CPC · California Plumbing Code

What are the rules for potable water supply tanks and private well tanks?

Homeowners: install potable tanks exactly as the maker directs, use materials and coatings certified for drinking water, screen vents/overflows with #24 mesh, provide at least a 16 sq.‑inch overflow, and if you have a pressurized private‑well tank, make sure it is listed to ASSE 1099/WSC‑PST 2000 — these are the California Plumbing Code requirements in Chapter 6, § 607.

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Last reviewed: July 6, 2026

What the code requires — plain English (2–4 sentences)

Potable water supply tanks must be installed per the manufacturer’s installation instructions and supported as required by the California Building Code — this is the general rule in § 607.1. Pressurized tanks used with private well water systems must meet the listing/standard ASSE 1099/WSC‑PST 2000 per § 607.2. Additional mandatory requirements for potable tanks (materials for drinking water, venting, overflow, and relief valves) are in the same section group (see § 607.3–§ 607.6).

The single most important rule: install potable water tanks exactly the way the manufacturer directs, and use the listed standards for pressurized private‑well tanks.

Requirements in detail

Scope / key definitions (first mentions bolded)

  • Potable water supply tanks — any tanks intended to supply drinking/domestic water (see § 607.0 and § 607.1).
  • Private well water tanks — pressurized tanks used with wells; these must comply with ASSE 1099/WSC‑PST 2000 per § 607.2.

Installation and support

  • Install tanks in accordance with the manufacturer’s installation instructions (mandatory). § 607.1 requires that tanks follow manufacturer instructions and be supported consistent with the California Building Code.

Materials for potable service

  • Interior tank coatings or liners (and the tank itself when intended to supply drinking water) must comply with NSF/ANSI/CAN 61 as required by § 607.3.

Venting and covers

  • Tanks used for potable water must be tightly covered and vented per the manufacturer’s instructions. Vent openings must be screened with corrosion‑resistant material of not less than number 24 mesh (see § 607.4).

Overflow

  • Tanks must have at least a 16 square inch overflow opening. The overflow must be screened with corrosion‑resistant material of at least number 24 mesh (see § 607.5).

Valves and pressure devices

  • Pressurized tanks: must have a listed pressure‑relief valve installed as the manufacturer directs; its discharge must comply with § 608.5. If the tank is located above the fixtures it serves, it must also have a vacuum relief valve that complies with ANSI Z21.22/CSA 4.4 (see § 607.6).

Private well tanks (specific)

  • Pressurized potable water tanks used with private well systems are required to comply with ASSE 1099/WSC‑PST 2000 (see § 607.2). This is the controlling standard for these tanks.

Decision table — quick dimensions and requirements

What you must check Minimum / Required value Where to find it (Code Reference)
Install per manufacturer and support Per manufacturer & California Building Code § 607.1
Private well pressurized tanks standard ASSE 1099 / WSC‑PST 2000 § 607.2
Tank materials/coatings for potable use NSF/ANSI/CAN 61 compliance § 607.3
Vent screening Corrosion‑resistant, #24 mesh minimum § 607.4
Overflow size 16 sq. in. minimum § 607.5
Pressure relief Listed pressure‑relief valve; discharge per § 608.5 § 607.6 and § 608.5
Vacuum relief (if tank above served fixtures) ANSI Z21.22/CSA 4.4 compliant § 607.6

Exceptions & special cases

  • The code repeatedly defers to the manufacturer’s installation instructions for venting, mounting, and relief‑valve placement; when the manufacturer defines specific venting or relief arrangements, follow those instructions as required by § 607.1 and § 607.4–§ 607.6.
  • Private‑well tanks are not allowed to rely on generic guidance alone — pressurized private‑well tanks must meet the specified listed standard ASSE 1099/WSC‑PST 2000 (no substitute) as required by § 607.2.

If a required detail (for example, exact relief‑valve discharge routing) is not explicitly stated in these sections, follow the manufacturer and the related sections cited (for example, § 608.5 for relief‑valve discharge).

