[Ord. No. 1042 §3-1, 2-20-1992]
[Ord. No. 1042 §3-2, 2-20-1992; Ord. No. 1543 §1, 11-6-2006]
A.
All installations shall be made in accordance with AWWA C600, APWA
Section 2900 as modified by the City's Technical Specifications and
Design Criteria for Utility and Street Construction, and with any
special applicable supplementary instructions issued by the manufacturers
of the equipment being installed. Pertinent parts of AWWA Standards
C600 and APWA Section 2900 as modified by the City's Technical Specifications
and Design Criteria for Utility and Street Construction shall also
be applicable along with manufacturer's instructions for installation
of other pipe material specified by the department.
[Ord. No. 1915, 7-16-2018]
B.
All
fittings six (6) inch size or larger shall be installed with suitable
concrete thrust blocks poured in place with the concrete deposited
against firm, undisturbed earth. All hydrants shall be installed with
suitable concrete thrust block or restrained joint connections.
C.
Mains
shall be laid on a loop or grid system with cross mains spaced not
more than one thousand (1,000) feet apart and with no dead-end lengths
exceeding three hundred (300) feet. Not more than one (1) fire hydrant
shall be located on any eight (8) inch dead-end main.
D.
The
horizontal distance between paralleling water mains and existing or
projected sewers shall not be less than ten (10) feet, except where
the water main is located at a higher elevation (one (1) foot minimum
from top of sewer to bottom of water main) than the top of the sewer,
in which case a minimum horizontal distance of six (6) feet will be
permissible.
E.
All
mains shall be laid with a minimum cover of forty-two (42) inches
from top of pipe to finished ground surface grade, except that at
obstructions which cannot be relocated or modified, the cover may
be reduced as necessary for short lengths (ten (10) to twenty (20)
feet) to pass over said obstruction using three (3) flexible joints
in the offset within a length of approximately eight (8) feet, but
in no case shall depth of cover be less than thirty (30) inches. Approved
bedding material shall be used wherever cover is less than forty-two
(42) inches and shall completely encase pipe. No tees, valves or house
service corporation cocks shall be installed in mains with less than
forty-two (42) inches of cover.
F.
Where
depth of cover would be less than thirty (30) inches over top of pipe
at obstruction, the water main shall pass under the obstruction clearing
the obstruction at least one (1) foot and completely encased up to
bottom of obstruction in concrete with not less than six (6) inches
of concrete on bottom and sides.
G.
Limiting Trench Width. Trenches shall be excavated to a
width which will provide adequate working space and pipe clearances
for proper pipe installation, jointing and embedment. However, the
limiting trench widths below an elevation six (6) inches (fifteen
(15) cm) above the top of the installed pipe shall be as follows:
|
Ductile - Iron Pipe
| |||
|---|---|---|---|
|
Pipe Size
|
Minimum Trench Width in Earth
|
Maximum Trench Width in Earth
|
Minimum Clearance in Rock
|
|
4" (100 mm)
|
18" (45 cm)
|
30" (75 cm)
|
6" (15 cm)
|
|
6" (150 mm)
|
24" (60 cm)
|
30" (75 cm)
|
6" (15 cm)
|
|
8" (200 mm)
|
26" (65 cm)
|
32" (80 cm)
|
6" (15 cm)
|
|
10" (250 mm)
|
28" (70 cm)
|
34" (85 cm)
|
6" (15 cm)
|
|
12" (300 mm)
|
28" (70 cm)
|
34" (85 cm)
|
6" (15 cm)
|
|
Where necessary to reduce earth load on trench banks to prevent
sliding and caving, banks may be cut back on slopes which shall not
extend lower than one (1) foot (thirty (30) cm) above the top of the
pipe.
|
H.
Pipe
installed in earth, rock or rock bottom trenches shall be excavated
to a grade six (6) inches below bottom of pipe in rock and four (4)
inches below bottom of pipe in earth and bedded with approved bedding
material, graded to provide a uniform support of each length of pipe
with material depression provided at joints. Protective earth backfill
or bedding material shall continue to twelve (12) inches above top
of pipe.
I.
Bedding
material shall be crushed stone or gravel with at least ninety-five
percent (95%) passing one-half (½) inch sieve and at least
ninety-five percent (95%) retained on a No. 4 sieve. It shall be sound
material with not more than fifteen percent (15%) loss after five
(5) cycles when tested with sodium sulfate as described in AASHTO
T104.
