WQ0043901_Engineering Specs & Details Manual_20221021

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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
SlEc o 3 — UTILITY TREINIcHES
Excavation and Preparation
RECENEDMCDENR/DW
OCT 2'1 2022
Water Quality
Regional Operations Section
Washington Regional Office
Preparation. Trenching for pipelines shall be excavated to the required depth to permit the
installation of the pipe (inclusive of pipes, wires, cables, ducts, and conduit) along the lines and
grades shown on the construction drawings. Prior to trenching for the construction of any utility
mains or connections, the Contractor shall locate all existing utilities within the construction
zone. This may include at a minimum contacting the North Carolina One Call Center at 811 or
1-800-632-4949. Where critical City of Goldsboro water and sewer utilities cannot be located
by traditional means, specialized utility locating, such as vacuum excavation or ground
penetrating radar (GPR) may be required to locate existing utilities before excavating. In all
cases where trenchless methods are planned to cross an existing utility corridor with water,
sewer, force main, reclaimed water and/or other City maintained pipelines, a Subsurface Utility
Exploration services firm shall be contracted to verify the depths of existing utilities prior to
boring. The Contractor shall be responsible for implementing all required safety provisions for
trenching in compliance with OSHA regulations and all other applicable safety requirements
and procedures.
Trenching. The minimum trench width at the top of the pipe shall be at least 18 inches greater
than the outside diameter of the pipe. Rock shall be removed to a depth of at least 6 inches
below the bottom of the pipe and the trench backfilled with suitable material. Open trenches
shall not exceed 100 feet. All trenches shall be confined to the limits of the right-of-way or
utility easement. Trenches in paved areas shall not be sloped. All trenches in or along
roadways shall be properly backfilled at the end of each working day.
Wet trenches shall be stabilized with a base layer of #78 M or #57 stone. The bottom of the
trench shall be shaped to provide uniform support along the entire length of the pipeline.
Severely unstable trench bottoms requiring undercut excavation shall receive a foundation
support system for the pipeline designed by a registered Geotechnical Engineer licensed in the
State of North Carolina. A space shall be excavated at each bell to provide ample space to
join the pipes with no misalignment. The Contractor shall take all necessary measures to
prevent water from entering the trench.
Pipe Laying and Backfilling
All pipe shall be laid in accordance with the manufacturer's recommendations. Pipe laying and
backfilling shall be accomplished in a manner to prevent damage and misalignment of the pipe.
The subgrade at the bottom of the trench shall be shaped to secure uniform support throughout
the length of the pipe. A space shall be excavated under the bell of each pipe to provide space
to relieve bearing pressure on the bell and to provide room to adequately make the joint. Open
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
ends of the pipe shall be plugged with a standard plug or cap at all times when pipe laying is
not in progress. Trench water shall not enter the pipe. Backfill material shall be free from
construction materials, debris, and frozen, organic, or unstable material. The top two feet of
backfill material shall be free from stones greater than 2 inches in diameter. Under roadways
and extending at a slope of 1 to 1 beyond the back of the curb, measured perpendicular from
the centerline, backfill shall be compacted to a density of no less than 100% Standard Proctor
maximum dry density as measured by AASHTO method T99.
Backfill shall be placed in lifts of 12 inches or less of uncompacted soil. Other fill material shall
be compacted to a density of no less than 95% of the maximum dry density as measured by
AASHTO method T99. Backfill material shall be placed in lifts of 12 inches or less of
uncompacted soil. Suitable backfill material shall be utilized and compacted in accordance
with the City compaction requirements and the pavement repair shall be in accordance with
the applicable section of this Manual.
All trenches shall be properly backfilled at the end of each working day. All curb cuts shall be
repaired within a maximum of 3 days from the date the cut is made. If conditions do not permit
a permanent repair within the given time limit, permission to make a temporary repair must be
obtained from the City Engineer.
In locations where backfill material is temporarily stockpiled on the roadway surface, a layer of
1.5 inches of screenings shall be used between the pavement surface and the backfill material.
Trenchless Pipe Installation
General. All utility crossings within City streets shall be made by trenchless methods. State
maintained streets within the City's ETJ should also be crossed using trenchless methods. In
cases where utility conflicts, rock, or other obstructions prevent trenchless crossings, the City
may consider approving other methods. The preferred trenchless method shall be auger
boring. Altemate trenchless methods including micro -tunneling, guided boring, conventional
tunneling, horizontal directional drilling or hand tunneling may be approved after thorough
evaluation by the Engineering Department. In addition to meeting or exceeding all City
requirements, all trenchless crossings shall be approved by and meet the requirements of all
controlling legal authorities, such as NCDOT, Norfolk Southern Railway and CSX Corporation.
Direct bores may be made without a casing pipe on pipelines 6 inches in diameter and smaller.
Encasement pipe shall be installed with all trenchless construction methods (excluding
horizontal directional drilling when it is approved and as noted above). There shall be a
minimum cover of 4 feet between the pavement subgrade and the top of the casing pipe. Under
no circumstances shall the pavement subgrade be disturbed. Permanent easements shall be
provided at all trenchless pits to allow for future access to casing pipes.
Encasement Pipe. Encasement pipe shall be new and manufactured of grade 'B' steel with
minimum yield strength of 35,000 psi in accordance with ASTM A139 and A283. All casing
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
pipe shall have machine cut, bevel ends that are perpendicular to the longitudinal axis of the
casing. Size and minimum wall thickness of smooth wall or spiral welded steel encasement
pipe shall be as shown in the below table. Actual wall thicknesses shall be determined by the
casing installer based on their evaluation of the required forces to be exerted on the casing
when it is installed.
Minimum Wall Thickness of Steel Encasement
Pipe
Encasement Pipe OD
(inches)
Minimum Wall
Thickness (inches)
12.75
0.188
14
0.250
16
0.250
18
0.250
20
0.250
24
0.250
26
0.312
28
0.312
30
0.312
36
0.375
42
0.500
48
0.500
54
0.500
60
0.500
66
0.625
Encasement pipe installed for railroad bores shall meet the requirements of the American
Railway Engineering Association (AREA) for boring under railroads.
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
Minimum Allowable Steel Encasement Diameter Per Carrier Size (inches)
Carrier Pipe Size
Inside Diameter
Carrier Pipe
Outside Bell Diameter
Steel Encasement
Nominal Diameter
6
9.19
12.75
8
11.33
16
10
13.56
18
12
15.74
20
14
19.31
24
16
21.43
26
18
23.7
28
20
25.82
30
24
29.88
36
30
36.34
42
36
42.86
48
42
49.92
60
48
56.36
66
Casing Pipe Spacers and End Closures. The carrier pipe shall rest on steel pipe alignment
spacers. The spacers shall have either a bituminous or epoxy coating. A minimum of 2 steel
spacers per joint shall be required on carrier pipe less than 36 inches. Carrier pipe greater
than or equal to 36 inches shall have a third spacer. The steel spacers shall be located evenly
along the carrier pipe alignment in such a manner that each spacer supports the same unit
weight of carrier main. The spacing interval of the steel spacers shall assure the necessary
grade, clearance, and support of the carrier main. The spacers shall be manufactured for the
specific carrier pipe and casing pipe diameters being used such that the risers do not allow the
pipe to float within the casing.
In cases where the encasement pipe is installed in closed proximity to facilities with stray
current, such as gas lines, high voltage power transmission lines, petroleum lines, railroad
tracks, etc. the steel spacers shall be provided with composite contacts on the runners such as
an EPDM rubber liner or an ultra -high molecular weight polyethylene plastic skid to prevent
transmitting the stray current to the carrier pipe.
The carrier pipe bells shall not be allowed to contact the interior of the encasement pipe under
any circumstances. No blocks or temporary spacers shall be wedged between the carrier pipe
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
and the top of the encasement pipe. The ends of the encasement pipe shall be sealed using
8 inch bricks and a non -shrink grout. A 2 inch galvanized vent pipe shall be provided on the
upper end of the casing on all stream and railroad crossings.
Carrier Pipe. All carrier pipe shall be locking joint ductile iron pipe resting on steel skids as
shown in the Standard Detail Drawings to prevent damage to the pipe bell. A minimum of 2
skids per joint of carrier pipe spaced evenly in the encasement pipe shall be required. Pipe
bells shall not contact the interior of the casing pipe. No blocks or spacers shall be wedged
between the pipe and the top of the casing.
External Corrosion Protection
External corrosion can occur at an accelerated rate in metallic pipelines such as steel and
ductile iron when they are installed in aggressive soils or when they are installed near other
structures or utilities that carry impressed currents. Such facilities that typically utilize
impressed current cathodic protection are gas pipelines. Other potential sources that may
create stray currents that contribute to accelerated pipeline corrosion are high voltage power
transmission lines and railroad crossings.
In cases where metallic steel and ductile iron pipelines or encasement pipes are planned for
installation in close proximity to any potential sources of stray current or aggressive soils, zinc
coated pipe shall be specified and a field analysis consisting of stray current evaluation and
soil testing shall be conducted by an experienced technician, as certified by the National
Association of Corrosion Engineers, (NAGE), to determine the potential for extemal corrosion
and the need for additional protection measures. In cases where stray current conditions
and/or aggressive soils are prevalent, a corrosion specialist certified by the NACE or other
applicable certification board shall be consulted regarding the design of pipeline protection
measures.
At a minimum, all stray current protection systems should include bonded joints and sacrificial
anodes with a 50 year or longer design life and test facilities in lieu of polyethylene encasement,
unless otherwise approved by the City of Goldsboro. The cathodic protection element of the
pipeline design package shall be sealed by Professional Engineer licensed in the State of NC.
Full impressed current cathodic protection shall only be utilized when extreme corrosion
potential has been proven and/or as otherwise directed by the City Engineer and the certified
corrosion engineer of record.
Trench and Cut Repairs
To protect cuts the street infrastructure and safety, all utility trench and cut repairs must be
perpendicular or parallel to the existing edge of pavement and square or rectangular in shape
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
with a minimum cut size to be 2 feet from any fixed object on all sides (manholes, utility valves,
concrete infrastructure). Repairs shall be completed in accordance with the following:
Asphalt Utility Cuts. If an asphalt trench and cut repair inside a City of Goldsboro maintained
right-of-way is left open for 10 calendar days, it shall consist of ABC compacted to 100%
Standard Proctor. From 11 to 30 calendar days, it shall consist of bituminous binder course of
Type 119.0B. From 31 calendar days, cut repair shall be completed with a wearing surface
course of Type SF9.5A. If an asphalt strip between a cut and the edge of the pavement is 3
feet or less, the strip will be removed and replaced as part of the cut. New asphalt utility cuts
within and over half of an existing asphalt utility repair area will require the replacement of the
entire existing repair area or at the discretion of the City Engineer or designee.
Trench cuts in asphalt roadways that exceed half of the roadway width in a shoulder section
shall require a full width overlay with SF9.5A extending 17.5 feet to each side of the trench.
For those trenches that exceed half of the roadway width in a gutter or curb and gutter section,
the full width mill and overlay with SF9.5A shall extend 5 feet to each side of the trench.
Trench cuts in asphalt roadways that exceed more than 20 feet parallel to the road will require
a minimum half roadway mill and overlay.
Utility cuts in asphalt roadways with an asphalt age of 3 years or less will require a minimum
half roadway mill and overlay.
All street markings and traffic control devices shall be replaced to City Standards.
Concrete Utility Cuts. Concrete trench and cut repairs inside a City of Goldsboro maintained
right of way shall be completed within 10 calendars days.
For utility cuts in concrete curb, curb and gutter, or sidewalk, the concrete must be removed
and replaced from nearest expansion on both sides of the utility cut or have an expansion joint
installed at the cut. Any replacement of sidewalk with a decorative stamp pattern must be
stamped with the same pattern as the existing sidewalk. Any existing sidewalk ramps removed
must be replaced to the current ADA Standards.
When concrete sidewalk utility cuts are required in locations where the sidewalk contains
reinforcing steel adjacent to a tree pit, a straight vertical cut shall be made to remove the
reinforced concrete. Repair the sidewalk cut by drilling 6 inches into the existing concrete along
the vertical face of the cut then dowel in and secure #4 steel rebar with approved epoxy.
Replace the sub -grade, then splice steel in the new cut at a minimum of 4 inches and replace
remaining steel before replacing the concrete.
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
Soil Utility Cuts. Soil cut inspection limits within a City of Goldsboro maintained right-of-way
is a minimum of 5 feet out from the edge of the pavement, 5 feet out from the back of curb, or
the back edge of the sidewalk furthest from the pavement. Soil trench and cut repairs inside a
City maintained right-of-way shall be completed within 10 calendar days.
