[Adopted 2-25-2008]
In accordance with and under the authority of RSA 41:11 and
47:17, VII and VIII, authorizing the Board of Selectmen to regulate
work in public ways and places in the Town of Hampton, the following
article is enacted.
It is the express intent and purpose of this article, and the
specifications it contains, to strictly regulate the standards to
be applied in the construction, reconstruction, repair, opening or
work in public roadways of the Town of Hampton in order to provide
for the public welfare and the public health and to promote the public
safety. These standards are intended to work in conjunction with,
but not supersede, the rules, regulations and ordinances of the Planning
Board.
The construction of streets, drainage facilities, sidewalks
and curbs must be done under the supervision of the Public Works Director
and the Town Manager of the Town of Hampton and/or their authorized
agents.
Before any construction begins, the builder, his contractor(s),
the Public Works Director, Chief of Police, Fire Chief, Sewer Superintendent,
Code Enforcement Officer, Inspection Engineer representing the Town,
Town Planner and the Town Manager and their duly authorized agent(s)
will conduct a preconstruction meeting, the purpose of which is to
clarify the design and construction standards contained herein and
to establish a workable inspection schedule for the project. It shall
be the responsibility of the contractor to organize this meeting,
keep minutes and distribute the same.
A.
The builder shall preserve the grade stakes, property line markers
and right-of-way bounds until the completion of the streets so that
the Town or its agents can readily verify data (check the grade) at
any location, and if stakes or any markers are removed or destroyed
the stakes shall be replaced at the expense of the builder by a licensed
land surveyor.
B.
Before street or improvement construction begins the applicant shall
cause grade stakes to be placed at fifty-foot intervals. Each stake
shall be driven firmly beyond the toe or top of slope in a location
where it will not be disturbed by construction operations and be clearly
marked, by a licensed land surveyor, to give the following information:
C.
Also, the builder shall place grade control stakes at fifty-foot
intervals and located near the shoulder break point or two feet outside
of the proposed curbline on both sides of the roadway. Each stake
shall be marked with the center-line station and a finished grade
mark.
The limits of clearing and grubbing shall be laid out on the
ground before any other work commences and shall extend five feet
beyond the excavation and embankment slope limits. Trees designated
by the Town or its agent(s) will be saved; particular reference is
made to fruit, ornamental or shade trees or plants at the edge of
roadside slopes.
A.
Clearing. Clearing shall be performed by cutting and disposing of
all trees, down timber, stubs, brush, bushes and debris.
B.
Grubbing. All stumps and large roots within the limits of construction
shall be removed and disposed of to a depth of three feet below subgrade.
Excavation caused by grubbing shall be filled with suitable material
that shall be compacted to conform to the surrounding ground.
C.
Roadside cleanup. Roadside cleanup of leaning, dead, unsound and
unsightly trees, branches, stubs, refuse, and slash shall be performed
generally to a limit of approximately 15 feet outside the toe and
top of slopes and the material disposed of appropriately.
D.
Inspection. The Town or its agent(s) shall be notified so that approval
of the clearing and grubbing can be made before any further work may
progress.
This section shall govern the excavation, placement and compaction
of embankment and the necessary disposal of other material.
A.
Excavation. Excavation here refers to the removal of earth, rock
and muck.
(1)
Conservation of growth. Excavation shall be carefully performed in
the proximity of trees and shrubs designated to be saved so as not
to cause undue injury to the designated trees or shrubs.
(2)
Topsoil. Topsoil and other desirable humus material shall be removed
in excavation areas and also in fill areas to such depths as directed
by the Public Works Director. Topsoil shall not be removed from the
project site without the written approval of the Town following the
issuance of an earth removal permit.
(3)
Rock excavation. All boulders that cannot be removed shall be broken
off to a depth of not less than 12 inches below the subgrade. Solid
rock shall be removed to a depth of not less than 12 inches below
subgrade and as required for ditches in cut sections. No rock excavation
by blasting shall be performed without prior written approval of the
Public Works Director and the Fire Chief and only after all required
permits have been obtained and are on site.
(4)
Muck excavation. Muck excavation consists of the removal of deposits
of saturated or unsaturated mixtures of soils and organic matter not
suitable for roadway foundation material regardless of moisture content.