Common mistakes

  • Assuming any vent screen is OK — the code requires corrosion‑resistant screening, minimum #24 mesh for vents and overflow (not cloth, not insect netting) per § 607.4 and § 607.5.
  • Using tanks or interior coatings that are not certified for potable water — interior coatings/liners must comply with NSF/ANSI/CAN 61 per § 607.3.
  • Installing a pressurized private‑well tank that is not listed to ASSE 1099/WSC‑PST 2000 — the code requires that listing per § 607.2.
  • Forgetting relief devices or routing relief discharge incorrectly — pressurized tanks need listed pressure‑relief valves and discharge per § 608.5, and vacuum relief is required if tank is above served fixtures (see § 607.6).

Worked example — concrete scenario

Scenario: A homeowner installs a new 120‑gallon pressurized bladder tank at a private single‑family well system. The tank will be installed on a concrete pad adjacent to the pump and will sit slightly higher than the house plumbing feed.

Step‑by‑step to meet the CPC:

  1. Confirm the tank model is listed to ASSE 1099/WSC‑PST 2000 (required by § 607.2). If it is not, do not use it for the private well potable system.
  2. Follow the manufacturer’s installation instructions for mounting and anchorage; ensure support meets California Building Code requirements (per § 607.1).
  3. Verify the tank interior (coating/liner) is NSF/ANSI/CAN 61 compliant since it supplies drinking water (per § 607.3).
  4. Install a listed pressure‑relief valve as manufacturer directs and route its discharge in accordance with § 608.5.
  5. Because the tank is located above the fixtures it serves, install a vacuum relief valve that meets ANSI Z21.22/CSA 4.4 as required by § 607.6.
  6. Provide a tightly fitting cover and a vent with #24 mesh corrosion‑resistant screening, and provide an overflow at least 16 sq. in. with the same screening (see § 607.4 and § 607.5).

If each of these checks is satisfied, the installation meets the explicit CPC provisions in the 607 series governing potable and private‑well tanks.

Related provisions (useful cross‑references)

  • § 607.3 — Potable water tanks, interior coatings/liners must comply with NSF/ANSI/CAN 61.
  • § 607.4 — Venting requirements; vents must be screened with corrosion‑resistant #24 mesh.
  • § 607.5 — Overflow minimum 16 sq. in. and screened #24 mesh.
  • § 607.6 — Valves: listed pressure‑relief valve required; vacuum relief valve requirements if tank is above served fixtures.
  • § 608.5 — Discharge piping requirements for relief valves (relevant to pressure‑relief valve discharge).
  • § 602.1–§ 603.5.5 — Cross‑connection and protection of water supply; protect tank inlets and supply in accordance with backflow prevention/air‑gap rules where applicable.
  • Appendix K (e.g., K 103.4, K 104.1, K 107.1) — if using tanks for potable rainwater systems, see the potable rainwater catchment appendices for additional storage and materials rules.

Code references

Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:

  • CPC § 606.6 High relevance — show source text

    Manufactured water distribution manifolds shall

    be in accordance with IAPMO IGC 109.

    606.6 Accessible. Required shutoff or control valves shall be accessible.

    606.7 Multiple Fixtures. A single control valve shall be installed on a water supply line ahead of an automatic metering valve that supplies a battery of fixtures. 606.8 [OSHPD 1, 1R, 2, 3, 4 & 5] Each riser or branch shall be provided with an accessible sectionalizing valve in hot-and cold-water systems to permit servicing or replace- ment of piping or equipment. Stop valves shall be provided at each fixture. 606.9 Check Valve Required. All systems that circulate water by means of a pump or other mechanical device or method shall have a check valve(s) or equal device(s) installed so as to ensure the direction of flow.

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    WATER SUPPLY AND DISTRIBUTION

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    606.10 Leak Detection Devices. Where leak detection devices for water supply and distribution are installed, they shall comply with ANSI/CAN/IAPMO Z1349.

    607.0 Potable Water Supply Tanks. 607.1 General. Potable water supply tanks shall be installed in accordance with the manufacturer’s installation instructions and supported in accordance with the California Building Code . 607.2 Private Well Water Tanks. Pressurized potable water tanks for private well water systems shall comply with ASSE 1099/WSC-PST 2000.

    607.3 Potable Water Tanks. Potable water supply tanks, interior tank coatings, or tank liners intended to supply drinking water shall comply with NSF/ANSI/CAN 61. 607.4 Venting. Tanks used for potable water shall be tightly covered and vented in accordance with the manufacturer’s

    installation instructions. Such vent shall be screened with a cor rosion-resistant material of not less than number 24 mesh.

    607.5 Overflow. Tanks shall have not less than a 16 square inch (0.01 m [2] ) overflow that is screened with a corrosionresistant material of not less than number 24 mesh.

    607.6 Valves. Pressurized tanks shall be provided with a listed pressure-relief valve installed in accordance with the manufacturer’s installation instructions. The relief valve shall be discharged in accordance with Section 608.5. Where a potable water supply tank is located above the fixtures, appliances, or system components it serves, it shall be equipped with a vacuum relief valve that complies with ANSI Z21.22/CSA 4.4.

    608.0 Water Pressure, Pressure Regulators, Pres- sure Relief Valves, and Vacuum Relief Valves. 608.1 Inadequate Water Pressure. Where the water pressure in the main or other source of supply will not provide a residual water pressure of not less than 15 pounds force per square inch (psi) (103 kPa), after allowing for friction and other pressure losses, a tank and a pump or other means that will provide said 15 psi (103 kPa) pressure shall be installed. Where fixtures, fixture fittings, or both are installed that, require a residual pressure exceeding 15 psi (103 kPa), that minimum residual pressure shall be provided.

    **608.2 Excessive Water Pressure.

  • CPC § 605.12 High relevance — show source text

    605.12 PVC Plastic Pipe and Joints . . . . .152

    605.13 Stainless Steel Pipe and Joints . . .152

    605.14 Slip Joints . . . . . . . . . . . . . . . . . . .153

    605.15 Dielectric Unions . . . . . . . . . . . . . .153

    605.16 Joints Between Various

    Materials . . . . . . . . . . . . . . . . . . . .153

    606.0 Valves . . . . . . . . . . . . . . . . . . . . . .153

    606.1 General . . . . . . . . . . . . . . . . . . . . .153

    606.2 Fullway Valve . . . . . . . . . . . . . . . .153

    606.3 Multidwelling Units . . . . . . . . . . . .153

    606.4 Multiple Openings . . . . . . . . . . . . .153

    606.5 Control Valve . . . . . . . . . . . . . . . .153

    606.6 Accessible . . . . . . . . . . . . . . . . . .153

    606.7 Multiple Fixtures . . . . . . . . . . . . . .153

    606.9 Check Valve Required . . . . . . . . .153

    606.10 Leak Detection Devices . . . . . . . .154

    607.0 Potable Water Supply Tanks . . . .154

    607.1 General . . . . . . . . . . . . . . . . . . . . .154

    607.2 Private Well Water Tanks . . . . . . .154

    607.3 Potable Water Tanks . . . . . . . . . .154

    607.4 Venting . . . . . . . . . . . . . . . . . . . . .154

    607.5 Overflow . . . . . . . . . . . . . . . . . . . .154

    607.6 Valves . . . . . . . . . . . . . . . . . . . . . .154

    608.0 Water Pressure, Pressure Regulators, Pressure Relief Valves, and Vacuum Relief

    Valves . . . . . . . . . . . . . . . . . . . . . .154

    608.1 Inadequate Water Pressure . . . . .154

    608.2 Excessive Water Pressure . . . . . .154

    608.3 Expansion Tanks, and Combination Temperature and Pressure-Relief Valves . . . . .154

    608.4 Pressure Relief Valves . . . . . . . . .154

    608.5 Discharge Piping . . . . . . . . . . . . .154

    608.6 Water-Heating Devices . . . . . . . . .155

    608.7 Vacuum Relief Valves . . . . . . . . .155

    609.0 Installation, Testing, Unions, and Location . . . . . . . . . . . . . . . . .155

    609.1 Installation . . . . . . . . . . . . . . . . . .155

    609.2 Trenches . . . . . . . . . . . . . . . . . . . .155

    609.3 Under Concrete Slab . . . . . . . . . .155

  • CPC § 607.2 High relevance — show source text

    607.2 Private Well Water Tanks . . . . . . .154

    607.3 Potable Water Tanks . . . . . . . . . .154

    607.4 Venting . . . . . . . . . . . . . . . . . . . . .154

    607.5 Overflow . . . . . . . . . . . . . . . . . . . .154

    607.6 Valves . . . . . . . . . . . . . . . . . . . . . .154

    608.0 Water Pressure, Pressure Regulators, Pressure Relief Valves, and Vacuum Relief

    Valves . . . . . . . . . . . . . . . . . . . . . .154

    608.1 Inadequate Water Pressure . . . . .154

    608.2 Excessive Water Pressure . . . . . .154

    608.3 Expansion Tanks, and Combination Temperature and Pressure-Relief Valves . . . . .154

    608.4 Pressure Relief Valves . . . . . . . . .154

    608.5 Discharge Piping . . . . . . . . . . . . .154

    608.6 Water-Heating Devices . . . . . . . . .155

    608.7 Vacuum Relief Valves . . . . . . . . .155

    609.0 Installation, Testing, Unions, and Location . . . . . . . . . . . . . . . . .155

    609.1 Installation . . . . . . . . . . . . . . . . . .155

    609.2 Trenches . . . . . . . . . . . . . . . . . . . .155

    609.3 Under Concrete Slab . . . . . . . . . .155

    609.4 Testing . . . . . . . . . . . . . . . . . . . . .155

    609.5 Unions . . . . . . . . . . . . . . . . . . . . .155

    609.6 Location . . . . . . . . . . . . . . . . . . . .155

    609.7 Abutting Lot . . . . . . . . . . . . . . . . .155

    609.8 Pumps . . . . . . . . . . . . . . . . . . . . .155

    609.9 Low-Pressure Cutoff Required on Booster Pumps for Water Distribution Systems . . . . . . . . . . .156

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    TABLE OF CONTENTS

    609.10 Disinfection of Potable Water System . . . . . . . . . . . . . . . . . . . . .156

    609.11 Water Hammer . . . . . . . . . . . . . . .156

    609.12 Pipe Insulation . . . . . . . . . . . . . . .156

    610.0 Size of Potable Water Piping . . . .156

    610.1 Size . . . . . . . . . . . . . . . . . . . . . . . .156

    610.2 Pressure Loss . . . . . . . . . . . . . . . .156

    610.3 Quantity of Water . . . . . . . . . . . . .157

  • CPC § 606.3 High relevance — show source text

    Such shutoff valves shall be accessible. A fullway valve shall be installed on the discharge piping from water supply tanks at or near the tank. A fullway valve shall be installed on the cold water supply pipe to each water heater at or near the water heater. 606.3 Multidwelling Units. In multidwelling units, one or more shutoff valves shall be provided in each dwelling unit so that the water supply to a plumbing fixture or group of fixtures in that dwelling unit can be shut off without stopping water supply to fixtures in other dwelling units. These valves shall be accessible in the dwelling unit that they control. 606.4 Multiple Openings. Valves used to control two or more openings shall be fullway gate valves, ball valves, or other approved valves designed and approved for the service intended.

    606.5 Control Valve. A control valve shall be installed immediately ahead of each water-supplied appliance and immediately ahead of each slip joint or appliance supply. Parallel water distribution systems shall provide a control valve either immediately ahead of each fixture being supplied or installed at the manifold, and shall be identified with the fixture being supplied. Where parallel water distribution system manifolds are located in attics, crawl spaces, or other locations not readily accessible, a separate shutoff valve shall be required immediately ahead of each individual fixture or appliance served. 606.5.1 Manifolds. Field installed manifolds for water distribution shall conform with the applicable requirements for valves, pipes, and fittings as referenced in this code. Manufactured water distribution manifolds shall

    be in accordance with IAPMO IGC 109.

    606.6 Accessible. Required shutoff or control valves shall be accessible.

    606.7 Multiple Fixtures. A single control valve shall be installed on a water supply line ahead of an automatic metering valve that supplies a battery of fixtures. 606.8 [OSHPD 1, 1R, 2, 3, 4 & 5] Each riser or branch shall be provided with an accessible sectionalizing valve in hot-and cold-water systems to permit servicing or replace- ment of piping or equipment. Stop valves shall be provided at each fixture. 606.9 Check Valve Required. All systems that circulate water by means of a pump or other mechanical device or method shall have a check valve(s) or equal device(s) installed so as to ensure the direction of flow.

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    606.10 Leak Detection Devices. Where leak detection devices for water supply and distribution are installed, they shall comply with ANSI/CAN/IAPMO Z1349.

    607.0 Potable Water Supply Tanks. 607.1 General. Potable water supply tanks shall be installed in accordance with the manufacturer’s installation instructions and supported in accordance with the California Building Code . 607.2 Private Well Water Tanks. Pressurized potable water tanks for private well water systems shall comply with ASSE 1099/WSC-PST 2000.

  • CPC § 601.8.1.1 High relevance — show source text

    601.8.1.1 Equipment using potable water shall be so installed as to prevent back-siphonage into the potable water system.

    601.8.1.2 Non-potable water is permitted only in those parts of o ffi cial plants where no edible product is han- dled or prepared, and then only for limited purposes, such as on ammonia condensers not connected with the potable water supply, in vapor lines serving inedi- ble product rendering tanks, in connection with equip- ment used for washing and washing inedible products preparatory to tanking, and in sewer lines for moving heavy solids in sewage. In all cases, non-potable water lines shall be clearly identi fi ed and shall not be cross connected with the potable water supply.

    Exception: Cross connection is permitted if this is necessary for fi re protection, and such connection is of a type with a break to ensure against accidental contamination, and is approved by local authorities or by the Department.

    601.8.2 All pipelines, reservoirs, tanks, cooling towers, and like equipment employed in handling reused water shall be constructed and installed so as to facilitate their cleaning and inspection.

    601.8.3 Hot water for cleaning rooms and equipment shall be delivered under pressure to outlets and shall be of such temperature as to accomplish a thorough cleanup.

    601.8.3.1 An ample supply of water at not less than 180°F (82°C) shall be available when used for san- itizing purposes.

    601.8.4 Pens, alleys, and runways shall have hose con- nections for cleanups purposes.

    602.0 Unlawful Connections.

    602.1 Prohibited Installation. No installation of potable water supply piping, or part thereof, shall be made in such a manner that it will be possible for used, unclean, polluted, or contaminated water, mixtures, or substances to enter a portion of such piping from a tank, receptor, equipment, or plumbing fixture by reason of backsiphonage, suction, or other cause, either during normal use and operation thereof, or where such tank, receptor, equipment, or plumbing fixture is flooded or subject to pressure exceeding the operating pressure in the hot or cold water piping. 602.2 Cross-Contamination. No person shall make a connection or allow one to exist between pipes or conduits carrying domestic water supplied by a public or private building supply system, and pipes, conduits, or fixtures containing or carrying water from any other source or containing or carrying water that has been used for any purpose whatsoever, or piping carrying chemicals, liquids, gases, or substances whatsoever, unless there is provided a backflow prevention device approved for the potential hazard and maintained in accordance with this code. Each point of use shall be separately protected where potential cross-contamination of individual units exists.

    602.3 Backflow Prevention. No plumbing fixture, device, or construction shall be installed or maintained, or shall be connected to a domestic water supply, where such installation or connection provides a possibility of polluting such water supply or cross-connection between a distributing system of water for drinking and domestic purposes and water that becomes contaminated by such plumbing fixture, device, or construction unless there is provided a backflow prevention device approved for the potential hazard.

  • CPC § 603.5.2 Medium relevance — show source text

    603.5.2 Ballcock. Water closet and urinal tanks shall be equipped with a ballcock. The ballcock shall be installed with the critical level not less than 1 inch (25.4 mm) above the full opening of the overflow pipe. In cases where the ballcock has no hush tube, the bottom of the water supply inlet shall be installed 1 inch (25.4 mm) above the full opening of the overflow pipe.

    603.5.3 Backflow Prevention. Water closet flushometer tanks shall be protected against backflow by an approved backflow prevention assembly, device, or method.

    603.5.4 Heat Exchangers. Heat exchangers used for heat transfer, heat recovery, or solar heating shall protect the potable water system from being contaminated by the

    heat-transfer medium. Single-wall heat exchangers used in indirect-fired water heaters shall meet the requirements of Section 505.4.1. Double-wall heat exchangers shall separate the potable water from the heat-transfer medium by providing a space between the two walls that are vented to the atmosphere. 603.5.5 Water Supply Inlets. Water supply inlets to tanks, vats, sumps, swimming pools, and other receptors shall be protected by one of the following means:

    (1) An approved air gap.

    (2) A listed vacuum breaker installed on the discharge side of the last valve with the critical level not less than 6 inches (152 mm) or in accordance with its listing.

    (3) A backflow preventer suitable for the degree of hazard, installed in accordance with the requirements for that type of device or assembly as set forth in this chapter. 603.5.6 Protection from Lawn Sprinklers and Irri- gation Systems. Potable water supplies to systems having no pumps or connections for pumping equipment, and no chemical injection or provisions for chemical injection, shall be protected from backflow by one of the following devices:

    (1) Atmospheric vacuum breaker (AVB)

    (2) Pressure vacuum breaker backflow prevention assembly (PVB)

    (3) Spill-resistant pressure vacuum breaker (SVB)

    (4) Reduced-pressure principle backflow prevention assembly (RP)

    (5) A valve complying with IAPMO PS 72 603.5.6.1 Systems with Pumps. Where sprinkler and irrigation systems have pumps, connections for pumping equipment, or auxiliary air tanks, or are otherwise capable of creating backpressure, the potable water supply shall be protected by the following type of device where the backflow device is located upstream from the source of backpressure:

    (1) Reduced-pressure principle backflow prevention assembly (RP) 603.5.6.2 Systems with Backflow Devices. Where systems have a backflow device installed downstream from a potable water supply pump or a potable water supply pump connection, the device shall be one of the following:

    (1) Atmospheric vacuum breaker (AVB)

    (2) Pressure vacuum breaker backflow prevention assembly (PVB)

    (3) Spill-resistant pressure vacuum breaker (SVB)

    (4) Reduced-pressure principle backflow prevention assembly (RP) 603.5.6.3 Systems with Chemical Injectors. Where systems include a chemical injector or provisions for chemical injection, the potable water supply shall be protected by a reduced-pressure principle backflow prevention assembly (RP).

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  • CPC § 604.11 Medium relevance — show source text

    604.11 Solder . . . . . . . . . . . . . . . . . . . . . .149

    604.12 Flexible Corrugated Connectors . .149

    604.13 Water Heater Connectors . . . . . . .149

    605.0 Joints and Connections . . . . . . . .149

    605.1 Copper or Copper Alloy Pipe, Tubing, and Joints . . . . . . . . . . . .149

    605.2 CPVC Plastic Pipe and Joints . . .150

    605.3 CPVC/AL/CPVC Plastic Pipe and Joints . . . . . . . . . . . . . . . . . . .150

    605.4 Ductile Iron Pipe and Joints . . . . .150

    605.5 Galvanized Steel Pipe and Joints . . . . . . . . . . . . . . . . . . . . . .151

    605.6 PE Plastic Pipe/Tubing and Joints . . . . . . . . . . . . . . . . . . . . . .151

    605.7 PE-AL-PE Plastic Pipe/Tubing and Joints . . . . . . . . . . . . . . . . . . .151

    605.8 PE-RT . . . . . . . . . . . . . . . . . . . . . .151

    605.9 PEX Plastic Tubing and Joints . . .151

    605.10 PEX-AL-PEX Plastic Tubing and Joints . . . . . . . . . . . . . . . . . . .152

    605.11 Polypropylene (PP) Piping and Joints . . . . . . . . . . . . . . . . . . .152

    605.12 PVC Plastic Pipe and Joints . . . . .152

    605.13 Stainless Steel Pipe and Joints . . .152

    605.14 Slip Joints . . . . . . . . . . . . . . . . . . .153

    605.15 Dielectric Unions . . . . . . . . . . . . . .153

    605.16 Joints Between Various

    Materials . . . . . . . . . . . . . . . . . . . .153

    606.0 Valves . . . . . . . . . . . . . . . . . . . . . .153

    606.1 General . . . . . . . . . . . . . . . . . . . . .153

    606.2 Fullway Valve . . . . . . . . . . . . . . . .153

    606.3 Multidwelling Units . . . . . . . . . . . .153

    606.4 Multiple Openings . . . . . . . . . . . . .153

    606.5 Control Valve . . . . . . . . . . . . . . . .153

    606.6 Accessible . . . . . . . . . . . . . . . . . .153

    606.7 Multiple Fixtures . . . . . . . . . . . . . .153

    606.9 Check Valve Required . . . . . . . . .153

    606.10 Leak Detection Devices . . . . . . . .154

    607.0 Potable Water Supply Tanks . . . .154

    607.1 General . . . . . . . . . . . . . . . . . . . . .154

    607.2 Private Well Water Tanks . . . . . . .154

  • CPC § 505.4 Medium relevance — show source text

    E 505.4 Flushing Device. Where the recreational vehicle park is provided with a piped water supply system, means for flushing the recreational vehicle holding tank and the sanitary disposal station slab shall be provided that consists of a piped supply of water under pressure, terminating in an outlet located and installed to prevent damage by automobiles or recreational vehicles. The flushing device shall consist of a properly supported riser terminating not less than 2 feet (610 mm) above the ground surface, with a [3] ⁄ 4 of an inch (20 mm) valved outlet adaptable for a flexible hose.

    The water supply to the flushing device shall be protected from backflow using a listed vacuum breaker or backflow prevention device located downstream from the last shutoff valve.

    Adjacent to the flushing arrangement shall be posted a sign of durable material not less than 2 feet by 2 feet (610 mm by 610 mm) in size. Inscribed thereon in clearly legible letters shall be the following:

    “DANGER – NOT TO BE USED FOR DRINKING OR

    DOMESTIC PURPOSES.”

    E 506.0 Recreational Vehicle Park Water Supply Sta- tions.

    E 506.1 Potable Watering Stations. A potable watering station, where provided for filling recreational vehicle potable water tanks, shall be located not less than 50 feet (15 240 mm) from a sanitary disposal station. Where such is provided, adjacent to the potable water outlet there shall be a posted sign of durable material not less than 2 feet by 2 feet (610 mm by 610 mm) in size. Inscribed thereon in clear, legible letters on a contrasting background shall be:

    “POTABLE WATER. NOT TO BE USED FOR FLUSHING

    WASTE TANKS.”

    The potable water shall be protected from backflow using a listed vacuum breaker located downstream from the last shutoff valve.

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    CALIFORNIA PLUMBING CODE – MATRIX ADOPTION TABLE

    APPENDIX F - FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS

    (Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

  • California Plumbing Code Medium relevance — show source text

    br>40
    35|148
    102
    82
    70
    62|210
    144
    116
    99
    88|448
    308
    247
    211
    187|806
    554
    445
    381
    337|1270
    873
    701
    600
    532|2650
    1820
    1460
    1250
    1110| |60
    70
    80
    90
    100|60
    70
    80
    90
    100|NA
    NA
    NA
    NA
    NA|16
    14
    13
    13
    12|32
    29
    27
    26
    24|56
    52
    48
    45
    43|79
    73
    68
    64
    60|170
    156
    145
    136
    129|306
    281
    262
    245
    232|482
    443
    413
    387
    366|1000
    924
    859
    806
    761| |125
    150
    175
    200
    250|125
    150
    175
    200
    250|NA
    NA
    NA
    NA
    NA|11
    10
    NA
    NA
    NA|22
    20
    18
    17
    15|38
    34
    31
    29
    26|53
    48
    45
    41
    37|114
    103
    95
    89
    78|206
    186
    171
    159
    141|324
    294<

  • California Plumbing Code Medium relevance — show source text

    |204
    |420
    |629
    |1210
    |1930
    |3410
    |6960
    | |1200
    |50
    |104
    |195
    |400
    |600
    |1160
    |1840
    |3260
    |6640
    | |1300
    |47
    |99
    |187
    |384
    |575
    |1110
    |1760
    |3120
    |6360
    | |1400
    |46
    |95
    |179
    |368
    |552
    |1060
    |1690
    |3000
    |6110
    | |1500
    |44
    |92
    |173
    |355
    |532
    |1020
    |1630
    |2890
    |5890
    | |1600
    |42
    |89
    |167
    |343
    |514
    |989
    |1580
    |2790
    |5680
    | |1700
    |41
    |86
    |162
    |332
    |497
    |957
    |1530
    |2700
    |5500
    | |1800
    |40
    |83
    |157
    |322
    |482
    |928
    |1480
    |2610
    |5330
    | |1900
    |39
    |81
    |152
    |312
    |468
    |901
    |1440
    |2540
    |5180
    | |2000|38|79|148|304|455|877|1400|2470|5040|

  • California Plumbing Code Medium relevance — show source text


    2
    5
    10
    15|36
    38
    51
    NA
    NA|93
    69
    63
    NA
    NA|57
    47
    44
    39
    NA|56
    57
    75
    95
    NA|190
    136
    128
    116
    NA|111
    93
    86
    79
    72|80
    80
    102
    128
    158|325
    225
    216
    201
    186|186
    149
    140
    131
    124|116
    115
    144
    182
    220|499
    337
    326
    308
    290|283
    224
    217
    203
    192|153
    148
    182
    228
    272|713
    473
    459
    438
    418|388
    314
    298
    284
    269| |20|0
    2
    5
    10
    15
    20|35
    37
    50
    NA
    NA
    NA|96
    74
    68
    NA
    NA
    NA|60
    50
    47
    41
    NA
    NA|54
    56
    73
    93
    NA
    NA|200
    148
    140
    129
    NA
    NA|118
    99
    94
    86
    80
    NA|78
    78
    100
    125
    155
    186|346
    248
    239
    223
    208
    192|201
    165
    158
    146
    136
    126|114
    113
    141
    177
    216
    254|537
    375
    363
    344
    325
    306|306
    248
    239
    224
    210
    196|149
    144
    178
    222
    264
    309|772
    528
    514
    491
    469
    448|428
    344
    334
    316
    301
    285| |30|0
    2
    5

  • California Plumbing Code Medium relevance — show source text


    (feet)|LATERAL
    L
    (feet)**|Min|Max|Max|Min|Max|Max|Min|Max|Max|Min|Max|Max|Min|Max|Max| |6|2
    5|NA
    NA|NA
    NA|28
    25|NA
    NA|NA
    NA|52
    49|NA
    NA|NA
    NA|86
    82|NA
    NA|NA
    NA|130
    117|NA
    NA|NA
    NA|180
    165| |8|2
    5
    8|NA
    NA
    NA|NA
    NA
    NA|29
    26
    24|NA
    NA
    NA|NA
    NA
    NA|55
    52
    48|NA
    NA
    NA|NA
    NA
    NA|93
    88
    83|NA
    NA
    NA|NA
    NA
    NA|145
    134
    127|NA
    NA
    NA|NA
    NA
    NA|198
    183
    175| |10|2
    5
    10|NA
    NA
    NA|NA
    NA
    NA|31
    28
    25|NA
    NA
    NA|NA
    NA
    NA|61
    57
    50|NA
    NA
    NA|NA
    NA
    NA|103
    96
    87|NA
    NA
    NA|NA
    NA
    NA|162
    148
    139|NA
    NA
    NA|NA
    NA
    NA|221
    204
    191| |15|2
    5
    10
    15|NA
    NA
    NA
    NA|NA
    NA
    NA
    NA|35
    35
    28
    NA|NA
    NA
    NA
    NA|NA
    NA
    NA
    NA|67
    62
    55
    48|NA
    NA
    NA
    NA|NA
    NA
    NA
    NA|114
    107
    97
    89|NA
    NA
    NA
    NA|NA
    NA
    NA
    NA|179
    164
    153
    141|53
    NA
    NA
    NA|475
    NA
    NA
    NA|250
    231
    216
    201| |20|2
    5

Frequently asked questions

Do private well pressure tanks need a specific listing?

Yes. Pressurized potable water tanks used with private well systems must comply with ASSE 1099/WSC‑PST 2000 as required by § 607.2.

What mesh size is required for vent and overflow screens?

The code requires corrosion‑resistant screening of not less than number 24 mesh for both vents and overflows (see § 607.4 and § 607.5).

Are tank interior coatings regulated?

Yes. Interior tank coatings or liners intended for potable supply must comply with NSF/ANSI/CAN 61 per § 607.3.

What if the tank is above the fixtures it serves?

If a potable supply tank is located above the fixtures, it must be equipped with a vacuum relief valve that conforms to ANSI Z21.22/CSA 4.4, per § 607.6.

Where does the relief valve discharge have to go?

Pressure‑relief valve discharge must be installed in accordance with the manufacturer and the discharge routing rules in § 608.5; the tank must have a listed relief device as required by § 607.6.

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