Other Utility Cuts. Brick trench and cut repair inside a City of Goldsboro maintained right-of-
way shall be completed within 10 calendar days by replacing existing brick above 6 inch lifts of
compacted soil and 8 inches of ABC stone compacted to 100% Standard Proctor.
Excess Spoil Piles. Any excess spoil piles shall be removed and soil disturbances and utility
cuts shall be restored to original or better condition.
Crack and Joint Sealing. The repair areas consisting of sealing existing longitudinal and
transverse pavement cracks, joints, and traffic signal detector loops with hot -poured rubber
asphalt, modified asphalt compound (peel and stick roll) and NCDOT approved Qualified
Products List Materials shall be applied as per the following requirements:
• Hot -Poured Rubber Asphalt. Hot -poured rubber asphalt must have a 2 inch sealed
overband and be applied as per the manufacturer's recommendations.
• Modified Asphalt Compound Tape. Modified asphalt compound tape must be 4
inches wide, centered over the crack or joint, and applied as per the manufacturer's
recommendations.
• Traffic Signal Detector Loop. See NCDOT QPL list and apply as per the
manufacturer's recommendations.
City of Goldsboro Right -of -Way Cut Permit
In the event that a resident, contractor, or utility company will be cutting asphalt, concrete, brick,
or dirt surfaces within the right-of-way maintained by the City of Goldsboro, then excavating
the subsurface for the purpose of installing or repairing public or private utilities as well as
above ground infrastructure, all parties are required to obtain a Right -of -Way Cut Permit.
Permit Application. Apply for the Right -of -Way Cut Permit at 200 North Center Street and be
able to provide the following information:
• Address nearest to the location of the cut.
• Name of the nearest intersecting street.
• Length and width dimensions
• Type of surface to be cut.
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
WASTEWATER
Wastewater Collection Systems
Design
All public sanitary sewer mains shall be installed in dedicated street right of way or in dedicated
utility easements. Mains installed in City right of way shall be located in the center of pavement
or as otherwise approved. Mains within easements shall be centered within the easement.
Mains located within NCDOT right of way shall be placed in accordance with NCDOT
standards.
In preparing engineering design plans for sanitary sewer mains, all elevations shall be tied to
NC grid system and the benchmark shall be described on the plans.
All private sewer collection mains inside the City of Goldsboro service area that will connect or
are planning to discharge into the City sewer system shall comply with all City of Goldsboro
design, siting and installation criteria outlined herein. The Owner of the private sewer collection
system shall meet all State design requirements and obtain a State permit to operate the private
system.
Gravity mains shall be installed in dedicated public right of way or in dedicated utility easements
as follows:
Standard Easement Width for Sanitary Sewer Mains
Pipe Size (diameter)
Pipe Depth (feet)
Easement Width (feet)
8-inch to 5 12-inch
10-ft or less
20-ft
8-inch to 5 12-inch
10-ft - 12.5-ft
25-ft
8-inch to 5 12-inch
12.5 - 15-ft
30-ft
8-inch to 5 12-inch
15-ft - 17.5-ft
35-ft
8-inch to 5 12-inch
17.5-ft - 20-ft
40-ft
> 12-inch to 5 24-inch
15-ft or less
30-ft
> 12-inch to 5 24-inch
15-ft - 17.5-ft
35-ft
> 12-inch to 5 24-inch
17.5-ft - 20-ft
40-ft
Greater than 24-inch
Any Depth
As Determined by the City
Any Size
Deeper than 20-ft
Dedicated easements for sewer mains and appurtenances shall be recorded as "City of
Goldsboro Permanent Utility Easement". City of Goldsboro sewer easements shall contain
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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only City of Goldsboro utilities unless otherwise approved by the site plan or an encroachment
agreement.
No permanent structures, equipment, retaining walls, embankments, impoundments, or other
elements that would inhibit maintenance operations shall be constructed within a sewer main
easement. Fences may be allowed across easements provided that appropriate access gates
have been installed to allow utility maintenance. In all cases, the City of Goldsboro shall have
access to secured access gates. Fill or cut slopes are not allowed to extend into easements
without full development plan approval or an approved encroachment agreement from the City.
All such pre-existing or planned conditions as noted herein that would impact operations and
maintenance within the noted sewer main easement shall be noted and disclosed during the
site plan approval process. Pre-existing conditions that are not disclosed during the site plan
review may nullify the approval and require relocating the sewer easement where there are no
existing conflicts.
Sewer line easements shall be graded smooth, free from rocks, boulders, roots, stumps, and
other debris, and seeded and mulched upon the completion of construction. Easements across
sloped areas shall be graded uniformly across the slope to no steeper than a 5 to 1 ratio.
Mains paralleling a creek shall be of sufficient depth to allow lateral connections below the
stream bed elevation. The top of the sewer main and laterals shall be at least one foot below
the stream bed. Concrete encasement and ductile iron pipe shall be required when the cover
between the top of the pipe and the stream bed is less than 3 feet.
Mains shall not be installed under any part of water impoundments. The following minimum
horizontal separations shall be maintained:
• 100 feet from any private or public water supply source, including wells, WS-1 waters or
Class I or Class II impounded reservoirs used as a source of drinking water (except as
noted below)
• 50 feet from wetlands and any waters (from normal high water) classified WS-II, WS-III,
B, SA, ORW, HOW or SB (except as noted below)
• 10 feet from any other stream, lake, or impoundment (except as noted below)
• With approval directly from PERCS, the following separations may be acceptable when
water main standards are implemented:
o All appurtenances shall be outside the 100 foot radius of wells.
• 25 feet from private wells (with no exceptions)
• 50 feet from public water wells (with no exceptions)
Where the required minimum separations cannot be obtained sewer pipe, ductile iron pipe shall
be used with joints equivalent to water main standards.
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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Sewer mains shall always be extended along natural drainage courses to all adjacent upstream
property lines.
Gravity sewer mains shall be deep enough to serve the adjoining property and allow for
sufficient slope in lateral lines. Gravity sewer pipe shall have the following minimum covers:
• 4 feet from the top of pipe to finished subgrade in roadways.
• 3 feet from the top of pipe to finished grade outside roadways.
Sewer mains over 20 feet deep require ductile iron for the entire run between manholes. Sewer
mains 14 feet to 18 feet along or in roadways shall also require ductile iron pipe for the entire
run between manholes. The maximum depth of sewer along or in roadways shall be 18 feet.
In all cases where fill material is added above existing sewer mains, the Engineer of Record
shall prepare a structural analysis of the existing pipeline and determine if it is capable of
supporting additional loading. If the additional fill material exceeds AWWA, DIPRA, UNIBELL
and/or manufacturer standards for loading, the pipeline shall either be reinforced to adequately
support the additional loading or replaced with a ductile iron pipe rated to support the added
loading.
Separation Between Sanitary Sewer and Storm Water Pipes. Sewer mains shall have a
minimum vertical separation of 24 inches between storm pipes when the horizontal separation
is 3 feet or less. Where sanitary and storm sewers cross with a vertical separation of less than
24 inches, the entire leg of sanitary sewer shall be made of standard ductile iron pipe with joints
rated for water main service and the void space between the pipe crossing shall be backfilled
with 3000-psi concrete or quick setting, minimum 500-psi, non-excavatable flowable fill that
meets or exceeds NCDOT Specifications.
Separation Between Sanitary Sewer and Sewer Force Main. There shall be a minimum 7 foot
horizontal separation between parallel gravity and/or force mains when the depth of installation
is 8-ft or Tess. Otherwise, the minimum horizontal separation between pipelines shall be 10-ft
up to 10-ft depth of installation. Otherwise, a project specific design shall be implemented.
Separation Between Sanitary Sewer and Water Main.
• Parallel Installations: 10-ft lateral separation (pipe edge to pipe edge) or minimum 3-ft
lateral separation, and water line at least 18-inches above sanitary sewer line measured
vertically from top of sewer pipeline to bottom edge of water main. In. unique cases
where the sanitary sewer and the water main are installed with at least 3-ft of lateral
separation but less than 10-ft of horizontal separation, and less than 18-inches of vertical
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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separation, both the water main and sanitary sewer shall be constructed of ductile iron
pipe with joints in full compliance with water main standards.
• Crossings (Water Main Over Sewer): All water main crossings of sewer lines shall be
constructed over the sewer line in conformance with City of Goldsboro Specifications.
At a minimum, 18-inches of clearance shall be maintained between the bottom edge of
the water main and the top edge of the sewer main. If 18-inches of clearance is not
maintained, the water main and sanitary sewer main shall:
o Both lines shall be constructed of ductile iron pipe with joints in conformance with
water main construction standards.
o The sanitary sewer pipe shall be ductile iron the entire run from manhole to
manhole.
o The void space between the pipes shall be filled with minimum 500-psi, quick
setting non-excavatable flowable fill extending 3-ft on both sides of the crossing.
Regardless of pipe material, at least 12-inches of vertical separation is required
for sanitary sewer crossings of potable water mains.
• Crossings (Water Main Under Sewer Line): Allowed only as approved by City of
Goldsboro, when it is not possible to cross the water main above the sewer line. At a
minimum, 18-inches of separation shall be maintained, (measured from pipe edge to
pipe edge) and the sanitary sewer shall be constructed of ductile iron in conformance
with water main construction standards the entire run from manhole to manhole. If local
conditions prevent providing 18-inches of clearance, then at least 12-inches of clearance
shall be provided and the void space between the pipes shall be filled with minimum
500-psi, quick setting, non-excavatable flowable fill extending at least 3-ft on both sides
of the crossing.
Main Size, Slope and Design Criteria
Public gravity mains shall be a minimum of 8 inches in diameter. Major interceptors shall be
sized appropriately using the following flow factors. At a minimum, all gravity sewer mains shall
be designed and sized to serve the ultimate tributary buildout of the drainage basin.
Residential flow rates
Land Use
Flow Factor
Single Family Residential
280 gpd per dwelling unit
Multi -Family Residential
100 gpd per bedroom
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
AND DETAILS MANUAL
For non-residential flow rates, use the current flow factors as required by the North Carolina
Department of Environmental Quality.
The ratio of peak to average daily flow shall be 3.3.
Sanitary sewers shall be designed to carry the projected peak flow at no more than 2/3 full.
The minimum velocity for sanitary sewer lines shall be 3-fps. Sanitary sewers shall be sized
based on Manning's Equation with Manning's roughness coefficient "n" = 0.013 or greater.
Pipe diameter sizes used in the calculation of Manning's Equation shall be nominal pipe sizes.
The minimum grades for public sanitary sewers shall be as follows:
Minimum Slopes for Gravity Sewer Mains
Main Size (diameter in inches)
Minimum Slope (feet per 100 feet)
V=3fps; 2/3 Depth
8
0.61
10
0.46
12
0.36
14
0.29
15
0.27
16
0.25
18
0.21
21
0.17
24
0.14
27
0.13
30
0.11
36
0.09
The minimum grade for the uppermost reach of a sanitary sewer line shall be 1 % regardless
of sewer line size.
The maximum grade for sanitary sewers is 10%. The maximum velocity in sanitary sewers is
15 ft/sec. These limits may only be exceeded with the approval of the City and the incorporation
of the following provisions, which apply to all sewers either designed or installed at grades
equal to or exceeding 10%:
• All sewers with a grade of 10% or higher must have the downstream run of pipe installed
with ductile iron pipe.
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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• High velocity manholes shall be used on all sewers with a grade of 10% or higher. High
velocity lines cannot tie directly to an existing line and must proceed 180° through the
invert into the downstream line.
• Concrete thrust collars shall be installed on all sewers designed at grades of 10% or
higher. The anchors shall be installed at the following spacing:
o Not over 36' center to center on grades from 10% to 25%
o Not over 24' center to center on grades from 25% to 40%
o Not over 16' center to center on grades exceeding 40%
• The Town reserves the right to require all high velocity requirements outlined herein for
sewer lines either designed or installed at grades of 10% or greater, regardless of the
flow velocity. In cases where the design grade established on the sewer design plan is
exceeded during construction and the10% threshold is exceeded, all high velocity
requirements shall apply without waiver.
Sewer extensions shall be designed for projected flows, even when the diameter of the
receiving sewer is less than the diameter of the proposed extension. All pipe diameter changes
shall occur only in manholes, with the invert of the larger pipe lowered sufficiently to maintain
the same energy gradient. An approximate method of obtaining this result is to place the 0.8
depth point of both sewers at the same elevation. As an alternative, the crown of the incoming
pipes may be designed for an elevation at or above the crown of the outgoing pipe. All
transitions of pipe material, pipe separations, grade changes and all angular deflection changes
shall occur only at manholes. Pipe trench excavation and backfilling shall be performed in
accordance with these Specifications.
