All construction plans shall be submitted to the Township for
water main approval and shall contain, but not be limited to, the
following information:
A. Certification. The plans and specifications shall be prepared under
the supervision of a civil engineer registered in the State of Michigan.
The title sheet of the plans shall contain the signature and seal
of that engineer.
B. Plan contents. Plans shall consist of a title sheet showing a plan
view of the complete job, split plan and profile sheets, and standard
detail sheets. Sheet sizes shall be 24 inches by 36 inches.
(1) Title sheet. A title sheet, or the first sheet of a set of plans,
shall identify:
(b)
Location map with North arrow and scale, drawn at a scale not
greater than one inch equals 100 feet nor smaller than one inch equals
2,000 feet. Locations of proposed sewers and relationship of general
project area to the surrounding area shall be shown.
(c)
Overall layout of the water system with valve and hydrant numbers.
(g)
Name, address, phone number and e-mail of proprietor.
(h)
Name, address, phone number and e-mail of designer.
(i)
Plan completion date and all revision dates.
(j)
A statement that the work shall conform to the Township's
current standards and specifications.
(2) Plan and profile sheets.
(a)
Scale of plan portion of sheets shall be one inch equals 50
feet, or larger, with scale of profile portion of sheet one foot equals
five feet vertical or proportionally larger.
(b)
Plan portion of sheet shall include at least:
[1]
Two bench marks shall be shown on each plan sheet. Plans shall
be prepared based on the Michigan South State Plane Coordinates, North
American Datum of 1983 (NAD 1983) for the x and y coordinate system
and based on the North American Vertical Datum of 1988 (NAVD88) for
the z coordinate system.
[2]
Existing topography extending 50 feet past the site boundaries,
including all existing and proposed improvements. Elevation contours
shall be at a minimum of two-foot intervals.
[3]
Street names, street and easement width, subdivision names,
lot numbers and lot dimensions.
[4]
Location, length, size of each section of proposed water main
between valves.
[5]
Locations of all hydrants, fittings and other water appurtenances
and special structures.
[6]
Service line location and diameter to all buildings other than
single-family detached dwellings.
[7]
Finish grades of all hydrants, gate well rims, and other water
structures. Hydrants and gate wells shall be consecutively numbered
on the plans.
[9]
Limits of special backfill requirements.
(c)
For all water mains 12 inches in diameter and larger, a profile
view must be submitted with the plan. The profile sheet shall contain
at least the following information:
[1]
Size, length, type and class of pipe.
[2]
Top-of-pipe elevations and locations of all horizontal and vertical
deflection points.
[3]
Limits of special backfill requirements.
[4]
Profiled elevations over center line of proposed sewer of existing
and proposed ground, and pavement surfaces. The existing profile shall
be obtained from actual field survey data.
[5]
All crossings with other utilities (existing or proposed) with
elevations of the top or bottom of the pipe, as appropriate, and shall
have "Warning" notes for all gas main crossings in profile.
[6]
Finish grade elevations for all gate well castings and fire
hydrants.
(3) Detail sheets. Provide Township standard detail sheets consisting
of specifications and drawings. Wayne County details shall also be
provided, where applicable.
All water mains and appurtenances proposed within the Township
shall be constructed in accordance with the standards and specification
contained herein:
A. Utility crossings. A minimum of 18 inches of clearance shall be provided
between the water main and any existing underground utility, unless
otherwise required by the Director. Whenever a main is installed under
any existing utility line such as gas, buried electric power, telephone
line, sewer or water, provisions shall be made to properly support
or distribute any concentrated load to avoid settlement and possible
failure of either main. Such provisions shall consist of concrete
bedding of the main, complete concrete encasement, or some other method
approved by the Director. In addition, water mains passing under sewers
shall be protected by providing:
(1) A vertical separation of at least 18 inches between the bottom of
the sewer and the top of the water main.
(2) Adequate structural support for the sewer to prevent excessive deflection
of joints and settlement of the sewer about the water main, i.e.,
a concrete saddle under the pipe with a span length extending to undisturbed
earth bearing.
