A.
No unauthorized person shall uncover, make any connections with or
open into, use, alter, disturb, introduce a new discharge or increase
the volume currently discharged to any public way, stormwater sewer,
or appurtenance thereof without first obtaining a written stormwater
connection permit from the DPW.
B.
Any connections to the stormwater system owned or maintained by the
Massachusetts Department of Transportation (MDOT) will require its
approval.
Each applicant for a stormwater connection permit must be made
at the office of the Department of Public Works on forms provided
for that purpose.
A.
There shall be two classes of stormwater connection permit applications:
(1)
Residential. This includes all single- and two-family individual
dwelling units, not including subdivisions. The permit and application
fee shall be $25, payable to the Town of Greenfield.
(2)
Nonresidential. This includes all multifamily dwellings, subdivisions,
commercial, industrial and institutional uses. The permit and application
fee shall be $100, payable to the Town of Greenfield.
B.
The application form shall be signed by the owner of the property
or by his authorized representative. Fees are nonrefundable. Applications
may be transferred to a new owner with permission of the DPW.
C.
In addition to the stormwater connection permit, the owner must obtain
an excavation permit (street opening permit) from the DPW where subsurface
work is to be done on public property or within the public way.
D.
Contact DIG SAFE 1-888-344-7233 for utility notification.
A.
Applications for residential stormwater connection permits must be
submitted to the Department of Public Works at least 10 working days
prior to the proposed connection date.
B.
Applications for nonresidential stormwater connection permits require
the submittal of a stormwater management plan. Applications shall
be submitted to the Department of Public Works at the same time as
the submittal of the site plan application, if site plan approval
is required, or 30 working days prior to the proposed connection date
if site plan approval is not required.
Two copies of a stormwater management plan shall be submitted
to the Department of Public Works for all nonresidential stormwater
connection permits. The applicant may request and the Superintendent
may grant a waiver from any information requirements the Superintendent
judges to be unnecessary to review of a particular plan.
A.
Computations. Pre- and post-development drainage calculations shall
be completed for a two-year and a ten-year twenty-four-hour storm
event. The one-hundred-year twenty-four-hour storm event must be evaluated
for downstream impacts (flooding). Peak discharge rates must be calculated
using the point of discharge or the downgradient property boundary.
Separate drainage calculations shall be submitted for each point of
discharge of flow from the site. Based on the particulars of each
site, the DPW Engineering Superintendent will determine the appropriate
methodology for developing drainage calculations.
B.
Existing site characteristics:
(1)
Location of all property boundaries.
(2)
Topographic survey showing the existing contours, including the area
necessary to determine downstream analysis for the proposed stormwater
management system.
(3)
Soils investigation, including borings and test pits, for areas where
construction of small ponds and infiltration practices will occur.
(4)
Description of all watercourses, impoundments, and wetlands on or
adjacent to the site or locations into which stormwater flows.
(5)
Delineation of the one-hundred-year floodplain and all wetlands,
if applicable.
(6)
Groundwater levels at the time of probable high groundwater elevation
(November to April) in areas to be used for stormwater retention,
detention and infiltration structures.
C.
Proposed site alterations:
(1)
Location of all existing and proposed buildings, other structures
and impervious surfaces.
(2)
Any proposed changes to the existing contours.
(3)
Location of all existing and proposed roads and utilities.
(4)
Location of all existing and proposed stormwater management systems.
(5)
Structural details of all components of the proposed stormwater management
system. Notes on the plan specifying materials to be used, construction
specifications, and typicals.
(6)
Location of erosion and sediment controls and details of types used.
(7)
Timing schedule and sequence of development, including: land clearing,
grubbing, and stripping, rough grading, construction, final grading
and vegetative stabilization.
(8)
Written inspection and maintenance plan of the stormwater management
system to ensure that it functions as designed. A maintenance schedule
shall be developed for the life of all stormwater management systems
and shall state the maintenance to be completed, the time period for
completion, and who shall perform the maintenance.
(9)
Breakdown of the estimated construction costs of the stormwater management
system.
The stormwater management plan shall be coordinated with any
order of conditions from the Conservation Commission and requirements
under the Wetlands Protection Act. The provisions of this regulation
do not supersede any requirements from the Environmental Protection
Agency (EPA), the Massachusetts Department of Environmental Protection
(DEP) or the Conservation Commission.
When one or more of these management standards cannot be met,
the applicant must demonstrate that an equivalent level of stormwater
protection will be provided.
A.
The stormwater management system shall be designed so that the post-development
peak discharge rates do not exceed the pre-development discharge rates
for a ten-year twenty-four-hour storm.
B.
Loss of annual recharge to groundwater should be minimized through
the use of infiltration measures to the maximum extent practicable.