Materials
Ductile Iron Pipe. Ductile Iron Pipe shall be designed and manufactured in accordance with
AWWA C150 and C151 and provided in nominal 20-ft lengths. The minimum requirements for
ductile iron pipe and required laying conditions are tabulated below. For all other installations
other than specified, the laying condition, bedding requirements or the minimum pressure class
rating and/or thickness class shall be increased in accordance with AWWAC151. A pipe
thickness design shall be submitted for extemal loading in all cases where the pipe depth
exceeds the specified range of depths outlined in the following table.
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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Pressure Class. Max. Depth and Laving Condition for DI Sewer Mains
Pipe Diameter
AWWA C-150,
Laying Condition
Pressure Class
(psi)
Max Depth of
Cover
8 inch
type 1
350
3-16 feet
8 inch
type 4
350
16-34 feet
10-12 inch
type 1
350
3-10 feet
10-12 inch
type 4
350
10-28 feet
10-12 inch
type 5
350
28-44 feet
14-20 inch
type 4
250
3-22 feet
14-20 inch
type 5
250
22-30 feet
14-20 inch
type 5
350
30-38 feet
24-30 inch
type 4
250
3-19 feet
24-30 inch
type 5
300
19-29 feet
24-30 inch
type 5
350
29-33 feet
36-42 inch
type 4
300
3-20 feet
36-42 inch
type 5
350
20-32 feet
For cases not specified, a ductile iron pipe and bedding design certified by a Professional
Engineer licensed in the State of North Carolina shall be required in compliance with AWWA
C150 and the Ductile Iron Pipe Research Association.
In cases where thickness class designation of ductile iron pipe is specified, the corresponding
thickness class designations are as outlined in the table below.
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Ductile Iron Pipe Thickness Class
Pipe Diameter
Pressure Class
(psi)
Nominal
Thickness
(inches)
Minimum
Corresponding
Thickness Class
4
350
0.25
51
6
350
0.25
50
8
350
0.25
50
10
350
0.26
50
12
350
0.28
50
14
250
0.28
50
16
250
0.30
50
18
250
0.31
50
20
250
0.33
50
24
250
0.37
50
24
300
0.40
51
30
250
0.42
51
30
300
0.45
52
36
300
0.51
52
36
350
0.56
53
42
300
0.57
52
42
350
0.63
53
Pipe joints shall be of the push -on type as per AWWA C111.
For 10-inch diameter and smaller gravity sewer mains, pipe lining shall be cement mortar with
a seal coat of bituminous material, all in accordance with AWWA C104.
For 12-inch diameter and larger gravity sewer mains, all ductile Iron pipe and fittings for sewer
construction shall receive an interior ceramic epoxy coating, consisting of an amine cured
novalac epoxy containing at least 20% by volume of ceramic quartz pigment, as manufactured
by Protecto 401. The interior coating shall be applied at a nominal dry film interior thickness of
40-mils. All DIP bells and spigots shall be lined with 8-mils of joint compound by Protecto 401
or approved equal applied by brush to ensure full coverage. All pipe supplied with Protecto
401 interior lining shall be provided free of holidays. Pipe installed with defects in the lining will
be rejected and required to be replaced. Patching of Protecto 401 coating defects after
installation shall not be approved. Protecto 401 lined pipe must be installed within one year of
the application date on the pipe.
All buried DIP and fittings shall have bituminous coating on the exterior surface in accordance
with AWWA C151. Pipe shall be supplied in minimum 20-ft lengths.
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All ductile iron pipes shall be marked in conformance with ASTM A-746.
Solid Wall PVC Pipe. PVC Pipe shall be solid wall and made of PVC plastic having a cell
classification of 12454 or 12364 (with minimum tensile modulus of 400,000 psi) as defined in
Specification D1784. PVC pipe shall have integral wall bell and spigot joints for the conveyance
of domestic sewage and shall be supplied in minimuml4 or 20 foot lengths. Fittings shall be
made of PVC plastic having a cell classification of 12454-B, as defined in ASTM D1784.
All PVC gravity sewer pipe and PVC fittings up to 15-inches in diameter shall be manufactured
in accordance with the latest version of ASTM D3034. All solid wall PVC pipe installed at
diameters from 18-inches to 27-inches in diameter shall be manufactured in conformance with
ASTM F679 and provided at minimum pipe stiffness of 115-psi. Fittings must be manufactured
by pipe supplier or approved equal, and have bell and/or spigot configurations compatible with
that of the pipe. PVC pipe shall be installed in accordance with the requirements of this
Specifications manual and ASTM D2321.
All PVC pipe up to and including 15 inches in diameter shall have a maximum Standard
Dimension Ratio (SDR) of 35 for depth of installation no shallower than 4-ft of cover from the
pipe crown and no deeper than 14-ft measured from the bottom of the pipe. All solid wall PVC
pipe for depth of installation greater than 14-ft shall have a maximum Standard Dimension
Ratio (SDR) of 26. Solid wall PVC pipe shall not be approved for depths of installation greater
than 20-ft. All solid wall PVC pipe shall be marked and certified in conformance with ASTM
D3034 or ASTM F679.
PVC Pipe Sizing and Minimum Wall Thickness
Nominal Pipe
Diameter
(inches)
Outside
Diameter
(inches)
Minimum Wall
Thickness SDR
35 (inches)
Minimum Wall
Thickness SDR
26 (inches)
8
8.400
0.240
0.323
10
10.500
0.300
0.404
12
12.500
0.360
0.481
15
15.300
0.437
0.588
18
18.701
0.720
21
22.047
0.849
24
24.803
0.956
27
27.953
1.077
Note: SDR 35 not approved for pipe diameters greater than 15-inches and for
depths greater than 14-ft.
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Sewer Main Installation. Pipe trench excavation and backfilling shall be performed in
accordance with these Specifications. Transitions of pipe material, pipe separations, grade
changes and all angular deflection changes shall occur only at manholes. All sewer mains
installed with less than 4-ft of cover or deeper than 20-ft shall be ductile iron pipe.
Pipe and fitting interiors shall be protected from foreign matter and shall be inspected for
damage and defects prior to installation. In the event foreign matter is present in pipe and
fittings, it shall be removed before installation. Open ends of pipe shall be covered and
protected when pipe laying is not in progress to prevent debris from entering the pipe.
All pipes shall be constructed with at least 48 inches of cover below the finished grade. Pipe
shall be laid on true lines as directed by the Engineer. Trenches shall be sufficiently wide to
adjust the alignment. Bell holes shall be dug at each joint to permit proper joint assembly. The
pipe shall be laid and adjusted so that the alignment with the next succeeding joint will be
centered in the joint and the entire pipeline will be in continuous alignment both horizontally
and vertically. Pipe joints shall be fitted so that a thoroughly watertight joint will result. All joints
will be made in conformance with the manufacturer's recommendations for the type of joint
selected.
Prior to beginning construction, the Contractor shall contact local utility companies and verify
the location of existing utilities. The Contractor shall be completely and solely responsible for
locating all existing buried utilities inside the construction zone before beginning excavation.
The Contractor shall be solely responsible for scheduling and coordinating the utility location
work. When an existing utility is in conflict with construction, it shall be exposed prior to
beginning construction to prevent damage to the existing utility.
Embedment Material. Bedding and embedment material classifications shall be defined as
follows:
• CLASS I - Angular, (1/4 to 1-1/2 inch) graded stone, including a number of fill materials
that have regional significance such as coral, slag, cinders, crushed stone, crushed
gravel, and crushed shells.
• CLASS II - Coarse sands and gravels with maximum particle size of 1-1/2 inch, including
variously graded sands and gravels containing small percentages of fines, generally
granular and non -cohesive, either wet or dry. Soil types GW, GP, SW and SP are
included in this class.
• CLASS III - Fine sand and clayey gravels, including fine sands, sand -clay mixtures, and
gravel -clay mixtures, Soil Types GM, GC, SM, and SC are included in this class.
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• CLASS IV - Silt, silty clays, and clays, including inorganic clays and silts of medium to
high plasticity and liquid limits. Soil Types MH, ML, CH and CL are included in this class.
These materials shall not be used for embedment.
Class I foundation material consisting of to 1'/2 -inch graded stone shall be required in
addition to standard bedding and embedment for all sewer installations, regardless of pipe
material, when the trench bottom is unstable due to water, rock, infiltration or soil type.
All bedding, embedment and backfill materials shall be compacted to a minimum of 95%
Standard Proctor density regardless of material. In instances where compliance with
compaction requirements is questionable as determined by the City, testing shall be provided
by the Contractor and a reputable licensed Geotechnical Engineer to verify compliance.
In any area where the pipe will be installed below existing or future ground water levels or
where the trench could be subject to inundation, additional Class I material shall be used for
bedding.
If hydraulic jack shoring is utilized for trench walls, it shall be restricted to the area just above
the top of the pipe. This will ensure the embedment materials and pipe will not be disturbed
when the shoring is removed.
DIP Specific Installation Requirements. Ductile iron pipe shall be installed in accordance
with the requirements of AWWA C600 and the Ductile Iron Pipe Handbook published by
the Ductile Iron Pipe Research Association. Materials at all times shall be handled with
mechanical equipment or in such a manner to protect them from damage. At no time
shall pipe and fittings be dropped or pushed into ditches.
Pipe shall be installed at laying conditions as specified herein and identified by the plan
drawings. Laying conditions for ductile iron pipe shall be as described in AWWA C151
and the Ductile Iron Pipe Research Association. Laying conditions shall be defined as
follows:
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Type 1: Flat Bottom Trench with Pipe Resting on Stable Undisturbed Earth. Unstable
conditions such as wet trench bottoms, intermediate rock layering, partially weathered rock, and other
unsuitable soil conditions shall require utilizing more stringent laying conditions. At a minimum, Type 4
laying condition shall be utilized with a minimum of 4- inches of bedding to overcome unstable conditions.
For severe unstable soil conditions, undercut excavation and an engineer designed foundation plan shall
be provided prior to pipeline installation.
Type 1 •
Type 4: Pipe bedded in Class 1 material, No. 67 or No. 78 crushed stone to a depth of
1/8 pipe diameter or a minimum of 4-inches. Embedment material consisting of Class 1, Class 2 or Class 3
materials shall be compacted to the top of the pipe greater than 95% Proctor. Careful attention must be
allocated to compacting embedment material under the bottom edges of the pipe.
Type 4
Type 5: Pipe bedded in Class 1 material, No. 67 or No. 78 crushed stone to the center of the pipe and
extending a minimum of 4-inches under the pipe. Granular or select embedment, consisting of Class
1 or Class 2 materials, compacted to greater than 95% Proctor installed to the top of the pipe.
Type 5
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PVC Specific Installation Requirements. The installation of PVC Pipe shall satisfy the
requirements of the manufacturer, and/or the following, whichever is more stringent. For PVC
pipe, the pipe shall be produced with bell and spigot end construction. Joining shall be
accomplished by rubber gasket in accordance with manufacturer's recommendation. Flexible
watertight elastomeric seals in accordance with ASTM D3212-1 may also be used. Each pipe
length shall be clearly marked with information including pipe size, profile number and class
number.
Installation of PVC pipe shall follow the recommendations of ASTM D-2321 "Underground
Installation of Thermoplastic Pipe for Sewers and other Gravity -Flow Applications". For PVC
pipe installation, bedding and embedment material shall be Class I, typically No. 67 or No. 78
washed stone. Bedding and embedment materials for PVC gravity sewers other than No. 67
or No. 78 washed stone shall be approved by the City of Goldsboro prior to use.
Typical bedding and embedment for SDR35 PVC Gravity Sewers, 4-ft to 14-ft in depth shall
consist of minimum 4-inches of No. 67 or No. 78 stone installed under the pipe. Embedment
shall extend to the top of the pipe. Bedding and embedment shall be compacted to 95%
standard proctor density. Careful attention shall be placed on compacting embedment under
the haunches of the pipe to prevent any potential voids.
Typical bedding and embedment for SDR26 PVC Gravity Sewers, 14-ft to 20-ft in depth shall
consist of minimum 6-inches of No. 67 or No. 78 stone installed under the pipe. The
embedment, consisting of the same material, shall extend 6-inches above the crown of the
pipe. Bedding and embedment shall be compacted to 95% standard proctor density. Careful
attention shall be placed on compacting embedment under the haunches to prevent any
potential voids.