B. Thrust blocks.
(1) Thrust blocks shall be installed at all bends of 11 1/4°
or greater, dead ends, trees and hydrants. Thrust by the safe bearing
load on the soil. Thrust and safe bearing loads for soils are shown
in Tables 1 and 2 below:
Table 1
Horizontal Thrust
(pounds)
|
---|
Main Size
(inches)
|
Tee-Dead-End
|
90° Bend
|
45° Bend
|
22 1/2° Bend
|
---|
6
|
4,250
|
6,000
|
3,250
|
1,660
|
8
|
7,540
|
10,670
|
5,770
|
2,940
|
12
|
16,970
|
23,990
|
12,980
|
6,620
|
16
|
30,160
|
42,650
|
23,090
|
11,770
|
20
|
47,120
|
66,650
|
36,070
|
18,390
|
24
|
67,860
|
98,000
|
51,940
|
26,480
|
36
|
152,680
|
215,920
|
116,860
|
59,580
|
Table 2
Safe Bearing Loads Against Horizontal Thrust
|
---|
Type of Soil
|
Safe Bearing Load
(pounds per square foot)
|
---|
Muck, peat, etc.
|
0
|
Soft clay
|
1,000
|
Sand
|
2,000
|
Sand and gravel cemented
|
3,000
|
Sand and gravel cemented with clay
|
4,000
|
Hard compacted clay
|
5,000
|
(2) In muck or peat, all thrust shall be resisted by pile supports driven
to solid foundations or by removal of muck or peat and replacement
with ballast of sufficient stability to resist thrusts. In all cases,
thrust block size and method of thrusting must be approved by the
Director before placement.
C. Minimum cover. Minimum cover over mains shall be six feet zero inches
or six feet zero inches below the existing/proposed road pavement,
whichever is lower. When installed parallel to a ditch, mains shall
have cover of five feet six inches minimum, as measured from the center
line of the ditch.
D. Backfill. Backfill material may be native or Class II granular material,
as approved by the Director. Where water main is constructed in pavement
areas or where the main is within a one-on-one influence of pavement,
compaction testing shall be performed by an independent testing laboratory.
Testing shall be performed at intervals of one test per layer per
75 feet of trench or as determined necessary by the Director.
E. Gate wells.
(1) A minimum of six inches and a maximum of 15 inches height of brick
shall be placed on the cone section of all precast structures.
(2) All brick, block, mortar and concrete work shall be properly cured
and protected from freezing for a minimum of 48 hours. When the temperature
is 49° F. and falling, brick mortar and concrete shall be heated
to a minimum temperature of 60° F.
(3) The joint between precast riser sections and the base of the structure
shall be set in a full bed of mortar on both the inside and the outside.
(4) All precast section lift holes shall be pointed and plugged, inside
and the outside, with mortar.
F. Hydrants.
(1) Hydrant leads shall have a minimum of 6.0 feet of cover in all areas,
including crossings through ditch sections.
(2) Lucas tee shall not be used.
(3) Hydrants shall be carefully plumbed, braced and backfilled so they
remain plumb.
(4) All grade, facing, and vertical alignment adjustment of hydrants
shall be completed prior to pressure testing and charging of the hydrants.
(5) All hydrants shall be cleaned and painted with a rust inhibitive,
oil base paint such as "Rustoleum" or approved equal to the Township's
color code prior to acceptance.
(6) The lubricant reservoirs in all hydrants having such construction
shall be filled with a lubricant acceptable to the MDEQ and recommended
by hydrant manufacturer.
(7) Backfilling around fire hydrants shall be carefully tamped sand in
six-inch layers from the center line of the lead main to a height
one foot below finished grade.
(8) Immediately after installation and until the time of acceptance,
a burlap sack or equivalent material shall be placed over the hydrant
nozzles.
(9) Fire hydrant nozzles shall be aligned as required by the Fire Marshal.
G. Acceptance tests.
(1) Conduct of and sequence for tests.
(a)
All tests shall be conducted under the supervision of the Director.
All water mains, branches and valves shall be poly-pigged for cleaning,
disinfected and pressure tested for leakage. A copy of all test results
shall be furnished to the Director. The contractor shall furnish all
material and labor to provide for an acceptable full-size blowoff
to flush the poly-pig out of the main at the far end of the project
not connected to the existing system.
(b)
The sequence for acceptance testing is as follows:
[1]
Connect to system on one end.
[7]
Connect to system at all other locations.
(2) Flushing.
(a)
The first flush of the water main shall be done with the use
of a "poly-pig." The connection location and number of poly-pigs required
to flush a project will be determined by the Director prior to the
installation of the water main. The pig shall be a B-1 poly-pig manufactured
by Pipeline Pigging Products or approved equal. The poly-pig shall
be constructed of flexible open-cell polyurethane foam with a polyurethane
elastomer coating on the rear. The installation and location of all
poly-pigs must be witnessed by the on-site construction observer.
All poly-pigs must be new and can be used once.