Muck shall be removed and suitable portions thereof may be used on
the embankment slopes or other appropriate uses approved by the Public
Works Director. The excavation work shall be handled in a manner that
will not permit the entrapment of muck within the backfill; the backfilling
of the excavated area shall follow immediately behind the excavation
of the muck in order that any soft material which is pushed ahead
of the backfill can be removed.
(5)
Common excavation. Common excavation consisting of all excavation
not included in the above classifications and unusable for roadway
construction shall be removed. With the approval of the Pubic Works
Director, suitable material may be used in fill areas and unsuitable
material may be used to flatten slopes where possible.
B.
Embankment. Embankments shall be formed of suitable and acceptable
excavated or borrow material and brought to the required lines and
grades. Embankment materials shall be placed and compacted in full
uniform layers not exceeding 12 inches. Continuous leveling and manipulation
shall be employed to ensure uniform density. Where end dumping is
employed, embankment material shall be dumped on the layer of embankment
being constructed and bulldozed ahead into place. End dumping over
compacted work which allows material to roll into place will not be
permitted by the Public Works Director.
(1)
Backfill of holes. Holes resulting from the removal of stumps, boulders,
and the like within the zone of anticipated frost action shall be
filled and compacted with material similar to that surrounding the
hole.
(2)
Unstable areas. Material used to backfill excavated muck shall consist of rock or granular material so graded that, of the material passing the No. 4 sieve, not more than 70% will pass the No. 4 sieve and not more than 12% will pass the No. 200 sieve. The process shall be as specified under Subsection A(4), Muck excavation, above. Material shall be placed compacted in full uniform layers not exceeding lifts of 12 inches.
(3)
Waste material. Waste materials from clearing, grubbing, and roadside
cleanup and from rock, muck and common excavation classified by the
Public Works Director as unsuitable for use in the construction of
roads, streets and landscaping shall not be deposited in any wetland
or other property within the Town, including any public disposal facility,
if at Town expense, but may be deposited in pit(s) dug on site and
covered with material and in a manner acceptable to the Public Works
Director. The pit(s) shall be away from any construction areas in
a nonbuildable buffer area that is acceptable to the Public Works
Director. The builder shall identify all such burial sites on the
completed as-built plans filed at the completion of the project with
the Town.
(4)
Rock embankment. Rock embankment shall consist of rock fragments
placed in layers not to exceed four feet. The rocks lifts shall be
worked in such a manner as to close the voids with smalls and fines
when available; otherwise use earth to make a tight surface prior
to placing the next lift.
(5)
Earth embankment. Earth shall be placed in layers the full width
of the roadway, generally parallel to the finished grade. The layers
shall not exceed 12 inches of loose depth. Each layer shall be spread
to a uniform thickness and compacted to at least 95% of maximum density
prior to placing the next layer. The Public Works Director, at the
applicant's expense, may require density tests.
(6)
Grading. Embankments shall be graded at all times to ensure the proper
runoff of water. Any saturation of nonporous material due to the builder's
selected method of operation shall occasion suspension of additional
work as specified by the Public Works Director until the situation
has been rectified.
(7)
Winter construction. No embankments shall be constructed on frozen
earth materials. Each layer of material shall be compacted to the
specified density before it freezes.
(8)
Borrow. When suitable and acceptable, and excavated material from
the job site has been exhausted, borrow materials may be brought onto
the job, if prior written permission of the Public Works Director
has been obtained concerning the quality of the material at the source.
The builder shall provide adequate disposal of surface runoff.
Location of drainageways, easements and structures shall have been
designed using the topography contour lines on the final plat as specified
in these regulations.
A.