The bedding and embedment materials shall be in accordance with ASTM D-2321. The
embedment materials shall be installed from trench wall to trench wall. The maximum
allowable deflection after installation shall BE LESS THAN 5% for PVC pipe. All PVC pipe
shall be stored properly to prevent UV damage prior to installation. Any PVC pipe with visible
fading caused by UV radiation from sunlight shall be rejected. All PVC pipe shall be free from
nicks, scratches and gouges at the time of installation. Such defects can impact the strength
of PVC pipe and all pipes with visible gouges shall be rejected.
Pipe Identification and Marking. Marking tape shall be installed continuously and longitudinally
along all sanitary sewer mains for new construction and for any repair or retrofit construction
using open trench methods. For service connections, the marking tape shall extend from the
main line to the cleanout at the right-of-way/easement. Marking tape shall be installed directly
above the center of the pipe and at least 16-inches deep from final grade to a maximum depth
of 24-inches below final grade.
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The marking tape shall be made of polyethylene (or approved equivalent) material, 6-inches
wide and a minimum of 6 millimeters thick. The marking tape shall have detectable markers
embedded in the tape and spaced adequately to provide continuous detection along the tape
from above the buried pipe at final grade. The tape shall be green in color and shall be marked
with words "CAUTION SEWER LINE BURIED BELOW" (or an approved equivalent wording).
The wording shall be repetitive along the full length of the tape.
Manholes
Location Sizing and Design. Manholes shall be spaced at a maximum distance of 400 feet for
lines 12 inches in diameter or less, and 500 feet for lines greater than 12 inches in diameter.
Manholes shall be installed at each deflection of line and/or grade. The flow channel through
manholes shall have a uniform and smooth finish free of irregularities or obstructions. The
invert channel shall conform to the shape and slope of the entering/exiting sewer line. Either
pre -cast or brick and mortar inverts may be used. When sewers of uniform slope pass through
a manhole, the slope shall be maintained and the invert at the center of the manhole shall be
provided. When sewers change slope at a manhole, the incoming and outgoing invert
elevations will be given on the plan drawings.
The maximum flow deflection angle in a manhole shall be dependent upon pipe size as shown
in the following table. Sufficient drop shall be provided in the manhole to compensate for
energy loss caused by the change of alignment. A minimum drop of 0.1-ft is required for a
change of alignment greater than 30-degrees.
Maximum Allowable Flow Deflection
Pipe Size (largest pipe
controls)
Maximum Deflection
Angle per Manhole
8-10 inch diameter
90 degrees
12-20 inch diameter
75 degrees
>20-inch diameter
60 degrees
Free falls of wastewater flow into the manhole invert from incoming sewer mains shall not be
allowed, except under limited circumstances.
In certain isolated circumstances standard free drops may be allowed, not exceeding 20-
inches, when pipe diameter changes occur at a manhole. In these cases, the smaller diameter
pipe crown shall be positioned no higher than the larger diameter pipe crown to limit the drop.
When free drops are necessary due to pipe size changes, the Contractor shall take preventive
measures to prevent free drops into the manhole invert, such as building a flume or trough up
to the incoming invert, or piping the flow to the primary invert flow channel.
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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Drop manholes are not allowed without the written approval of the City of Goldsboro. While
certain physical constraints may dictate the need for drop manholes, they may not be used
merely to decrease trenching depth. Upstream slope changes shall be used to avoid the need
for drop manholes. In the event that drop manholes are required, they shall be constructed
with an outside drop connection. The entire incoming sewer main leading to the drop shall be
made of ductile iron pipe. Drops shall be concrete encased and constructed in accordance
with the Standard Details. Inside drop manholes shall only be allowed in unique circumstances
on a limited basis and can only be approved by the City of Goldsboro.
Manholes shall not be obstructed from view or access. It is illegal to bury or obstruct access
to manholes.
Manhole covers shall be elevated as follows:
• Roadways: Manholes installed in roadways and road shoulders shall be installed with
the cover flush with the top of pavement.
• Outside of Roadways: Manholes installed outside of roadways shall be elevated at least
1-ft above the surface grade unless otherwise noted.
• Wooded Outfalls: All manholes installed in wooded, forested or brushy areas shall be
elevated at least 2-ft above the surface elevation.
• 100-Year Flood Zone: All manholes located within the 100-year flood elevation shall be
elevated at least 24 inches above the 100-year flood elevation or specify watertight
covers and vents that extend at least 24 inches above the 100-year flood elevation.
• Well Maintained Areas: All manholes installed in well maintained areas, such as yards,
sidewalks or otherwise inside an improved right-of-way shall be installed flush with the
finished surface.
Manholes higher than 30 inches above finished grade shall be constructed with a flat top and
outside steps. Manholes shall be provided without interior steps. When connecting a new
sewer main to an existing main, the connection shall be established with a "Doghouse" type of
manhole inserted over the existing main.
Manhole Sizing. Manholes shall be sized as shown in the following table. The next larger size
shall be required if the pipe size, depth, drop connection or number of main line connections
warrants a larger size. In consideration of main line connections, all will be considered
regardless of type, whether inside drop, outside drop, force main or standard connection.
Manhole Sizing Guide
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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Manhole
Size
(diameter)
Maximum
Allowable
Pipe Size
(diameter)
Maximum
Depth of
Cover
(invert to
surface)
Maximum
Depth with
Extended
Base
(invert to
surface)
Frame
and
Cover
Size
(outside
of paved
areas)
(diameter)
Maximum
Sewer Main
Connections
(quantity)
4-ft
8-12
inches
12-ft
25-fte
24-inches
3b
5-ftd
14-24
inches
12-ft
35-ft
24-inches
2°
6-ftd
27-42
inches
12-ft
35-ft
36-inches
2°
8-ftd
48 inches
12-ft
35-ft
36-inches
2°
10-ftd
54 inches
12-ft
35-ft
35-inches
2°
aDepths beyond 14-ft in roadways shall require a 5-ft diameter manhole with
extended base.
bFour connections may be permitted in a 4-ft diameter manhole when the
separation between each incoming connection is at least 85°
°Additional smaller diameter connections that meet the spacing requirements listed
in the Installation section may be approved by the City.
dDue to the limited manhole wall area that could exist between the invert in and out,
some manholes may require upsizing as directed by the City.
All manholes 5-ft in diameter shall be extended to surface elevation with no further reduction
in diameter until the eccentric cone section. Manhole transitions for 6-ft and larger diameter
manholes are only allowed in the top 5-ft of the manhole. In no case shall the smallest barrel
size be Tess than 5-ft diameter. At least 5-ft of vertical clearance shall be maintained above the
pipe crown before transitioning to a smaller diameter riser, or transition shall not be utilized.
An eccentric flat slab reducer from 6-ft diameter or larger manhole base sections to 5-ft
diameter risers (non -paved areas) or eccentric cones (paved areas) shall be used to make any
transition.
Manholes outside of paved areas that are 6-ft in diameter and greater and are too shallow to
maintain 5-ft of vertical clearance above the crown of the pipe shall maintain the full manhole
diameter up to the design surface elevation and be provided with a flat top slab cover with
eccentric hole.
Manholes inside of paved areas that are 6-ft in diameter and greater shall be constructed with
an eccentric, flat top reducer to 5-ft diameter and provided with a 5-ft diameter eccentric,
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tapered cone at the finished grade. When the depth of the manhole is too shallow to maintain
5-ft of vertical clearance above the crown of the pipe a 3-ft tall eccentric, tapered cone shall be
used without any additional 5-ft diameter risers.
Materials
Concrete Manholes. Manholes shall be precast concrete with a minimum compressive
strength of 4000-psi and utilize minimum grade 60 rebar in compliance with ASTM C478. All
4-ft and 5-ft diameter manholes and all 6-ft diameter manholes in paved areas shall be provided
with eccentric cone sections. Flat top manholes are required in outfall areas for 6-ft and larger
diameter manholes.
Precast concrete manholes shall meet all design and manufacturing requirements of ASTM
C478 and all H-20 loading requirements. Minimum wall thickness shall be 5-inches and shall
increase with depth and diameter in accordance with ASTM standards. The standard joint shall
be sealed with a plastic cement putty meeting Federal Specification SS-S-00210, such as Ram-
Nek or a butyl rubber sealant. All lift holes must be plugged with non -shrinking grout after
installation.
All manholes greater than 5-ft diameter shall have minimum 8-inch (6-inch for 4-ft diameter
manholes), 4,000-psi concrete bottoms resting on a minimum of 12 inches of #57 stone. Sewer
mains shall enter and exit radially through the manhole. Inverts shall be constructed with a
width equal to the effluent pipe and a height equal to 1/2 that of the effluent pipe. Inverts shall
be so finished with sufficient drop across the manhole to compensate for all resulting energy
loss across the invert. Flat invert channels shall not be allowed. At each inlet and outlet of 8
inches or greater, resilient connectors or manhole boots shall be provided in conformance with
ASTM C923. Rings and clamps are to meet standards of ASTM A167 and/or ASTM C923.
Precast manhole components shall not be installed, transported, or removed from the casting
yard prior to reaching the minimum compressive strength of 4,000-psi and at least 7 days have
elapsed since casting.
Manhole flat slab, eccentric reducers provided for 6-ft diameter and larger manholes shall be
provided with minimum slab thickness of 12-inches. Flat slab, eccentric reducers shall not be
allowed for manhole diameters less than 6-ft.
Manhole flat top slab covers for outfall manholes 6-ft diameter and greater shall be designed
and, manufactured for H-20 loading and provided in minimum slab thickness of 8-inches.
Manhole flat top covers shall be provided with a minimum clear opening of 36-inches when
utilized with a 36-inch clear span manhole frame and cover.
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Manhole benches shall slope upwards from the spring line of the pipe to the projected level of
the pipe crown at the manhole wall, or 8-inches above the spring line, whichever is less. Bowl
type inverts recessed inside of precast benches shall not be accepted.
Manhole Frame and Cover Materials. Manhole Frames and Covers shall be Class 35 gray iron
with "Sanitary Sewer" forged into the cover. Ring and cover shall be stamped with make and
model. All manhole frames and covers shall be domestically made and manufactured in the
USA from domestic iron.
Types:
• Manhole Frames and Covers in Paved Areas and some Unpaved Areas: For all
installations in roadways or within the right of way, use Type 1 ring and cover, and place
sufficient depth of concrete below the pavement around the ring to ensure contact with
manhole. Type 1 covers shall be provided with 1 vent hole. Type 1 covers shall be
designed for a proof load of 40,000 lbs. and be provided in Class 35B gray iron in
conformance with ASTM A48. At a minimum, Type 1 manhole rings shall weigh 190 lbs.
and the cover shall weigh 120 lbs.
• Manhole Frames and Covers for Outfalls: For installation in outfall areas, with 4-ft and
5-ft diameter manholes use Type 2 ring and covers. Type 2 covers shall not be installed
in areas subject to traffic loading. Type 2 covers shall be provided with an integrated
frame and cover assembly in which the cover rotates away from the frame for access.
The rotating assembly shall be provided with a cast in stainless steel rod assembly.
Type 2 covers shall be provided with a minimum 24-inch clear span opening along the
axis with the stainless steel rod assembly. Security shall be provided by 3 exterior cast
lugs at 3/4-inch thickness that allow padlock installation or bolting with 3 stainless steel
bolts with stainless steel zinc plated nuts. Type 2 covers shall be made of Class 35B
iron in conformance with ASTM A48 and designed for a proof load of 12,000 lbs. The
frame and cover weight shall not be less than 60-Ibs for the cover and 80-lbs for the
ring. The Type 2A frame and cover assembly shall be provided with a gasket that makes
the cover assembly watertight when bolted at all three lugs. Type 2A covers shall be
provided inside the 100-year flood elevation or other areas subject to flooding. Type 2B
covers are not watertight and are not required to have a gasket.
• Manhole Frames and Covers for Large Diameter Outfall Manholes: Type 3 ring and
cover assemblies shall be provided with a minimum 36-inch clear span opening and
utilized for 6-ft diameter or larger manhole installations with eccentric flat top manholes
outside of paved areas. (Within paved areas, use standard Type 1 cover on a 5-ft
diameter eccentric cone.) The type 3 frame and cover shall be provided with a 36-inch
cover with an inset cover of 26-inches in diameter. The frame and cover assembly shall
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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be provided in the watertight configuration in areas within the 100-year flood elevation
or other areas subject to flooding.
All castings shall be machined to give even and continuous bearing on the full length of the
frame. Castings shall be free of porosity and blow holes. All manhole frames shall be bolted
to the manhole, except in paved streets.
