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SECTION 02533
CONNECTIONS TO EXISTING STRUCTURES OR SEWER MAINS
PART 1 - GENERAL
1.01 WORK INCLUDED:
The Contractor shall furnish materials, tools, labor and equipment to cut suitable openings
into the existing sewer manholes, make connections to existing sewers and all other work
necessary to direct the existing sewage flow as indicated on the drawings and as herein
specified.
1.02 RELATED WORK:
Section 02631, PRECAST MANHOLES AND CATCH BASINS
Section 02085, POLYVINYL CHLORIDE GRAVITY PIPE AND FITTINGS
Section 01735, CUTTING, CORING and PATCHING

1.03 SUBMITTALS: INACCORDANCE WITH REQUIREMENTS OF THE GENERAL
SPECIFICATIONS, SUBMIT THE FOLLOWING:

Prior to start of work, submit details of the methods proposed for doing the work and for
maintaining the sewage flow as herein specified.

PART 2 - PRODUCTS

A. Products for attaching to existing sewer manholes are described in Sections 02631, Precast
Manholes and Catch Basins; and Section 01735, Cutting, Coring and Patching.

B. Products for attaching sewer service lines or drain lines to existing sewer mains:

1. Connection of new sewer service or drain pipe to existing sewer mains shall be by
mechanical saddles (as described in items 2 and 3 below). The connection device
shall provide a firm base that will hold and attach the service main to the existing pipe
without the possibility of the pipe becoming loose or detaching from the main.
Putting the pipe in the main and grouting around it will not be allowed.

2. Where feasible and sizing allows this type of connection, the preferred method of
attachment of PVC service or drain pipe to the existing main is by aROMAC “CB”
Sewer Saddles or equal.

2019 Sewer Replacement Project Connections to Existing Structures or Sewer Mains
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3. Should the ROMAC type service connection not be feasible due to pipe size or other
constraints, the connection may be made using a Kor-N-Tee, Inserta Tee or equal.
These types of fittings rely on having enough of the pipe wall thickness present to
create tension between the fittings the pipe wall such that fitting will be held securely
in place. Should the Contractor elect to use this type of fitting the submittal must
include an evaluation of the existing pipe wall thickness and provide cut sheets from
the manufacturer showing this type of fitting will achieve the desired results.

PART 3 - EXECUTION

3.01 INSTALLATION:

A. The Contractor shall provide temporary plugs or provide other suitable means for
maintaining the new sewer free of sewage flow until such time as it can be inspected and
tested for leakage.

B. Connections to the new sewer shall be made when directed by the Engineer and only after
the new pipeline has been inspected and has successfully passed the leakage test.

C. The Contractor shall modify each existing structure for installation of the necessary piping,
but in so doing shall confine the cutting to the smallest amount possible consistent with the
work to be done.

D. All new piping connected to existing structures shall be encased in concrete in a manner
satisfactory to the Engineer.

E. All work shall be done with the proper tools and by careful workmen competent to do
work.

F. The Contractor shall cut, reshape and fill the existing manhole tables and plug existing
outlets as indicated on the drawings and as directed by the Engineer, to accommodate the
new connections. Reshaped manhole invert channels shall be smoothly shaped to permit
the flow of sewage. Manhole invert channels shall be reconstructed as specified under
Section 02631, PRECAST MANHOLES AND CATCH BASINS and shall comply with
the City of Nashua Standard Specifications for Sewers and Drains.

END OF SECTION

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SECTION 02534
FILL SEWER PIPE TO BE ABANDONED
PART 1 - GENERAL
1.01 WORK INCLUDED:
The existing sewer pipe to be abandoned in place shall be completely filled with
"Flowable Fill" after the sewerage has been re-routed through the new sewer main.
The work shall include all materials, labor, pumping, shoring, and cleanup required
to complete this item.
1.02 RELATED WORK:
Section 02631, PRECAST MANHOLES AND CATCH BASINS

1.03 SUBMITTALS: IN ACCORDANCE WITH REQUIREMENTS OF THE GENERAL
SPECIFICATIONS, SUBMIT THE FOLLOWING:

The contractor shall submit his proposed method for filling the pipe to be abandoned
to the Engineer for approval two (2) weeks prior to scheduling the work. The
"Flowable Fill" mix shall be comprised of Portland cement, water, sand and other
additives to insure that the material shall flow the entire length of the pipe and
completely fill the void. The mix design for the "Flowable Fill" shall be submitted to
the Engineer for approval.

