The following definitions describe the meanings of the terms
used in this bylaw:
ADVERSE IMPACT
Any deleterious effect on waters or wetlands, including their
quality, quantity, surface area, species composition, aesthetics or
usefulness for human or natural uses, which are or may potentially
be harmful or injurious to human health, welfare, safety or property,
to biological productivity, diversity, or stability or which unreasonably
interfere with the enjoyment of life or property, including outdoor
recreation.
AUTHORIZED ENFORCEMENT AGENCY
Refers to the Planning Board, its employees or agents designated
to enforce this bylaw. The Planning Board may delegate this authority
in writing to employees or agents of the Town of South Hadley.
BEST MANAGEMENT PRACTICES (BMPs)
A structural or nonstructural technique for managing stormwater
to prevent or reduce nonpoint source pollutants from entering surface
waters or groundwaters. A structural stormwater best management practice
includes a basin, discharge outlet, swale, rain garden, biofilter,
or other stormwater treatment practice or measure either alone or
in combination, including, without limitation, any discharge pipe,
overflow pipe, conduit, weir control structure that a) is not naturally
occurring; b) is not designed as a wetland replication area; and c)
has been designed, constructed, and installed for the purpose of conveying,
collecting, storing, discharging, recharging, or treating stormwater.
Nonstructural stormwater best management practices include source
control and pollution prevention measures.
CONSTRUCTION ACTIVITY
Disturbance of the ground by removal of vegetative surface
cover or topsoil, grading, excavation, clearing or filling.
DESIGN STORM
A rainfall event of specified size and return frequency that
is used to calculate the runoff volume and peak discharge rate to
a BMP.
DETENTION
The temporary storage of storm runoff in a BMP, which is
used to control the peak discharge rates and which provides gravity
settling of pollutants.
DEVELOPMENT PERMIT
Any approval by the Planning Board, including, but not limited
to, a definitive plan or Form H plan under the Subdivision Regulations, or site plan review, special permit, or earth removal,
fill, or excavation permit under the Zoning Bylaw.
DISTURBANCE
Any land clearing, grading, bulldozing, digging or similar activities, including any activities not exempt under Article
III of this bylaw.
DRAINAGE AREA
That area contributing runoff to a single point measured
in a horizontal plane, which is enclosed by a ridgeline.
DRY WELL
Similar to an infiltration trench but smaller with inflow
from a pipe; commonly covered with soil and used for drainage areas
of less than one acre such as roadside inlets and rooftop runoff.
EASEMENT
A grant or reservation by the owner of land for the use of
such land by others for a specific purpose or purposes, and which
must be included in the conveyance of land affected by such easement.
EROSION CONTROL
The prevention or reduction of the movement of soil particles
of rock fragments carried by stormwater runoff.
FLOW ATTENUATION
Prolonging the flow time of runoff to reduce the peak discharge.
HYDROLOGY MODEL
May include one of the following:
A.
TR-20, a watershed hydrology model developed by the Natural
Resources Conservation Service Act that is used to route a design
storm hydrograph through a pond;
B.
TR-55, or Technical Release 55, "Urban Hydrology for Small Watersheds,"
is a publication developed by the Natural Resources Conservation Service
to calculate stormwater runoff and aid in designing detention basins;
D.
Any alternative stormwater management tool or model as approved
and deemed acceptable by the Director of Planning and Conservation
or their designee, including computer programs specifically designed
to simulate stormwater flow characteristics.
ILLICIT CONNECTION
A surface or subsurface drain or conveyance, which allows
an illicit discharge into the municipal storm drain system, including,
without limitation, sewage, process wastewater, or wash water and
any connections from indoor drains, sinks, or toilets, regardless
of whether said connection was previously allowed, permitted, or approved
before the effective date of this bylaw.