Installation
General. The upstream side of the last manhole(s) of a sanitary sewer line extension under
construction shall be plugged by constructing a brick/block wall to prevent the passage of
groundwater, runoff and sediment into the sanitary sewer system. All water upstream of the
wall shall be pumped out of the sanitary sewer line and all sediment and solids shall be removed
and properly disposed of by the Contractor. The wall shall not be removed until the line has
been inspected by the City to ensure that all possible points of inflow or infiltration have been
eliminated.
Manholes shall not be buried or hidden.
All manhole penetrations, whether sewer main or service lateral, shall be cored with a concrete
coring machine. All pipe connections must be made with flexible watertight couplings or boots.
For new manholes, there shall be a minimum of 9-inches or IA the pipe outside diameter (OD),
whichever is greater, between the pipe hole openings. (Pipe hole opening is typically 4" greater
than the pipe OD.) When the adjacent pipes are different sizes, the OD of the smaller pipe
shall be used to determine the spacing requirement, but shall never be less than 9-inches.
For connections to existing manholes, there shall be a minimum of 9-inches or 3.5-inches plus
'A the OD of the existing pipe, whichever is greater, between the pipe hole openings.
All external manhole joints shall be wrapped with an approved joint seal material.
Manholes Subject to Inundation. Manholes subject to flooding shall be watertight and vented
24 inches above the 100-YR flood elevation. In flood prone areas, the manholes shall be
vented at least every 1000-ft or every other manhole, whichever is greater.
The exterior of all manholes within the 100-year flood elevation and in wetland areas shall
receive an exterior coating of an approved bitumastic coal tar epoxy or an approved epoxy
coating at 40-mils to prevent weepage or attack by acidic soils.
Anti -flotation design measures shall be implemented as required in flood prone areas.
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Manholes Located on Large Collection Mains. The City reserves the right to require all
manholes located on interceptor or outfall mains 24-inches in diameter and larger to have the
manhole interior and bench coated with an approved epoxy coating at 80-mils thickness. The
epoxy coating shall be field applied and tested as described herein.
Force Main Discharge Manholes. All manholes located on gravity mains that serve or will serve
as discharge points for sanitary sewer force mains shall receive an interior epoxy coating at
80-mils thickness. In addition to the receiver manhole, the City reserves the right to require
epoxy coating of the next two consecutive manholes downstream of the receiver manhole or
all downstream manholes within 1500-If of the receiver manhole.
Epoxy Coating. Concrete manholes must be well cured prior to application of the protective
epoxy coating. Generally, 28 days is adequate cure time for standard Portland cement. If
earlier application is desired, compressive or tensile strength of the concrete can be tested to
determine if acceptable cure has occurred. (Note: Bond strength of the coating to the concrete
surface is generally limited to the tensile strength of the concrete itself. An Elcometer pull test
to determine suitability of concrete for coating may be required).
Surface preparation shall be based on the requirements of the manufacturer of the epoxy
coating and applicable NACE International standards.
A minimum 80-mils thickness shall be field applied to new manholes (120-mils for existing
manholes). During application a wet film thickness gage, meeting ASTM D4414 -Standard
Practice for Measurement of Wet Film Thickness of Organic Coatings by Notched Gages, shall
be used to ensure a monolithic coating and uniform thickness during application.
Temperature of the surface to be coated should be maintained between 40°F and 120°F during
application. Prior to and during application, care should be taken to avoid exposure of direct
sunlight or other intense heat source to the structure being coated. Where varying surface
temperatures do exist, care should be taken to apply the coating when the temperature is falling
versus rising or in the early morning. The humidity should also be observed to ensure
compliance with the epoxy manufacturers' recommendations.
Manufacturer approved heated plural component spray equipment shall be used in the
application of the specified protective epoxy coating. The spray equipment shall be specifically
designed to accurately ratio and apply the specified protective coating materials and shall be
regularly maintained and in proper working order. If necessary, subsequent top coating or
additional coats of the protective coating should occur as soon as the basecoat becomes tack
free, ideally within 12 hours but no later than the recoat window for the specified products.
Additional surface preparation procedures will be required if this recoat window is exceeded.
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Service Connections
Design. Direct sewer service taps shall not be allowed on sewer interceptor or outfall mains
15-inches in diameter or larger, except by manhole connection. All residential subdivision lots
shall be served by gravity unless otherwise approved. If a pump is approved, it shall be
privately maintained and must pump into either a service connection placed on the lot or
through a private force main to a manhole. The pump and force main (if needed) must have a
note on the recorded plat indicating the following: "Privately maintained sewer pump and force
main is required to serve this lot".
Service connections to the main lines shall be perpendicular to the main line and shall extend
to the edge of the right of way or easement line. Cleanouts are required on all services with a
maximum spacing of 75 feet on 4 inch services and 100 feet on 6 inch services, and at the right
of way line or edge of easement. All cleanouts shall extend a minimum of 6 inches above
finished grade with brass caps or meet the optional cleanout method requirements in
accordance with the Standard Details. Sewer cleanouts located in paved areas, which bear
vehicle loading, must have ductile iron risers, ductile iron fittings and a traffic rated cast iron
cover assembly.
All 6 inch service connections shall be into a manhole. Service lines connected to manholes
shall not be through the cone section or manhole joints. Service lines shall be installed 6"
above, but no more than 30 inches above the invert or shall be installed with a standard drop.
Multiple service connections shall not be maintained by the City. For 6-ft diameter and larger
manholes no service is allowed in the reduced diameter riser sections of the manhole.
The use of in -line wyes for service connections shall be required for all new construction. When
connecting to existing sewer mains, service saddle taps will be allowable. Taps shall be at the
10 or 2 o'clock position, and shall not be top taps.
Service connections to mains at depths of 14-ft and greater shall utilize ductile iron pipe
between the main and the cleanout, including a ductile iron wye for the cleanout stack. Location
and angle of fittings shall be as shown in the standard detail drawings. Where the flood level
rims of plumbing fixtures are below the elevation of the manhole cover of the next upstream
manhole in the public sewer, such fixtures shall be protected by a backwater valve installed in
the building drain, branch of the building drain or horizontal branch serving such fixtures.
Plumbing fixtures having flood level rims above the elevation of the manhole cover of the next
upstream manhole in the public sewer shall not discharge through a backwater valve.
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Pipe Materials
PVC pipe shall be schedule 40 or greater supplied in minimum 18-ft lengths. Schedule 40 PVC
pipe shall be manufactured with a cell classification of 12454 in conformance with ASTM
D1784. Schedule 40 pipes shall be manufactured to dimensional tolerances as specified in
ASTM D1785 and rated for service conditions up to temperatures of 140-degrees Fahrenheit.
The pipe may be joined by solvent weld in conformance with ASTM D2564.
Schedule 40 PVC Service Pipe Sizing
Nominal Pipe
Diameter
(inches)
Outside
Diameter
(inches)
Inside
Diameter
(inches)
Thickness
(inches)
4
4.50
4.02
0.24
6
6.62
6.03
0.28
PVC pipe for sewer services shall require bedding based upon depth as follows:
• 3 to 14-ft Depth — 4-inches of stone bedding extended to springline
• 8 to 20-ft Depth — 6-inches of stone bedding extended 6-inches above pipe crown
Ductile Iron Pipe shall be sued for sanitary sewer services with Tess than 4 fee of cover or in
excess of 20 feet of cover. Ductile iron services shall also be used in all cases where a well is
located within 100-ft of the sewer service line. Ductile iron service piping shall be provided in
conformance with the ductile iron piping standards outlined herein including cement mortar
lining.
DIP Service Pipe Sizing
Nominal Pipe
Diameter
(inches)
Outside
Diameter
(inches)
Inside
Diameter
(inches)
Thickness
(inches)
4
4.80
4.30
0.25
6
6.90
6.40
0.25
Sewer Service Fittings, New Construction
All sewer service connections for new construction shall be provided with in -line wye fittings.
DIP Main with DIP Service. In -line wye fittings for ductile iron main lines joined with ductile iron
service lines shall be typical ductile iron mechanical joint fittings as specified herein. In this
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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case all fitting sizes shall conform to AWWA C153. Wye fittings through 10-inches in diameter
shall be provided with cement mortar lining in accordance with AWWA C104 and provided with
exterior asphaltic coating per AWWA C151. Wye fittings for lines larger than 10-inches in
diameter shall be provided with Protecto 401 lining as specified herein for ductile iron pipe of
the same sizing.
DIP Main with PVC Service. For ductile iron sewer mains to be joined with PVC service lines,
the in -line wye fittings shall be slip joint ductile iron with an IPS sized branch for PVC schedule
40 service lines. Ductile iron fittings for connecting PVC service lines shall be deep bell,
gasketed joint and air test rated. Gasket grooves shall be machined. Bell depths shall meet
the minimum socket depth requirements of ASTM D3034 and ASTM F1336. Wall thickness
shall meet the requirements of AWWA C153. Ductile iron wye fittings through 10-inches in
diameter with IPS connections shall be provided with cement mortar lining in accordance with
AWWA C104 and provided with exterior asphaltic coating per AWWA CI51. Ductile iron wye
fittings for PVC lines larger than 10-inches in diameter shall be provided with Protecto 401
lining as specified herein.
PVC Main with PVC Service. For PVC sewer mains to be joined with PVC service lines, PVC
in -line wye fittings shall be provided. Typical Schedule 40 PVC fittings shall be provided at the
cleanout wye and stack.
PVC Main with DIP Service. A ductile iron tee/wye shall be provided when the service line is
required to be ductile iron due to a crossing or other obstruction. The fitting shall be specifically
manufactured for ASTM 3034 PVC pipe such that a smooth flow way exists on the main line
through the fitting. The branch shall be gasketed to receive the 4-inch DIP service line without
additional fittings. The ductile iron tee/wye fitting shall be Protecto 401 lined.
Service Saddle Connections, Existing Sewer Mains
PVC service saddles shall be of the same material as the main, and shall be solvent welded
and fastened with double stainless steel bands.
For existing DIP main lines, ductile iron service saddles shall be used. The saddle assembly
shall consist of a virgin SBR or NBR gasket compounded for sewer service, a ductile iron
saddle casting, a 304 stainless steel adjustable strap for fastening the gasket and the saddle
casting to the sewer main and a 304 stainless steel adjustable circle clamp for securing the
service line into the rubber gasket.
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Installation
Sewer laterals shall not be located in easements when gravity service can be provided to the
property frontage at the street. Each separately owned structure requires a separate tap to a
public sewer. All service lines with less than 3-ft of cover or deeper than 20-ft shall be made
of ductile iron pipe. Four inch lines shall have a minimum slope of 1.0-ft/100 feet and 6 inch
lines shall have a minimum slope of 0.60-ft/100 feet.
All service connections to existing sanitary sewer mains shall be made by the City. Service
connections to new mains may be made by the Contractor, but shall include the use of wye
(not tee) connections. Saddle taps on to new lines shall not be allowed. Saddle taps into
existing PVC mains shall be made at the 10 o'clock or 2 o'clock position of the main with the
wye saddle angled 45-degrees towards the direction of flow in the main. Taps shall only be
made by a mechanical circular cutting saw providing a smooth and uniform cut for the saddle
installation.
Service connections shall be made using an approved sewer saddle when the existing sewer
line is 8", 10", or 12" in diameter. This service connection shall not be used when the sewer
main material is truss sewer pipe. The opening in the sewer main for the sewer saddle shall
be cut with a hydraulically or pneumatically driven circular tapping saw of the same nominal
diameter as the sewer service line.
Testing and Inspections
The Contractor shall furnish all materials, labor, and equipment to perform all testing. The
Contractor may arrange to obtain water for testing purposes from the City. The Contractor
shall reimburse the City for all water used for construction at current inside utility rates.
Visual Testing and Observation. All materials used must be approved by the City of Goldsboro
prior to installation. Rejected materials shall be immediately removed from the job.
Gravity sanitary sewer lines shall be clean and free from obstructions, and shall be visually
inspected from every manhole. Lines which do not exhibit a true line and grade or which have
structural defects shall be corrected. Sanitary sewer service connections shall be visually
inspected prior to backfilling.
Air Testing. Low-pressure air testing in accordance with ASTM F1417 shall be performed on
all sewer mains before the laterals or stubs are installed on the line, and after the trench has
been backfilled to finished grade. Plugs shall be installed at each manhole to seal off the test
section. The line will be pressurized with a single hose and monitored by a separate hose
connection from the plug. Air then shall be slowly introduced into the sealed line until the
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internal air pressure reaches 4.0 psig. The air pressure shall then be allowed to stabilize for a
minimum of 2 minutes at no Tess than 3.5 psig (plus groundwater pressure, if any). When the
pressure reaches 3.5, the time required for the pressure to drop 1.0 psi will be observed and
recorded. The line shall be "acceptable" if the pressure does not drop more than 1.0 psi in the
time prescribed for the test in the Sanitary Sewer Air Test table found in the Standard Detail
Drawings. An abbreviated version of the air test table is shown below.