Culverts. In addition to the location as determined above, the length
of a culvert structure shall be graphically determined by cross-section
scale drawing(s) of the proposed street showing existing ground, side
ditches, back slope(s), side slope(s), subgrade, finished grade and
the culvert, with headwall(s) if required. For skew installations,
a plan view also shall be drawn to scale. Culverts without headwalls
or drop inlets shall be extended to the intersection of the street
side slope with the old ground in an earth fill section or with the
back slope in an earth cut section governed by the cover over the
culvert specified below. Culverts with headwalls may be shorter as
governed by the intersection of the street side slope with the back
of the headwall five inches below the top of the headwall. Culverts
also can be terminated by catch basins located on the normal ditch
line of an earth cut section. The minimum inside diameter of any culvert
under streets shall be 12 inches; a larger size may be required as
a result of the rainfall information discussed and designs required
in these regulations, as well as the general necessity for adequate
disposal of surface water. Culverts may be plastic if loading can
be achieved and if approved by the Public Works Director. Locking
devices for field jointing culvert sections shall meet the manufacturer's
specifications. Driveways of the subdivision street(s) shall have
a minimum culvert size of 12 inches. The pipe shall be placed on prepared
bedding of fine granular material to fit the lower 10% of the pipe
height and to ensure that the flow line of the pipe(s) will conform
to the required grade line. The minimum culvert slope required to
maintain a self-cleaning water velocity is 0.4%. Acceptable material
for culvert pipes and closed drainage system pipes shall be smooth-walled
PVC or Hancor HDPE pipes.
B.
Underdrains. The Town may require the builder to provide underdrains
to remove water from the roadway subgrade.
C.
Ditch grades. Roadside ditch grades shall not be less than 1% to
prevent ponding. Steep roadside ditch grades may require energy-absorbing
crushed stone and/or cross culvert relief if anticipated flow is significant.
D.
Headwalls and catch basins. A stone or masonry headwall on the inlet
end of a culvert, when required, shall be designed to prevent physical
damage to the culvert pipe and have a base, below the pipe, to avoid
seepage and erosion below the culvert. Headwalls on the outlet end
of the culvert may be required, but without a deep base. Catch basins
or drop inlets may be required in areas with curb inlets or located
in normal ditch lines of an earth cross section. All stone or masonry
headwalls shall be constructed in accordance with New Hampshire Department
of Transportation (NH DOT) Standard Specifications. All drainage catch
basins, drop inlets and manholes shall be pre-cast reinforced concrete
constructed to NH DOT Standard Specifications. All frames and grates
shall be cast iron and shall meet or exceed NH DOT specification and
shall be Type B4 flange frame and cast-iron grate.
E.
Backfilling.
(1)
All backfill material for culvert trenches, headwalls, drop inlets,
catch basins and manholes shall be soil approved by the Public Works
Director. Backfill material shall be free of hard lumps or clods larger
than three inches in diameter and free of rocks and stumps. Uniformly
fine material shall be placed next to any of the culverts, headwalls,
and basins liable to denting or breaking. Approved castings are LeBaron
L24SG1 and Neenah R3405A.
(2)
Backfill shall be in layers not exceeding six inches at near optimum
moisture content, and care shall be exercised to backfill under the
haunches of culverts and in firm contact with the sides. Compaction
shall not be less than 95% in the vicinity of pipes.
F.
Intersections. Special consideration will be needed where streets
or roads intersect established streets or roads to provide proper
drainage and avoid conditions leading to accumulation of ice during
freezing weather.
G.
Easements. Drainage easements shall be obtained by the builder over
any adjacent land that will be subjected to an increased flow of surface
water because of the alterations caused by the construction.
H.
Inspections. All material supplied for the drainage work shall be
certified by the applicant to the Town of Hampton. The Public Works
Director, or his designee, shall inspect and approve all materials
before placement. The Public Works Director, or his designee, shall
be notified as to when the installation of each item required will
occur. No backfilling will be done until the installation has been
inspected. No drainage structures shall be placed until the base upon
which they will sit has been inspected. The Public Works Director
will inspect all backfilling.
Upon completion of excavation, placement of embankment and installation
and backfilling of drainage structures, the subgrade shall be fine
graded to conform to the subgrade profile and cross slope. High spots
shall be honed down and low spots filled with material acceptable
to the Public Works Director. The process of vibratory compacting
shall continue until no further depressions result. Slopes and ditches
shall be shaped to reasonably smooth surfaces in keeping with the
character of the adjacent terrain and merge into it without any noticeable
break. Culverts and waterways shall be cleared of all obstructions.