ILLICIT DISCHARGE
Direct or indirect discharge to the municipal storm drain system that does not consist entirely of stormwater, except as exempted in §
200-4. The term does not include a discharge in compliance with the an NPDES stormwater discharge permit or a surface water discharge permit, or resulting from firefighting activities exempted pursuant to §
200-4 of this bylaw.
IMPERVIOUS SURFACES
Areas, such as pavement or rooftops, which prevent the infiltration
of water into the soil.
INFILTRATION
The downward movement of water from the surface to the subsoil.
INFILTRATION TRENCH
A stormwater management excavation filled with aggregate
which removes both soluble and particulate pollutants. Trenches are
not intended to trap coarse sediments.
LOW IMPACT DEVELOPMENT (LID) TECHNIQUE
Stormwater management practices that are modeled to mimic
natural hydrologic features. Low impact development techniques manage
rainfall at the source using uniformly distributed decentralized micro-scale
controls. Low impact development techniques use small cost-effective
landscape features located at the site level. Refer to the most recent
version of Massachusetts Stormwater Design Manual for examples of
LID techniques.
MUNICIPAL SEPARATE STORM SEWER SYSTEM (MS4) or MUNICIPAL STORM
DRAIN SYSTEM or MUNICIPAL STORM SEWER SYSTEM
A conveyance or system of conveyances designed or used for
collecting or convening stormwater, including any road with a drainage
system, municipal street, catch basins, gutter, curb, inlet, piped
storm drain, pumping facility, retention or detention basin, natural
or man-made or altered drainage channel, ditch, reservoir, and other
drainage structure that together comprise the storm drainage system
owned or operated by the Town of South Hadley.
OUTFALL
The terminus of a storm drain or other stormwater structure
where the contents are released.
PEAK DISCHARGE
The maximum instantaneous rate of flow during a storm, usually
in reference to a specific design storm event.
PERMEABLE SOILS
Soil materials with a sufficiently rapid infiltration rate
so as to greatly reduce or eliminate surface and stormwater runoff.
These soils are generally classified as NRCS hydrologic soil types
A and B.
PERSON
Any individual, group of individuals, association, partnership,
corporation, company, business, organization, trust, estate, administrative
agency, public or quasi-public corporation or body, the commonwealth
or political subdivision thereof.
REDEVELOPMENT
The development, replacement, rehabilitation, expansion,
demolition or phased projects that disturb the ground surface or increase
the impervious area on previously developed or disturbed sites. Standards
for redevelopment only apply to those portions of a parcel or property
that have been previously altered by human activities.
RETENTION
The holding of runoff in a basin without release except by
means of evaporation, infiltration, or emergency bypass.
START OF CONSTRUCTION
The first land-disturbing activity associated with a development,
including land preparation such as clearing, grading and filling;
installation of streets and walkways; excavation for basements, footings,
piers or foundations; erection of temporary forms; and installation
of accessory buildings such as garages.
STORMWATER DESIGN MANUAL
Any single manual or set of multiple volumes of manuals promulgated
by the Massachusetts Department of Environmental Protection (or a
successor agency) which sets forth best management practices, stormwater
management design concepts, and/or stormwater management standards
which must be adhered to in the management of stormwater resulting
from development activity. A copy of the current stormwater design
manual shall be kept on file in the office of the Planning Board.
SWALE
A natural depression or wide shallow ditch used to temporarily
store, route, or filter runoff.
TOXIC OR HAZARDOUS CHEMICALS, MATERIAL OR WASTE
Any material which, because of its quantity, concentration,
chemical, corrosive, flammable, reactive, toxic, infectious or radioactive
characteristics, either separately or in combination with any substance
or substances, constitutes a present or potential threat to human
health, safety, welfare, or to the environment. Toxic or hazardous
materials include any synthetic organic chemical, petroleum product,
heavy metal, radioactive or infectious waste, acid, alkali, and any
substance defined as toxic or hazardous under MGL c. 21C and c. 21E,
and regulations at 310 CMR 30.000 and 310 CMR 40.000.