Specification Time (min:sec) Required for Pressure Drop From 3-1/2 to 2-1/2 PSIG
Nominal Pipe Diameter (inches)
8
12
15
16
18
21
24
27
30
36
42
Length of Test Section
50
7:33
11:20
14:10
15:11
17:00
19:48
22:40
25:30
28:19
34:00
39:40
100
7:33
11:20
14:10
15:11
17:00
19:48
22:47
28:51
35:37
51:17
69:48
150
7:33
11:20
14:10
15:12
19:14
26:10
34:11
43:16
53:25
76:55
104:42
200
7:33
11:24
17:48
20:16
25:39
34:54
45:35
57:42
71:13
102:36
139:36
250
i 7:33
14:15
22:16
25:20
32:03
43:37
56:58
72:07
89:02
128:12
174:30
300
7:35
17:06
26:43
30:23
38:28
52:21
68:22
86:32
106:48
153:54
209:25
350
8:52
19:57
31:10
35:27
44:52
61:05
79:46
101:00
124:42
179:30
244:19
400
10:07
22:48
35:37
40:31
51:17
69:48
91:10
115:24
142:30
205:06
279:13
450
11:23
25:39
40:04
45:35
57:42
78:31
102:36
129:48
160:18
230:48
314:07
500 1 2:39
28:30
44:31
50:39
64:06
87:15
114:00
144:12
178:06
256:24
349:02
If the section fails to meet these requirements, the source of leakage shall be repaired and the
pipe section re -inspected.
The City may require that an infiltration test be performed that shall not exceed 100
GPD/inch/mile.
Deflection Testing for Flexible Pipe. The mandrel (go/no-go) deflection test shall be performed
on each line prior to acceptance and no sooner than 30 days after installation. The pipeline
shall be thoroughly clean and free of debris and/or sediment prior to testing. The Contractor
shall supply the mandrel used for this performance test. The mandrel device shall be cylindrical
in shape having 9 possible contact points with the pipe. The mandrel's length and diameter
(ID of proving ring) shall be in accordance with the following tables, and shall be subject to the
City's approval.
For flexible pipes such as PVC, the following shall apply:
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Nominal
Diameter
(Inches)
Pipe
Class
Average
Inside
Pipe
Diameter
(inches)
5%
Deflection
Mandrel
Diameter
(inches)
Length
of
Mandrel
(inches)
Minimum
Fins
Included
with
Mandrel
8
SDR 26
7.715
7.329
10
9
8
SDR 35
7.891
7.496
10
9
10
SDR 26
9.644
9.162
10
9
10
SDR 35
9.864
9.371
10
9
12
SDR 26
11.480
10.906
10
9
12
SDR 35
11.737
11.150
10
9
15
SDR 26
14.053
13.350
10
9
15
SDR 35
14.374
13.655
10
9
18
SDR 26
17.261
16.398
24
9
21
SDR 26
20.349
19.332
24
9
24
SDR 26
22.891
21.746
24
9
27
SDR 26
25.799
24.509
24
9
Note: Calculated 5% deflection allowance does not include additional manufacturing tolerances provided
by pipe manufacturers. For purposes of testing, 5% deflection shall be calculated from standard pipe
Inside diameter as published in ASTM D3034 and ASTM F679.
The mandrel shall be advanced through the pipeline to determine if bedding and embedment
has been provided in compliance with ASTM D2321 to assure joint deflection of less than 5%.
If the mandrel becomes obstructed for any reason while being pulled through the line with less
than 100-Ibs of force, the location of the defect shall be noted and the mandrel shall be removed
from the pipeline. Under no circumstances shall heavy equipment be utilized to force the
mandrel through the pipeline. Deflection testing may be done concurrently with sewer
televising inspections, provided the mandrel is kept within visible range of the camera.
Video Assessment and Cleaning. As a final measure required for acceptance, the Contractor
shall clean and televise all newly installed sewer mains prior to acceptance by the City. The
Contractor shall televise the sewer main and all lateral connections installed from the upstream
to downstream manhole with no reverse setups or cutaways. Throughout shooting, the camera
shall be panned and tilted for a complete view of the main. Lighting shall be adequate to view
the entire sewer main and service connections from beginning to end. The video inspection
shall be submitted to the Inspector on a CD and formatted with software compatible and
readable by the City. The City shall not be responsible for purchasing additional software
necessary to view the CD's.
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The camera shall be advanced at a uniform rate not to exceed 20 feet per minute that allows
a full and thorough inspection of the new sewer main. The camera shall be a color, pan and
tilt camera capable of producing a five hundred line resolution picture. Lighting for the camera
shall be sufficient to yield a clear picture of the entire periphery of the pipe. The picture quality
shall be acceptable and sufficient to allow a complete inspection with no lapses in coverage.
The length of the sewer main shall be measured and recorded on the video screen. The
distance counter shall be calibrated before shooting the inspection video.
The Contractor shall clean the sewer mains ahead of video inspection with a high -velocity water
jet. The video inspection shall take place within 2-hours of cleaning operations as witnessed
by the Inspector. All construction debris shall be collected in the downstream manhole and
shall not be released into the sewer system.
The Inspector shall be present throughout the cleaning and televising of the sewer mains to
verify that the video work complies with the Specifications.
Prior to submitting the CD's to the Inspector, the Contractor shall label the CD's with the
following information:
• Name of the Project/Development.
• Name and contact information of responsible party.
• Date of televising.
• Manhole identification as shown on the design plans.
Testing of the marker tape shall be performed by the Contractor at the completion of the project
to assure it is working properly and completely detectable. It is the Contractor's responsibility
to provide the necessary equipment to test the markers. Any defective, missing, or otherwise
non -locatable segments shall be replaced.
Manhole Testing
Vacuum Testing. All newly installed manholes shall pass a vacuum test in accordance with
ASTM C 1244. The Contractor shall supply all equipment and materials necessary to vacuum
test the manholes. Vacuum Testing shall be completed prior to any specified coating and lining
materials being installed. The Inspector shall be present and witness all vacuum testing. The
following vacuum testing criteria shall apply for compliance with the testing procedure:
• A vacuum of 10-inches of mercury shall be drawn with an approved vacuum testing unit.
• The testing time shall not be measured until after the vacuum pump has been shut off.
• The time required for the vacuum to drop from 10-inches to 9-inches of mercury shall
meet or exceed the values listed in the following table.
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Manhole Vacuum Testing Time (seconds)
Depth
(feet)
Manhole Diameter (inches)
48
60
72
8
20
26
33
10
25
33
41
12
30
39
49
14
35
48
57
16
40
52
67
18
45
59
73
20
50
65
81
22
55
72
89
24
59
78
97
26
64
85
105
28
69
91
113
30
74
98
121
Repairs and Modifications
Vitrified Clay Pipe. Replace damaged section with SDR-35 PVC and Shearguard coupling at
each end.
PVC Pipe. Replace damaged section with PVC Pipe and install a Shearguard coupling at each
end.
ABS/PVC Truss Pipe. Replace damaged section with SDR-35 PVC and install a Shearguard
coupling at each end.
Asbestos Cement Pipe. Replace damaged section with SDR-35 PVC and couplings.
All repairs to damaged sanitary sewer lines in paved areas shall be backfilled with ABC stone
(crusher run) to a density of 95 percent Standard Proctor. All repairs to damaged sanitary
sewer lines shall be bedded with 6-inches of washed stone and compacted to a minimum of
95% Standard Proctor density before installing the new joint of ductile iron or PVC pipe.
A detailed pumping and emergency plan shall be required for any sewer line draining event.
All sanitary sewer mains and sewer force mains 20-inches and larger, active, inactive, or
abandoned shall begin to be drained by tapping the bottom half of the pipe. A corporation stop
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AND DETAILS MANUAL
or other valve shall be provided to control flow. All effluent shall be pumped to a downstream
manhole (when available) or other containment tank utilizing continuous piping. The use of a
sump pit on lines 20-inches and larger is not allowed.
In sensitive environmental areas and in other various scenarios the City may require lines Tess
than 20-inches also be tapped in order to be drained.
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SECTION 9 - WATERFO
General
CE MAINS
These Specifications apply to all force mains that are to be owned, operated, and maintained
by the City of Goldsboro. Design of private pump stations and force mains and associated
facilities is not covered by these Specifications or otherwise herein, and the applicant should
look for guidance from other appropriate agencies (NCDENR, NC Plumbing Code, etc.).
All aspects of the design of wastewater force mains, and associated facilities shall, at a
minimum, meet the requirements of the latest version of the NCDENR "Minimum Design
Criteria for the Fast -Track Permitting of Pump Stations and Force Mains". Requirements
presented in the City of Goldsboro Standard Specifications hereunder that are more restrictive
or go above and beyond the requirements of the Minimum Design Criteria are required by the
City of Goldsboro.
All aspects of the design of pump stations, force mains, and associated facilities shall be
submitted for review and approval by the City of Goldsboro.
Wastewater force main interconnections shall be prohibited. All wastewater force mains shall
extend to the nearest gravity sewer or pump station wet well that has sufficient long term
capacity.
Design
Force mains shall be installed with a minimum cover of 4 feet measured from the top of the
pipe to the finished grade.
Force mains shall be installed in dedicated public right of way or in dedicated utility easements
as follows. When wastewater force mains are constructed adjacent to gravity sewer mains or
for construction of parallel wastewater force mains, the minimum horizontal clearance shall be
at minimum 7-ft from pipe edge to pipe edge when the depth of installation is 8-ft or less.
Otherwise, the minimum horizontal separation between pipelines shall be 10-ft up to installation
depth of 10-ft. Clearances for pipelines greater than 10-ft depth shall be designed by Engineer
of Record and approved by the City of Goldsboro. Easement widths outlined below shall be
widened by at least the clearance between the pipelines when constructing a shared gravity
sewer and wastewater force main corridor.
Standard Easement Width for Sewer Force Mains
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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Pipe Size
(diameter)
Pipe Depth (feet)
Easement Width
(feet)
8-inch to 12-inch
10-ft or Tess
20-ft
8-inch to 12-inch
10-ft to 12.5-ft
25-ft
8-inch to 12-inch
12.5-ft to 15-ft
30-ft
8-inch to 12-inch
15-ft to 17.5-ft
35-ft
8-inch to 12-inch
17.5-ft to 20-ft
40-ft
12-inch to 24-inch
15-ft or less
30-ft
12-inch to 24-inch
15-ft to 17.5-ft
35-ft
12-inch to 24-inch
17.5-ft to 20-ft
40-ft
Greater than 24-inch
Any Depth
Specified by the City
Any Size
Deeper than 20-ft
Dedicated easements for force mains and appurtenances shall be recorded as "City of
Goldsboro Utility Easement". City of Goldsboro force main easements shall contain only City
of Goldsboro utilities unless otherwise approved by an encroachment agreement.
Wastewater force main discharge manholes and intermediate air release locations that require
odor control shall be provided with sufficient easement area to accommodate the odor control
systems as designed by the Engineer of Record, whether utilizing passive, forced -air or
chemical treatment for odor control. The maintenance easement for odor control systems shall
be sized based on site specific conditions and shall provide sufficient area for routine
maintenance operations, such as refilling media, chemicals, replacing equipment, etc.
Force mains shall discharge at the invert of the receiving manhole and shall be as close as
possible to 180 degrees from the outlet pipe.
Force main design shall facilitate cleaning and inspection. The use of 90 degree bends is
prohibited.
Force mains shall be constructed with a pigging/bypass connection located within 50-ft of the
pump station valve vault.
Force main minimum design velocity shall not be Tess than 2-ft per second throughout the
length of the force main. As a design preference, force main systems when operating at higher
flows shall reach velocities of 3 to 5 ft/s to re -suspend any settled solids.
Force main systems shall be of adequate sizing and design to effectively convey the ultimate
peak flows as applied by the connected pump station to the discharge point.
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The force main route shall be such that the number of high points requiring combination air
valves is minimized to the extent possible. Combination Air Valves rated for use with raw
wastewater shall be installed at all the high points or runs exceeding 3000-ft on all force mains
in accordance with the Standard Details. A high point shall be determined as any location
where the vertical separation between the adjacent low point and high point in the force main
is greater than or equal to 10 vertical feet.