J.
All
material used for backfilling of trenches shall be free of excessive
amounts of deleterious materials such as all organic matter, frozen
clods and sticky masses of clay and gumbo which are difficult to properly
compact. Any rock materials used for backfill shall be no larger than
four (4) inches in greatest dimension and shall not be placed within
twelve (12) inches of the installed pipe in any direction, including
under, around and on top of the pipe. The pipe shall be embedded in
a good quality earth or approved bedding material.
1.
Backfill shall be placed in six (6) inch layers from the bottom of
the trench to a point at least twelve (12) inches above the top of
the pipe. Above this point, backfill shall be deposited in layers
of a thickness which will permit compaction to a density as specified
hereinafter.
2.
Wherever pipe is installed in open fields or areas which carry no
vehicular traffic, the remaining trench shall be filled with backfill
compacted to prevent significant future settlement and slightly humped
to provide for future settlement. The top portion of the backfill
areas which are to be seeded or resodded shall be composed of topsoil
at least six (6) inches in depth.
3.
The layers of material shall be compacted to a density of at least
ninety-five percent (95%) of the maximum density at optimum moisture
content as determined by the AASHO T99 under all pavements, shoulders
and areas for future pavements. Pavement shall not be restored over
trenches until the backfill material has been tested and determined
as satisfactory according to the tests.
4.
Back slopes, berms, median strips and yards shall be compacted to
a density of at least ninety percent (90%) of the maximum density
at optimum moisture conditions.
K.
All
mains, branches and dead ends shall be equipped with blowoffs and/or
hydrants of adequate size and number to develop a velocity in the
main of at least two and one-half (2½) feet per second. Branches
of five (5) feet in length or less from tee or cross to valve, or
blind flange or plug need not be equipped with a blowoff provided
a tablet of chlorine releasing compound is installed and fixed in
place in the branch during construction. All lines shall be thoroughly
flushed through the blowoffs and/or hydrants provided immediately
prior to testing for final acceptance by the department. Water used
will be provided by the department at no charge to the developer or
contractor installing the main.
[Ord. No. 1042 §3-3, 2-20-1992]
A.
Corporation
cocks shall be provided for disinfection by the installing contractor
at locations designated by the department. The department will monitor
the chlorination of the lines and test their cleanliness before permitting
connections for service. The disinfection will be done by the contractor
according to APWA Section 2902.9. The department will take samples
for bacteriological testing after chlorination and flushing, prior
to the water line being placed in service.
1.
After installation, the entire main shall be flushed and disinfected
by chlorination. Flushing shall be carried out until a turbidity-free
water is obtained from all points along the main.
2.
Chlorination by the contractor shall conform to AWWA C601 and be
performed using a one percent (1%) chlorine solution prepared from
granular calcium hypochlorite (one (1) pound (0.45 kg) of HTH per
eight (8) gallons (30.3 litre) of water). Water entering the new main
shall receive a dose of the chlorine solution fed at a constant rate
such that the water will have not less than twenty-five (25) mg/l
free chlorine.
|
Chlorine Required to Produce 25 mg/l Concentration
in 100 Feet (30.5 m) of Pipe
| ||||
|---|---|---|---|---|
|
Pipe Diameter
|
One Percent (1%) Chlorine Solution
| |||
|
In
|
mm
|
Gallon
|
Litres
| |
|
4
|
100
|
0.16
|
0.61
| |
|
6
|
150
|
0.36
|
1.36
| |
|
8
|
200
|
0.65
|
2.46
| |
|
10
|
250
|
1.02
|
3.86
| |
|
12
|
300
|
1.44
|
5.45
| |
3.
The chlorinated water shall be retained in the main for at least
twenty-four (24) hours, during which time all valves and hydrants
in the section treated shall be operated in order to disinfect the
appurtenances.
4.
At the end of the twenty-four (24) hour period, the treated water
in all portions of the main shall have a residual of not less than
ten (10) mg/l free chlorine.
5.
Mains shall be flushed prior to placing in service. The flushing
water shall be disposed of without damage to public or private property.
6.
The contractor shall repeat disinfection procedure should initial
treatment fail to yield satisfactory results.
B.
Not
more than four thousand (4,000) feet of main shall be installed without
testing and disinfection. Contractor shall not proceed with construction
until preceding section has been accepted by the department.
[Ord. No. 1042 §3-4, 2-20-1992]
Water mains shall be tested by the procedures as outlined in
APWA Section 2902.9.
