CODES

ADOPTS WITH AMENDMENTS:

International Residential Code 2015 (IRC 2015)

Chapter 1 Scope and Administration

Chapter 2 Definitions

Chapter 3 Building Planning

Chapter 4 Foundations

Chapter 5 Floors

Chapter 6 Wall Construction

Chapter 7 Wall Covering

Chapter 8 Roof-Ceiling Construction

Chapter 9 Roof Assemblies

Chapter 10 Chimneys and Fireplaces

Chapter 11 [RE] Energy Efficiency

Chapter 12 Mechanical Administration

Chapter 13 General Mechanical System Requirements

Chapter 14 Heating and Cooling Equipment and Appliances

Chapter 15 Exhaust Systems

Chapter 16 Duct Systems

Chapter 17 Combustion Air

Chapter 18 Chimneys and Vents

Chapter 19 Special Appliances, Equipment and Systems

Chapter 20 Boilers and Water Heaters

Chapter 21 Hydronic Piping

Chapter 22 Special Piping and Storage Systems

Chapter 23 Solar Thermal Energy Systems

Chapter 24 Fuel Gas

Chapter 25 Plumbing Administration

Chapter 26 General Plumbing Requirements

Chapter 27 Plumbing Fixtures

Chapter 28 Water Heaters

Chapter 29 Water Supply and Distribution

Chapter 30 Sanitary Drainage

Chapter 31 Vents

Chapter 32 Traps

Chapter 33 Storm Drainage

Chapter 34 General Requirements

Chapter 35 Electrical Definitions

Chapter 36 Services

Chapter 37 Branch Circuit and Feeder Requirements

Chapter 38 Wiring Methods

Chapter 39 Power and Lighting Distribution

Chapter 40 Devices and Luminaries

Chapter 41 Appliance Installation

Chapter 42 Swimming Pools

Chapter 43 Class 2 Remote-Control, Signaling and Power-Limited Circuits

Chapter 44 Referenced Standards

Appendix A Sizing and Capacities of Gas Piping

Appendix B Sizing of Venting Systems serving Appliances Equipped with Draft Hoods, Category I Appliances, and Appliances Listed for Use with Type B Vents

Appendix C Exit Terminals of Mechanical Draft and Direct-Vent Venting Systems

Appendix D Recommended Procedure for Safety Inspection of an Existing Appliance Installation

Appendix E Manufactured Housing used as Dwellings

Appendix F Passive Radon Gas Controls

Appendix G Piping Standards for Various Applications

Appendix J Existing Building and Structures

Appendix K Sound Transmission

Appendix N VENTING METHODS

Appendix O Automatic Vehicular Gates

Appendix P Sizing of Water Piping System

Appendix R Light Straw-Clay Construction

Appendix S Strawbale Construction

Potable water shall be supplied to plumbing fixtures and plumbing appliances except where treated rainwater, treated gray water or municipal reclaimed water is supplied to water closets, urinals and trap primers. The requirements of this section shall not be construed to require signage for water closets and urinals.
Where nonpotable water systems are installed, the piping conveying the nonpotable water shall be identified either by color marking, metal tags or tape in accordance with Sections P2901.2.1 through P2901.2.2.3.
Nonpotable water outlets such as hose connections, open-ended pipes and faucets shall be identified with signage that reads as follows: "Nonpotable water is utilized for [application name]. CAUTION: NONPOTABLE WATER. DO NOT DRINK." The words shall be legibly and indelibly printed on a tag or sign constructed of corrosion-resistant water-proof material or shall be indelibly printed on the fixture. The letters of the words shall be not less than 0.5 inches (12.7 mm) in height and in colors in contrast to the background on which they are applied. In addition to the required wordage, the pictograph shown in Figure P2901.2.1 shall appear on the required signage.

FIGURE P2901.2.1
PICTOGRAPH-DO NOT DRINK
Nonpotable distribution piping shall be purple in color and shall be embossed or integrally stamped or marked with the words: "CAUTION: NONPOTABLE WATER-DO NOT DRINK" or the piping shall be installed with a purple identification tape or wrap. Pipe identification shall include the contents of the piping system and an arrow indicating the direction of flow. Hazardous piping systems shall contain information addressing the nature of the hazard. Pipe identification shall be repeated at intervals not exceeding 25 feet (7620 mm) and at each point where the piping passes through a wall, floor or roof. Lettering shall be readily observable within the room or space where the piping is located.
The color of the pipe identification shall be discernable and consistent throughout the building. The color purple shall be used to identify reclaimed, rain and gray water distribution systems.
The size of the background color field and lettering shall comply with Table P2901.2.2.2.


Table 2.26.12.1
Symbol Identification
PIPE DIAMETER
(inches)
LENGTH OF BACKGROUND COLOR FIELD
(inches)
SIZE OF LETTERS
(inches)
34 to 114 8 0.5
112 to 2 8 0.75
212 to 6 12 1.25
8 to 10 2 2.5
over 10 32 3.5
For SI: 1 inch = 25.4 mm
Where used, identification tape shall be not less than 3 inches (76 mm) wide and have white or black lettering on a purple field stating "CAUTION: NONPOTABLE WATER-DO NOT DRINK." Identification tape shall be installed on top of nonpotable rainwater distribution pipes and fastened not greater than every 10 feet (3048 mm) to each pipe length, and run continuously the entire length of the pipe.
A potable water supply system shall be designed and installed as to prevent contamination from nonpotable liquids, solids or gases being introduced into the potable water supply. Connections shall not be made to a potable water supply in a manner that could contaminate the water supply or provide a cross-connection between the supply and a source of contamination except where approved backflow prevention assemblies, backflow prevention devices or other means or methods are installed to protect the potable water supply. Cross-connections between an individual water supply and a potable public water supply shall be prohibited.
The supply lines and fittings for every plumbing fixture shall be installed so as to prevent backflow. Plumbing fixture fittings shall provide backflow protection in accordance with ASME A112.18.1/CSA B125.1.
A means of protection against backflow shall be provided in accordance with Sections P2902.3.1 through P2902.3.6. Backflow prevention applications shall conform to Table P2902.3, except as specifically stated in Sections P2902.4 through P2902.5.5.


TABLE P2902.3
APPLICATION FOR BACKFLOW PREVENTERS
DEVICE DEGREE OF HAZARDa APPLICATIONb APPLICABLE
STANDARDS
Backflow Prevention Assemblies
Double check backflow prevention assembly and
double check fire protection backflow prevention
assembly
Low hazard Backpressure or backsiphonage
Sizes 38" - 16"
ASSE 1015, AWWA C510,
CSA B64.5, CSA B64.5.1
Double check detector fire protection backflow
prevention assemblies
Low hazard Backpressure or backsiphonage
Sizes 2" - 16"
ASSE 1048
Pressure vacuum breaker assembly High or low hazard Backsiphonage only Sizes 12" - 2" ASSE 1020, CSA B64.1.2
Reduced pressure principle backflow prevention
assembly and reduced pressure principle fire pro-
tection backflow prevention assembly
High or low hazard Backpressure or backsiphonage
Sizes 38" - 16"
ASSE 1013, AWWA C511,
CSA B64.4, CSA B64.4.1
Reduced pressure detector fire protection back-
flow prevention assemblies
High or low hazard Backsiphonage or backpressure
(Fire sprinkler systems)
ASSE 1047
Spill-resistant vacuum breaker High or low hazard Backsiphonage only Sizes 14" - 2" ASSE 1056, CSA B64.1.3
Backflow Preventer Plumbing Devices
Antisiphon-type fill valves for gravity water closet
flush tanks
High hazard Backsiphonage only ASSE 1002, CSA B125.3
Backflow preventer with intermediate atmo-
spheric vents
Low hazard Backpressure or backsiphonage
Sizes 14" - 38"
ASSE 1012, CSA B64.3
Dual-check-valve-type backflow preventers Low hazard Backpressure or backsiphonage
Sizes 14" - 1"
ASSE 1024, CSA B64.6
Hose-connection backflow preventer High or low hazard Low head backpressure, rated
working pressure backpressure or
backsiphonage Sizes 12"- 1"
ASSE 1052, CSA B64.2.1.1
Hose-connection vacuum breaker High or low hazard Low head backpressure or backsi-
phonage Sizes 12" 34", 1"
ASSE 1011, CSA B64.2,
B64.2.1
Laboratory faucet backflow preventer High or low hazard Low head backpressure and back-
siphonage
ASSE 1035, CSA B64.7
Pipe-applied atmospheric-type vacuum breaker High or low hazard Backsiphonage only Sizes 14" - 4 " ASSE 1001, CSA B64.1.1
Vacuum breaker wall hydrants, frost-resistant,
automatic-draining type
High or low hazard Low head backpressure or backsi-
phonage Sizes 34" - 1"
ASSE 1019, CSA B64.2.2
Other Means Or Methods
Air gap High or low hazard Backsiphonage only ASME A112.1.2
Air gap fittings for use with plumbing fixtures,
appliances and appurtenances
High or low hazard Backsiphonage or backpressure ASME A112.1.3
For SI: 1 inch= 25.4 mm.
  1. Low hazard-See Pollution (Section R202). High hazard-See Contamination (Section R202).
  2. See Backpressure (Section R202). See Backpressure, Low Head (Section R202). See Backsiphonage (Section R202).
Air gaps shall comply with ASME A112.1.2 and air gap fittings shall comply with ASME A112.1.3. An air gap shall be measured vertically from the lowest end of a water outlet to the flood level rim of the fixture or receptor into which the water outlets discharges to the floor. The required air gap shall be not less than twice the diameter of the effective opening of the outlet and not less than the values specified in Table P2902.3.1.