All valves and fittings shall be restrained. Pipe joints shall also be restrained an adequate
length away from valves and fittings in accordance with AWWA manual M41 (or the latest
edition of Thrust Restraint Design for Ductile Iron Pipe as published by the Ductile Iron Pipe
Research Association). In all cases, there must be a pipe restraint plan with the method of
restraint to be used and the length of pipe to be restrained clearly identified on the plans at all
necessary locations. The pipe restraint plan shall be included under the design responsibility
of the NC Professional Engineer sealing the plan drawings.
• Pipe Joints: The standard joint restraint method shall be to use manufacturer provided
restrained joint pipe. Pipe up to and including 12-inches in diameter may also utilize
either mechanical joint pipe with approved wedge action retainer glands (for the
specified distance) or reaction blocking at fittings as an altemative. All joint restraint
products that include the means of restraint within the joint gasket shall be prohibited.
• Valves: Valves shall be restrained in a manner consistent with operation as a dead end.
This includes restraining the valve to the pipe and restraining a sufficient number of pipe
joints on both sides of the valve to accommodate dead end restraint.
A plug valve shall be installed at least every 3000 feet of force main length.
All air release valves, plug valves greater than 12-inches, or other appurtenances that have
moving or operating parts and require maintenance and routine access shall have a manhole
placed over them or over the operating portion of the device.
Separation between Sewer Force Main and Storm Water Pipes: Sewer force mains shall have
a minimum vertical separation of 24 inches between storm pipes when the horizontal
separation is 3 feet or less. Where sanitary and storm sewers cross with a vertical separation
of less than 24 inches, the entire leg of sanitary sewer shall be made of standard ductile iron
pipe with joints rated for water main service and the void space between the pipe crossing shall
be backfilled with 3000-psi concrete or minimum 500-psi, quick setting, non-excavatable
flowable fill that meets or exceeds NCDOT Specifications.
Separation between Sanitary Sewer and Sewer Force Main: There shall be a minimum 7 foot
horizontal separation between parallel gravity and/or force mains in outfall locations when the
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CITY OF GOLSDBORO ENGINEERING DEPARTMENT SPECIFICATIONS
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depth of installation is 8-ft or less. Otherwise, the minimum horizontal separation between
pipelines shall be 10-ft in outfalls.
Separation between Sewer Force Main and Water Main: Parallel Installations: 10-ft lateral
separation (pipe edge to pipe edge) or minimum 3-ft lateral separation, and water line at least
18-inches above sewer force main measured vertically from top of sewer pipeline to bottom
edge of water main. In unique cases where the sewer force main and the water main are
installed with at least 3-ft of lateral separation but less than 10-ft of horizontal separation, and
less than 18-inches of vertical separation, both the water main and sewer force main shall be
constructed of ductile iron pipe with joints in full compliance with water main standards.
Crossings (Water Main over Sewer Force Main): All water main crossings of sewer force mains
shall be constructed in conformance with City of Goldsboro Specifications. At a minimum, 18-
inches of clearance shall be maintained between the bottom edge of the water main and the
top edge of the sewer force main. If 18-inches of clearance is not maintained, the water main
and sewer force main shall both be constructed of ductile iron pipe with joints in conformance
with water main construction standards. The ductile iron sewer force main shall extend 10-ft
on both sides of the crossing. When the separation between pipelines is 18-inches or less, the
void space between the pipes shall be filled with minimum 500-psi, quick setting, and non-
excavatable flowable fill extending 3-ft on both sides of the crossing. Regardless of pipe
material, at least 12-inches of vertical separation is required for sewer force main crossings of
potable water mains.
Crossings (Water Main under Sewer Force Main): Allowed only as approved by City of
Goldsboro, when it is not possible to cross the water main above the sewer force main. At a
minimum, 18-inches of separation shall be maintained, (measured from pipe edge to pipe edge)
and both the water main and sewer force main shall be constructed of ductile iron in
conformance with water main construction standards to a minimum of 10-ft on both sides of
the crossing. If local conditions prevent providing 18-inches of clearance, then at least 12-
inches of clearance shall be provided and the void space between the pipes shall be filled with
minimum 500-psi, quick setting, and non-excavatable flowable fill extending at least 3-ft on
both sides of the crossing. In all cases the water main pipe shall be centered at the point of
crossing with joints equally spaced from the point of crossing.
Sanitary Sewer Force Main and Stream Crossings: The top of the sewer force main shall be
at least one foot below the stream bed. Concrete encasement and ductile iron pipe shall be
required when the cover between the top of the pipe and the stream bed is Tess than 3 feet.
Sewer force mains shall not be installed under any part of water impoundments.
The following minimum horizontal separations shall be maintained:
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• 100 feet from any private or public water supply source, including wells, WS-1 waters or
Class I or Class II impounded reservoirs used as a source of drinking water (except as
noted below)
• 50 feet from any waters (from normal high water) classified WS-II, WS-III, B, SA, ORW,
HQW or SB (except as noted below)
• 10 feet from any other stream, lake, or impoundment (except as noted below)
• 25 feet from private wells (with no exceptions)
• 50 feet from sources of public water supply (with no exceptions)
Where the required minimum separations cannot be obtained, ductile iron sewer force main
pipe with joints equivalent to water main standards shall be used.
Materials
Pipe Materials: The minimum wastewater force main size shall be 4-inches in diameter. SDR-
35 PVC or ductile iron pipe shall be required for all wastewater force mains. SDR-35 PVC or
ductile iron pipe shall be designed and manufactured in accordance with AWWA C150 and
C151 and provided in nominal 20-ft lengths. The minimum requirements for ductile iron pipe
and required laying conditions are tabulated below. For all other installations other than
specified, the laying condition, bedding requirements or the minimum pressure class rating
and/or thickness class shall be increased in accordance with AWWA C151. A pipe thickness
design shall be submitted for extemal loading in all cases where the pipe depth exceeds the
specified range of depths outlined in the following table.
Pressure Class, Max. Depth and Laying Condition for DI Wastewater Force
Mains
Pipe Diameter
AWWA C-150,
Laying Condition
Pressure Class
Maximum Depth
of Cover
4 to 8 inch
type 1
350 psi
3-16 feet
4 to 8 inch
type 4
350 psi
16-20 feet
10 to 12 inch
type 1
350 psi
3-10 feet.
10 to 12 inch
type 4
350 psi
10-20 feet
14 to 20 inch
type 4
350 psi
3-28 feet
24 inch
type 4
350 psi
3-25 feet
Note: For cases not specified, a ductile iron pipe and bedding design certified by a Professional
Engineer licensed in the State of North Carolina shall be required in compliance with AWWA
C150 and the Ductile Iron Pipe Research Association.
All pipe shall be marked in conformance with ASTM A-746.
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All ductile iron wastewater force mains and fittings for sewer construction shall receive an
interior ceramic epoxy coating, consisting of an amine cured novalac epoxy containing at least
20% by volume of ceramic quartz pigment, as manufactured by Protecto 401. The interior
coating shall be applied at a nominal dry film interior thickness of 40-mils. All DIP bells and
spigots shall be lined with 8-mils of Protecto 401 joint compound applied by brush to ensure
full coverage. All pipe supplied with Protecto 401 interior lining shall be provided free of
holidays. Pipe installed with defects in the lining will be rejected. Patching of Protecto 401
coating defects after installation shall not be approved. Protecto 401 Tined pipe must be
installed within one year of the application date on the pipe.
Pipe fittings shall be made of ductile iron designed and manufactured per AWWA C110 or
C153. All fittings up to and including 24 inches in diameter shall be designed for a minimum
internal pressure of 350 psi, unless otherwise approved by the City of Goldsboro. Fittings shall
be mechanical joint or proprietary manufacturer provided restrained joint. Gaskets shall be in
accordance with AWWA C111. All fittings shall be interior coated with Protecto 401 as specified
herein for ductile iron pipe.
Restrained Joint Ductile Iron Pipe shall be the boltless type unless otherwise approved. For
installations requiring welded locking rings, the rings shall be factory welded. The restrained
joints shall provide a minimum of 4-degrees of deflection for pipe sizes, 4-inches through 12-
inches in diameter. All proprietary pipe restraint systems shall be approved by the City of
Goldsboro and provided in compliance with all standards for coatings, linings, pressure
classes, etc. as required for ductile iron pipe. All restrained joint pipe shall be installed based
on laying conditions, pressure class, etc. as required for typical ductile iron pipe.
Manhole Materials: All sewer force main manholes shall be installed according to the City of
Goldsboro Standard Specifications when design and installation criteria are not otherwise
covered herein.
All force main discharge locations and other manholes for wastewater force mains (excluding
those housing large diameter plug valves) shall be epoxy coated at minimum 80-mils thickness.
Sewer force main receiver manholes, sewer force main combination air valve manholes and
other concrete structures subject to high levels of hydrogen sulfide gas shall be provided with
an approved monolithic epoxy coating system consisting of a 100% solids, solvent -free, two -
component epoxy resin that meets the following Specifications for up to 100 mils of coating
with a manufacturer approved set time of 6-hours or Tess.
Force Main Receiver Manholes: Sewer force mains shall not discharge directly into existing
gravity sewer lines. Sewer force mains shall typically discharge into a receiver manhole that
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has been epoxy coated as specified herein. The receiver manhole shall be provided in the
typical eccentric tapered design at minimum 5-ft diameter. The bench shall be sloped up to 8-
inches from the invert channel to the manhole wall. The invert shall be provided with a gradual
up sloping alignment from the force main entry to the gravity transition point. Sufficient grade
shall be placed on the invert such that wastewater falls back into the force main when the
pumps are not in operation creating a vapor lock between the force main and the manhole.
Drop connections into force main receiver manholes shall be prohibited.
Combination Air Valve Manholes: Manholes for combination air valve installation shall be
provided in flat top configuration to accommodate the excess length of wastewater combination
air valves. In cases where the combination air valve assembly shall be located in a paved
area, provide typical eccentric, tapered manhole design with typical manhole frame and cover
for paved areas. The minimum manhole diameter for combination air valve assemblies shall
be 5-ft. Minimum 6-ft diameter manholes shall be used with force mains 20-inches and larger
and when an odor control system is required. Any manholes located in NCDOT or street right-
of-way shall be provided flush with finished grade.
Installation
General. Ductile iron pipe shall be installed in accordance with the requirements of AWWA
C600 and the Ductile Iron Pipe Handbook published by the Ductile Iron Pipe Research
Association. Materials at all times shall be handled with mechanical equipment or in such a
manner to protect them from damage. At no time shall pipe and fittings be dropped or pushed
into ditches.
Pipe trench excavation and backfilling shall be performed in accordance with these
Specifications.
Pipe and fitting interiors shall be protected from foreign matter and shall be inspected for
damage and defects prior to installation. In the event foreign matter is present in pipe and
fittings, it shall be removed before installation. Open ends of pipe shall be plugged or capped
when pipe laying is not in progress.
All pipe shall be constructed with at least 48 inches of cover below the finished surface grade.
Pipe shall be laid on true lines as directed by the Engineer. The wastewater force main shall
be installed at a grade which will allow air to migrate to a high point where the air can be
released through an air valve. A minimum pipe slope of 1 foot in 500 feet should be maintained
and there shall be no intermediate high points in the line.
Trenches shall be sufficiently wide to adjust the alignment. Bell holes shall be dug at each joint
to permit proper joint assembly. The pipe shall be laid and adjusted so that the alignment with
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the next succeeding joint will be centered in the joint and the entire pipeline will be in continuous
alignment both horizontally and vertically. Pipe joints shall be fitted so that a thoroughly
watertight joint will result. All joints will be made in conformance with the manufacturer's
recommendations for the type of joint selected. All transition joints between different types of
pipe shall be made with transition couplings approved on shop drawings showing the complete
assembly to scale.
Embedment Material. Bedding and embedment material classifications shall be defined as
follows:
• CLASS I - Angular, (1/4 to 1-1/2 inch) graded stone, including a number of fill materials
that have regional significance such as coral, slag, cinders, crushed stone, crushed
gravel, and crushed shells.
• CLASS II - Coarse sands and gravels with maximum particle size of 1-1/2 inch, including
variously graded sands and gravels containing small percentages of fines, generally
granular and non -cohesive, either wet or dry. Soil types GW, GP, SW and SP are
included in this class.
• CLASS III - Fine sand and clayey gravels, including fine sands, sand -clay mixtures, and
gravel -clay mixtures, Soil Types GM, GC, SM, and SC are included in this class.
• CLASS IV - Silt, silty clays, and clays, including inorganic clays and silts of medium to
high plasticity and liquid limits. Soil Types MH, ML, CH and CL are included in this class.
