The following shall be the minimum required standards:
A. Catch basins. All catch basins shall be one of the approved designs
presented in Drawings 2 and 3. They shall be indicated on the drainage
plan by their identifying number. Standard inlet and manhole cover
and frame designs are presented in Drawings 4 through 7.
B. Seepage basins. In unusual conditions where small areas are not adaptable
to other prescribed means of drainage, seepage basins may be used
if approved by the Planning Board.
(1) The construction of seepage basins shall be similar to that of catch
basins, except that the sidewalls shall be constructed entirely of
eight-inch seepage blocks.
(2) If additional storage volume is needed, additional basins or cells
may be constructed next to the first with a common wall of eight-inch
seepage block. The additional basins or cells may not need inlets
but they shall each have a manhole.
(3) Such seepage basins shall be connected by slotted pipe surrounded
by a minimum of six inches of gravel to an overflow basin or area.
The overflow from such basin or area shall not overload any other
drainage system.
C. Culverts.
(1) All culverts shall be constructed of reinforced concrete pipe or
shall be reinforced concrete box culverts and shall have reinforced
concrete headwalls similar to that shown on Drawing 17, unless another
detail is approved for a specific installation.
(2) A chain link fence four feet high, similar in quality to that for
recharge basins, shall be provided along the right-of-way line at
the headwall on each end of the culvert and extending at least four
feet beyond the top of the ditch or brook bank on each side of the
headwall.
D. Manholes. All manholes shall be one of the approved designs presented
in Drawings 9 through 16. They shall be indicated on the final drainage
plan by their identifying number. Standard manhole cover and frame
designs are presented in Drawings 4 through 6. All manholes located
in the street paving shall be located on the center line unless this
specification is waived.
E. Storm-drain pipe. All storm-drain pipes shall be reinforced concrete
pipe laid on undisturbed subgrade with full, firm and even bearing.
Backfill and compaction shall be in accordance with good engineering
practice. They shall be indicated on the final drainage plan with
notation as to size, slope and invert elevations. Necessary easements
shall be shown on the drainage plan and the final plat and shall be
not less than 10 feet wide.
(1) Pipe 18 inches or less in diameter shall be of the bell-and-spigot
type.
(2) Pipe over 18 inches in diameter shall be of the internal-bell type
or slip-joint type.
F. Stormwater recharge basins. Stormwater recharge basins shall be constructed
in accordance with the requirements of this regulation and the detail
drawing of the basin as approved with the final drainage plan by the
Planning Board.
(1) Test hole. At least one test hole shall be dug on the site of each
proposed recharge basin before preparation of the final drainage plan.
(a)
The test hole shall be dug to a depth at least five feet below
the proposed bottom elevation of the basin or groundwater level, if
it is encountered at a lesser depth.
(b)
A representative of the Village Engineer shall be notified when
the test hole is open and shall inspect it.
(c)
Upon approval of the side for a recharge basin by such representative,
the final drainage plan shall be prepared.
(2) Detailed drawing. A detailed plan of the stormwater recharge basin
shall be submitted for approval as a part of the public improvement
and utilities plan and profiles and shall be prepared in accordance
with the following requirements:
(a)
The plan shall show to scale the property line and planting
screen, fence and gate location, top and bottom of slope, outline
of maximum design water level, access ramp, location of inlet pipes
and headwalls and sluices, elevations on bottom of basin of the maximum
design water level and control elevations on curb and top of slope.
(b)
Where the planting screen is placed outside of the fence, a
berm width of 10 feet shall be provided between the fence and the
top of slope. Where the planting strip is located inside the fence,
a fifteen-foot berm width shall be provided between the top of slope
and the fence. The berm width shall be increased at corners to provide
sufficient area for a service truck to negotiate the turn. The top
of the slope shall be not less than one foot higher than the curb.
(c)
The maximum slope for the sides of the recharge basin shall
be one on two and shall be so indicated on the plan.
(d)
Dikes shall be avoided, but where they are necessary they shall
be constructed in accordance with specifications furnished by the
Village Engineer.
(e)
Rights-of-way providing access to recharge basins shall have
a minimum width of 20 feet.
(f)
The access ramp shall be so designed that it starts at the elevation
and location of the top of the basin side and provides easy access
to the higher of the two levels of the basin bottom. It shall be 12
feet wide with a stabilized surface and have a gradient not to exceed
5%.
(g)
Headwalls shall be shown in their proper locations and shall
be constructed in accordance with Drawing 17. Inlets into the recharge
basin shall lead into the lower area of the basin bottom.
(h)
The perimeter, or berm, of the recharge basin shall be so graded
that no water will drain across it into the basin except in sluices
properly designed for that purpose. Wherever possible, the perimeter
area shall be so graded that the adjacent land will slope away from
the recharge basin. The proposed grading shall not adversely affect
adjacent property.
(i)
The recharge basin bottom shall be designed with two elevations,
one a minimum of two feet higher than the other. The lower elevation
shall not be more than 10 feet below the overflow elevation. The lower
elevation shall be at least two feet above the potential high groundwater
level.
(j)
The recharge basin design shall include an overflow so that
the stored water shall not exceed a depth of 10 feet. Such overflow
shall flow directly onto a street surface or by means of an adequate
pipe system flow to some other point of disposal.
(k)
The following information shall be noted on the stormwater recharge
basin detail drawing:
[1]
Total area for which the recharge basin has been designed.
[2]
Coefficient of runoff used.