Rubbish, brush, loose rock, boulders and all other debris from the
construction work shall be removed and disposed of as directed by
the Public Works Director. The entire roadway must present a uniformly
finished appearance at the completion of fine grading. The Public
Works Director shall be notified so that approval of fine grading
of the subgrade, side and back slopes and ditches can be made before
any further work can progress. Base courses shall be furnished and
placed on previously prepared subgrade or base course. The materials
shall be free from organic materials and shall conform to the following
gradations:
A.
Gravel. The base twelve-inch course depth shall consist of gravel
that conforms to Section 304 of the latest issue of the Standard Specifications
for Road and Bridge Construction, State of New Hampshire Department
of Transportation.
B.
Crushed gravel.
(1)
The top aggregate base course shall be a minimum of six inches of
crushed gravel for all the street sizes regardless of whether a pavement
is to be installed later or not. The required grading is:
|
Sieve Size
|
Percentage by Weight Passing
|
|---|---|
|
3 inches
|
100%
|
|
2 inches
|
95% to 100%
|
|
1 inch
|
55% to 85%
|
|
No. 4
|
27% to 52%
|
|
No. 200 (based on the fraction
passing the No. 4 sieve)
|
0% to 12%
|
(2)
At least 50% by weight of the materials retained in the one-inch
sieve shall have a fractured face. If the crushed gravel is to be
paved with bituminous concrete, the crushed gravel shall be "washed"
to remove fines. Crushed gravel must conform to Section 304 of the
Standard Specifications for Road and Bridge Construction, State of
New Hampshire Department of Transportation.
A.
The subgrade shall be to the specified crown and grade and maintained
in a smooth condition, free from holes and ruts. If the hauling equipment
should cause ruts in the subgrade or previously placed base course,
the equipment shall be operated only on the course being placed, behind
the spreading equipment.
B.
Care shall be taken to avoid segregation when placing gravel and
crushed gravel. When base course material is dumped in piles, it should
be dumped in the course being placed and spread at once onto the previously
placed layer. If spreading equipment is not available, dumping will
not be permitted. Any segregation which occurs shall be remedied or
the materials removed and replaced at the applicant's expense.
C.
Each entire layer of gravel shall be thoroughly scarified for the
depth of the layer to bring all oversized stones to the surface for
disposal prior to placing the subsequent course. Such scarifying will
not be required when the contractor's method of operation is such
that oversized stones are not delivered to the project.
D.
Prior to fine grading, hard spots in the surface of the top layer
shall be eliminated by scarifying the top four inches.
E.
Previously tested and accepted materials contaminated by earthen,
organic, or other foreign matter, or degraded by hauling equipment,
to such an extent that the materials cease to meet the requirements,
shall be removed and replaced or otherwise made acceptable at the
builder's expense.
F.
To prevent segregation of crushed gravel during spreading and to
assist in obtaining the required density of the mixture, water shall
be added to the crushed gravel prior to performing the grading operations.
The course shall be maintained in a moist condition until it is covered.
Water shall be uniformly applied over the other base courses during
compaction in the amount necessary for proper consolidation.
G.
The compaction of gravel and crushed gravel shall be done with an
approved vibratory roller until 95% of maximum density is achieved.
H.
The Public Works Director shall be notified so that approval of the
placement and compaction of the gravel courses may be made before
any further work progresses.
I.
Source approval. The source(s) of gravel and crushed gravel shall
be as approved by the Public Works Director prior to bringing the
materials to the job site.
J.
Fine grading of top course. The top course of six inches of crushed
gravel shall be fine graded to conform to the profile grade of this
course and the cross slope. High spots shall be removed and low spots
filled with approved material. The process of rolling shall continue
until no further depressions result.
K.
Inspection. The Public Works Director shall be notified so that approval
of fine grading of the top course can occur before any further work
progresses.
All streets shall be surfaced with bituminous materials as approved
by the Public Works Director that shall conform to Section 401 of
the State of New Hampshire Department of Transportation Standard Specifications
for Road and Bridge Construction and in accordance with the following:
A.
Bituminous concrete. A minimum of three inches of bituminous concrete,
plant hot mixes (two-inch base and one-inch wearing surface), shall
be used. The bituminous material shall be asphalt cement of penetration
grade 100-200.
B.
Approvals. The Public Works Director or his agent shall approve the
paving contractor and materials to be used. No paving shall be done
until the top course of the base courses has been approved.
C.
Placing hot bituminous pavement.