These materials shall not be used for embedment.
Class I foundation material consisting of'/ -inch to 11/2-inch graded stone shall be required in
addition to standard bedding and embedment for all sewer installations, regardless of pipe
material, when the trench bottom is unstable due to water, rock, infiltration or soil type.
All bedding, embedment and backfill materials shall be compacted to a minimum of 95%
Standard Proctor density regardless of material. In instances where compliance with
compaction requirements is questionable as determined by the Inspector, testing shall be
provided by the Contractor and a reputable licensed Geotechnical Engineer to verify
compliance.
The minimum trench width shall be one pipe diameter plus 9 inches on each side of the pipe
as described in these Specifications.
In any area where the pipe will be installed below existing or future ground water levels or
where the trench could be subject to inundation, additional Class I material shall be used for
bedding.
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If hydraulic jack shoring is utilized for trench walls, it shall be restricted to the area just above
the top of the pipe. This will ensure the embedment materials and pipe will not be disturbed
when the shoring is removed.
Laying Conditions. Pipe shall be installed at laying conditions as specified by the plans. Laying
conditions for ductile iron pipe shall be as described in AWWA C151 and the Ductile Iron Pipe
Research Association. Laying conditions shall be defined as follows:
Type 1: Flat Bottom Trench with Pipe Resting on Stable Undisturbed Earth. Unstable
conditions such as wet trench bottoms, intermediate rock layering, partially weathered rock,
and other unsuitable soil conditions shall require utilizing more stringent laying conditions. At
a minimum, Type 4 laying condition shall be utilized with a minimum of 4-inches of bedding to
overcome unstable conditions. For severe unstable soil conditions, undercut excavation and
an engineer designed foundation plan shall be provided prior to pipeline installation
i
Type 1 w
Type 4: Pipe bedded in Class 1 material, No. 67 or No. 78 crushed stone to a depth of 1/8 pipe
diameter or a minimum of 4-inches. Embedment material, consisting of Class 1, Class 2 or
Class 3 materials, shall be compacted greater than 95% Proctor to the top of the pipe. Careful
attention must be allocated to compacting embedment material under the bottom edges of the
pipe.
Type 4
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Type 5: Pipe bedded in Class 1 material, No. 67 or No. 78 crushed stone to the center of the
pipe and extending a minimum of 4-inches under the pipe. Granular or select embedment,
consisting of Class 1 or Class 2 materials, compacted to greater than 95% Proctor installed to
the top of the pipe.
Type 5
Installation Below the Water Table. For installations below the water table, a single layer of
engineering fabric shall be installed between the pipe and trench floor/trench wall. The fabric
shall fully encapsulate the force main, bedding, and embedment material with a minimum of
12-inch overlap at the top of the embedment material.
Utility Coordination. Prior to beginning construction, the Contractor shall contact local utility
companies and verify the location of existing utilities. The Contractor shall be completely and
solely responsible for locating all existing buried utilities inside the construction zone before
beginning excavation. The Contractor shall be solely responsible for scheduling and
coordinating the utility location work. When an existing utility is in conflict with construction, it
shall be exposed prior to beginning construction to prevent damage to the existing utility.
Marking Tape. Marking tape shall be installed continuously and longitudinally along all_sewer
force mains for new construction and for any repair or retrofit_construction using open trench
methods. Marking tape shall be installed directly above the center of the pipe and at least 16-
inches_deep from final grade to a maximum depth of 24-inches below final grade.
The marking tape shall be made of polyethylene (or approved equivalent) material, 6-inches
wide and a minimum of 6 millimeters thick. The marking tape shall have detectable markers
embedded in the tape and spaced adequately to provide continuous detection along the tape
from above the buried pipe at final grade. The tape shall be green in color and shall be marked
with words that read "CAUTION SEWER LINE BURIED BELOW" (or an approved equivalent
wording). The wording shall be repetitive along the full length of the tape.
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Valves and Appurtenances
The rated working pressure of all valves and appurtenances shall meet the maximum design
pressure of the pump station and pipeline.
Check Valve: Check valves shall be iron bodied, fully bronze mounted with bronze clapper
disc and bronze seat ring, and shall have a spring loaded lever arm capable of being mounted
on either side of the valve.
Plug Valve: Plug valves shall be non -lubricating, eccentric action and resilient plug facing with
heavy duty Type 316 stainless steel bearings. Plug valves shall be designed for a minimum
working pressure of 175 psi for valves 12 inches and smaller, 150 psi for valves 14 inches and
larger. Valves shall be bi-directional and meet the pressure rating in both directions of flow.
The plug valve body shall be cast iron ASTM A126 Class B with welded -in overlay of 90%
nickel alloy content on all surfaces contacting the face of the plug. Sprayed, plated, nickel
welded rings or seats screwed into the body are not acceptable.
All plug valves 12 inches and smaller shall have round port design that provides a minimum
80% port area. The valve plug shall be ductile iron ASTM A536 Grade 65-45-12 up to 20-
inches in diameter, with EPDM, Buna N, or Neoprene resilient seating surface to mate with the
body seat. Valves 24-inches and larger may have plugs made of cast iron in accordance with
ASTM A126 class B. Large plug valves with rectangular plugs shall provide clean passage for
a solid sphere of at least 67% of the adjoining pipe diameter to facilitate pigging of the force
main. Force main plug valves with rectangular port shall be "full -port" cross -sectional area
perpendicular to the flow of at least 100% of the adjoining pipe.
All buried plug valves shall be provided with worm gear actuators. All plug valves shall be
buried and provided with a 2-inch operator nut and valve box as shown in the details. Plug
valves greater than 12-inches shall be installed such that the actuator and gearing is accessible
in a manhole as shown in the details. All plug valves shall be provided with typical mechanical
joint end connections and restrained with wedge action retainer glands on both ends of the
valve assembly as described herein.
Valves shall be installed according to the manufacturer's recommendations. Typically for
wastewater this means installing the seat side toward the pump station so that the flow is
against the face of the plug in the closed position. In the open position, the plug should rotate
up to the top of the pipeline which may require installing the valve on its side.
Rubber Seated Ball Valve: For larger diameter force mains where plug valves are not available,
rubber seated ball valves shall be of the tight -closing, shaft -mounted type that fully comply with
AWWA Standard C507 to provide a full port unobstructed waterway with no additional pressure
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drop. Design pressure ratings shall be 150 psi or greater and provide tight shutoff against flow.
With the valve in the closed position, the rubber seated valve shall be bubble tight at rated
pressure. All ball valves shall be provided in an epoxy coated manhole with worm gear
actuators and a handwheel.
Valve Box Covers: Force main plug valves or ball valves shall have valve box covers and/or
manhole lids with the word "Sewer" cast into them.
Combination Air Valves: Combination Air Valves shall be provided to purge air from the system
at startup, vent small pockets of air while the system is being pressurized and running, and
prevent critical vacuum conditions during draining. Combination air valves approved for use in
wastewater force main installations shall be installed at all high points of wastewater force
mains 6 inches in diameter or larger and at other locations, such as major changes in slope,
as directed by the City. A high point shall be determined as any high location where the
difference between the high elevation and adjacent low elevation exceeds 10-ft unless
otherwise determined by the City based on special circumstances. The combination air valve
shall automatically exhaust large volumes of air from the system when it is being filled and
allow air to re-enter the pipe when the system is being drained. The wastewater force main
shall be installed at a continuous grade between low and high points without intermediate high
points unless an air release valve is being installed. A minimum pipe slope of 1 foot in 500 feet
should be maintained. Combination air valves shall be sized by the Engineer and approved by
the City.
• Combination air valves shall be of the single housing style with Type 304 or 316 stainless
steel body that combines the operation of both an air/vacuum and air release valve. The
valve must meet the requirements of AWWA C512 and be installed in accordance with
the Details. The valve shall have a minimum 145-psi working pressure unless the
pipeline design requires a higher pressure rating.
• The valve shall have a minimum 2-inch male NPT inlet for a 2-inch valve assembly.
Combination air valves sized from 3-inches to 8-inches shall be provided with studded
inlet connectors or flanged connections. The combination air valve shall be provided
with cylindrical shaped floats and anti -shock orifice made of high density polyethylene.
Combination air valves with spherical floats shall not be accepted. All combination air
valves shall be installed in accordance with the Details.
• Installation of Combination Air Valve Assembly:
o The Engineer of Record shall provide ample depth of installation to accommodate
the extended height of combination air valves for wastewater force mains. All
combination air valves shall be connected to the main by an MJ x FLG tee with
the branch diameter equal to at least half of the main diameter.
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o The 2-inch combination air valve shall be provided with male NPT threads and
isolated with a 2-inch gate valve. The isolation valve shall be provided with NPT
threads and connected with brass or bronze piping.
o Combination air valves 3-inches and greater shall be connected by flange or
studs. If needed due to a larger diameter tee, a flanged reducer shall be provided
between the tee and the isolation valve. Gate valves shall be used for 3-inch
assemblies. Combination air valves 4-inches and larger shall be isolated with a
plug valve. In all cases the isolation valve shall be sized equal to the combination
air valve.
Pigging Station: Force mains shall be constructed with a pigging/bypass connection located
within 50-ft of the pump station valve vault. This pigging leg shall consist entirely of Protecto
401 coated ductile iron pipe of the same diameter as the main. A restrained MJ wye shall be
provided in the main line and valved on each branch. The pigging leg shall extend out of the
ground and be closed with a blind flange. The protruding pipe shall be protected by concrete
bollards spaced 6-ft apart.
Bypass Connection Assembly: On some wastewater force mains, an additional bypass
connection assembly may be required. The size, criticality and proximity to a downstream
manhole will be important factors in the need for this connection. The bypass assembly shall
include either a ball valve or plug valve assembly for isolation from the primary wastewater
force main. Additionally, the primary force main shall be provided with a main line plug valve
or ball valve on the upstream side of the bypass assembly to prevent bypass flow from draining
back to the pump station. The bypass assembly shall be brought to the final graded surface
with a visible blind flange assembly for connection by an outside pumping contractor.
Force Main Odor Control Systems: Force main odor control shall be included in the design
plans for any proposed force main at discharge locations, intermediate air release locations
and otherwise as directed by the City. In limited cases, air release valves located in isolated
areas may be approved without odor control systems. The suggested odor control technology
shall be designed by the Engineer of Record to achieve 95% or greater hydrogen sulfide
removal. All systems, including those utilizing activated carbon, shall be manufactured
specifically for addressing hydrogen sulfide gas. Forced air systems should be avoided due to
the need to include provisions for electrical power to the odor control system. For all odor
control systems, the Engineer of Record shall provide sufficient easement area for long term
maintenance of the system.
Inspections
All materials and equipment used in the construction of the wastewater pumping system must
be verified for compliance with the Specifications (or other approval granted by the City) by the
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Inspector prior to installation. Non -conforming materials or equipment shall be immediately
removed from the job site. Compliance with plans and Specifications shall be verified on a
regular basis by the Inspector.
Testing
The Contractor shall fumish all materials, labor, and equipment to perform all testing. Water
for testing purposes may be obtained from the City. The Contractor shall reimburse the City
for all water used at Inside Utility Rates.
All water or wastewater used during testing of the pump station, force main, or any of the
systems described in this section, must be returned to the City of Goldsboro sanitary sewer
system after proper coordination with the City.
All on -site testing and/or installation verification shall be performed in the presence of the
Inspector or other representative authorized by the City.
The force main shall be completely filled with water, all air shall be expelled from the pipe, and
the discharge end of the pipeline shall be plugged and adequately blocked before the
hydrostatic test begins.
The force main shall be tested to a pressure of 100 psi or three times the rated Total Dynamic
Head of the pumps in psi, whichever is larger, as measured at the lowest elevation of the
pipeline, for a duration of 2 hours. The pressure gauge used in the hydrostatic test shall be
calibrated in increments of 5 psi or less. At the end of the test period, the leakage shall be
measured with an accurate water meter.
All leaks shall be located and repaired regardless of the amount of leakage. If the force main
does not pass the leakage test requirements, the cause of the failure shall be identified and
repaired. Testing shall be repeated until the force main passes.
Allowable Leakage, L= S x D x V(P)
133,200
Where: L = leakage (gph)
S = length of pipe (feet)
D = nominal diameter of pipe segment tested (inches)
P = test pressure (pounds per square inch)
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Testing of the tracer wire and marker tape shall be performed by the Contractor at the
completion of the project to assure they are all working properly. It is the Contractor's
responsibility to provide the necessary equipment to test. Any defective, missing, or otherwise
non -locatable units shall be replaced.
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