PART 2 - PRODUCTS - NOT APPLICABLE

PART 3 - EXECUTION

3.01 INSTALLATION:

A No work shall be done without approval from the Engineer. The contractor shall
demonstrate to the Engineer by visual inspection or other means that the existing
pipe has been completely filled.

B. All work shall be done with the proper tools and by careful workmen competent to do

work.

END OF SECTION

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SECTION 02631

PRECAST MANHOLES AND CATCH BASINS

PART 1 - GENERAL
1.01 WORK INCLUDED:

A. This Section covers all precast manholes and catch basins complete, including, but not
limited to, bases, walls, cones, mortar, inverts, frames and covers.

B. Work shall comply with City of Nashua Standard Specifications for Sewers and Drains
(Appendix A).

1.02 RELATED WORK:

Section 01330, SUBMITTALS

Section 02085, POLYVINYL CHLORIDE GRAVITY PIPE AND FITTINGS
Section 02300, EARTHWORK.

Section 02745, ROAD RESTORATION

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Section 03302, FIELD CONCRETE

1.03 SYSTEM DESCRIPTION:

A. _ Precast sections shall conform in shape, size, dimensions, materials, and other respects to the
details indicated on the drawings or as ordered by the Engineer.

B. All manholes and catch basins shall have precast concrete bases, risers and cone sections.
Invert channels shall be formed of brick and mortar upon the base.

C. Catch basins shall have a 3-foot deep sump unless otherwise specified.
1.04 REFERENCES:

A. The following standards form a part of this specification as referenced:

American Society for Testing and Materials (ASTM)

ASTM A48 Gray Iron Castings
ASTM C32 Sewer and Manhole Brick
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ASTM C144 Aggregate for Masonry Mortar

ASTM C207 Hydrated Lime for Masonry Purposes
ASTM C478 Precast Reinforced Concrete Manhole Sections
ASTM C923 Specification for Resilient
Connectors Between Reinforced Concrete
Manhole Structures and Pipes
ASTM C1244 Standard Test Method for Concrete Sewer Manholes by the

Negative Air Pressure (Vacuum) Test.
American Association of State Highway and Transportation Officials (AASHTO)
AASHTO M198Joints for Circular Concrete Sewer and Culvert Pipe Using
Flexible Watertight Gaskets
Occupational Safety and Health Administration
OSHA 29 CFR 1910.27 Fall Prevention Protection

1.05 SUBMITTALS: IN ACCORDANCE WITH REQUIREMENTS OF GENERAL
SPECIFICATIONS, SUBMIT THE FOLLOWING:

A. Six sets of manufacturer literature of the materials of this section shall be submitted to the
Engineer for review.

B. Tests reports as required shall be submitted to the Engineer.
PART 2 - PRODUCTS 2.01 PRECAST CONCRETE SECTIONS:

A. All precast concrete sections shall conform to ASTM C478 with the following exceptions
and additional requirements:

1. The wall thickness of precast sections shall be as designated on the drawings,
meeting the following minimum requirements:

Section Diameter (Inches) Minimum Wall Thickness (Inches)
48 5
60 6
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T2 7
4 8

2. Type Il cement shall be used except as otherwise approved.

3. Sections shall be steam cured and shall not be shipped until at least five days after
having been cast.

4. Minimum compressive strength of concrete shall be 4000 psi at 28 days.
5. No more than two lift holes may be cast or drilled in each section.

6. The date of manufacture and the name or trademark of the manufacturer shall be
clearly marked on the inside of each precast section.

7. Acceptance of the sections will be on the basis of material tests and inspection of the
completed product.

8. Circumferential steel reinforcement in walls and bases shall be a minimum of 0.12
sq. in./lin. ft. for 4-foot diameter sections and 0.15 sq. in./lin. ft. for 5- and 6-foot
diameter sections. Reinforcing shall extend into tongue and groove.

B. Conical reducing sections shall have a wall thickness not less than 5-inches at the bottom
and wall thickness of 8-inches at the top. Conical sections shall taper from a minimum of 48-
inches diameter to 30-inches diameter at the top, as shown on the drawings.

C. Except where insufficient depth of cover dictates the use of a shorter base, bases shall be a
minimum of 4 feet in height.

D. Slab top sections and flat riser sections (Grade Rings) shall conform to the contract
drawings, with particular attention focused upon the reinforcing steel and be designed to
meet or exceed an H-20 Loading requirement.