(1)
Weather limitations.
(a)
Mixtures shall be placed only when the underlying surface is substantially
dry and frost free and the surface temperature is at least 40°
F. and rising. The Public Works Director may permit, in the case of
sudden rain, the placing of mix then in transit from the plant, if
laid on a base free from pools of water, provided that all other specifications
are met. No load shall be sent out so late in the day that spreading
and compaction cannot be completed during daylight. Wearing course
shall not be placed after October 1 of any year.
(2)
Any
material delivered to the spreader having a temperature lower than
250° F. shall not be used.
(3)
Compaction of hot bituminous pavement.
(a)
Immediately after the bituminous has been spread, struck off
and surface irregularities adjusted, it shall be thoroughly and uniformly
compacted by rolling. The initial rolling shall be done with a static
steel-wheeled roller followed by the use of a vibratory roller. The
minimum weight of static steel-wheeled rollers shall be eight tons.
A vibratory steel-wheeled roller shall have a minimum applied dynamic
force of 27,000 pounds (manufacturer's rated capacity). Vibratory
rollers shall have separate controls for energy and propulsion and
be specifically designed to compact bituminous mixtures. When a vibratory
roller is being used, the vibration shall be stopped while the roller
is stopped or reversing its direction of travel.
(b)
Base courses shall be rolled until all roller marks are eliminated.
The wearing course shall be rolled until all roller marks are eliminated
and a minimum density of 95% of laboratory specimens, made by the
AASHTO T-24 method in the proportions of the job-mix formula, has
been obtained.
A.
Utilities. Utilities will be placed after the project has been brought
to subgrade and rough slope work has been completed. Their respective
companies will inspect the lines. It is required that all electric,
telephone, cable and other lines be placed underground.
B.
Guardrails. Guardrails will be required where slopes drop more than
three feet vertically from the height of the break in shoulder to
the original grade on a slope steeper than 4:1 or in other hazardous
areas which will be determined by the Public Works Director. Where
a guardrail is required, it shall be constructed and placed in accordance
with New Hampshire Department of Transportation construction specifications
and the AASHTO Roadside Design Guide.
C.
Survey and monument standards for streets and rights-of-way.
(1)
Permanent survey monuments shall be set in the boundary of all property
corners and rights-of-way at intersection of streets, point of curvature
and point of tangency of curves; the point of intersection of short
curves may be used instead, where such is practical, at the discretion
of the Public Works Director. Monuments shall be placed on both sides
of the street and rights-of-way.
(2)
All monuments used as property corners and to designate rights-of-way
will be granite at least four inches by four inches and 42 inches
long and shall be installed after the subgrade of the street is in
place. A plug, brass plate, or pin shall serve as a reference point,
and a magnetic rod or other suitable metal device shall be located
adjacent to the monument to allow for recovery.
(3)
All surveys shall be prepared and all monuments shall be set in accordance
with the minimum standards adopted by the New Hampshire Land Surveyors
Association for standard property surveys. All survey bounds will
be located in New Hampshire state plane coordinates.
D.
Traffic control and street name signs. Traffic control and street
name signs of a size, type and design approved by the Public Works
Director shall be erected by the builder.
A.
As-built drawings. Following completion of all improvements, the
builder shall submit as-built plan(s) to the Board. The plan(s) shall
be drawn to scale and shall indicate, by angles and dimensions, all
underground or overhead utilities, road profiles and center-line elevations
and final grading plans showing swales and ditches. The plan(s) shall
show all easements, dedicated roadways, roadbeds and other improvements.
Accompanying said plans shall be all of the above plans on a CAD format
compatible with that used by the Town.
B.
Planning Board approvals. Upon completion of all the required improvements
and the completion of any maintenance period required by the Planning
Board, the builder shall provide evidence that the Planning Board
has released the street or way for acceptance by the Board of Selectmen
as a public highway.
The Public Works Director may attach hereto drawings depicting
construction standards to be used in the construction of streets to
become public highways under this article.
These regulations are adopted by the Board of Selectmen on the
date indicated below[1] and repeal all previously adopted regulations for standards
for the construction of streets intended as public highways or to
be accepted as public highways by the Town of Hampton.
[1]
Editor's Note: This article was adopted 2-25-2008.
