SECTION 06500
RECLAIMED WATER DISTRIBUTION SYSTEM
TABLE
OF CONTENTS
06510 GENERAL
06520 RECLAIMED WATER DISTRIBUTION PIPE
A.
Design
B.
Pipe Materials
C.
Pipe Installation
06530 VALVES AND APPURTENANCES
A.
Valves
B.
Appurtenances
06540 RECLAIMED WATER SERVICE TAPS
A.
Design
B.
Materials
06550 RECLAIMED WATER IRRIGATION SYSTEMS
06560 TESTING AND INSPECTION
A.
General
B.
Testing
06570 REPAIR OF RECLAIMED WATER SYSTEM
06510 GENERAL
1.
All
aspects of the design and construction of any portion of the reclaimed water
distribution system shall, at a minimum, meet the requirements of the North
Carolina Department of Environment and Natural Resource (DENR) Division of
Water Quality (DWQ) and the North Carolina Administrative Code Section 15A NCAC
02T 0909. Requirements presented in the
Town of
2.
There
shall be no direct cross connections between the reclaimed water and potable
water systems. In all cases where
reclaimed and municipal potable water are supplied to the same structure and/or
other same facility, a reduced pressure principle backflow preventer shall be
provided on the municipal potable water service. The privately owned and maintained reclaimed
water service piping and other appurtenances shall be identified in conformance
with the North Carolina Plumbing Code.
3.
Extensions
of the existing reclaimed water distribution system including locations and
sizing shall adhere to any and all Policy Statements and/or Master Plans
pertaining to the reclaimed water distribution system, or other requirements as
initiated by the Director of Engineering.
4.
All
relocations of existing or permitted reclaimed water infrastructure including
service piping and meter boxes shall be permitted and inspected in conformance
with Town policies and procedures.
5.
Any reclaimed water that leaves the reclaimed water distribution
system other than by means of a properly permitted use must be disposed of into
the Town of
6.
In all cases where potable water is used to temporarily charge a
reclaimed water system, there shall be an approved above-ground reduced
pressure principle backflow preventer or air gap separation between the potable
water system and the reclaimed water system.
06520 RECLAIMED WATER DISTRIBUTION PIPE
A. DESIGN
1.
Location: In accordance with Policy Statement Number
23, reclaimed water lines shall be extended along the roadway to the adjacent
property line. All reclaimed water mains
shall be provided within dedicated street rights-of-way or within dedicated
Town of
2.
Sizing: Reclaimed water mains shall be sized in
accordance with good design procedures to provide adequate pressures throughout
the system or as directed by the Director of Engineering. The minimum pipe size for reclaimed water
mains shall be 4 inches.
3.
Installation: All utility extension permits
must be obtained prior to construction.
All reclaimed water mains shall have a minimum cover of 4 feet
measured from the top of the pipe to the finished grade. When reclaimed water mains are installed
along a roadway, which does not have curb and gutter, the reclaimed water main
shall be installed at sufficient depth to prevent conflict with future road
improvements or vertical alignment changes.
4.
Relation to Potable Water Mains and Other Utilities
a)
Reclaimed water mains shall be laid with at least 10 feet of
horizontal separation from existing potable water mains, measured laterally
edge to edge, unless the elevation of the top of the reclaimed water main is at
least 18 inches below the bottom of the potable water main, with a horizontal
separation of at least 3 feet. Where a
reclaimed water main and potable water main cross, the crossing shall be
constructed at a 90-degree angle and the reclaimed water main shall cross at
least 18-inches below the potable water main and the reclaimed water main shall
be constructed of ductile iron pipe to water main standards at least 20-ft on
both sides of the crossing and wrapped with purple polyethylene wrap as
specified herein.
b)
Reclaimed water mains shall be laid with at least 10 feet of
horizontal separation from existing sanitary sewer lines, measured laterally
edge to edge unless the elevation of the bottom of the reclaimed water main is
at least 18 inches above the top edge of the sanitary sewer, with a horizontal
separation of at least 3 feet. Where a reclaimed water main and a sanitary
sewer main cross, the crossing shall be constructed at a 90-degree angle and
the reclaimed water main shall cross at least 18-inches above the sanitary
sewer line.
c)
Reclaimed
water mains shall be laid below storm sewer mains with a minimum vertical
separation of 12 inches when horizontal separation is less than 3 feet, unless
otherwise approved by the Director of Engineering. Where a reclaimed water main and a storm
sewer cross, the crossing shall be constructed at a 90-degree angle and the
reclaimed water main shall cross at least 18-inches below the storm sewer.
d)
The
following minimum horizontal separations shall be maintained:
i. 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)
ii. 50 feet from any waters (from normal
high water) classified WS-II, WS-III, B, SA, ORW, HQW or SB (except as noted
below)
iii. 10 feet from any other stream, lake, or
impoundment (except as noted below)
iv. 25 feet from private wells (with no
exceptions)
v. 50 feet from sources of public water
supply (with no exceptions)
Where the required minimum separations cannot be
obtained, ductile iron sanitary sewer pipe with joints equivalent to potable
water main standards shall be used.