The annual recharge from the post-development site should approximate
the annual recharge from the pre-development or existing site conditions
based on soil types.
C.
New development shall be designed to remove 80% of the average annual
load (post-development conditions) of total suspended solids (TSS).
It is presumed that this is met when:
(1)
Suitable nonstructural practices for source control and pollution
prevention are implemented.
(2)
Stormwater management best management practices (BMPs) are used to
capture the prescribed runoff volume. For details on BMPs, see the
Massachusetts DEP's Stormwater Management, Vol. 1 & 2, March 1997.
(3)
Stormwater management BMPs are maintained as designed.
D.
Redevelopment projects must meet these management standards to the
maximum extent practicable. If it is not practicable to meet all the
minimum standards, the stormwater management systems shall be designed
to improve existing conditions.
E.
Erosion and sediment controls must be implemented to prevent impacts
during construction or land disturbance activities.
A.
Stormwater management systems are encouraged to be designed to incorporate
the use of natural topography and land cover. The use of such features
as natural swales and depressions as they exist prior to development,
to the degree that they can accommodate the additional flow of water,
are recommended.
B.
All stormwater management systems shall be designed to provide an
emergency overflow system, and incorporate measures to provide a nonerosive
velocity of flow along its length and at any outfall.
C.
The applicant shall consider public safety in the design of a stormwater
management system. The banks of detention, retention, and infiltration
basins shall be sloped at a gentle grade into the water as a safeguard
to personal safety, to encourage the growth of vegetation and to allow
the alternative flooding and exposure of areas along the shore. Basins
shall be fenced or shall have a slope of 4:1 to a depth two feet below
the control elevation. Side slopes must be stabilized and planted
with vegetation to prevent erosion and provide pollution removal.
The banks of detention and retention areas shall be designed with
sinuous rather than straight shorelines, so that the length of the
shoreline is maximized and offering more space for the growth of vegetation.
All costs and expense incident to the installation, connection,
use, and maintenance of the stormwater system shall be borne by the
owner. The owner shall indemnify the Town from any loss or damage
that may directly or indirectly be occasioned by the installation,
connection, use, and maintenance of the stormwater system. The owner
shall further indemnify the Town from any loss or damage from stormwater
backups, overflows, or blockages.
The size, slope, alignment, materials of construction of a stormwater
management system, and the methods to be used in excavating, placing
of the pipe, jointing, testing, and backfilling the trench, shall
conform to the requirements of the building and plumbing code or other
applicable rules and regulations of the Department of Public Works.
The DPW shall perform the following inspections and shall, in
writing, either approve it or notify the applicant in what respects
there has been a failure to comply with the requirements of the approved
stormwater management plan. The applicant shall promptly correct any
portion of the work that does not comply with the approved plan.
A.
Initial site inspection: prior to approval of any stormwater management
plan.
B.
Erosion control inspection: after commencement of construction; to
ensure erosion control practices are in compliance with the approved
plan.
C.
Construction inspection: prior to backfilling any underground drainage
or stormwater conveyance structures.
D.
Final inspection: when all work, including construction of the stormwater
management system, has been completed and the applicant has submitted
as-built plans. The Superintendent will provide certification of completion.
A.
Prior to issuance of any stormwater permit for which a stormwater
management plan is required, the applicant will be required to execute
an inspection and maintenance agreement with the Town binding on all
subsequent owners of land served by the private stormwater management
system. Such agreement shall provide for access to the stormwater
management system at reasonable times for regular inspections by the
Superintendent to ensure that the system is maintained and is in proper
working condition to meet the performance standards and any provision
established.
B.
The inspection and maintenance agreement and the stormwater management
plan shall be recorded by the applicant and/or owner in the land records
of the Franklin County Registry of Deeds prior to the issuance of
a stormwater permit.
The owner(s) of the property on which work has been done pursuant
to this regulation for a private stormwater management system, or
any other person or agent in control of such property, shall maintain
in good condition and promptly repair and restore all grade surfaces,
walls, drains, dams, structures, vegetation, erosion and sediment
control measures, and other protective devices. Repairs or restoration
and maintenance shall be done in accordance with an approved stormwater
management plan.
The Director may require from the developer a surety or cash
bond, irrevocable letter of credit, or other means of security acceptable
to the Town as reviewed by its attorney, prior to the issuance of
a stormwater permit. The amount of the security shall not be less
than the total estimated construction cost of the stormwater management
system. The bond so required in this section shall include provisions
relative to forfeiture for failure to complete work specified in the
approved stormwater management plan, compliance with all the provisions
of this chapter and other applicable laws and regulations, and any
time limitations. The bond shall not be fully released without a final
inspection of the completed work by the DPW representative, submission
of "as-built" plans, and certification of completion by the DPW of
the stormwater management system as being in compliance with the approved
plan.
