[Ord. No. 45-1999, § 500.1, 2-1-2000]
Sewer extensions, including individual building sewers from
the sewer to the property line or the right-of-way bound road, may
be constructed by the City under public contract if, in the opinion
of the City council, the number of properties to be served by such
extension warrants its cost and/or the extension is deemed by the
council to be in the public (versus private) interest and if the treatment
plant has the capacity to handle the extension. Unless the City agrees
to pay, the property owner shall pay for and install the building
sewer from the public sewer to his residence or place of business
in accordance with the requirements of this article, including but
not necessarily limited to division 3 of this article. Property owners
may propose sewer extensions within the City by drafting a written
petition, signed by a majority of the benefiting property owners,
and filing it with the City. The cost of such extensions may be assessed
to the benefited property owners in accordance with state statutes
and/or local ordinance, or by a formula developed and agreed upon
by the property owners and the City, and shall be agreed to in advance
by either payments from property owners or signed promissory notes.
See division 5 of this article and the City Clerk regarding existing
recapture fees.
[Ord. No. 45-1999, § 500.2, 2-1-2000]
If the City does not elect to construct a sewer extension at
public expense, the property owner, builder or developer may construct
the necessary sewer extension, if such extension is approved by the
City council in accordance with the requirements of this section.
He or they must pay for the entire extension, including all expenses
incidental thereto. If the City council determines it to be in the
public's interest, a cost-sharing agreement between the property owner,
builder, or developer and the City may be mutually agreed upon. Each
building sewer must be installed and inspected as required by this
article and the connection fee shall be paid. Design of sewers shall
be as specified in this division. The installation of the sewer extension
may be subject to such inspection as the City deems necessary and
the expenses for such inspections shall be paid by the owner, builder
or developer prior to connection to the City sewer. The City's decisions
shall be final in matters of quality and methods of construction.
The sewer, as constructed, must pass all tests required in this division
before it is to be used. Except in instances where there is a mutual
agreement for cost sharing as mentioned in this section, the cost
of sewer extensions thus made shall be paid by the developers or the
property owners, including the costs of all building sewers.
[Ord. No. 45-1999, §§ 500.2a, 2-1-2000]
In making a determination regarding who shall bear the cost
of extensions, the City council shall use the following guidelines,
but will be free to consider other exigencies:
(1)
Case A. When property owners in a section of the City demonstrate
widespread support and interest in a sewer extension to that section,
the City will estimate the total cost of the extension, decide what
portion of the cost should be borne by the property owners who could
hook up to the extension, and adopt a formula that distributes that
portion of costs among those property owners. In advance of any work
on the extension, the City will ask the property owners to sign a
statement committing them to pay a special assessment in an amount
given in the statement. If a substantial majority of property owners
make such a commitment, then the City may decide to proceed with the
extension and pay for it through a combination of special assessments
on all property owners in the second and general tax revenues.
(2)
Case B. When, in the absence of widespread support and interest,
one or a few substantial property owners seek a sewer extension to
their section of the City, the City manager will confer with the property
owners seeking the extension to determine a fair and reasonable contribution
by them to the project. With such a commitment, the City may decide
to proceed with the extension.
(3)
Case C. When the City determines that a sewer extension should be
undertaken because it will foster substantial economic growth that
will clearly benefit all sections of the City, then the City may decide
to undertake the extension even though property owners in the area
of the extension do not indicate a willingness to contribute to its
costs. In this case, the City will fund the project entirely with
general tax revenues.
[Ord. No. 45-1999, § 500.3, 2-1-2000]
All extensions to the sanitary sewer system shall be designed
by a professional engineer registered in the state. Plans and specifications
for sewer extensions shall be submitted to the City 45 days before
the regularly scheduled council meeting at which City approval of
the extension will be required. The expenses incurred by the City
in reviewing the plans and specifications shall be paid from a deposit
made by the owner, builder, or developer at the time of application.
The design of sewers and pump stations to be deeded to the City shall
anticipate and allow for flows from possible future system extensions
or developments within the future drainage areas.
[Ord. No. 45-1999, § 500.4, 2-1-2000]
Sewer design shall be in accordance with the following:
(1)
Pipes generally; joints and fittings.
a.
Pipe material shall be PVC made from virgin plastic conforming to
ASTM D1784, type 1, grade 1, and manufactured in accordance with ASTM
D3034, SDR 35 or ASTM F-789; ductile iron conforming to ANSI specification
A21.51, with iron grade 60-42-10, and cement lining meeting ANSI specification
A21.4, but twice the thickness specified; or other material approved
by the City.
c.