(b)
Mains shall be flushed with clean potable water until the water
runs clear.
(3) Chlorination.
(a)
All new mains and pipe or any existing mains contaminated by
the contractor shall be chlorinated to a minimum residual chlorine
concentration of 50 parts per million with commercial liquid chlorine
solution or approved equal.
(b)
The chlorinated water shall be allowed to stand in the mains
for 24 hours. At the end of the twenty-four-hour period, the chlorinated
water at all parts of the mains shall show a free available chlorine
residual of not less than 25 parts per million. If less than 25 parts
per million residual is shown at the end of the first twenty-four-hour
period, additional chlorine shall be added until a residual of not
less than 25 parts per million at all parts of the system is shown
after a subsequent twenty-four-hour period. The chlorinated water
shall then be removed from the mains and the mains flushed with potable
water for bacteriological testing.
(4) Bacteriological testing.
(a)
The contractor shall schedule bacteriological sample of the
water in the mains for analysis at two different times. The bacteriological
sampling will be performed by an independent laboratory hired by the
contractor. The first samples will be taken 24 hours after the mains
have been satisfactorily chlorinated, flushed and filled with potable
water. The second sample will be taken after satisfactory pressure
testing, if pressure testing follows chlorination, or at a minimum
48 hours subsequent to taking the first samples.
(b)
The contractor shall provide a sufficient number of corporation
stops and copper tubing for taking samplers. Samples shall not be
collected from hoses or fire hydrants.
(5) Pressure testing.
(a)
Testing against valves will not be permitted except for the
valve at the one connection made for poly-pigging the water main.
(b)
Before applying the specified test pressure, all air shall be
expelled from the pipe. If hydrants are not available at high points,
the contractor shall make the necessary taps to release the air and
insert plugs after the test has been completed, or install corporation
stops, and leave them in place after testing.
(c)
Preliminary pressure testing of the mains shall be done by the
contractor to ascertain if there are any breaks.
(d)
Temporary connections (jumpers) between existing water mains
and the newly constructed system for testing purposes shall include
a reduced zone backflow preventer (Watts 900, Febco 825Y, or approved
equal) to prevent backflow and possible contamination of the public
water.
(e)
The contractor shall pressure-test sections of water main as
sections of 2,000 feet or less unless otherwise authorized by the
Director.
(f)
When permitted to test lengths in excess of 2,000 feet, only
the allowable leakage from 2,000 feet will be permitted.
(g)
All ductile-iron and PVC C-900/C-905 water mains shall be subject
to a hydrostatic pressure of 150 psi based on the elevation of the
lowest point in the system. The main shall be maintained under the
test pressure for a minimum continuous period of two hours by pumping
potable water into the line at frequent intervals. The volume of water
so added shall be measured and considered to represent the leakage
from the main. No pipeline installed will be accepted until the leakage
measured over a one-hour period is less than 0.092 gallon per inch
diameter of the pipe per 1,000 feet. All visible leaks must be corrected.
(h)
In the event that the leakage exceeds the specified amount,
the main shall be carefully inspected for leaks and repaired as necessary.
Any cracked or defective pipe, fittings, valves or hydrants discovered
shall be removed and replaced with sound material and the test repeated
to the satisfaction of the engineer.
(i)
All HDPE water main shall be pressure tested after the line
and all fittings and valves have been installed and before being put
into service. Mechanical joint or flange joint connections may be
left exposed for visual leak inspection. Pressure testing shall be
conducted in accordance with this specification, the standard specification/detail
drawings, and the manufacturer's recommended procedure.
(6) Documents required prior to final acceptance. Prior to the acceptance
of a water system by the Township, the following documents shall be
submitted:
(a)
Bill of sale conveying the water system and all appurtenances
to the Township.
(b)
Construction record drawings in accordance with Article
XII of these standards.
(c)
Maintenance bond in the amount of 25% of the cost of construction
extending for a term of one year after conveyance to and acceptance
of the water system by the Township.
(d)
A final waiver of lien from the contractor(s) and subcontractor(s)
who constructed the water system and the suppliers of materials used
in the construction of the water system and a sworn statement from
the proprietor of the development that all financial obligations of
every nature in connection with the water system and its appurtenances
have been paid, and that there are no outstanding bills, liens, judgments,
etc., against the water system.
(e)
Water main easements (if required). Easements shall be submitted
on the current Northville Township easement form with exhibits prepared
on sheets 8 1/2 inches by 14 inches. The exhibits shall include
a drawing of the location of the main relative to the property boundary
and a written legal description.