[3]
Required capacity in cubic feet.
[4]
Capacity provided in cubic feet.
[5]
Total excavation in cubic yards.
(3) Fence and gate. A fence and gate shall be constructed in accordance
with the requirements of this regulation and the following specifications:
(a)
A concrete curb six inches wide (minimum) by 24 inches deep
shall be constructed under the entire length of the fence and gate,
and unless otherwise approved, the top of the curb shall be flush
with the established grade. The curb shall be centered under the fence
and shall be made of one part cement to five parts' mineral aggregate
free from silt or clay, using not more than 7 1/2 gallons of
water per bag of cement. Wood forms shall be used along the top of
the curb to provide straight, parallel sides six inches apart at least
3 1/2 inches deep.
(b)
Posts.
[1]
Line posts shall be two-inch-outside-diameter pipe, 2.72 pounds
per foot, hot galvanized or equivalent H-section, set not more than
10 feet o.c. Corner posts shall be two-and-one-half-inch-outside-diameter
pipe, 3.65 pounds per foot, hot galvanized. Gateposts shall be four-inch-outside-diameter
pipe, 9.11 pounds per foot, hot galvanized.
[2]
All posts shall be nine feet long and shall extend three feet
below the top of the concrete curb, which shall be thickened and deepened
at the posts to provide three inches of concrete cover on the posts.
Corner posts and gateposts shall be properly braced with one-and-five-eighths-inch-outside-diameter
pipe, 2.27 pounds per foot, hot galvanized with rod and turnbuckle
attachment.
[3]
A one-and-five-eighths-inch-outside-diameter toprail, weighing
not less than 2.27 pounds per lineal foot, shall be installed along
the entire length of the fence. The fence fabric shall be tied to
the toprail every two feet with No. 9 gauge aluminum or galvanized
tie wires.
(c)
Fabric.
[1]
Fabric shall be two-inch-mesh No. 9 steel wire, hot-dipped galvanized,
six feet high with barbed edges top and bottom, attached to the posts
so that the bottom of the wire is not more than one inch above the
curb. The wire shall be fastened to each post by means of six "hook
and hook" type clips.
[2]
The fabric shall be anchored to the curb by means of five-sixteenths-inch
galvanized steel rods 12 inches long anchored in the curb and clinched
to the fabric. These tie rods shall be spaced two feet apart.
(d)
Barbed wire. All posts shall be fitted with barbed wire arms
at the top to support three strands of four-point hot-dipped galvanized
or bethanized barbed wire, the top wire being one foot above the top
of the fabric. Arms shall make an angle of 45° with the post and
shall extend inward toward the basin. Barbed wire shall be tightly
stretched and shall be securely tied to the arms.
(e)
Gates. Gate openings shall be 16 feet with double gates having
a one-hundred-eighty-degree swing. Gate frames shall be made of two-inch-outside-diameter
pipe or two-inch-square tubing weighing not less than 2.72 pounds
per foot, hot galvanized, with malleable iron corner castings or welded
at all corners and properly braced against sagging. Hinges shall be
of malleable iron securely fastened to gate and post. All gates shall
be double gates equipped with a drop-bar locking device. The bottom
of the gates shall be not more than two inches above the curb. Gates
shall be fitted with three strands of barbed wire to the same height
as that on the fence. The center block shall be of a design which
can be easily cleaned. A pipe center block shall not be used.
(4) Planting screen. A planting screen shall be established on the perimeter of the stormwater recharge basin. The screen area shall be five feet wide except as set forth in Subsection
F(4)(c) below, and shall conform to the following:
(a)
When the adjacent property is a part of the lot pattern of the
same subdivision, the planting shall be placed on the outside of the
fence on the adjacent plot. Such planting shall become a part of that
plot and shall be maintained by its owner. In this location the fence
shall be set one foot inside the property line on the stormwater recharge
basin site.
(b)
When the adjacent property is not owned by the subdivider, the
planting screen shall be placed inside the fence, which shall be set
one foot inside the property line on the stormwater recharge basin
site.
(c)
When the stormwater recharge basin abuts a street, the fence
shall be set 40 feet inside the property line on the recharge basin
site, and the area between the property line and fence shall be landscaped
with plant materials native to this area as directed by the Planning
Board upon approval of the final plat.
(d)
The berm area between the property line and the top of slope
shall be covered with six inches of topsoil and satisfactorily grass-seeded.
(e) The planting screen shall be planted in accordance with the requirements set forth in Subsection
F(4) of the construction specifications for public improvements, except as described in Subsection
F(4)(c) above.
(5) Safety requirements. During the period after the excavation has been
started and before the fence and gate have been completely installed,
the contractor shall provide at all times such guard or guards as
shall be necessary to keep unauthorized persons off the construction
site, provided that if the fence and gate have been completely installed,
no guard or guards will be required during the time when the gate
is closed and securely locked. It is hereby declared the policy of
the Planning Board that recharge basins, once started, shall be completed
in as short a time as possible consistent with good practice, and,
further, that the public safety shall be safeguarded until such time
as the recharge basins are completed.
(6) Upon final approval and acceptance of the stormwater recharge basin
by the Village Engineer, the developer's key to the lock shall
be turned over to the Superintendent of Highways.
G. The Village Engineer and the Village Superintendent of Highways, upon a joint determination by them, may accept equal or better specifications in lieu of any of the specifications set forth herein in Subsections
A through
F, when in their judgment such alternates accrue to the public benefit.