E. The tops of the bases shall be suitably shaped by means of accurate ring forms to receive the
riser sections.

F. Precast sections shall be manufactured to contain wall openings of the minimum size to
receive the ends of the pipes, such openings being accurately set to conform with line and
grade of the sewer or drain. Subsequent cutting or tampering in the field, for the purpose of
creating new openings or altering existing openings, will not be permitted except as
directed by the Engineer.

G. —_"Drop-over" manholes shall be placed where indicated on the drawings. The Contractor
shall accurately measure the diameter of the existing outlet pipe and inform the
manufacturer of its size, so that the "Drop-over" type opening can be cut into the precast
manhole base. The bottom shall be precast; or cast in place by the Contractor as required
by the Engineer. The invert channel shall be formed of brick and mortar, as specified in

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this specifications section. The sub-base shall be a compacted, level foundation of crushed
stone, at least 6-inches thick, as specified in Section 02300 EARTHWORK, but shall
vary to the depth necessary to reach sound undisturbed earth.

H. All manholes and catch basins shall be coated on the exterior with a bituminous damp-
proofing coating.

J. The Engineer reserves the right to reject any unsatisfactory precast section and the rejected
unit shall be tagged and removed from the job site immediately.

J. The Engineer may also require the testing of concrete sections as outlined under Physical
Requirements in ASTM C478 with the Contractor bearing all testing costs.

2.02 BRICK MATERIALS:

A. Brick shall be sound, hard, and uniformly burned brick, regular and uniform in shape and
size, of compact texture, and satisfactory to the Engineer. Bricks shall comply with ASTM
C32, for Grade SS, hard brick, except that the mean of five tests for absorption shall not
exceed 8 percent by weight.

B. Rejected brick shall be immediately removed from the work and brick satisfactory to the
Engineer substituted.

C. Mortar shall be composed of portland cement, hydrated lime, and sand in which the volume
of sand shall not exceed three times the sum of the volumes of cement and lime. The
proportions of cement and lime shall be as directed and may vary from 1:1/4 for dense
hard-burned brick to 1:3/4 for softer brick. In general, mortar for Grade SS Brick shall be
mixed in the volume proportions of 1:1/2:4-1/2; portland cement to hydrated lime to sand.

D. Cement shall be Type II portland cement as specified for concrete masonry.

E. Hydrated lime shall be Type S conforming to ASTM C207.

F. The sand shall comply with ASTM C144 specifications for "Fine Aggregate," except that all
of the sand shall pass a No. 8 sieve.

2.03 FRAMES, GRATES AND COVERS:

A. Castings shall be of good quality, strong, tough, even-grained cast iron, smooth, free from
scale, lumps, blisters, sandholes, and defects of every nature which would render them unfit for
the service for which they are intended. Contact surfaces of covers and frame seats shall
be machined to prevent rocking of covers.

B. All castings shall be thoroughly cleaned and may be subject to a careful hammer inspection at
the Engineer's discretion.

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C. Castings shall be ASTM A48 Class 30B or better.

D. The surface of the manhole covers shall have a diamond pattern with the cast words
"DRAIN" or "SEWER," whichever is appropriate.

E. Manhole frames with 32-inch covers for 30-inch openings shall be 500 pounds minimum by
E.L. LeBaron Foundary Co., No. LC328; Quality Water Products, Style 47; Neenah
Foundry Co., R1740B or approved equal.

F. Watertight type manhole frames with 32-inch diameter covers (bolted and gasketed) shall be
4 bolt, 630 pounds minimum by E.L. LeBaron Foundary Co. No. LCB328; Quality Water
Products, Style C47WT; Neenah Foundary Co., R-17550-H or approved equal.

G. Catch basin castings shall have 2-inch square grate openings, 23-7/8-inch square grates,
and shall be 8-inches in height and weigh 460 pounds minimum. They shall be Neenah
Foundry Co. No. 3405; Quality Water Products No. 45; E.L. LeBaron Type F; or approved
equal.

H. — Catch basin frames set against curbing shall have three flanges only.

2.04 SEWER MANHOLE ACCESSORIES:

A. Gasket materials shall be top grade (100% solids, vulcanized) butyl rubber and shall meet or
exceed AASHTO M-198.

B. Couplings at the manhole-pipe interface shall be made with a rubber seal system (with or
without stainless steel straps) meeting the requirements of ASTM C923 and recommended
for this type of connection.

