATIVE VEGETATION AND PLANTINGS
Plants that are indigenous to the region, adapted to the
local soil and rainfall conditions, and require minimal supplemental
watering, fertilizer, and pesticide application.
PERENNIAL TURF GRASS
A type of turf grass that is suited to the climate and growing
conditions of an area and that grows back year after year when the
appropriate growing season arrives.
PERVIOUS SURFACE
Any surface, whether natural, man-made, or modified, that
can effectively absorb or infiltrate water including, but not limited
to, vegetated surface, such as woodlands, planted beds, and lawns,
and those pavements specifically designed and maintained to effectively
absorb and infiltrate water.
POLLUTANT LOAD
An amount of pollutants that is introduced into a receiving
water body measured in units of concentration or mass per time [e.g.,
concentration (mg/l) or mass (pounds per day)].
REDEVELOPMENT
Any construction, alteration, or improvement where the existing
land use is commercial, industrial, institutional, governmental, recreational,
or multifamily residential. Building demolition and expansion is included
as an activity defined as "redevelopment" but building renovation
is not. Similarly, removal of roadway materials down to the erodible
soil surface is an activity defined as "redevelopment," but simply
resurfacing a roadway surface is not. Pavement excavation and patching
that is incidental to the primary project purpose, such as replacement
of a collapsed storm drain, is not classified as redevelopment.
RETENTION
The amount of precipitation on a drainage area that does
not escape as runoff. It can be expressed as the difference between
total precipitation and total runoff from an area.
RUNOFF
Stormwater that does not infiltrate into the ground and flows
toward a below ground or surface discharge location.
STORMWATER
Water that originates from precipitation events and accumulates
on land.
STORMWATER MANAGEMENT PLAN
A written plan describing the proposed methods and measures
to be implemented to prevent or minimize water quality and quantity
impacts from stormwater associated with a development or redevelopment
project both during and after construction. It identifies selected
BMPs, LID source controls and treatment practices to address those
potential impacts and contains the engineering design plans, specifications
and calculations of the management and treatment practices, and maintenance
requirements for proper performance of the proposed practices.
WATER QUALITY VOLUME
The storage volume needed to capture and treat the runoff
from the one-inch, twenty-four-hour rainstorm for a specific contributing
area. See Table 1.
WATERSHED
All land and water area from which runoff may run to a common
(design) discharge point.