Minimum internal pipe diameter shall be eight inches.
d.
Branch fittings for house services shall be PVC wyes or tee-wyes,
or ductile iron saddles with stainless steel straps and O-ring seal
set in mastic to create a watertight connection.
e.
Sanitary sewers shall be laid at least 10 feet horizontally from
any existing or proposed water main, per state department of human
services regulations. The distance shall be measured from edge of
pipe to edge of pipe. At crossings, one full length of sewer pipe
shall be located so both joints will be as far from the water pipe
as possible. Special structural support for the water and sewer pipes
may be required.
(2)
Minimum slope of pipe. The minimum slope of sewer pipe shall be as
follows:
|
Pipe Diameter
(inches)
|
Minimum Slope in Feet per 100 Feet
| |
|---|---|---|
|
8
|
0.40
| |
|
10
|
0.28
| |
|
12
|
0.22
| |
|
14
|
0.17
| |
|
15
|
0.15
| |
|
16
|
0.14
|
(3)
Bedding.
a.
The pipe shall be bedded with crushed or screened stone from six
inches below the pipe to six inches above the pipe. The trench shall
be excavated to the required grade and six inches of bedding installed
and compacted. The pipe shall be installed on the bedding and the
joints assembled in accordance with the recommendations of the manufacturer.
Bedding material shall then be installed to the midpoint of the pipe.
The bedding shall be worked and packed under the edges of the pipe
with hand shovels and then it shall be compacted. Bedding material
shall then be installed to six inches above the pipe and compacted.
b.
All compacting of bedding material shall be done with a vibrating
plate compactor for the full trench width. Care shall be taken to
prevent movement of the pipe during bedding installation, compacting,
and backfilling.
c.
Blocking (installation of the pipe prior to bedding and then support
of the pipe while bedding is installed under it) shall not be allowed.
d.
All field cutting and beveling of pipe shall comply with the manufacturer's
recommendations. Ends shall be cut square and perpendicular to the
pipe axis. Ends shall be beveled, filed smooth and stop marked with
a felt tip marker so that they are comparable to factory pipe spigots.
e.
Screened stone shall consist of clean, hard, durable stone particles.
It shall be screened and contain uniformly graded stone particles
ranging in size from 10 to 20 mm unless otherwise specified. Screened
stone shall be free of fine gravel, sand, dirt, vegetation, disintegrated
or laminated soils, and other unsuitable material.
f.
Crushed stone shall consist of clean, hard, durable stone fragments.
It shall be crushed and contain uniformly graded stone fragments ranging
in size from 20 to 30 mm unless otherwise specified. Crushed stone
shall be free of fine gravel, sand, dirt, vegetation, disintegrated
or laminated soils and other unsuitable material.
g.
Crushed or screened stone shall be placed in lifts which will compact
to a six-inch maximum layer. Gravel and borrow shall be placed in
eight-inch maximum lifts. All placement and compacting of borrow and
bedding shall comply with subsection (4) of this section, pertaining
to backfilling.
(4)
Backfilling and restoration of surface.
a.
Backfill material shall then be placed and compacted. Generally,
the excavated soil shall be suitable as backfill and shall be replaced
in the excavation. Exceptions include frozen fill, fill containing
large stones, stumps or other rubble, and any material deemed unsuitable
by the City.
b.
Backfilling shall proceed as soon as possible after underground construction
has been completed. Backfill shall be extended to the grade indicated
on the plans, compacted and graded.
c.
Fill material shall be placed in layers not to exceed eight inches
and compacted to a density equal to at least 95% of the optimum density
determined by the modified Proctor test. Compacting may be done by
vibrating compactor or roller.
d.
The contractor shall take care not to damage or disturb any structure,
including his own, during backfilling and compacting. The contractor
shall be held liable for any such damage.
e.
Excavations in paved areas shall be paved according to specifications
as soon as possible. Other areas shall be loamed and seeded or otherwise
restored to a condition equal to or better than that of adjacent areas
as soon as possible.
f.
The contractor shall not withdraw any sheeting without the approval
of the City. All voids created by such removal shall be filled and
compacted. Any backfilling which does not conform to these specifications,
or which settles differentially, shall be excavated to a depth sufficient
to correct the problem and refilled as required. Any pavement or structure
which is damaged due to settlement of backfill shall be repaired by
the contractor at his expense.
g.
All excavations required for the installation of sewer extensions
shall be open trench work unless approved by the City. No backfill
shall be placed until the work has been inspected by the City.
(5)
Manholes.
a.
Manholes shall be constructed at the end of all lines, at all changes
in slope or alignment or at intervals not exceeding 400 linear feet,
unless acceptable to the City, and shall be precast concrete.
b.
All manholes shall be constructed of precast concrete. Manholes shall
be designed for H-20 loading. Concrete manholes shall have 4,000 psi
twenty-eight-day strength for four-foot diameter and 5,000 psi for
any larger diameter, and shall acquire 75% of their twenty-eight-day
strength before being shipped to the project. Manholes shall have
factory cast holes at the proper location and elevation as shown on
the contract drawings. Manhole sections shall be joined with butyl
rubber Kent Seal No. 2. Minimum thickness of the reinforced barrel
sections and base shall be five inches. All manholes shall have eccentric
cones. The tops of the cones shall be eight inches wide to accommodate
bricks. Two coats of bituminous waterproofing shall be applied to
the outside of all manholes. Damaged manholes shall be rejected.
c.
Mortar to be used in the construction of inverts and placement of
frames shall be type II Portland cement (one part), sand (two parts)
and hydrated lime (not over 10 pounds per bag of cement). Bricks shall
be solid red clay bricks, not concrete units.
d.
Manhole steps shall be polypropylene plastic coated steel by M.A.
Industries, or approved equal. Steps shall be cast into the manhole
sections and spaced a maximum of 12 inches on center vertically.
e.
Covers shall be 24 inches in diameter and shall be clearly marked
"SEWER." Frames shall have a clear opening of 22 inches. The castings
shall be of good quality even-grained gray cast iron (ASTM-A48 grade
30) and shall be free of lumps, blisters, scales, and other defects.
Manhole covers shall have two lift holes and shall be matched to the
frames with machined surfaces. The covers and frames shall be factory
coated with a smooth nonbrittle coat of coal tar epoxy. Frames and
covers shall have an H-20 load rating.
f.
Pipe sleeves shall be lock joint flexible sleeves which shall be
cast or locked into the manhole base. These sleeves shall be capable
of allowing substantial off-center alignment. The sleeves shall be
attached securely to the outside of the pipe with stainless steel
bands to provide a watertight seal.
g.
Manhole bases shall be installed before laying pipe to the manhole.
The manhole base shall be set on a twelve-inch compacted stone bed.
Once the sewer pipe has been connected to the manhole, barrel sections
shall be installed after installing the Kent Seal at the joints. The
pipe shall extend into the manhole so that it is flush with the inside
wall. There shall be no pipe bells inside the manhole.
h.
Manhole inverts shall be installed using bricks and mortar as shown
on the contract drawings. The trough and table shall be lined with
bricks. The trough depth shall be equal to the pipe diameter. The
tables shall slope toward the trough at one inch per foot for drainage.
The finished surface of the invert shall be smooth and free of any
obstructions and shall have a uniform pitch from inlet to outlet.
The finish surface for both inverts and tables shall be brick.
i.
Frames and covers shall be installed as shown on the plans. The frames
shall be brought to the proper grade with brick and mortar or cast-in-place
concrete. All voids between bricks shall be filled with mortar and
the bricks shall be coated with mortar on both the interior and exterior
of the manhole. The mortar surface shall be smooth and even and shall
slope inward on the exterior of the manhole to avoid lifting from
frost. Frames shall not be backfilled until the mortar has set and
acquired sufficient strength to avoid damage. When manholes are in
paved areas, the frame and cover shall be adjusted to grade once the
base pavement has been placed. The cost of adjusting the frame and
cover to grade, including pavement cutting and replacement, is incidental
to the manhole cost. In paved areas the frame and cover shall be set
1/4 inch below final grade.
j.
All manholes shall be vacuum tested immediately after assembly and
prior to backfilling. All lift holes shall be plugged with an approved
nonshrink grout. All pipes entering the manhole shall be plugged.
The plugs shall be securely braced to prevent them from being sucked
into the manholes. The test head shall be placed at the inside of
the top of the cone section and the seal inflated in accordance with
the manufacturer's recommendations. A vacuum of 10 inches of mercury
shall be drawn and the vacuum pump shut off. With the valves closed,
the time shall be measured for the vacuum to drop to nine inches.
The manhole shall pass the test if the time is greater than 60 seconds
for forty-eight-inch diameter, 75 seconds for sixty-inch diameter
and 90 seconds for seventy-two-inch diameter manholes. If the manhole
fails the initial test, necessary repairs shall be made with a nonshrink
grout while the vacuum is still being drawn. Retesting shall proceed
until a satisfactory test is obtained.
[Ord. No. 45-1999, § 500.5, 2-1-2000]
(a)
Required. All sewer mains shall be tested prior to acceptance. All
testing shall be done in the presence of the City. The contractor
shall notify the City at least 48 hours in advance of any testing.
(b)
Testing equipment and methods; maximum infiltration.
(1)
The contractor shall only use testing equipment, plugs and compressors
specifically designed for low pressure sewer testing. Equipment shall
include a pressure relief valve set no higher than nine psig. The
contractor shall follow the manufacturer's recommendations for operation
and safety. Equipment shall only be operated by personnel trained
and experienced with its proper use.
(2)
For a sewer main test to be considered for acceptance, the sewer
main segment must be part of a manhole-to-manhole reach of pipe that
has been completed and backfilled to final grade. The manholes on
each end of the reach of pipe shall be successfully tested prior to
testing of the sewer main.
(3)
The maximum allowable infiltration limit for all pipe shall
be 100 gallons/day/inch/mile of pipe installed. If there is evidence
of poor workmanship or improper storage of pipe, or if test results
are unsatisfactory, the engineer may direct that additional tests
be made on any and all of the pipe.
(c)
Air tests.
(1)
All gravity sewer lines shall be tested for leakage by conducting
a low pressure exfiltration air test. All sewer lines shall be cleaned
to remove all sediment and debris prior to testing.
(2)
Test plugs shall be properly installed and braced.
(3)
A minimum of four pounds per square inch air pressure shall
be applied to the line being tested. The air compressor shall then
be shut off. A pressure drop, from the applied pressure, of less than
1.0 psi during the period of time specified in the following table
will constitute an acceptable air pressure test. If the pressure drop
during the indicated time interval is exceeded, the test will be determined
as failure and the contractor shall locate and correct the leak associated
with the failure. Following correction of the leak, the pipe shall
be retested at the contractor's expense.
|
Table of Air Test Durations
| ||
|---|---|---|
|
Sewer Diameter
(inches)
|
Test Duration
(minutes)
| |
|
4
|
2
| |
|
6
|
3
| |
|
8
|
4
| |
|
10
|
5
| |
|
12
|
6
| |
|
15
|
8
| |
|
18
|
9
| |
|
21
|
10
| |
|
24—30
|
11.5
| |
(4)
All sewer lines not complying with the requirements for infiltration
and/or air testing shall be repaired or replaced at the contractor's
expense. The contractor shall repair and retest the line at his expense
until an acceptable test is achieved. No repairs will be made internally
on the pipe unless specifically authorized by the City in writing.
All repairs shall be made externally to the sewer lines. If any pipe
is defective, it shall be removed and replaced.
(5)
If, during the process of repairing the new sewer main or during
other operations not necessarily related to sewer construction (such
as constructing roadways, cleanup, etc.), debris and sediment enters
the new sewer or manholes, the sewer shall again be cleaned before
final acceptance shall be made.
(d)
Deflection test. Prior to final acceptance of the sewer, the contractor
shall take deflection measurements of all PVC sewer mains by use of
a mandrel assembly (7 1/2%) pulled through the entire length
of each sewer run. If a deflection in the diameter of the pipe equal
to or greater than 7 1/2% of the specified pipe diameter is measured,
the defective pipe will be removed and replaced by the contractor
at the contractor's expense. The pipe shall then be retested.
[Ord. No. 45-1999, § 500.6, 2-1-2000]
No builder or developer shall be issued a building permit for
a new dwelling or structure requiring sanitary facilities within the
City unless a suitable and approved method of sewage disposal is proposed.
No certificate of occupancy shall be issued until connection is made
to an approved sewer and all fees owed to the City have been paid.
[Ord. No. 45-1999, § 500.7, 2-1-2000]
Connection of the sewer extension to the City's facilities shall
not be permitted until the completed sewer has been tested and passed
to the satisfaction of the City, all fees have been paid to the City,
and reproducible mylar record drawings of the completed sewer have
been furnished to the City. If the developer desires to convey the
sewer extension to the City, he must give the City a one-year maintenance
bond in an amount and form acceptable to the City. In no event shall
such bond be in an amount less than 10% of the cost of the extension.
The City shall in no event be required to accept an offer of conveyance
of a sewer extension.