C. Stubs installed as specified and indicated on the drawings shall be short pieces of the same
class pipe as that entering the manhole and shall have either stoppers or end caps as shown on
the drawings. Stoppers or end caps shall be especially designed for that application.

2.04 CATCH BASIN ACCESSORIES:

A. Anoil and debris trap shall be furnished and installed on outlet pipes in all catch basins. The
trap shall be The Eliminator® as manufactured by Groundwater Rescue, or approved equal.

PART 3 - EXECUTION
3.01 INSTALLATION:

A. PRECAST SECTIONS:

1. Precast bases shall be supported on a compacted level foundation of crushed stone, as
specified in Section 02300 EARTHWORK, at least 6-inches thick, but shall vary to

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the depth necessary to reach sound undisturbed earth.

2. Precast reinforced concrete sections shall be set vertical and with sections in true
alignment.

3. Butyl rubber joint sealant shall be installed between each concrete section. Catch
basin sections do not require joint sealant if so indicated on the drawings.

4. All holes in sections used for handling the sections shall be thoroughly plugged with
mortar. Mortar shall be one part cement to 1-1/2 parts sand, mixed slightly damp to
the touch (just short of "balling"), hammered into the holes until it is dense and an
excess of paste appears on the surface, and then finished smooth and flush with the
adjoining surfaces.

B. BRICK WORK:

1. Bricks shall be moistened by suitable means, as directed, until they are neither so dry
as to absorb water from the mortar nor so wet as to be slippery when laid.

2. Each brick shall be laid as a header in a full bed and joint of mortar without requiring
subsequent grouting, flushing or filling, and shall be thoroughly bonded as directed.

3. The brick inverts shall conform accurately to the size of the adjoining pipes. Side
inverts shall be curved and main inverts (where direction changes) shall be laid out in
smooth curves of the longest possible radius which is tangent to the centerlines of
adjoining pipe.

C. CASTINGS:

1. Cast iron frames, grates and covers shall be as specified. The frames and covers
shall be set by the Contractor to conform accurately to the grade of the finished
pavement, existing ground surface, or as indicated on the drawings. Frames shall be
adjusted to meet the street surface.

2. Cast iron manhole frames and covers not located in paved areas shall be set 6-inches
above finished grade, at a height as directed by the Engineer, or as indicated on the
drawings. The top of the cone shall be built up with a minimum of 1 course and a
maximum of 5 courses of brick and mortar used as headers for adjustment to final

grade.

3. Frames shall be set concentric with the top of the concrete section and in a full bed of
mortar so that the space between the top of the concrete section or brick headers and
the bottom flange of the frame shall be completely filled and made watertight. A
thick ring of mortar extending to the outer edge of the concrete shall be placed all
around the bottom flange. The mortar shall be smoothly finished to be flush with the top
of the flange and have a slight slope to shed water away from the frame.

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4. Covers and/or grates shall be left in place in the frames, for safety reasons, except
while work is being performed.

D. ACCESSORIES:
1. All accessories shall be installed in accordance with manufacturer's instructions.

2. Stubs shall be set accurately to the dimensions indicated on the drawings. Stubs
shall be sealed with suitable watertight plugs.

3.02 LEAKAGE TESTS:

A. Leakage tests shall be made by the Contractor and observed by the Engineer on each
manhole. The test shall be by vacuum or by water exfiltration as described below:

B. VACUUM TEST:

1. The vacuum test shall be conducted in accordance with ASTM C1244. Test results
will be judged by the length of time it takes for the applied vacuum to drop from 10
inches of mercury to 9 inches. If the time is less than that listed in Table 1 of ASTM
C1244, the manhole will have failed the test. Test times from Table 1 are excerpted

below.
TABLE | Minimum Test Times for Various Manhole Diameters

Diameter (Inches)

Depth (Feet) 48 60 72
Times (Seconds)

0-12 30 39 49

12-16 40 52 67

16-20 50 65 81

20-24 59 78 97

26-30 714 98 121

2. If the manhole fails the initial test, the Contractor shall locate the leaks and make
proper repairs. Leaks may be filled with a wet slurry of accepted quick setting
material. If the manhole should again fail the vacuum test, additional repairs shall be
made, and the manhole water tested as specified below.

C. WATER EXFILTRATION TEST:

1. After the manhole has been assembled in place, all lifting holes shall be filled and
pointed with an approved non-shrinking mortar. All pipes and other openings into the
manhole shall be suitably plugged and the plugs braced to prevent blow out. The test
shall be made prior to placing the shelf and invert. If the groundwater table has been

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