5.
Identification of Reclaimed Piping
a)
General:
All new distribution
piping in the reclaimed water system, including service lines, valves and other
appurtenances shall either be colored purple and embossed or be integrally
stamped/marked with the words “CAUTION:
RECLAIMED WATER – DO NOT DRINK,” or be installed with a purple
identification tape, and a purple polyethylene vinyl wrap. The warning shall be stamped on opposite
sides of the pipe and repeated every 3-feet or less.
Existing potable or
nonpotable water lines that are being converted to reclaimed water use should
first be accurately located and tested in accordance with regulatory
requirements. If required, the necessary
actions to bring the line and appurtenances into compliance with regulatory
standards should be taken. If the
existing lines meet approval of the reclaimed water supplier and NCDENR, the
lines can be approved for
reclaimed water
distribution. If verification of the
existing lines is not possible, the lines should be uncovered, inspected, and
identified prior to use.
b)
Polyethylene Wrap: Buried ductile iron fittings, gate valves and
other appurtenances shall either be painted Pantone 522 purple and/or wrapped
with a Pantone 522 purple polyethylene membrane conforming to ANSI A21.5, and
installed in accordance with AWWA C105.
The polyethylene sheets shall be 8 mils thick, minimum.
c)
Tracer Wire: Tracer wire shall be installed along all PVC reclaimed
water mains and polyethylene service piping.
At a minimum, tracer wire shall be provided as a single copper strand of
#12 AWG attached to the main line in at least 5-ft intervals. The copper tracer wire shall be jacketed with
a purple polyethylene film. All tracer
wire for main lines shall be connected to valve boxes to allow reading
equipment to follow the main line location from the valve box.
d)
Identification Tape:
Identification tape shall be required for all instances in which the
reclaimed water piping for main lines is not labeled, embossed or integrally
stamped/marked with the words “CAUTION:
RECLAIMED WATER – DO NOT DRINK,” repeated on opposite sides of the pipe
every 3-feet or less. Identification
tape shall be prepared with white or black printing on a purple field (Pantone
522) having the words “CAUTION:
RECLAIMED WATER – DO NOT DRINK.”
The overall width of the tape should be at least 3 inches.
Identification tape
shall be installed on the top of the distribution piping longitudinally and should
be centered over the pipe. The
identification shall be continuous in its coverage on the pipe and should be
fastened to each pipe length in at least 10-ft intervals. Tape attached to sections of pipe before they
are placed in the trench should have flaps sufficient for continuous
coverage. Other satisfactory means of
securing the tape during backfill of the trench may be used if suitable for the
work, as determined by the Director of Engineering.
The identification tape
differentiating the reclaimed water piping from other utility lines should be
consistent throughout the service area.
B. PIPE MATERIALS
1.
Material: All
reclaimed water main distribution pipe shall be C900 or C905 PVC pipe. The Engineering Department will maintain a list of approved
manufacturers for all reclaimed water distribution products. New manufacturers must submit requests for
approval to the Engineering Department in accordance with Standard Procedure
120, Manufacturer Approval Guidelines.
2.
C900, PVC Pipe, 4 through 12 inches in diameter:
a)
All
PVC pipe in the range of 4 through 12 inches in diameter shall be designed and
manufactured in accordance with AWWA C900.
The PVC pipe shall be made of virgin PVC resin that provides chemical
and physical
properties that meet or exceed cell
class 12454 as defined in ASTM D1784. All
PVC pipe shall be supplied with a minimum pressure rating of 200-psi corresponding to a
diameter ratio of 14. All PVC pipe shall
be supplied in standard laying lengths of 20-ft. PVC pipe shall have integral wall, bell and
spigot joints fabricated with elastomeric gaskets in conformance with ASTM F477
with joints that meet or exceed the performance requirements of ASTM
D3139. All PVC pipe joints shall be
provided with an approved method of restraint.
All PVC pipe supplied for reclaimed water applications shall be color
coded purple, Pantone 522 as required by the North Carolina Administrative
Code, 15A, NCAC, 02T 0909. Pipe
identification for reclaimed water by the manufacturer with the words “CAUTION
– RECLAIMED WATER DO NOT DRINK” repeated on opposite
sides of the pipe every 3-feet or less shall be a preferred alternative to
identification tape.
C-900 PVC Pipe Sizes
|
Nominal Pipe Diameter |
Pressure Rating |
Diameter Ratio |
Wall Thickness (inches) |
Outside Diameter |
|
4-inch |
200 |
14 |
0.343 |
4.80 |
|
6-inch |
200 |
14 |
0.493 |
6.90 |
|
8-inch |
200 |
14 |
0.646 |
9.05 |
|
12-inch |
200 |
14 |
0.943 |
13.20 |
b)
C-905, PVC Pipe, 16 through 24 inches in diameter:
All PVC pipe in the range of 16
through 24 inches in diameter shall be designed and manufactured in conformance
with AWWA C905. The PVC pipe shall be
made of virgin PVC resin that provides chemical and physical properties that
meet or exceed cell class 12454 as defined in ASTM D1784. All PVC pipe shall be supplied with a
pressure rating of 200-psi corresponding to a diameter ratio of 21. All PVC pipe shall be supplied in standard
laying lengths of 20-ft. PVC pipe shall
have integral wall, bell and spigot joints fabricated with elastomeric gaskets
in conformance with ASTM F477 with joints that meet or exceed the performance
requirements of ASTM D3139. All PVC pipe
joints shall be provided with an approved method of restraint. All PVC pipe supplied for reclaimed water
applications shall be color coded purple, Pantone 522 as required by the North
Carolina Administrative Code, 15A, NCAC, 02T 0909. Pipe identification for reclaimed water by
the manufacturer with the words “CAUTION – RECLAIMED WATER DO NOT DRINK” repeated on opposite sides of the pipe every 3-feet or less
shall be a preferred alternative to identification tape.
C-905 PVC Pipe Sizes
|
Nominal Pipe
Diameter |
Pressure Rating |
Diameter Ratio |
Wall Thickness
(inches) |
Outside Diameter |
|
16-inch |
200 |
21 |
0.829 |
17.40 |
|
18-inch |
200 |
21 |
0.929 |
19.50 |
|
20-inch |
200 |
21 |
1.029 |
21.60 |
|
24-inch |
200 |
21 |
1.229 |
25.80 |
c)
PVC
All PVC bell joints shall be
restrained for both C900 and C905 PVC pipe.
The bell joint restraint shall consist of either an approved restrained
PVC joint provided by the same manufacturer of the PVC pipe or an approved bell
joint restraint harness. All bell joint
restraint harness assemblies shall be made of DIP, coated with a manufacturer
applied epoxy coating or polyester powder coating, including stainless steel
bolts, nuts and rods. The bell joint
restraint harness shall be manufacturer approved for use with PVC pipe and
rated for at least 200-psi with a 3:1 safety factor.
C. PIPE INSTALLATION
1.
PVC
pipe shall be installed in accordance with AWWA C605. At a minimum, all PVC pipe shall be installed
at a Type 3 laying condition as specified by AWWA C605 for depth of
installation from 4-ft to 10-ft measured from the top of the pipe. The Type 3 laying condition requires the pipe
to be bedded on a minimum of 4-inches of select granular material that will
conform to the bottom of the pipe.
Select granular material shall consist of well-graded sand, gravel,
crushed gravel, crushed stone or crushed slag composed of hard, tough and
durable particles, and shall contain not more than 10 percent by weight of
material passing a 0.075 mm (No. 200) mesh sieve and no less than 95 percent by
weight passing the 25 mm (1 inch) sieve. Pipe laying on a flat bottom trench is
unacceptable.
Embedment material shall be
compacted to the top of the pipe. When
using mechanical compactors, avoid contact with the pipe. When compacting over the pipe crown, a
minimum cover of at least 8-inches or more in conformance with the
manufacturer’s requirements shall be maintained over the top of the pipe prior
to compacting. The maximum embedment
sizing shall be limited to materials passing a 3/4-inch sieve for angular
materials or 1-1/2-inches for rounded rock.
Embedment materials consisting of select material or native soils shall
be well drained, granular, free of rocks and other foreign materials and shall
be selected and placed to prevent gouges, crimping, or puncture of pipe, joints
or appurtenances.
2.
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.
3.
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.
4.
All
pipe shall be in nominal lengths of (20) twenty feet and shall be installed
with at least 48 inches of cover below the finished subgrade. Pipe shall be laid on true lines as directed
by the Engineer. Trenches shall be
sufficiently wide to adjust the alignment.
5.
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.
6.
Valves in the existing Town of
06530 VALVES AND APPURTENANCES
A. VALVES
1.
General
a)
Valves
shall be installed on all branches from feeder reclaimed water mains according
to the following schedule: 3 valves at
crosses; 2 valves at tees. When a loop
section of reclaimed water line is connected back into the feeder reclaimed
water main within a distance of 200 feet or less, only one valve will be
required in the feeder reclaimed main.
b)
Where
no reclaimed water line intersections are existing, a main line valve shall be
installed at every 100 feet per 1 inch diameter main up to a distance of 2000
feet between valves.
c)
Gate Valves, 12-inches and Smaller in Diameter:
All valves for reclaimed water
applications, 12-inches in diameter and smaller shall be resilient seated wedge
gate valves in conformance with the requirements of AWWA C509, (grey or ductile
iron body) or AWWA C515, (reduced wall ductile iron body) and provided with a
full circumferential pipe opening. All
gate valves shall be designed for a working pressure of 250-psi with a minimum
ULFM rating of 200-psi. Gate valves
shall be fusion bonded epoxy, (FBE) coated both interior and exterior at a
minimum of 10mils and the FBE coating shall be provided in conformance with AWWA
C550.
All gate valves 12-inches in
diameter and smaller shall be installed in the vertical position and shall be
provided with mechanical joint fittings.
Gate valves shall be restrained by wedge action retainer glands or other
approved manufacturer provided restraining systems. In all cases, the valve and piping shall be
restrained on both sides to sufficiently allow the valve to function as a dead
end.
All gate valves shall open left with
a non-rising stem and be provided with a 2-inch square operating nut. All gate valves shall be constructed with
triple o-ring seals in which 2 o-rings are located above the thrust collar and
1 o-ring is located below the thrust collar.
The two upper o-rings shall be replaceable with the valve fully open and
subjected to full rated working pressure.
The gate valve wedge shall be fully
encapsulated in molder rubber and fully retractable. All valves shall be rated for bi-directional
flow. All sealing gaskets shall be made
of EPDM rubber materials.
d)
Gate Valves, 16-inches through 24-inches:
Gate valves 16-inches through
24-inches shall comply with all specifications outlined for gate valves
12-inches and smaller in the previous section including the 250-psi pressure
rating. Gate valves 16-inches through
24-inches shall be fabricated exclusively with ductile iron construction in
conformance with AWWA C515.
As additional requirement, gate
valves 16-inches through 24-inches if installed vertically, shall be provided
with a minimum of 2-ft of overhead clearance between the top of the operator
nut and the finished subgrade.
e)
Gate valves, sixteen (16) inches and larger, installed in a horizontal
position, shall only be provided, as permitted by the Director of Engineering
for special circumstances where vertical alignment is not possible. All horizontal gate valves shall meet or
exceed the specifications outlined herein for vertical gate valves including
the 250-psi pressure rating. All
horizontal gate valves shall be equipped with bevel gears resulting in 4:1 turn
ratios through 24-inches in diameter,
f)
All
gate valves for reclaimed water applications shall be painted purple, Pantone
522 with an approved field application paint by the contractor prior to
installation or otherwise wrapped in purple
polyethylene wrap for required identification as a reclaimed water valve.
g)
Valves
shall be properly located, operable and at the correct elevation. All valves and reducers shall be rodded to
the tee or cross if one is located within 10 feet as shown in the Details.
If reducers cannot be rodded, concrete blocking or other restraining
methods will be required. The maximum
depth of the valve nut shall be 5 feet.
When valve extension kits are used, they must be manufactured by the
same company which manufactured the valve.
2.
Combination Air Valves
a)
Combination
air valves approved for use in reclaimed water installations shall be installed
at all high points of reclaimed water lines 8 inches in diameter or
larger and at other locations, such as major changes in slope, as directed by
the Town. A
b)
Combination
air valves shall be of the single housing style 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.
c)
Manholes
installed for the combination air valves shall meet all
requirements of Section 07000. The contractor shall paint the inside of all
manholes housing ARV’s with Pantone 522 purple paint and stencil the words “Caution: Reclaimed Water - Do Not Drink”
on the inside of the manhole in at least 2 locations on both sides of the
ARV. The lettering shall be at least
3-inches in height and be painted in black visible paint that can be easily
noticed from ground level.
3.
Valve Boxes
a)
Valve
boxes shall be cast iron, screw or telescopic type, with a 5 inch opening. Valve box ring adjustments will not be
allowed.
b)
Valve
box covers shall be square in shape (NOT round) and shall be designed for
AASHTO H-20 truck loadings. All valve
box covers shall be of non-interchangeable shape with potable water covers, and
cast on the top surface with a recognizable inscription indicating “Reclaimed
Water”. All valve box covers shall be
painted purple, Pantone 522.
c)
The
valve box shall be centered over the wrench nut and seated on compacted
backfill without touching the valve assembly.
All valve boxes shall be encased in a trowel finished 2' x 2' x 6"
pad of 3000-psi concrete beneath the asphalt with the cover flush with the top
of the pavement or flush with the finished grade. Precast concrete valve box encasements may not
be used for valve box encasement outside of paved areas. The maximum depth of the valve nut shall be 5
feet. When valve extension kits are
used, they must be manufactured by the same company that manufactured the
valve.
B. APPURTENANCES
1.
Pipe Fittings: Pipe fittings shall be cast or ductile iron
designed and manufactured as per AWWA C110.
Sizes of fittings up to and including 24 inches shall be designed
for an internal pressure of 350 psi, and larger size fittings shall be designed
for an internal pressure of 250 psi.
Compact ductile iron mechanical joint fittings designed and manufactured
as per AWWA C111 are also acceptable.
Gaskets shall be provided in conformance with AWWA C111 with EPDM rubber
preferred over SBR. Joints for fittings shall be mechanical and lined with
cement mortar with a seal coat of bituminous material, all in accordance with
AWWA C104. All fittings shall be
restrained to C900 or C905 pipe with an approved wedge action retainer gland or
other approved restraining method. All DIP fittings for reclaimed water use
shall be identified by painting or wrapping with polyethylene wrap in Pantone
522 purple.
2.
Blowoffs
a)
Blowoffs
installed on reclaimed water mains at the end of cul-de-sacs shall be a minimum
of 2 inches. Where
there is not sufficient pressure to thoroughly flush the system, a larger
blowoff will be required.
b)
Blowoff Assemblies shall be constructed as shown in the
Details. Blowoff assembly sizing for distribution
mains, 4-inches through 8-inches in diameter, shall be the typical 2-inch
assembly as shown in the details. The 2-inch valves shall be gate type
provided with threaded connections with a non‑rising stem and a 2 inch
operating nut, O-ring
seals and screwed ends. A full size valve is required on mains that
are planned to be extended. Typical
2-inch blowoff assemblies shall be provided with SDR 21 purple PVC pipe rated
at 200-psi and labeled for use with reclaimed water systems. The SDR 21 PVC pipe shall be joined with bell
and spigot joints restrained by solvent weld.
The PVC pipe shall be joined to the threaded connections of the 2-inch gate
valve with PVC transition couplings with metal threads. The metal inserts of the transition couplings
shall be made of stainless steel, brass or bronze. The transition couplings shall be connected
to the gate valve with threaded brass nipples.
Threaded PVC pipe and joints with connections threaded in PVC shall not
be allowed. All threaded connections
shall be provided with metal threads to maintain the pressure rating of the
blowoff assembly.
c)
For blowoff assemblies on main lines larger than 8-inches in
diameter, a blowoff assembly design including calculations for sizing shall be
provided by the design engineer of record and approved by the Engineering
Department.
d)
All blowoffs shall drain to the nearest sanitary sewer manhole when
there is a sewer manhole within 200-ft.
In cases where a sewer manhole is not within 200-ft, the blowoff
assembly may be omitted at the discretion of the Director of Engineering in
cases where another blowoff assembly is in close proximity.
e)
All blowoff assemblies for reclaimed water installations in which
the system will be initially charged with potable water, shall be required to
maintain an air gap separation from the blowoff discharge pipe to the sanitary
sewer manhole.
3.
Paint: An approved Pantone 522 purple is required to
meet color identification requirements under NC ACAC 02T .0909 and referenced
herein as the color code identification for reclaimed water piping, valves and
other appurtenances. Field application
of Pantone 522 purple to valves, fittings, manholes and other appurtenances
shall be implemented in conformance with manufacturer specifications including
surface preparation. In all cases a
minimum film thickness of 10-mils shall be applied. For applications open to daylight, the paint
shall have UV protection. The paint
shall consist of a two coat system consisting of a part high solids cured epoxy
as the primer with a polyurethane top coat.
For applications not exposed to sunlight, the paint shall be a two coat
application of a high solids cured epoxy.
4.
Wedge Action Retainer Glands
All fittings, valves, blowoffs and
appurtenances other than pipeline joints shall be restrained with approved
wedge action retainer glands. All wedge
action
retainer glands shall be manufactured as a one piece retainer gland for use with typical DIP mechanical joint fittings, gate valves and PVC C900 or C905 pipe. <