TABLE P2902.3.1
MINIMUM AIR GAP
FIXTURE MINIMUM AIR GAP
Away from a walla
(inches)
Close to a wall
(inches)
Effective openings greater than 1 inch Two times the diameter
of the effective opening
Three times the diameter
of the effective opening
Lavatories and other fixtures with effective opening not greater than 12 inch
in diameter
1 1.5
Over-rim bath fillers and other fixtures with effective openings not greater
than 1 inch in diameter
2 3
Sink, laundry trays, gooseneck back faucets and other fixtures with effective
openings not greater than 34 inch in diameter
1.5 2.5
For SI: 1 inch = 25.4 mm.
  1. Applicable where walls or obstructions are spaced from the nearest inside edge of the spout opening a distance greater than three times the diameter of the effective opening for a single wall, or a distance greater than four times the diameter of the effective opening for two intersecting walls.
Atmospheric-type vacuum breakers shall conform to ASSE 1001 or CSA B64.1.1. Hose-connection vacuum breakers shall conform to ASSE 1011, ASSE 1019, ASSE 1035, ASSE 1052, CSA B64.2, CSA B64.2.1, CSA B64.2.1.1, CSA B64.2.2 or CSA B64.7. Both types of vacuum breakers shall be installed with the outlet continuously open to the atmosphere. The critical level of the atmospheric vacuum breaker shall be set at not less than 6 inches (152 mm) above the highest elevation of downstream piping and the flood level rim of the fixture or device.
Backflow preventers with intermediate atmospheric vents shall conform to ASSE 1012 or CSA B64.3. These devices shall be permitted to be installed where subject to continuous pressure conditions. These devices shall be prohibited as a means of protection where any hazardous chemical additives are introduced downstream of the device. The relief opening shall discharge by air gap and shall be prevented from being submerged.
Pressure vacuum breaker assemblies shall conform to ASSE 1020 or CSA B64.1.2. Spill-resistant vacuum breaker assemblies shall comply with ASSE 1056. These assemblies are designed for installation under continuous pressure conditions where the critical level is installed at the required height. The critical level of a pressure vacuum breaker and a spill-resistant vacuum breaker assembly shall be set at not less than 12 inches (304 mm) above the highest elevation of downstream piping and the flood level rim of the fixture or device. Pressure vacuum breaker assemblies shall not be installed in locations where spillage could cause damage to the structure.
Reduced pressure principle backflow prevention assemblies and reduced pressure principle fire protection backflow prevention assemblies shall conform to ASSE 1013, AWWA C511, CSA B64.4 or CSA B64.4.1. Reduced pressure detector fire protection backflow prevention assemblies shall conform to ASSE 1047. These devices shall be permitted to be installed where subject to continuous pressure conditions. The relief opening shall discharge by air gap and shall be prevented from being submerged.
Double check backflow prevention assemblies shall conform to ASSE 1015, CSA B64.5, CSA B64.5.1 or AWWA C510. Double check detector fire protection backflow prevention assemblies shall conform to ASSE 1048. These assemblies shall be capable of operating under continuous pressure conditions.
Dual check backflow preventers shall conform with ASSE 1024 or CSA B64.6.
Potable water openings and outlets shall be protected by an air gap, a reduced pressure principle backflow prevention assembly, an atmospheric vent, an atmospheric-type vacuum breaker, a pressure-type vacuum breaker assembly or a hose connection backflow preventer.
Flush tanks shall be equipped with an antisiphon fill valve conforming to ASSE 1002 or CSA B 125.3. The critical level of the fill valve shall be located not less than 1 inch (25 mm) above the top of the flush tank overflow pipe.
Approved deck-mounted or equipment-mounted vacuum breakers and faucets with integral atmospheric vacuum breakers or spill-resistant vacuum breaker assemblies shall be installed in accordance with the manufacturer's instructions and the requirements for labeling. The critical level of the breakers and assemblies shall be located at not less than 1 inch (25 mm) above the flood level rim.
Sillcocks, hose bibbs, wall hydrants and other openings with a hose connection shall be protected by an atmospheric-type or pressure-type vacuum breaker, a pressure vacuum breaker assembly or a permanently attached hose connection vacuum breaker.

Exceptions:
  1. This section shall not apply to water heater and boiler drain valves that are provided with hose connection threads and that are intended only for tank or vessel draining.
  2. This section shall not apply to water supply valves intended for connection of clothes washing machines where backflow prevention is otherwise provided or is integral with the machine.
Connections to the potable water shall conform to Sections P2902.5.1 through P2902.5.5.
Where chemicals will not be introduced into a boiler, the potable water supply to the boiler shall be protected from the boiler by a backflow preventer with an intermediate atmospheric vent complying with ASSE 1012 or CSA B64.3. Where chemicals will be introduced into a boiler, the potable water supply to the boiler shall be protected from the boiler by an air gap or a reduced pressure principle backflow prevention assembly complying with ASSE 1013, CSA B64.4 or AWWA C511.
Heat exchangers using an essentially toxic transfer fluid shall be separated from the potable water by double-wall construction. An air gap open to the atmosphere shall be provided between the two walls. Single-wall construction heat exchangers shall be used only where an essentially nontoxic transfer fluid is utilized.
The potable water supply to lawn irrigation systems shall be protected against backflow by an atmospheric vacuum breaker, a pressure vacuum breaker assembly or a reduced pressure principle backflow prevention assembly. Valves shall not be installed downstream from an atmospheric vacuum breaker. Where chemicals are introduced into the system, the potable water supply shall be protected against backflow by a reduced pressure principle backflow prevention assembly.
The potable water supply to automatic fire sprinkler systems shall be protected against backflow by a double check-valve assembly or a reduced pressure principle backflow preventer.

Exception: Isolation of the water distribution system is not required for deluge, preaction, or dry pipe system.

R 408.30539a
Where systems contain chemical additives or antifreeze, or where systems are connected to a nonpotable secondary water supply, the potable water supply shall be protected against backflow by a reduced pressure principle backflow prevention assembly or a reduced pressure principle fire protection backflow prevention assembly. Where chemical additives or antifreeze is added to only a portion of an automatic fire sprinkler or standpipe system, the reduced pressure principle fire protection backflow preventer shall be permitted to be located so as to isolate that portion of the system.
Where a solar thermal system heats potable water to supply a potable hot water distribution or any other type of heating system, the solar thermal system shall be in accordance with Section P2902.5.5.1, P2902.5.5.2 or P2902.5.5.3 as applicable.
Water supplies of any type shall not be connected to the solar heating loop of an indirect solar thermal hot water heating system. This requirement shall not prohibit the presence of inlets or outlets on the solar heating loop for the purposes of servicing the fluid in the solar heating loop.
Where a solar thermal system directly heats potable water for a potable water distribution system, the pipe, fittings, valves and other components that are in contact with the potable water in the system shall comply with the requirements of Chapter 29.
Where a solar thermal system directly heats water for a system other than a potable water distribution system, a potable water supply connected to such system shall be protected by a backflow preventer with an intermediate atmospheric vent complying with ASSE 1012. Where a solar thermal system directly heats chemically treated water for a system other than a potable water distribution system, a potable water supply connected to such system shall be protected by a reduced pressure principle backflow prevention assembly complying with ASSE 1013.
Access shall be provided to backflow preventers as specified by the manufacturer's installation instructions.
Outdoor enclosures for backflow prevention devices shall comply with ASSE 1060.
Backflow preventers shall not be located in areas subject to freezing except where they can be removed by means of unions, or are protected by heat, insulation or both.
The termination of the piping from the relief port or air gap fitting of the backflow preventer shall discharge to an approved indirect waste receptor or to the outdoors where it will not cause damage or create a nuisance.
The water service and water distribution systems shall be designed and pipe sizes shall be selected such that under conditions of peak demand, the capacities at the point of outlet discharge shall not be less than shown in Table P2903.1.


TABLE P2903.1
REQUIRED CAPACITIES AT POINT OF OUTLET DISCHARGE
FIXTURE SUPPLY
OUTLET SERVING
FLOW RATE (gpm) FLOW PRESSURE (psi)
Bathtub, balanced-pressure, thermostatic or combination balanced - pressure/thermostatic mixing valve 4 20
Bidet, thermostatic mixing valve 2 20
Dishwasher 2.75 8
Laundry tray 4 8
Lavatory 0.8 8
Shower, balanced-pressure, thermostatic or combination balanced - pressure/thermostatic mixing valve 2.5a 20
Sillcock, hose bibb 5 8
Sink 1.75 8
Water closet, flushometer tank 1.6 20
Water closet, tank, close coupled 3 20
Water closet, tank, one-piece 6 20
For SI: 1 pound per square inch= 6.895 kPa, 1 gallon per minute= 3.785 L/m.
  1. Where the shower mixing valve manufacturer indicates a lower flow rating for the mixing valve, the lower value shall be applied.
The maximum water consumption flow rates and quantities for plumbing fixtures and fixture fittings shall be in accordance with Table P2903.2.


TABLE P2903.2
MAXIMUM FLOW RATES AND CONSUMPTION FOR PLUMBING FIXTURES AND FIXTURE FITTINGSb
PLUMBING FIXTURE
OR FIXTURE FITTING
PLUMBING FIXTURE
OR FIXTURE FITTING
Lavatory faucet 2.2 gpm at 60 psi
Shower head#a 2.5 gpm at 80 psi
Sink faucet 2.2 gpm at 60 psi
Water closet 1.6 gallons per flushing cycle
For SI: 1 gallon per minute= 3.785 L/m, 1 pound per square inch= 6.895 kPa.
  1. A handheld shower spray shall be considered a shower head.
  2. Consumption tolerances shall be determined from referenced standards.
Where the water pressure supplied by the public water main or an individual water supply system is insufficient to provide for the minimum pressures and quantities for the plumbing fixtures in the building, the pressure shall be increased by means of an elevated water tank, a hydropnuematic pressure booster system or a water pressure booster pump.
The static water pressure shall be not greater than 80 psi (551 kPa). Where the main pressure exceeds 80 psi (551 kPa), an approved pressurereducing valve conforming to ASSE 1003 or CSA B356 shall be installed on the domestic water branch main or riser at the connection to the water service pipe.
A means for controlling increased pressure caused by thermal expansion shall be installed where required in accordance with Sections P2903.4.1 and P2903.4.2.
For water service system sizes up to and including 2 inches (51 mm), a device for controlling pressure shall be installed where, because of thermal expansion, the pressure on the down stream side of a pressure-reducing valve exceeds the pressure-reducing valve setting.
Where a backflow prevention device, check valve or other device is installed on a water supply system using storage water heating equipment such that thermal expansion causes an increase in pressure, a device for controlling pressure shall be installed.
The flow velocity of the water distribution system shall be controlled to reduce the possibility of water hammer. Water-hammer arrestors shall be installed in accordance with the manufacturer's instructions. Water-hammer arrestors shall conform to ASSE 1010.
Supply loads in the building water distribution system shall be determined by total load on the pipe being sized, in terms of water supply fixture units (w.s.f.u.), as shown in Table P2903.6, and gallon per minute (gpm) flow rates [see Table P2903.6(1)]. For fixtures not listed, choose a w.s.f.u. value of a fixture with similar flow characteristics.


TABLE P2903.6
WATER-SUPPLY FIXTURE-UNIT VALUES FOR VARIOUS PLUMBING FIXTURES AND FIXTURE GROUPS
TYPE OF FIXTURES OR GROUP OF FIXTURES WATER-SUPPLY FIXTURE-UNIT VALUE (w.s.f.u.)
Hot Cold Combined
Bathtub (with/without overhead shower head) 1.0 1.0 1.4
Clothes washer 1.0 1.0 1.4
Dishwasher 1.4 - 1.4
Full-bath group with bathtub (with/without shower head) or shower stall 1.5 2.7 3.6
Half-bath group (water closet and lavatory) 0.5 2.5 2.6
Hose bibb (sillcock)#a - 2.5 2.5
Kitchen group (dishwasher and sink with or without food-waste disposer) 1.9 1.0 2.5
Kitchen sink 1.0 1.0 1.4
Laundry group (clothes washer standpipe and laundry tub) 1.8 1.8 2.5
Laundry tub 1.0 1.0 1.4
Lavatory 0.5 0.5 0.7
Shower stall 1.0 1.0 1.4
Water closet (tank type) - 2.2 2.2
For SI: 1 gallon per minute= 3.785 Um.
  1. The fixture unit value 2.5 assumes a flow demand of 2.5 gpm, such as for an individual lawn sprinkler device. If a hose bibb or sill cock will be required to furnish a greater flow, the equivalent fixture-unit value may be obtained from this table or Table P2903.6(1).




TABLE P2903.6(1)
CONVERSIONS FROM WATER SUPPLY FIXTURE UNIT TO GALLON PER MINUTE FLOW RATES
SUPPLY SYSTEMS PREDOMINANTLY FOR FLUSH TANKS SUPPLY SYSTEMS PREDOMINANTLY FOR FLUSHOMETER VALVES
Load Demand Load Demand
(Water supply fixture units) (Gallons per minute) (Cubic feet per minute) (Water supply fixture units) (Gallons per minute) Cubic feet per minute)
1 3.0 0.04104 - - -
2 5.0 0.0684 - - -
3 6.5 0.86892 - - -
4 8.0 1.06944 - - -
5 9.4 1.256592 5 15.0 2.0052
6 10.7 1.430376 6 17.4 2.326032
7 11.8 1.577424 7 19.8 2.646364
8 12.8 1.711104 8 22.2 2.967696
9 13.7 1.831416 9 24.6 3.288528
10 14.6 1.951728 10 27.0 3.60936
11 15.4 2.058672 11 27.8 3.716304
12 16.0 2.13888 12 28.6 3.823248
13 16.5 2.20572 13 29.4 3.930192
14 17.0 2.27256 14 30.2 4.037136
15 17.5 2.3394 15 31.0 4.14408
16 18.0 2.90624 16 31.8 4.241024
17 18.4 2.459712 17 32.6 4.357968
18 18.8 2.513184 18 33.4 4.464912
19 19.2 2.566656 19 34.2 4.571856
20 19.6 2.620128 20 35.0 4.6788
25 21.5 2.87412 25 38.0 5.07984
30 23.3 3.114744 30 42.0 5.61356
35 24.9 3.328632 35 44.0 5.88192
40 26.3 3.515784 40 46.0 6.14928
45 27.7 3.702936 45 48.0 6.41664
50 29.1 3.890088 50 50.0 6.684
For SI: 1 gallon per minute= 3.785 L/m, 1 cubic foot per minute= 0.4719 L/s.
The size of the water service pipe shall be not less than 34 inch (19 mm) diameter. The size of water service mains, branch mains and risers shall be determined from the water supply demand [gpm (L/m)], available water pressure [psi (kPa)] and friction loss caused by the water meter and developed length of pipe [feet (m)], including equivalent length of fittings. The size of each water distribution system shall be determined according to design methods conforming to acceptable engineering practice, such as those methods in Appendix P and shall be approved by the code official.
Hot water and cold water manifolds installed with parallel-connected individual distribution lines and cold water manifolds installed with gridded distribution lines to each fixture or fixture fitting shall be designed in accordance with Sections P2903.8.1 through P2903.8.5. Gridded systems for hot water distribution systems shall be prohibited.
Manifolds shall be sized in accordance with Table P2903.8.1. Total gallons per minute is the demand for all outlets.

TABLE P2903.8.1
MANIFOLD SIZING
PLASTIC METALLIC
Nominal Size ID
(inches)
Maximum#a
gpm
Nominal Size ID
(inches)
Maximum#a
gpm
#3.4 17 #3/4 11
1 29 1 20
1#1.2 66 1#1.2 44
For SI: 1 inch= 25.4 mm, 1 gallon per minute= 3.785 L/m,
1 foot per second = 0.3048 m/s.
Note: See Table P2903.6(1) for w.s.f.u and Table 2903.6(1) for gallon-perminute(gpm) flow rates.
  1. Based on velocity limitation: plastic-12 fps; metal-8 fps.
Where the developed length of the distribution line is 60 feet (18288 mm) or less, and the available pressure at the meter is not less than 40 pounds per square inch (276 kPa), the size of individual distribution lines shall be not less than 38 inch (10 mm) diameter. Certain fixtures such as one-piece water closets and whirlpool bathtubs shall require a larger size where specified by the manufacturer. If a water heater is fed from the end of a cold water manifold, the manifold shall be one size larger than the water heater feed.
Plastic piping bundles shall be secured in accordance with the manufacturer's instructions and supported in accordance with Section P2605. Bundles that have a change in direction equal to or greater than 45 degrees (0.79 rad) shall be protected from chafing at the point of contact with framing members by sleeving or wrapping.
Fixture valves, when installed, shall be located either at the fixture or at the manifold. Valves installed at the manifold shall be labeled indicating the fixture served.
A readily accessible air bleed shall be installed in hose bibb supplies at the manifold or at the hose bibb exit point.
Valves shall be installed in accordance with Sections P2903.9.1 through P2903.9.5.
Each dwelling unit shall be provided with an accessible main shutoff valve near the entrance of the water service. The valve shall be of a full-open type having nominal restriction to flow, with provision for drainage such as a bleed orifice or installation of a separate drain valve. Additionally, the water service shall be valved at the curb or lot line in accordance with local requirements.
A readily accessible full-open valve shall be installed in the cold-water supply pipe to each water heater at or near the water heater.
Shutoff valves shall be required on each fixture supply pipe to each plumbing appliance and to each plumbing fixture other than bathtubs and showers. Valves serving individual plumbing fixtures, plumbing appliances, risers and branches shall be accessible.
Valves shall be compatible with the type of piping material installed in the system. Valves shall conform to one of the standards listed in Table P2903.9.4 or shall be approved. Valves intended to supply drinking water shall meet the requirements of NSF 61.



TABLE P2903.9.4
VALVES
MATERIAL STANDARD
Chlorinated polyvinyl chloride (CPVC) plastic ASME A112.4.14, ASME A112.18.1/CSA B125.1,
ASTM F1 970, CSA B125.3
Copper or copper alloy ASME A112.4.14, ASME A112.18.1/CSA B125.1,
ASME B16.34, CSA B125.3, MSS SP-67, MSS SP-80, MSS SP-110
Gray and ductile iron ASTM Al126, AWW A C500, AWWA C504, AWWA C507,
MSS SP-42, MSS SP-67, MSS SP-70, MSS SP-71, MSS SP-72,
MSS SP-78
Cross-linked polyethylene (PEX) plastic ASME A112.4.14, ASME A112.18.1/CSA B125.1, CSA B125.3,
NSF 359
Polypropylene (PP) plastic ASME A112.4.14, ASTM F2389
Polyvinyl chloride (PVC) plastic ASME A112.4.14, ASTM F1970
Potable water outlets and combination stop-and-waste valves shall not be installed underground or below grade. Freezeproof yard hydrants that drain the riser into the ground are considered to be stop-and-waste valves.

Exception: Installation of freezeproof yard hydrants that drain the riser into the ground shall be permitted if the potable water supply to such hydrants is protected upstream of the hydrants in accordance with Section P2902 and the hydrants are permanently identified as nonpotable outlets by approved signage that reads as follows: "Caution, Nonpotable Water. Do Not Drink."
Hose bibbs subject to freezing, including the "frostproof' type, shall be equipped with an accessible stop-and-waste-type valve inside the building so that they can be controlled and drained during cold periods.

Exception: Frostproof hose bibbs installed such that the stem extends through the building insulation into an open heated or semiconditioned space need not be separately valved (see Figure P2903.10).



FIGURE P2903.10
TYPICAL FROSTPROOF HOSE BIBB INSTALLATION NOT REQUIRING SEPARATE VALUE
Drain water heat recovery units shall be in accordance with Section N1103.5.4.
Where installed, residential fire sprinkler systems, or portions thereof, shall be in accordance with NFPA 13D.

R 408.30539a
The installation of water service pipe, water distribution pipe, fittings, valves, appurtenances and gaskets shall be prohibited in soil and groundwater that is contaminated with solvents, fuels, organic compounds or other detrimental materials that cause permeation, corrosion, degradation or structural failure of the water service or water distribution piping material.
Where detrimental conditions are suspected by or brought to the attention of the building official, a chemical analysis of the soil and groundwater conditions shall be required to ascertain the acceptability of the water service material for the specific installation.
Where a detrimental condition exists, approved alternate materials or alternate routing shall be required.
The lead content in pipe and fittings used in the water supply system shall be not greater than 8 percent.
Pipe, pipe fittings, joints, valves, faucets and fixture fittings utilized to supply water for drinking or cooking purposes shall comply with NSF 372 and shall have a weighted average lead content of 0.25 percent lead or less.
Polyethylene pipe shall be cut square using a cutter designed for plastic pipe. Except where joined by heat fusion, pipe ends shall be chamfered to remove sharp edges. Pipe that has been kinked shall not be installed. For bends, the installed radius of pipe curvature shall be greater than 30 pipe diameters or the coil radius where bending with the coil. Coiled pipe shall not be bent beyond straight. Bends within 10 pipe diameters of any fitting or valve shall be prohibited. Joints between polyethylene plastic pipe and fittings shall comply with Section P2906.3.1 or P2906.3.2.
Joint surfaces shall be clean and free from moisture. Joint surfaces shall be heated to melting temperature and joined. The joint shall be undisturbed until cool. Joints shall be made in accordance with ASTM F2620 and the manufacturer's instructions.

R 408.30544c
Mechanical joints shall be installed in accordance with the manufacturer's instructions.
Water service pipe shall conform to NSF 61 and shall conform to one of the standards indicated in Table P2906.4. Water service pipe or tubing, installed underground and outside of the structure, shall have a working pressure rating of not less than 160 pounds per square inch at 73°F (1103 kPa at 23°C). Where the water pressure exceeds 160 pounds per square inch (1103 kPa), piping material shall have a rated working pressure equal to or greater than the highest available pressure. Water service piping materials not third-party certified for water distribution shall terminate at or before the full open valve located at the entrance to the structure. Ductile iron water service piping shall be cement mortar lined in accordance with AWWA C104/A21.4.



TABLE P2906.4
WATER SERVICE PIPE
MATERIAL STANDARD
Acrylonitrile butadiene styrene (ABS) plastic pipe ASTM D1527; ASTM D2282
Chlorinated polyvinyl chloride (CPVC) plastic pipe ASTM D2846; ASTM F441; ASTM F442; CSA B137.6
Chlorinated polyvinyl chloride/aluminum/chlorinated polyvinyl chloride
(CPVC/AL/CPVC) plastic pipe
ASTMF2855
Copper or copper-alloy pipe ASTM B42; ASTM B43; ASTM B302
Copper or copper-alloy tubing (Type K, WK, L, WL, M or WM) ASTM B75; ASTM B88; ASTM B251 ; ASTM B447
Cross-linked polyethylene/aluminum/cross-linked polyethylene
(PEX-AL-PEX) pipe
ASTM F1281; ASTM F2262; CSA B137.10
Cross-linked polyethylene/aluminum/high-density polyethylene
(PEX-AL-HDPE) pipe
ASTMFJ986
Cross-linked polyethylene (PEX) plastic tubing ASTM F876; ASTM F877; CSA B137.5
Ductile iron water pipe AWWA C115/A21.15; AWWA Cl51/A21.51
Galvanized steel pipe ASTMA53
Polyethylene/aluminum/polyethylene (PE-AL-PE) pipe ASTM F1282 ; CSA B137.9
Polyethylene (PE) plastic pipe ASTM D2104 ; ASTM D2239 ; AWWA C901; CSA B137.1
Polyethylene (PE) plastic tubing ASTM D2737 ; AWWA C901; CSA B137.1
Polyethylene of raised temperature (PE-RT) plastic tubing ASTM F2769
Polypropylene (PP) plastic tubing ASTM F2389; CSA B137.11
Polyvinyl chloride (PVC) plastic pipe ASTM D1785 ; ASTM D2241; ASTM D2672; CSA B137.3
Stainless steel (Type 304/304L) pipe ASTM A312; ASTM A778
Stainless steel (Type 316/316L) pipe ASTM A312; ASTM A778
Trenching, pipe installation and backfilling shall be in accordance with Section P2604. Where water service piping is located in the same trench with the building sewer, such sewer shall be constructed of materials listed in Table P3002.1(2). Where the building sewer piping is not constructed of materials indicated in Table P3002.1(2), the water service pipe and the building sewer shall be horizontally separated by not less than 5 feet (1524 mm) of undisturbed or compacted earth. The required separation distance shall not apply where a water service pipe crosses a sewer pipe, provided the water service is sleeved to a point not less than 5 feet (1524 mm) horizontally from the sewer pipe centerline on both sides of such crossing. The sleeve shall be of pipe materials indicated in Table P2906.4, P3002.1(2) or P3002.2. The required separation distance shall not apply where the bottom of the water service pipe that is located within 5 feet (1524 mm) of the sewer is not less than 12 inches (305 mm) above the highest point of the top of the building sewer.
Water-distribution piping within dwelling units shall conform to NSF 61 and shall conform to one of the standards indicated in Table P2906.5. Hot-water-distribution pipe and tubing shall have a pressure rating of not less than 100 psi at 180°F (689 kPa at 82°C).


TABLE P2906.5
WATER DISTRIBUTION PIPE
MATERIAL STANDARD
Chlorinated polyvinyl chloride (CPVC) plastic pipe and tubing ASTM D2846; ASTM F441; ASTM F442;
CSAB137.6
Chlorinated polyvinyl chloride/aluminum/chlorinated polyvinyl chloride
(CPVC/AL/CPVC) plastic pipe
ASTM F2855
Copper or copper-alloy pipe ASTM B42; ASTM B43; ASTM B302
Copper or copper-alloy tubing (Type K, WK, L, WL, M or WM) ASTM B75; ASTM B88; ASTM B251;
ASTM B447
Cross-linked polyethylene (PEX) plastic tubing ASTM F876; ASTM F877; CSA B137.5
Cross-linked polyethylene/aluminum/cross-linked polyethylene (PEX-AL-PEX) pipe ASTM F1281; ASTM F2262; CSA 1l37.10
Cross-linked polyethylene/aluminum/high-density polyethylene (PEX-AL-HDPE) pipe ASTM F1986
Galvanized steel pipe ASTM A53
Polyethylene/aluminum/polyethylene (PE-AL-PE) composite pipe ASTM F1282
Polyethylene of raised temperature (PE-RT) plastic tubing ASTM F2769
Polypropylene (PP) plastic pipe or tubing ASTM F2389; CSA B137.11
Stainless steel (Type 304/304L) pipe ASTM A312; ASTM A778
Pipe fittings shall be approved for installation with the piping material installed and shall comply with the applicable standards indicated in Table P2906.6. Pipe fittings used in water supply systems shall comply with NSF 61.


TABLE P2906.6
PIPE FITIINGS
MATERIAL STANDARD
Acrylonitrile butadiene styrene (ABS) plastic ASTM D2468
Cast-iron ASTM D2468
Chlorinated polyvinyl chloride (CPVC) plastic ASSE 1061; ASTM D2846; ASTM F437; ASTM F438;
ASTM F439; CSA B137.6
Copper or copper alloy ASSE 1061; ASME B16.15; ASME B16.18; ASME B16.22;
ASME B16.26; ASME B16.51
Cross-linked polyethylene/aluminum/high-density polyethylene
(PEX-AL-HDPE)
ASTM F1986
Fittings for cross-linked polyethylene (PEX) plastic tubing ASSE 1061; ASTM F877; ASTM F1807; ASTM F1960;
ASTM F2080; ASTM F2098; ASTM F2159; ASTM F2434;
ASTM F2735; CSA B137.5
Gray iron and ductile iron AWWA C110/A21.10; AWWA C153/A21.53
Malleable iron ASME B16.3
Insert fittings for
Polyethylene/aluminum/polyethylene (PE-AL-PE) and cross-linked
polyethylene/aluminum/cross-linked polyethylene (PEX-AL-PEX)
ASTM F1974; ASTM F1281; ASTM F1282; CSA B137.9;
CSA B137.10
Polyethylene (PE) plastic ASTM D2609; CSA B137.1
Fittings for polyethylene of raised temperature (PE-RT) plastic tubing ASTM F1807; ASTM F2098; ASTM F2159; ASTM F2735;
ASTM F2769
Polypropylene (PP) plastic pipe or tubing ASTM F2389; CSA B137.11
Polyvinyl chloride (PVC) plastic ASTM D2464; ASTM D2466; ASTM D2467; CSA B137.2;
CSA B137.3
Stainless steel (Type 304/304L) pipe ASTM A312; ASTM A778
Stainless steel (Type 316/316L) pipe ASTM A312; ASTM A778
Steel ASME B16.9; ASME B16.11; ASME B16.28
Flexible water connectors, exposed to continuous pressure, shall conform to ASME A112.18.6/CSA B125.6. Access shall be provided to flexible water connectors.
Joints and connections in the plumbing system shall be gas tight and water tight for the intended use or required test pressure.
Joints in plastic piping shall be made with approved fittings by solvent cementing, heat fusion, corrosion-resistant metal clamps with insert fittings or compression connections. Flared joints for polyethylene pipe shall be permitted in accordance with Section P2906.3.
Solvent-cemented joints shall comply with Sections P2906.9.1.1 through P2906.9.1.3.
Solvent cement for ABS plastic pipe conforming to ASTM D2235 shall be applied to all joint surfaces.
Joint surfaces shall be clean and free from moisture. Joints shall be made in accordance with the pipe, fitting or solvent cement manufacturer's installation instructions. Where such instructions require a primer to be used, an approved primer shall be applied, and a solvent cement, orange in color and conforming to ASTM F493, shall be applied to joint surfaces. Where such instructions allow for a one-step solvent cement, yellow or red in color and conforming to ASTM F493, to be used, the joint surfaces shall not require application of a primer before the solvent cement is applied. The joint shall be made while the cement is wet, and in accordance with ASTM D2846 or ASTM F493. Solvent cement joints shall be permitted above or below ground.
Joint surfaces shall be clean and free from moisture, and an approved primer shall be applied. Solvent cement, orange in color and conforming to ASTM F493, shall be applied to all joint surfaces. The joint shall be made while the cement is wet, and in accordance with ASTM D2846 or ASTM F493. Solvent-cement joints shall be installed above or below ground.

Exception: A primer shall not be required where all of the following conditions apply:
  1. The solvent cement used is third-party certified as conforming to ASTM F493.
  2. The solvent cement used is yellow in color.
  3. The solvent cement is used only for joining 12-inch (12.7 mm) through 1-inch (25 mm) diameter CPVC/AL/CPVC pipe and CPVC fittings.
  4. The CPVC fittings are manufactured in accordance with ASTM D2846.
A purple primer that conforms to ASTM F656 shall be applied to PVC solvent-cemented joints. Solvent cement for PVC plastic pipe conforming to ASTM D2564 shall be applied to all joint surfaces.
Joints between cross-linked polyethylene plastic tubing or fittings shall comply with Section P2906.9.1.5.1 or Section P2906.9.1.5.2.
Flared pipe ends shall be made by a tool designed for that operation.
Mechanical joints shall be installed in accordance with the manufacturer's instructions. Fittings for cross-linked polyethylene (PEX) plastic tubing shall comply with the applicable standards indicated in Table P2906.6 and shall be installed in accordance with the manufacturer's instructions. PEX tubing shall be factory marked with the applicable standards for the fittings that the PEX manufacturer specifies for use with the tubing.
Joints between polypropylene plastic pipe and fittings shall comply with Section P2906.10.1 or P2906.10.2.
Heat fusion joints for polypropylene pipe and tubing joints shall be installed with socket-type heat-fused polypropylene fittings, butt-fusion polypropylene fittings, or electrofusion polypropylene fittings. Joint surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in accordance with ASTM D2657 and the manufacturer's instructions.

R 408.30544c
Mechanical and compression sleeve joints shall be installed in accordance with the manufacturer's instructions.
Joints between polyethylene/aluminum/ polyethylene (PE-AL-PE) and cross-linked polyethylene/ aluminum/ cross-linked polyethylene (PEX-AL-PEX) pipe and fittings shall comply with Section P2906.11.1.
Mechanical joints shall be installed in accordance with the manufacturer's instructions. Fittings for PE-AL-PE and PEX-AL-PEX as described in ASTM F1974, ASTM F1281, ASTM F1282, CSA B137.9 and CSA B137.10 shall be installed in accordance with the manufacturer's instructions.
Joints between stainless steel pipe and fittings shall comply with Section P2906.12.1 or P2906.12.2.
Mechanical joints shall be installed in accordance with the manufacturer's instructions.
Joint surfaces shall be cleaned. The joint shall be welded autogenously or with an approved filler metal in accordance with ASTM A312.
Threaded joints shall conform to American National Taper Pipe Thread specifications. Pipe ends shall be deburred and chips removed. Pipe joint compound shall be used only on male threads.
Soldered joints in copper and copper alloy tubing shall be made with fittings approved for water piping and shall conform to ASTM B828. Surfaces to be soldered shall be cleaned bright. Fluxes for soldering shall be in accordance with ASTM B813. Brazing fluxes shall be in accordance with AWS A5.31M/A5.31. Solders and fluxes used in potable water-supply systems shall have a lead content of not greater than 0.2 percent.
Flared joints in water tubing shall be made with approved fittings. The tubing shall be reamed and then expanded with a flaring tool.
Joints within the building between copper pipe or CPVC tubing, in any combination with compatible outside diameters, shall be permitted to be made with the use of approved push-in mechanical fittings of a pressure-lock design.
Joints between different piping materials shall be made in accordance with Section P2906.17.1, P2906.17.2 or P2906.17.3, or with a mechanical joint of the compression or mechanical sealing type having an elastomeric seal conforming to ASTM D1869 or ASTM F477. Joints shall be installed in accordance with the manufacturer's instructions.
Joints between copper or copper-alloy tubing and galvanized steel pipe shall be made with a copper alloy fitting or dielectric fitting. The copper tubing shall be joined to the fitting in an approved manner, and the fitting shall be screwed to the threaded pipe.
Joints between different types of plastic pipe or between plastic pipe and other piping material shall be made with an approved adapter fitting.
Joints between stainless steel and different piping materials shall be made with a mechanical joint of the compression or mechanical-sealing type or a dielectric fitting.
Press-connect joints shall conform to one of the standards indicated in Table P2906.6. Press-type mechanical joints in copper tubing shall be made in accordance with the manufacturer's instructions. Cut tube ends shall be reamed to the full inside diameter of the tube end. Joint surfaces shall be cleaned. The tube shall be fully inserted into the press connect fitting. Press-connect joints shall be pressed with a tool certified by the manufacturer.
Joints between polyethylene of raised temperature plastic tubing and fittings shall be in accordance with Section P2906.19.1.
Mechanical joints shall be installed in accordance with the manufacturer's instructions. Fittings for polyethylene of raised temperature plastic tubing shall comply with the applicable standards listed in Table P2906.6 and shall be installed in accordance with the manufacturer's instructions. Polyethylene of raised temperature plastic tubing shall be factory marked with the applicable standards for the fittings that the manufacturer of the tubing specifies for use with the tubing.
Changes in direction in copper tubing shall be permitted to be made with bends having a radius of not less than four diameters of the tube, provided that such bends are made by use of forming equipment that does not deform or create loss in cross-sectional area of the tube.
Pipe and tubing support shall conform to Section P2605.
Drinking water treatment units shall meet the requirements of NSF 42, NSF 44, NSF 53, NSF 60 or CSA B483.1.
Point-of-use reverse osmosis drinking water treatment units, designed for residential use, shall meet the requirements of NSF 58 or CSA B483.1. Waste or discharge from reverse osmosis drinking water treatment units shall enter the drainage system through an air gap or an air gap device that meets the requirements of NSF 58.
The tubing to and from drinking water treatment units shall be of a size and material as recommended by the manufacturer. The tubing shall comply with NSF 14, NSF 42, NSF 44, NSF 53, NSF 58 or NSF 61.
The provisions of this section shall govern the materials, design, construction and installation of systems for the collection, storage, treatment and distribution of nonpotable water. The use and application of nonpotable water shall comply with laws, rules and ordinances applicable in the jurisdiction.
Nonpotable water for each end use application shall meet the minimum water quality requirements as established for the intended application by the laws, rules and ordinances applicable in the jurisdiction. Where nonpotable water from different sources is combined in a system, the system shall comply with the most stringent requirements of this code applicable to such sources.
Where chlorine is used for disinfection, the nonpotable water shall contain not more than 4 ppm (4 mg/L) of chloramines or free chlorine. Where ozone is used for disinfection, the nonpotable water shall not contain gas bubbles having elevated levels of ozone at the point of use.

Exception: Reclaimed water sources shall not be required to comply with the requirements of this section.
Nonpotable water utilized for water closet and urinal flushing applications shall be filtered by a 100 micron or finer filter.

Exception: Reclaimed water sources shall not be required to comply with the requirements of this section.
Nonpotable water outlets such as hose connections, open-ended pipes and faucets shall be identified at the point of use for each outlet with signage that reads as follows: "Nonpotable water is utilized for [application name]. CAUTION : NONPOTABLE WATER. DO NOT DRINK." The words shall be legibly and indelibly printed on a tag or sign constructed of corrosion-resistant, waterproof material or shall be indelibly printed on the fixture. The letters of the words shall be not less than 0.5 inches (12.7 mm) in height and in colors contrasting the background on which they are applied. In addition to the required wordage, the pictograph shown in Figure P2910.3 shall appear on the signage required by this section.

FIGURE P2910.3
PICTOGRAPH-DO NOT DRINK
Permits shall be required for the construction, installation, alteration and repair of nonpotable water systems. Construction documents, engineering calculations, diagrams and other such data pertaining to the nonpotable water system shall be submitted with each permit application.
Where a potable system is connected to a nonpotable water system, the potable water supply shall be protected against backflow in accordance with Section P2902.
Piping, plumbing components and materials used in collection and conveyance systems shall be manufactured of material approved for the intended application and compatible with any disinfection and treatment systems used.
The system shall be protected to prevent the entrance of insects and vermin into storage tanks and piping systems. Screen materials shall be compatible with contacting system components and shall not accelerate the corrosion of system components.
Where sustained freezing temperatures occur, provisions shall be made to keep storage tanks and the related piping from freezing.
Nonpotable water storage tanks shall comply with Sections P2910.9.1 through P2910.9.11.
The holding capacity of the storage tank shall be sized in accordance with the anticipated demand.
Storage tanks shall be installed above or below grade. Above-grade storage tanks shall be protected from direct sunlight and shall be constructed using opaque, UV-resistant materials such as, but not limited to, heavily tinted plastic, lined metal, concrete and wood; or painted to prevent algae growth; or shall have specially constructed sun barriers including, but not limited to, installation in garages, crawlspaces or sheds. Storage tanks and their manholes shall not be located directly under any soil piping, waste piping or any source of contamination.
Where collected on site, water shall be collected in an approved tank constructed of durable, nonabsorbent and corrosion-resistant materials. The storage tank shall be constructed of materials compatible with any disinfection systems used to treat water upstream of the tank and with any systems used to maintain water quality within the tank. Wooden storage tanks that are not equipped with a makeup water source shall be provided with a flexible liner.
Storage tanks shall be supported on a firm base capable of withstanding the weight of the storage tank when filled to capacity. Storage tanks shall be supported in accordance with this code.
Where the soil can become saturated, an underground storage tank shall be ballasted or otherwise secured to prevent the tank from floating out of the ground when empty. The combined weight of the tank and hold-down ballast shall meet or exceed the buoyancy force of the tank. Where the installation requires a foundation, the foundation shall be flat and shall be designed to support the storage tank weight when full, consistent with the bearing capability of adjacent soil.
Where installed below grade, storage tank installations shall be designed to withstand earth and surface structural loads without damage and with minimal deformation when empty or filled with water.
Where an uninterrupted nonpotable water supply is required for the intended application, potable or reclaimed water shall be provided as a source of makeup water for the storage tank. The makeup water supply shall be protected against backflow by means of an air gap not less than 4 inches (102 mm) above the overflow or an approved backflow device in accordance with Section P2902. A full-open valve located on the makeup water supply line to the storage tank shall be provided. Inlets to the storage tank shall be controlled by fill valves or other automatic supply valves installed to prevent the tank from overflowing and to prevent the water level from dropping below a predetermined point. Where makeup water is provided, the water level shall be prohibited from dropping below the source water inlet or the intake of any attached pump.
Makeup water systems shall be fitted with a warning mechanism that alerts the user to a failure of the inlet control valve to close correctly. The alarm shall activate before the water within the storage tank begins to discharge into the overflow system.
The storage tank shall be equipped with an overflow pipe having a diameter not less than that shown in Table P2910.9.6. The overflow outlet shall discharge at a point not less than 6 inches (152 mm) above the roof or roof drain; floor or floor drain; or over an open water-supplied fixture. The overflow outlet shall be covered with a corrosion-resistant screen of not less than 16 by 20 mesh per inch (630 by 787 mesh perm) and by 14-inch (6.4 mm) hardware cloth or shall terminate in a horizontal angle seat check valve. Drainage from overflow pipes shall be directed to prevent freezing on roof walks. The overflow drain shall not be equipped with a shutoff valve. Not less than one cleanout shall be provided on each overflow pipe in accordance with Section P3005.2.


TABLE P2910.9.6
SIZE OF DRAIN PIPES FOR WATER TANKS
TANK CAPACITY
(gallons)
DRAIN PIPE
(inches)
Up to 750 1
751 to 1500 112
1501 to 3000 2
3001 to 5000 212
5001 to 7500 3
Over 7500 4
For SI: 1 gallon = 3.875 liters, 1 inch = 25.4 mm.
Not less than one access opening shall be provided to allow inspection and cleaning of the tank interior. Access openings shall have an approved locking device or other approved method of securing access. Below-grade storage tanks, located outside of the building, shall be provided with a manhole either not less than 24 inches (610 mm) square or with an inside diameter not less than 24 inches (610 mm). Manholes shall extend not less than 4 inches (102 mm) above ground or shall be designed to prevent water infiltration. Finished grade shall be sloped away from the manhole to divert surface water. Manhole covers shall be secured to prevent unauthorized access. Service ports in manhole covers shall be not less than 8 inches (203 mm) in diameter and shall be not less than 4 inches (102 mm) above the finished grade level. The service port shall be secured to prevent unauthorized access.

Exception: Storage tanks under 800 gallons (3028 L) in volume installed below grade shall not be required to be equipped with a manhole, but shall have a service port not less than 8 inches (203 mm) in diameter.
Storage tanks shall be provided with a vent sized in accordance with Chapter 31 and based on the aggregate diameter of all tank influent pipes. The reservoir vent shall not be connected to sanitary drainage system vents. Vents shall be protected from contamination by means of an approved cap or a U-bend installed with the opening directed downward. Vent outlets shall extend not less than 4 inches (102 mm) above grade, or as necessary to prevent surface water from entering the storage tank. Vent openings shall be protected against the entrance of vermin and insects in accordance with the requirements of Section P2902.7.
A drain shall be located at the lowest point of the storage tank. The tank drain pipe shall discharge as required for overflow pipes and shall not be smaller in size than specified in Table P2910.9.6. Not less than one cleanout shall be provided on each drain pipe in accordance with Section P3005.2.
Each nonpotable water storage tank shall be labeled with its rated capacity. The contents of storage tanks shall be identified with the words "CAUTION: NONPOTABLE WATER-DO NOT DRINK." Where an opening is provided that could allow the entry of personnel, the opening shall be marked with the words, "DANGER-CONFINED SPACE." Markings shall be indelibly printed on the tank, or on a tag or sign constructed of corrosion-resistant waterproof material that is mounted on the tank. The letters of the words shall be not less than 0.5 inches (12.7 mm) in height and shall be of a color in contrast with the background on which they are applied.
Storage tanks shall be tested in accordance with the following:
  1. Storage tanks shall be filled with water to the overflow line prior to and during inspection. Seams and joints shall be left exposed and the tank shall remain water tight without leakage for a period of 24 hours.
  2. After 24 hours, supplemental water shall be introduced for a period of 15 minutes to verify proper drainage of the overflow system and leaks do not exist.
  3. Following a successful test of the overflow, the water level in the tank shall be reduced to a level that is 2 inches (51 mm) below the makeup water trigger point by using the tank drain. The tank drain shall be observed for proper operation. The makeup water system shall be observed for proper operation, and successful automatic shutoff of the system at the refill threshold shall be verified. Water shall not be drained from the overflow at any time during the refill test.
If the owner of an on-site nonpotable water reuse system or rainwater collection and conveyance system elects to cease use of or fails to properly maintain such system, the system shall be abandoned and shall comply with the following:
  1. System piping connecting to a utility-provided water system shall be removed or disabled.
  2. The distribution piping system shall be replaced with an approved potable water supply piping system. Where an existing potable water pipe system is already in place, the fixtures shall be connected to the existing system.
  3. The storage tank shall be secured from accidental access by sealing or locking tank inlets and access points, or filled with sand or equivalent.
Nonpotable water collection and distribution piping and reclaimed water piping shall be separated from the building sewer and potable water piping underground by 5 feet (1524 mm) of undisturbed or compacted earth. Nonpotable water collection and distribution piping shall not be located in, under or above cesspools, septic tanks, septic tank drainage fields or seepage pits. Buried nonpotable water piping shall comply with the requirements of Section P2604.

Exceptions:
  1. The required separation distance shall not apply where the bottom of the nonpotable water pipe within 5 feet (1524 mm) of the sewer is not less than 12 inches (305 mm) above the top of the highest point of the sewer and the pipe materials conforms to Table P3002.2.
  2. The required separation distance shall not apply where the bottom of the potable water service pipe within 5 feet (1524 mm) of the nonpotable water pipe is not less than 12 inches (305 mm) above the top of the highest point of the nonpotable water pipe and the pipe materials comply with the requirements of Table P2906.5.
  3. The required separation distance shall not apply where a nonpotable water pipe is located in the same trench with a building sewer that is constructed of materials that comply with the requirements of Table P3002.2.
  4. The required separation distance shall not apply where a nonpotable water pipe crosses a sewer pipe provided that the nonpotable water pipe is sleeved to not less than 5 feet (1524 mm) horizontally from the sewer pipe centerline on both sides of such crossing, with pipe materials that comply with Table P3002.2.
  5. The required separation distance shall not apply where a potable water service pipe crosses a nonpotable water pipe, provided that the potable water service pipe is sleeved for a distance of not less than 5 feet (1524 mm) horizontally from the centerline of the nonpotable pipe on both sides of such crossing, with pipe materials that comply with Table P3002.2.
  6. The required separation distance shall not apply to irrigation piping located outside of a building and downstream of the backflow preventer where nonpotable water is used for outdoor applications.
Sillcocks, hose bibs, wall hydrants, yard hydrants and other outdoor outlets supplied by nonpotable water shall be located in a locked vault or shall be operable only by means of a removable key.
The provisions of this section shall govern the construction, installation, alteration and repair of on-site nonpotable water reuse systems for the collection, storage, treatment and distribution of on-site sources of nonpotable water as permitted by the jurisdiction.
On-site nonpotable water reuse systems shall collect waste discharge only from the following sources: bathtubs, showers, lavatories, clothes washers and laundry trays. Water from other approved nonpotable sources including swimming pool backwash operations, air conditioner condensate, rainwater, foundation drain water, fluid cooler discharge water and fire pump test water shall be permitted to be collected for reuse by on-site nonpotable water reuse systems, as approved by the building official and as appropriate for the intended application.
Reverse osmosis system reject water, water softener backwash water, kitchen sink wastewater, dishwasher wastewater and wastewater containing urine or fecal matter shall not be collected for reuse within an on-site nonpotable water reuse system.
Traps serving fixtures and devices discharging waste water to on-site nonpotable water reuse systems shall comply with the Section P3201.2.
On-site nonpotable water reuse systems shall utilize drainage piping approved for use within plumbing drainage systems to collect and convey untreated water for reuse. Vent piping approved for use within plumbing venting systems shall be utilized for vents within the gray-water system. Collection and vent piping materials shall comply with Section P3002.
Collection piping conveying untreated water for reuse shall be installed in accordance with Section P3005.
Collection piping conveying untreated water for reuse shall utilize joints approved for use with the distribution piping and appropriate for the intended applications as specified in Section P3002.
Collection piping conveying untreated water for reuse shall be sized in accordance with drainage sizing requirements specified in Section P3005.4.
Additional marking of collection piping conveying untreated water for reuse shall not be required beyond that required for sanitary drainage, waste and vent piping by the Chapter 30.
Untreated water collected for reuse shall be filtered as required for the intended end use. Filters shall be accessible for inspection and maintenance. Filters shall utilize a pressure gauge or other approved method to provide indication when a filter requires servicing or replacement. Filters shall be installed with shutoff valves immediately upstream and downstream to allow for isolation during maintenance.
Nonpotable water collected on site for reuse shall be disinfected, treated or both to provide the quality of water needed for the intended end-use application. Where the intended end-use application does not have requirements for the quality of water, disinfection and treatment of water collected on site for reuse shall not be required. Nonpotable water collected on site containing untreated gray water shall be retained in collection reservoirs for not more than 24 hours.
water used for flushing water closets and urinals shall be disinfected and treated by an on-site water reuse treatment system complying with NSF 350.
Storage tanks utilized in on-site nonpotable water reuse systems shall comply with Section P2910.9 and Sections P2911.7.1 through P2911.7.3.
Storage tanks shall be located with a minimum horizontal distance between various elements as indicated in Table P2911.7.1.


TABLE P2911.7.1
LOCATION OF NONPOTABLE WATER REUSE STORAGE TANKS
ELEMENT MINIMUM HORIZONTAL DISTANCE
FROM STORAGE TANK
(feet)
Critical root zone (CRZ) of
protected trees
2
Lot line adjoining private lots 5
Seepage pits 5
Septic tanks 5
Water wells 50
Streams and lakes 50
Water service 5
Public water main 10
For SI: 1 foot = 304.8 mm
Storage tank inlets shall be designed to introduce water into the tank with minimum turbulence, and shall be located and designed to avoid agitating the contents of the storage tank.
Outlets shall be located not less than 4 inches (102 mm) above the bottom of the storage tank, and shall not skim water from the surface.
Valves shall be supplied on on-site nonpotable water reuse systems in accordance with Sections P2911.8.1 and P2911.8.2.
One three-way diverter valve certified to NSF 50 or other approved device shall be installed on collection piping upstream of each storage tank, or drainfield, as applicable, to divert untreated onsite reuse sources to the sanitary sewer to allow servicing and inspection of the system. Bypass valves shall be installed downstream of fixture traps and vent connections. Bypass valves shall be labeled to indicate the direction of flow, connection and storage tank or drainfield connection. Bypass valves shall be installed in accessible locations. Two shutoff valves shall not be installed to serve as a bypass valve.
Backwater valves shall be installed on each overflow and tank drain pipe. Backwater valves shall be in accordance with Section P3008.
Mechanical equipment including pumps, valves and filters shall be accessible and removable in order to perform repair, maintenance and cleaning. The minimum flow rate and flow pressure delivered by the pumping system shall be appropriate for the application and in accordance with Section P2903.
Where the water pressure supplied by the pumping system exceeds 80 psi (552 kPa) static, a pressure-reducing valve shall be installed to reduce the pressure in the nonpotable water distribution system piping to 80 psi (552 kPa) static or less. Pressure-reducing valves shall be specified and installed in accordance with Section P2903.3.1.
Distribution piping utilized in on-site nonpotable water reuse systems shall comply with Sections P2911.11.1 through P2911.11.3.

Exception: Irrigation piping located outside of the building and downstream of a backflow preventer.
Distribution piping shall conform to the standards and requirements specified in Section P2906 for nonpotable water.
On-site nonpotable water reuse distribution piping systems shall be designed and sized in accordance with Section P2903 for the intended application.
On-site nonpotable water distribution piping labeling and marking shall comply with Section P2901.2
Tests and inspections shall be performed in accordance with Sections P2911.12.1 through P2911.12.6.
Drain, waste and vent piping used for on-site water reuse systems shall be tested in accordance with Section P2503.
Storage tanks shall be tested in accordance with Section P2910.11.
The testing of makeup water supply piping and distribution piping shall be conducted in accordance with Section P2503.7.
The testing of backflow preventers and backwater valves shall be conducted in accordance with Section P2503.8.
Inlets and vents to the system shall be inspected to verify that each is protected to prevent the entrance of insects and vermin into the storage tank and piping systems in accordance with Section P2910.7.
The quality of the water for the intended application shall be verified at the point of use in accordance with the requirements of the jurisdiction.
Operation and maintenance materials shall be supplied with nonpotable on-site water reuse systems in accordance with Sections P2910.13.1 through P2910.13.4.
A detailed operations and maintenance manual shall be supplied in hard-copy form for each system.
The manual shall include a detailed system schematic, the location of system components and a list of system components that includes the manufacturers and model numbers of the components.
The manual shall provide a schedule and procedures for system components requiring periodic maintenance. Consumable parts including filters shall be noted along with part numbers.
The manual shall include system startup and shutdown procedures. The manual shall include detailed operating procedures for the system.
The provisions of this section shall govern the construction, installation, alteration, and repair of rainwater collection and conveyance systems for the collection, storage, treatment and distribution of rainwater for nonpotable applications, as permitted by the jurisdiction.
Rainwater shall be collected only from above-ground impervious roofing surfaces constructed from approved materials. Collection of water from vehicular parking or pedestrian walkway surfaces shall be prohibited except where the water is used exclusively for landscape irrigation. Overflow and bleed-off pipes from roof-mounted appliances including, but not limited to, evaporative coolers, water heaters and solar water heaters shall not discharge onto rainwater collection surfaces.
Downspouts and leaders shall be connected to a roof washer and shall be equipped with a debris excluder or equivalent device to prevent the contamination of collected rainwater with leaves, sticks, pine needles and similar material. Debris excluders and equivalent devices shall be self-cleaning.
An amount of rainwater shall be diverted at the beginning of each rain event, and not allowed to enter the storage tank, to wash accumulated debris from the collection surface. The amount of rainfall to be diverted shall be field adjustable as necessary to minimize storage tank water contamination. The roof washer shall not rely on manually operated valves or devices, and shall operate automatically. Diverted rainwater shall not be drained to the roof surface, and shall be discharged in a manner consistent with the storm water runoff requirements of the jurisdiction. Roof washers shall be accessible for maintenance and service.
Gutters and downspouts shall be constructed of materials that are compatible with the collection surface and the rainwater quality for the desired end use. Joints shall be watertight.
Roof gutters, leaders and rainwater collection piping shall slope continuously toward collection inlets and shall be free of leaks. Gutters and downspouts shall have a slope of not less than 18 inch per foot (10.4 mm/ m) along their entire length. Gutters and downspouts shall be installed so that water does not pool at any point.
Cleanouts shall be provided in the water conveyance system to allow access to filters, flushes, pipes and downspouts.
Water drained from the roof washer or debris excluder shall not be drained to the sanitary sewer. Such water shall be diverted from the storage tank and shall discharge to a location that will not cause erosion or damage to property. Roof washers and debris excluders shall be provided with an automatic means of self-draining between rain events and shall not drain onto roof surfaces.
Rainwater collection and conveyance systems shall utilize drainage piping approved for use within plumbing drainage systems to collect and convey captured rainwater. Vent piping approved for use within plumbing venting systems shall be utilized for vents within the rainwater system. Collection and vent piping materials shall comply with Section P3002.
Collection piping conveying captured rainwater shall be installed in accordance with Section P3005.3.
Collection piping conveying captured rainwater shall utilize joints approved for use with the distribution piping and appropriate for the intended applications as specified in Section P3003.
Collection piping conveying captured rainwater shall be sized in accordance with drainage-sizing requirements specified in Section P3005.4.
Additional marking of collection piping conveying captured rainwater for reuse shall not be required beyond that required for sanitary drainage, waste, and vent piping by Chapter 30.
Collected rainwater shall be filtered as required for the intended end use. Filters shall be accessible for inspection and maintenance. Filters shall utilize a pressure gauge or other approved method to provide indication when a filter requires servicing or replacement. Filters shall be installed with shutoff valves installed immediately upstream and downstream to allow for isolation during maintenance.
Where the intended application for rainwater requires disinfection or other treatment or both, it shall be disinfected as needed to ensure that the required water quality is delivered at the point of use.
Storage tanks utilized in nonpotable rainwater collection and conveyance systems shall comply with Section P2910.9 and Sections P2912.10.1 through P2912.10.3.
Storage tanks shall be located with a minimum horizontal distance between various elements as indicated in Table P2912.10.1.


TABLE P2912.10.1
LOCATION OF RAINWATER STORAGE TANKS
ELEMENT MINIMUM HORIZONTAL DISTANCE FROM STORAGE TANK(feet)
Critical root zone (CRZ) of protected
trees
2
Lot line adjoining private lots 5
Seepage pits 5
Septic tanks 5
For SI: 1 foot= 304.8 mm
Storage tank inlets shall be designed to introduce collected rainwater into the tank with minimum turbulence, and shall be located and designed to avoid agitating the contents of the storage tank.
Outlets shall be located not less than 4 inches (102 mm) above the bottom of the storage tank and shall not skim water from the surface.
Valves shall be supplied on rainwater collection and conveyance systems in accordance with Sections P2912.11.1 and P2912.11.2.
A means shall be provided to divert storage tank influent to allow for maintenance and repair of the storage tank system.
Backwater valves shall be installed on each overflow and tank drain pipe. Backwater valves shall be in accordance with Section P3008.
Mechanical equipment including pumps, valves and filters shall be easily accessible and removable in order to perform repair, maintenance and cleaning. The minimum flow rate and flow pressure delivered by the pumping system shall appropriate for the application and in accordance with Section P2903.
Where the water pressure supplied by the pumping system exceeds 80 psi (552 kPa) static, a pressure-reducing valve shall be installed to reduce the pressure in the rainwater distribution system piping to 80 psi (552 kPa) static or less. Pressure-reducing valves shall be specified and installed in accordance with Section P2903.3.1.
Distribution piping utilized in rainwater collection and conveyance systems shall comply with Sections P2912.14.1 through P2912.14.3.

Exception: Irrigation piping located outside of the building and downstream of a backflow preventer.
Distribution piping shall conform to the standards and requirements specified in Section P2906 for nonpotable water.
Distribution piping systems shall be designed and sized in accordance with the Section P2903 for the intended application.
Nonpotable rainwater distribution piping labeling and marking shall comply with Section P2901.2.
Tests and inspections shall be performed in accordance with Sections P2912.15.1 through P2912.15.8.
Roof gutters shall be inspected to verify that the installation and slope is in accordance with Section P2912.5.1. Gutters shall be tested by pouring not less than one gallon of water (3.8 L) into the end of the gutter opposite the collection point. The gutter being tested shall not leak and shall not retain standing water.
Roofwashers shall be tested by introducing water into the gutters. Proper diversion of the first quantity of water in accordance with the requirements of Section P2912.4 shall be verified.
Drain, waste and vent piping used for rainwater collection and conveyance systems shall be tested in accordance with Section P2503.
Storage tanks shall be tested in accordance with the Section P2910.11.
The testing of makeup water supply piping and distribution piping shall be conducted in accordance with Section P2503.7.
The testing of backflow preventers and backwater valves shall be conducted in accordance with Section P2503.8.
Inlets and vents to the system shall be inspected to verify that each is protected to prevent the entrance of insects and vermin into the storage tank and piping systems in accordance with Section P2910.7.
The quality of the water for the intended application shall be verified at the point of use in accordance with the requirements of the jurisdiction.
Operation and maintenance manuals shall be supplied with rainwater collection and conveyance systems in accordance with Sections P2912.16.1 through P2912.16.4.
A detailed operations and maintenance manual shall be supplied in hard-copy form for each system.
The manual shall include a detailed system schematic, the location of system components and a list of system components that includes the manufacturers and model numbers of the components.
The manual shall provide a maintenance schedule and procedures for system components requiring periodic maintenance. Consumable parts, including filters, shall be noted along with part numbers.
The manual shall include system startup and shutdown procedures, and detailed operating procedures.
The provisions of this section shall govern the construction, installation, alteration and repair of systems supplying nonpotable reclaimed water.
Where the reclaimed water pressure supplied to the building exceeds 80 psi (552 kPa) static, a pressure-reducing valve shall be installed to reduce the pressure in the reclaimed water distribution system piping to 80 psi (552 kPa) static or less. Pressure-reducing valves shall be specified and installed in accordance with Section P2903.3.1
The design of the reclaimed water systems shall conform to accepted engineering practice.
Distribution piping shall comply with Sections P2913.3.1.1 through P2913.3.1.3.

Exception: Irrigation piping located outside of the building and downstream of a backflow preventer.
Distribution piping conveying reclaimed water shall conform to standards and requirements specified in Section P2905 for nonpotable water.
Distribution piping systems shall be designed and sized in accordance with Section P2903 for the intended application.
Nonpotable rainwater distribution piping labeling and marking shall comply with Section P2901.2.
Tests and inspections shall be performed in accordance with Sections P2913.4.1 and P2913.4.2.
The testing of makeup water supply piping and reclaimed water distribution piping shall be conducted in accordance with Section P2503.7.
The testing of backflow preventers shall be conducted in accordance with Section P2503.8.
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