[Ord. No. 1042 §3-5, 2-20-1992]
Water mains not meeting requirements of these standards shall
be replaced or repaired in a manner approved by the department. Defective
materials shall be completely removed and replaced with new materials.
[Ord. No. 1042 §3-6, 2-20-1992]
Blasting, where required, shall be done with care in accordance
with all applicable Federal, State and local laws, ordinances and
regulations and shall not be done within a distance of twenty-five
(25) feet from previously laid pipeline or a previously installed
structure if, in the opinion of the department, the safety or soundness
of existing facilities are in any manner endangered.
[Ord. No. 1042 §3-7, 2-20-1992]
During construction operations, care should be exercised to
protect, brace, support and maintain all underground pipes, conduits,
drains, and other underground structures uncovered or otherwise affected
by the construction work being performed. All pavement, surfacing,
driveways, curbs, walks, buildings, utility poles, guy wires and other
surface structures, together with all sod and shrubs in yards and
parkings crossed by or adjacent to the main under construction, shall
be maintained and if removed or otherwise damaged, shall be replaced
or restored to the original condition thereof. All replacements of
such underground and surface structures or parts thereof shall be
made with new materials. All damage resulting from construction operations
to streets, roads, highways, shoulders, ditches, embankments, culverts,
bridges or other public or private property or facility, regardless
of location or character, which may be caused by construction and/or
by moving, hauling or otherwise transporting equipment, materials
or men to or from the work or any part of site thereof shall be the
responsibility of the developer, his/her contractor or subcontractor.
Satisfactory arrangements shall be made without delay with the owner
or owners of, or the agency or authority having jurisdiction over,
the damaged property, surface, structure or facility concerning its
repair or replacement and payment of cost incurred in connection with
said damage.
[Ord. No. 1042 §3-8, 2-20-1992]
A.
Maintenance Of Traffic. Construction operations shall be
scheduled so as to interfere as little as possible with public travel,
whether vehicular or pedestrian. Whenever it is necessary to cross
or interfere with roads, driveways and walks, whether public or private,
suitable and safe bridges, detours or other temporary expedients for
the accommodation of public and private travel shall be provided and
maintained. Reasonable notice shall be given to owners of private
drives before interfering with them.
B.
Barricades And Lights. All streets, roads, highways and
other public thoroughfares which are closed to traffic, under the
authority of a proper permit, shall be protected by means of effective
barricades on which shall be placed acceptable warning signs; such
barricades being located at the nearest intersecting public highway
or street on each side of the blocked section of such public thoroughfare.
1.
All open trenches and other excavations shall be provided with suitable
barriers, signs and lights to the extent that adequate protection
is provided to the public against accident by reason of such open
construction. Obstructions, such as material piles and equipment,
shall be provided with similar warning signs and lights.
2.
All barricades and obstructions shall be illuminated by means of
acceptable warning lights at night, and all lights used for this purpose
shall be kept burning from sunset to sunrise. Materials stored upon
or alongside public streets, roads and highways shall be so placed,
and the work at all times shall be so conducted, as to cause the minimum
obstruction and inconvenience to the traveling public.
3.
All barricades, signs, warning lights and other protective devices
shall be installed and maintained in conformity with applicable statutory
requirements and, where within public thoroughfare rights-of-way,
as required by the authority having jurisdiction thereover.
C.
Operations Along Streets And Highways. No equipment, pipeline
or excavated materials shall be stored on the pavement, or on shoulders
of uncurbed roads, or in ditches or at other locations obstructing
traffic or drainage.
1.
Construction operations shall be confined to no more than one thousand
(1,000) feet under construction with a maximum open trench of three
hundred (300) feet. "Under construction" shall include
all operations between start of excavation of the trench to final
tamping of backfill and/or restoration of pavement to public use.
Traffic shall not be obstructed in more than one (1) lane during construction
operations. The length of one (1) lane traffic shall be limited to
three hundred (300) feet. Two (2) flagmen shall be provided to control
traffic. Advance warning signs shall be provided. All obstructions
shall be removed and the pavement cleaned at all road crossings at
the end of each day's operation.
2.
All pipe strung along the right-of-way shall be blocked to prevent
movement.
[Ord. No. 1042 §3-9, 2-20-1992]
A.
The
attached City standard detail drawings shall be utilized in the design,
the furnishing of materials and the construction of water mains in
Oak Grove, Missouri:
