Los Angeles County Municipal Code Title 22 Planning and Zoning — of the Los Angeles County Code

(Ord. 2025-0049 § 15, 2025.)

TABLE H 201.1(1) CAPACITY OF SEPTIC TANKS1, 2, 3, 4, 5

For SI units: 1 gallon = 3.785 L

Notes:

1 Extra bedroom, 150 gallons (568 L) each.

2 Extra dwelling units over 10:250 gallons (946 L) each.

3 Extra fixture units over 100: 25 gallons (94.6 L) per fixture unit.

4 Septic tank sizes in this table include sludge storage capacity and the connection of domestic food waste disposers without further volume increase.

5 Applies to mobile homes not installed in a mobile home park.

(Ord. 2025-0049 § 16, 2025.)

TABLE H 201.1(2) DESIGN CRITERIA OF SIX TYPICAL SOILS

For SI units: 1 square foot = 0.0929 m 2 , 1 gallon = 3.785 L, 1 gallon per square foot = 40.7 L/m 2

(Ord. 2025-0049 § 17, 2025.)

TABLE H 201.1(3) LEACHING AREA SIZE BASED ON SEPTIC TANK CAPACITY

REQUIRED SQUARE FEET OF LEACHING AREA PER 100 GALLONS SEPTIC MAXIMUM SEPTIC TANK SIZE ALLOWABLE TANK CAPACITY (gallons) (square feet per 100 gallons)

For SI units: 1 square foot per 100 gallons = 0.000245 m 2 /L, 1 gallon = 3.785 L

(Ord. 2025-0049 § 18, 2025.)

TABLE H 201.1(4) ESTIMATED WASTE SEWAGE FLOW RATES1, 2

For SI units: 1 square foot = 0.0929 m 2 , 1 gallon per day 3.785 L/day

Notes:

1 See Section H 201.1.

2 Because of the many variables encountered, it is not possible to set absolute values for waste/sewage flow rates for all situations. The designer should evaluate each situation and, where figures in this table need modification, they should be made with the concurrence of the Authority Having Jurisdiction.

(Ord. 2025-0049 § 19, 2025.)

H 301.1   General.

. . .

(3)

No excavation for a leach line or leach bed shall be located within 5 feet (1524 mm) of groundwater nor to a depth where sewage may contaminate the underground water stratum.

Exception: When approved by the Authority Having Jurisdiction, this distance may be reduced to 5 feet (1524 mm) from ocean water. The applicant shall supply evidence of groundwater depth to the satisfaction of the Authority Having Jurisdiction.

(4)

The minimum effective absorption area in any seepage pit shall be calculated as the excavated sidewall area below the inlet exclusive of any hardpan, rock, clay, or other impervious formations. The minimum required area of porous formation shall be provided in one or more seepage pits. No excavation shall extend within 10 feet (3048 mm) of groundwater nor to a depth where sewage may contaminate the underground water stratum.

Exception: When approved by the Authority Having Jurisdiction, this distance may be reduced to 5 feet (1524 mm) from ocean water.

. . .

(Ord. 2025-0049 § 20, 2025.)

H 401.3   Absorption Rates.

Where a percolation test is required, the proposed system shall have the capability to absorb a quantity of clear water in a 24-hour period equal to at least five times the liquid capacity of the proposed septic tank. No private disposal system shall be permitted to serve a building if that test shows the absorption capacity of the soil is less than 0.83 gallons per square foot (gal/ft 2 ) (33.8 L/m 2 ) or more than 5.12 gal/ft 2 (208.6 L/m 2 ) of leaching area per 24 hours. Where the percolation test shows an absorption rate greater than 5.12 gal/ft 2 (208.6 L/m 2 ) per 24 hours, a private disposal system shall be permitted where the site does not overlie groundwaters protected for drinking water supplies, a minimum thickness of 2 feet (610 mm) of the native soil below the entire proposed system is replaced by loamy sand, and the system design is based on percolation tests made in the loamy sand.

(Ord. 2025-0049 § 21, 2025.)

H 601.5   Distribution Boxes.

Where two or more drain lines are installed, an approved distribution box of sufficient size to receive lateral lines shall be installed at the head of each disposal field. The inverts of outlets shall be level, and the invert of the inlet shall be not less than 1 inch (25.4 mm) above the outlets. Distribution boxes shall be designed to ensure equal flow and shall be installed on a level concrete slab in natural or compacted soil. Distribution boxes shall be coated on the inside with a bituminous coating or other approved method acceptable to the Authority Having Jurisdiction.

(Ord. 2025-0049 § 22, 2025.)

H 601.8   Dosing Tanks.

Automatic syphon or dosing tanks shall be installed when required or as permitted by the Authority Having Jurisdiction.

(Ord. 2025-0049 § 23, 2025.)

H 701.2   Multiple Installations.

Multiple seepage pit installations shall be served through an approved distribution box or be connected in series. When connected in series, the effluent shall leave each pit through an approved vented leg fitting extending not less than 12 inches (305 mm) downward into such existing pit and having its outlet flow line at least 6 inches below the inlet. All pipe between pits shall be laid with approved watertight joints.

(Ord. 2025-0049 § 24, 2025.)

H 1001.1   Inspection.

Inspection requirements shall comply with the following:

(1)

Applicable provisions of Section 104.0 of this Code and this Appendix shall be required. Plans shall be required in accordance with Section 102.1 of this Code.

. . .

(5)

Disposal fields and seepage pits shall not be installed in uncompacted fill.

(Ord. 2025-0049 § 25, 2025.)

H 1101.6   Excavation.

No excavation for an abandoned sewer or sewage facility shall be left unattended at any time, unless the permittee shall have first provided a suitable and adequate barricade to assure public safety.

(Ord. 2025-0049 § 26, 2025.)

APPENDIX T - SWIMMING POOLS

T 1.0 Swimming pool waste water shall be disposed of as hereinafter set forth in this Section and the type of disposal proposed shall be approved by the Authority Having Jurisdiction prior to the commencement of any work. A means of disposal of the total contents of the pool (periodic emptying) without surface runoff shall be established to the satisfaction of the Authority Having Jurisdiction.

T 2.0 The following are legal methods of swimming pool waste water disposal.

(1)

To a public sewer.

(2)

On the property if the property is large enough to ensure that runoff will not encroach on abutting property.

(3)

To a tank truck.

(4)

In the case where none of the above can be accomplished, alternate methods of disposal acceptable to the State Regional Water Quality Control Board (SRWQCB) may be used. Prior to discharge, the swimming pool water must be tested by the owner to ensure that it is within all water quality standards established by the SRWQCB. Contact Department of Public Works, Environmental Programs Division for information.

T 3.0 No direct connection shall be made between any storm drain, sewer, drainage system, drywell or subsoil irrigation line and any line connected to a swimming pool.

T 4.0 Waste water from any filter, scum gutter overflow, pool emptying line or similar apparatus or appurtenance when discharging to any part of a drainage system, shall be provided with a three (3) inch (76.2 mm) trap.

T 5.0 Except as provided in Section T 6.0, the discharge outlet terminal from any pool or filter shall be protected from backflow by an air gap at least six (6) inches (152.4 mm) above the flood rim of the receptor.

T 6.0 No scum gutter drain, overflow drain, backwash discharge drain, or pool emptying line shall enter any receptor below the rim unless the pool piping at its deepest point, the bottom of the filters, and the bottom of the scum gutter drain trough or overflow inlets are at least six (6) inches (152.4 mm) above the overflow rim of the receptor.

T 7.0 A positive point of potable water supply to each swimming pool shall be established and shall be installed as required by Chapter 6 of this Code.

T 8.0 Plans for other than private swimming pools shall be approved by the Health Officer before any water supply or waste discharge permit is issued.

Note: The forgoing applies only to outdoor swimming, bathing, or wading pools. Plans and specifications for all indoor installations shall be submitted to the Authority Having Jurisdiction for approval prior to the commencement of any work, and all piping, equipment and construction shall be equal to the types prescribed in the Installation Requirements of this Code for indoor work.

T 9.0 All new swimming pools constructed or installed in Fire Zone 4 or in a Very High Fire Hazard Severity Zone and having a capacity of 5000 gallons or more shall have a minimum four (4) inch diameter drain and discharge line connected to a draft hydrant, the type, location, and installation of which shall be approved by the chief of the fire department. Materials used for

the discharge line shall be as approved in this Code for potable water systems except that brass, cast iron, galvanized wrought iron, and copper shall not be used. If PVC is used, it shall be a minimum of Schedule 40.

Exception: Swimming pools constructed or installed with the bottom of the pool more than 15 feet below the proposed draft hydrant connection elevation, measured vertically, need not be provided with a draft hydrant system.

To identify that pool draft system, an appropriate sign (as designated by the fire department) including the location of the swimming pool shall be posted on the pool safety fence and/or at the draft hydrant location.

T 10.0 For one- and two-family dwellings, any new permanently installed outdoor in-ground swimming pool or spa shall be equipped with an automatic cover. For irregular-shaped pools where it is infeasible to cover 100 percent of the pool due to its irregular shape, the largest possible area of the pool (minimum 80 percent) shall be covered. For additions and alterations, non-automatic covers shall be accepted.

(Ord. 2025-0049 § 27, 2025.)

APPENDIX U - SOLAR THERMAL ENERGY SYSTEMS

U 1.0 - General.

In addition to the requirements of this Appendix, the provisions of this Code and Title 29 — Mechanical Code — of the Los Angeles County Code shall apply to the erection, installation, alteration, relocation, replacement, addition to, use, maintenance and repair of solar thermal energy systems, including, but not limited to, equipment and appliances intended to utilize solar thermal energy for water heating and swimming pool heating.

(Ord. 2025-0049 § 28, 2025.)

U 2.0 - Definitions.

For the purpose of this Appendix, certain terms, words, phrases, and their derivatives shall be construed as set forth in this Section. Whenever terms are not defined, their ordinary dictionary meaning shall apply.

Absorber. That part of the solar collector that receives the incident radiation energy.

Absorptance. The collecting of heat, measured as percent of total radiation available.

Ambient Temperature. Surrounding temperature.

Anchors. See Supports.

Antifreeze. An additive used in water-based heat transfer fluids to decrease the freezing temperature of the fluids and protect hydronic systems from freezing.

Appliance. A device that utilizes an energy source to produce light, heat, power, refrigeration, or air conditioning. This definition also includes electric storage or tankless water heaters.

Area, Absorber. The total projected heat transfer area from which the absorbed solar irradiation heats the transfer media.

Area, Aperture. The maximum projected area of a solar collector through which the unconcentrated solar radiant energy is admitted.

Automatic. That which provides a function without the necessity of human intervention.

Auxiliary Heating System. Equipment using non-solar energy sources to supplement or back up the output provided by a solar thermal energy system.

Closed Loop System. A system where the fluid is enclosed in a piping system that is not vented to the atmosphere.

Collector. See Solar Collector.

Collector System. That section of the solar collector system that includes the collector and piping or ducts from the collector to the storage system.

Combustible Liquid. A liquid having a flash point at or above 100°F (38°C). Combustible liquids shall be divided into the following classifications:

(1)

Class II liquids having a flash point above 100°F (38°C) and below 140°F (60°C).

(2)

Class IIIA liquids having a flash point at or above 140°F (60°C) and below 200°F (93°C).

(3)

Class IIIB liquids having a flash point at or above 200°F (93°C).

The classifications of combustible liquids do not include compressed gases or cryogenic fluids.

Concentrating Solar Collector. A solar collector that uses reflectors, lenses, or other optical elements to concentrate the radiant energy passing through the aperture onto an absorber of which the surface area is smaller than the aperture area.

Corrosion. The gradual degradation and destruction of metals and other natural and synthetic materials typically resulting from and/or electrochemical reactions with their environment including, but not limited to, weathering, dissolution, and direct photochemical attack.

Cover, Collector (Glazing). The material covering the aperture to provide thermal and environmental protection.

Design Pressure. The maximum allowable pressure for which a specific part of a system is designed.

Design Temperature. The maximum allowable continuous or intermittent temperature for which a specific part of a solar energy system is designed to operate safely and reliably.

Distribution System. That section of the solar energy system from the storage system to the point of use.

Drainback System. A closed loop system which allows gravity draining of the heat transfer fluid into lower portions of the solar loop under prescribed circumstances.

Draindown (Drainback). An active solar energy system in which the fluid in the solar collector is drained from the solar energy system under prescribed circumstances.

Energy Collector Fluid. That fluid used to transfer energy from the collector to the storage system or point of use.

Energy Storage Fluid (or Media). That fluid (or media) used in the storage container for storing collected energy.

Energy Transfer Fluid. That fluid used within a closed system either from the collector to the storage system or from the storage system to the point of use.

Essentially Nontoxic Transfer Fluid. Fluid generally recognized as safe by the Food and Drug Administration (FDA) as food grade.

External Auxiliary Heating. Auxiliary heating device located outside the storage. The heat is transferred to the storage by direct or indirect charging via a charge loop.

Flammable Liquid. Any liquid that has a flash point below 100°F (38°C), and has a vapor pressure not exceeding 40 psi (276 kPa) at 100°F (38°C). Flammable liquids shall be known as Class I liquids and shall be divided into the following classifications:

(1)

Class IA liquids having a flash point below 73°F (23°C) and a boiling point below 100°F (38°C).

(2)

Class IB liquids having a flash point below 73°F (23°C) and a boiling point at or above 100°F (38°C).

(3)

Class IC liquids having a flash point at or above 73°F (23°C) and below 100°F (38°C).

Flash Point. The minimum temperature corrected to a pressure of 14.7 psi (101 kPa) at which a test flame causes the vapors of a portion of the sample to ignite under the conditions specified by the test procedures and apparatus. The flash point of a liquid shall be determined in accordance with ASTM D 56, ASTM D 93, or ASTM D 3278.

Freeze Protection. Any method for protecting solar thermal systems from damage due to freezing conditions where installed in locations where freezing ambient temperature conditions exist.

Freeze Protection, Fail-Safe. A freeze-protection method that does not rely on the activation or continued operation of any mechanical or electrical component.

Heat Exchanger. A device that transfers heat from one medium to another.

Heat Transfer Medium. The medium used to transfer energy from the solar collectors to the thermal storage or load.

Immersed Heat Exchanger. Heat exchanger, which is completely surrounded with the fluid in the storage tank.

Instantaneous Efficiency. The amount of energy removed by the transfer fluid per gross collector area, during a specified time period, divided by the total solar radiation incident on the collector per unit area during the same test period, under steady state or quasi-steady state.

Integral Collector Storage. A solar thermal heating system that uses a solar collector that has all or most of its heat transfer medium inside the collector.

Langelier Saturation Index. A formula used to measure water balance or mineral saturation control of pool, spa, or hot tub water. Total alkalinity, calcium hardness, pH, water temperature, and total dissolved solids are measured, given a factor, and calculated to determine whether water has a tendency to be corrosive or scale forming.

Open Loop System. A system where the fluid is enclosed in a piping system that is vented to the atmosphere.

Out-Gassing. As applied to thermal energy, the thermal process by which materials expel gas.

Passive Solar Systems. As used in these requirements, are solar energy systems that utilize elements of a building, without augmentation by mechanical components such as blowers or pumps, to provide for the collections, storage, or distribution of solar energy for heating, cooling, or both.

Rock Storage. A bin, basement, or other container filled with rock to act as an energy reservoir for a solar energy system.

Solar Collector. A device used to absorb energy from the sun.

Solar Energy System. A configuration of equipment and components to collect, convey, store, and convert the sun's energy for a purpose.

Solar Energy System Components. Any appliance, assembly, device, equipment, or piping used in the conversion of solar energy into thermal energy for service water heating, pool water heating, space heating and cooling, and electrical service.

Solar Thermal Energy System. See Solar Thermal System.

Solar Thermal System. A complete assembly of subsystems which convert solar energy into thermal energy and utilize this energy for service water heating, pool water heating, space heating and cooling purposes.

Storage Temperature. Temperature of the storage medium.

Supports. Supports, hangers, and anchors are devices for properly supporting and securing pipe, fixtures, and equipment.

Thermal Energy. The amount of sensible heat energy stored within a material or fluid. The product of the mass, specific thermal capacity, and temperature increase/decrease of the material or fluid. Also known as sensible heat energy.

Thermal Storage. A tank or vessel used in a solar thermal, hydronic, or geothermal system, in which thermal energy is stored.

Thermosiphon. The natural circulation of fluids due to temperature differential.

Total Alkalinity. The sum of all alkaline minerals in the water that is primarily in bicarbonate form, but also as sodium, calcium, magnesium, potassium carbonates, and hydroxides. It is a measure of the water's ability to resist changes in pH.

(Ord. 2025-0049 § 28, 2025.)

U 3.0 - Permits Required.

It shall be unlawful for a person, firm, or corporation to construct, install, alter, repair, replace, or remodel a solar thermal energy system regulated by this Code or cause the same to be done without first obtaining a separate permit for each separate system or interconnected set of systems as specified in Section 103.0 of this Code.

(Ord. 2025-0049 § 28, 2025.)

U 4.0 - Plans and Specifications.

Plans, engineering calculations, diagrams, and other data shall be submitted in one or more sets with each application for a permit. Where required by the Authority Having Jurisdiction, the plans, computations, diagrams, specifications, and other data shall be prepared by, and the solar thermal energy system designed by, an engineer, an architect, or both, who shall be licensed by the state to practice as such.

Exception: The submission of plans, calculations, or other data may be waived where the Authority Having Jurisdiction determines that the nature of the work applied for is such that reviewing of plans is not necessary to obtain compliance within the Code.

(Ord. 2025-0049 § 28, 2025.)

U 5.0 - Installation.

U 5.1   Listed Appliances.

Except as otherwise provided in this Code, the installation of appliances regulated by this Code shall be in accordance with the conditions of the listing. The appliance installer shall leave the manufacturer's installation and operating instructions attached to the appliance. Clearances of listed appliances from combustible materials shall be as specified in the listing or on the rating plate.

U 5.2   Standards.

Standards listed or referred to in this Appendix or other provisions of this Code cover materials that will conform to the requirements of this Code, where used in accordance with the limitations prescribed in this Code and their listing. Where a standard covers materials of various grades, weights, quality, or configurations, the portion of the listed standard that is applicable shall be used. Design and materials for special conditions or materials not provided for herein may be permitted as authorized by Section 301.3. A list of standards that appear in specific sections of this Appendix are referenced in Table U

A list of additional standards, publications, practices, and guides that are not referenced in specific sections of this

Appendix appear in Table U 18.2. The documents indicated in Table U 18.2 shall be permitted in accordance with Section 301.3.

(Ord. 2025-0049 § 28, 2025.)

U 6.0 - Inspection and Testing.

U 6.1   General.

Solar thermal energy systems for which a permit is required by this Code shall be inspected by the Authority Having Jurisdiction. No solar thermal energy system or portion thereof shall be covered, concealed, or put into use until it first has been tested, inspected, and approved as prescribed in this Code. Neither the Authority Having Jurisdiction nor the jurisdiction shall be liable for expense entailed in the removal or replacement of material required to permit inspection. Solar thermal energy systems regulated by this Code shall not be connected to the water, the energy fuel supply, or the sewer system until authorized by the Authority Having Jurisdiction. Installation of a solar thermal energy system shall comply with other parts of this Code, including Section 104.0.

U 6.2   Required Inspection.

New solar thermal energy system work and such portions of existing systems as affected by new work, or changes, shall be inspected by the Authority Having Jurisdiction to ensure compliance with the requirements of this Code and to ensure that the installation and construction of the solar thermal energy system is in accordance with approved plans. The Authority Having Jurisdiction shall make the following inspections and other such inspections as necessary. The permittee or the permittee's authorized agent shall be responsible for the scheduling of such inspections as follows:

(1)

Underground inspection shall be made after trenches or ditches are excavated and bedded, piping installed, and before backfill is put in place.

(2)

Rough-in inspection shall be made prior to the installation of wall or ceiling membranes.

(3)

Final inspection shall be made upon completion of the installation.

U 6.3   Testing.

Solar thermal energy systems shall be tested and approved as required by this Code or the Authority Having Jurisdiction.

U 6.3.1   Piping.

The piping of the solar thermal system shall be tested with water, air, a heat transfer medium, or as recommended by the manufacturer's instructions, except that plastic pipe shall not be tested with air. The Authority Having Jurisdiction shall be permitted to require the removal of plugs, etc., to ascertain where the pressure has reached all parts of the system.

U 6.3.2   System Requirements.

Prior to the installation of insulation and startup, a solar thermal system, including piping, collectors, heat exchangers, and other related equipment, shall be tested and proved airtight.

U 6.3.2.1   Direct (Open Loop) Systems.

Direct (open loop) systems shall be tested under a water pressure not less than one and one-half times the maximum design operating pressure or 150 pounds force per square inch (psi) (1034 kPa), whichever is more. Systems shall withstand the test without leaking for a period of not less than 15 minutes.

U 6.3.2.2   Indirect (Closed Loop) Systems.

Indirect (closed loop) systems shall be hydrostatically tested at one and one-half times the maximum designed operating pressure in accordance with the manufacturer's installation instructions. Systems shall withstand the test without leaking for a period of not less than 15 minutes.

U 6.3.3   Test Pressure for Storage Tanks.

The test pressure for storage tanks that are subject to water pressure from utility mains (with or without a pressure reducing valve) shall be two times the working pressure but not less than 300 psi (2068 kPa).

U 6.3.3.1   Pressure Type.

Pressure-type storage tanks exceeding 15 psi (103 kPa) shall be tested in accordance with ASME BPVC Section VIII. Pressure-type storage tanks not exceeding 15 psi (103 kPa) shall be hydrostatically tested at one and one-half times the maximum design operating pressure.

U 6.3.3.2   Atmospheric-Type.

Atmospheric-type thermal storage tanks shall be tested by filling with water for a period of 24 hours prior to inspection and shall withstand the test without leaking. No thermal storage tank or portion thereof shall be covered or concealed prior to approval.

U 6.3.4   Connection to Service Utilities.

No person shall make connections from a source of energy or fuel to a solar thermal energy system or equipment regulated by this Code and for which a permit is required until approved by the Authority Having Jurisdiction. No person shall make connection from a water-supply line nor shall they connect to a sewer system regulated by this Code and for which a permit is required until approved by the Authority Having Jurisdiction. The Authority Having Jurisdiction shall be permitted to authorize temporary connection of the solar thermal energy system equipment to the source of energy or fuel for the purpose of testing the equipment.

(Ord. 2025-0049 § 28, 2025.)

U 7.0 - Water Heating Systems.

U 7.1   Solar Water Heating System.

Solar water heating systems shall be in accordance with IAPMO S1001.1 or ICC 900/SRCC 300. Where solar collectors are capable of being isolated from the remainder of the system, a suitable pressure relief valve shall be installed in the isolatable section.

U 7.2   Auxiliary Heating System.

An auxiliary heating system shall be installed in conjunction with the solar thermal system and shall be adequate to provide service in the absence of solar thermal energy input. An auxiliary heating system that utilizes electricity as the energy source shall be in accordance with Section U 15.0. Auxiliary heating systems that utilize solid fuel or fuel gas as the energy source shall be in accordance with Title 29 — Mechanical Code — of the Los Angeles County Code.

(Ord. 2025-0049 § 28, 2025.)

U 8.0 - Abandonment.

U 8.1   General.

An abandoned solar thermal energy system or part thereof shall be disconnected from remaining systems, drained, plugged, and capped in a manner satisfactory to the Authority Having Jurisdiction.

U 8.2   Storage Tank.

An underground water storage tank that has been abandoned or discontinued otherwise from use in a solar thermal energy system shall be completely drained and filled with earth, sand, gravel, concrete, or other approved material or removed in a manner satisfactory to the Authority Having Jurisdiction.

(Ord. 2025-0049 § 28, 2025.)

U 9.0 - Tanks.

U 9.1   Storage Tanks.

U 9.1.1   Plans.

Plans for tanks shall be submitted to the Authority Having Jurisdiction for approval, unless listed by an approved listing agency. Such plans shall show dimensions, reinforcing, structural calculations, and such other pertinent data as required by the Authority Having Jurisdiction.

U 9.1.2   Atmospheric Tanks.

Atmospheric storage tanks shall be vented to the atmosphere and installed in accordance with the manufacturer's installation instructions.

U 9.1.2.1   Overflow.

Gravity tanks shall be installed with an overflow opening of not less than 2 inches in diameter. The openings shall be above ground and installed with a screened return bend.

U 9.1.2.2   Makeup Water.

Makeup water from a potable water system to an atmospheric tank shall be protected by an air gap.

U 9.1.2.3   Draining.

An overflow shall be provided for an atmospheric tank. The overflow shall be provided with a means of drainage in accordance with Section 303.0 of this Code. The overflow for an atmospheric tank containing nonpotable water shall be emptied into an approved container.

U 9.1.3   Prefabricated Storage Tanks.

Prefabricated tanks shall be listed by an approved agency and labeled.

U 9.1.4   Pressure Vessels.

A pressure-type storage tank exceeding an operating pressure of 15 psi (103kPa) shall be constructed in accordance with ASME BPVC Section VIII.1. Fiber-reinforced plastic storage tanks shall be constructed in accordance with ASME BPVC Section X.

U 9.1.5   Devices.

Devices attached to or within a tank shall be accessible for repair and replacement.

U 9.1.5.1   Safety Devices.

Pressure-type thermal storage tanks shall be installed with a listed combination temperature and pressure relief valve in accordance with Section U 14.3.1. The temperature setting shall not exceed 210°F (99°C) and the pressure setting shall not exceed 150 percent of the maximum designed operating pressure of the system, or 150 percent of the established normal operating pressure of the piping materials, or the labeled maximum operating pressure of a pressure-type storage tank,

whichever is less. The pressure and temperature setting shall not exceed the pressure and temperature rating of the tank or as recommended by the tank manufacturer.

Storage tanks and bottom fed tanks connected to a water heater shall be designed to withstand vacuum induced pressure, or shall be provided with a vacuum relief in accordance with Section U 14.3.4. The vacuum relief valve shall be installed at the top of the tank and shall have an operating pressure not to exceed 200 psi (1379 kPa) and a temperature rating not to exceed 250°F (121°C). The size of such vacuum relief valves shall have a minimum rated capacity for the equipment served. This Section shall not apply to pressurized captive air diaphragm or bladder tanks.

U 9.1.6   Separate Storage Tanks.

For installations with separate storage tanks, a pressure relief valve and temperature relief valve or combination thereof shall be installed on both the main storage tank and auxiliary tank.

U 9.1.6.1   Isolation Valves.

Storage tanks shall be provided with isolation valves for servicing.

U 9.1.7   Underground Storage Tanks.

Tanks shall be permitted to be buried underground where designed and constructed for such installation.

U 9.1.8   Tank Covers.

Tank covers shall be structurally designed to withstand anticipated loads and pressures in accordance with the manufacturer's instructions.

U 9.1.9   Drainage Pan.

Where water heater, boiler, or other thermal storage tank is installed in an attic, attic-ceiling assembly, floor-ceiling assembly, or floor subfloor assembly where damage could result from a leaking water heater, boiler or tank, a watertight pan of corrosion-resistant materials shall be installed beneath the water heater, boiler, or tank, with not less than 3/4 of an inch (20 mm) diameter drain to an approved location. Such pan shall be not less than 1 ½ inches (38mm) in depth.

U 9.1.10   Storage Tank Construction and Materials.

U 9.1.10.1   Construction.

Storage tanks shall be constructed of durable materials not subject to excessive corrosion or decay and shall be watertight. Each such tank shall be structurally designed to withstand anticipated loads and pressures and shall be installed level and on a solid bed.

U 9.1.10.2   Concrete.

The walls and floor of each poured-in-place, concrete tank shall be monolithic. The exterior walls shall be double-formed so as to provide exposure of the exterior walls during the required water test. The compressive strength of a concrete tank wall, top and covers, or floor shall be not less than 2500 pounds-force per square inch (psi) (lb/in 2 ) (1.7236 E+04, kPa). Where required by the Authority Having Jurisdiction, the concrete shall be sulfate resistant (Type V Portland Cement).

U 9.1.10.3   Metal Tanks.

Metal tanks shall be welded, riveted and caulked, brazed, bolted, or constructed using a combination of these methods.

U 9.1.10.4   Filler Metal.

Filler metal used in brazing shall be non-ferrous metal or an alloy having a melting point above 1000°F (538°C) and below that of the metal joined.

U 9.1.10.5   Insulation.

Tank insulation shall have a thermal resistance not less than as shown in Table U 9.1.10.5. The temperature difference shall be calculated as the difference between the design operating temperature of the tank and the temperature of the surrounding air, or soil where the tank is installed underground. Where such data is not available, a temperature difference of 50°F (28°C) shall be used.

TABLE U 9.1.10.5

For SI units: °C = °F(0.5555556), 1 degree Fahrenheit hour square foot per British thermal unit = [0.176 (m2•K)/W], 1 British thermal unit inch per degree Fahrenheit hour square feet = 0.1441 W/(m•K)* Based on thermal conductivity (k) of 0.20 [(Btu•inch)/(°F•h•ft 2 )] (0.03 W/(m•K)

U 9.2   Expansion Tanks.

U 9.2.1   Where Required.

An expansion tank shall be installed in a solar thermal energy system as a means for controlling increased pressure caused by thermal expansion. Expansion tanks shall be of the closed type and securely fastened to the structure. Tanks shall be rated for the pressure of the system. Supports shall be capable of carrying twice the weight of the tank filled with water without placing strain on the connecting piping.

Solar thermal energy systems incorporating hot water tanks or fluid relief columns shall be installed to prevent freezing under normal operating conditions.

Exception: An engineered fluid expansion storage system shall be permitted to incorporate fluid storage in vessels open to the atmosphere. Storage tanks and components for such systems shall be constructed of non-corrosive materials, or the system fluid shall be treated to inhibit corrosion. [See Figure U 9.2.1(2) for an example of an engineered fluid expansion storage system which incorporates fluid storage in a vessel open to the atmosphere.]

FIGURE U 9.2.1(1)1, 2 EXAMPLE OF A CLOSED-LOOP SYSTEM WITH DIAPHRAGM TYPE EXPANSION TANK (SIMPLIFIED SCHEMATIC)

Notes:

1 This schematic does not include all system components, and configurations may vary based on design.

2 A makeup supply may be provided using any type of fluid source. The makeup supply is not considered part of the closed- loop.

FIGURE U 9.2.1(2)1, 2 EXAMPLE OF AN ENGINEERED FLUID EXPANSION STORAGE SYSTEM (ATMOSPHERIC) (SIMPLIFIED SCHEMATIC)

Notes:

1 This schematic does not include all system components, and configurations may vary based on design.

2 The atmospheric expansion tank accommodates thermal expansion and, or contraction of the system fluid.

U 9.2.2   Closed-Type Solar Thermal Energy Systems.

Closed-type systems shall have an airtight tank or other approved air cushion that will be consistent with the volume and capacity of the system, and shall be designed for a hydrostatic test pressure of two and one-half times the allowable working pressure of the system. Expansion tanks for systems designed to operate at more than 30 pounds-force per square inch (psi)

(207 kPa) shall comply with ASME BPVC Section VIII.1. Provisions shall be made for draining the tank without emptying the system.

U 9.2.3   Minimum Capacity of Closed-Type Expansion Tanks.

The minimum capacity for a gravity-type hot water system expansion tank shall be in accordance with Table U 9.2.3(1). The minimum capacity for a forced-type hot water system expansion tank shall be in accordance with Table U 9.2.3(2) or Equation U 9.2.3(1). The minimum capacity for diaphragm tanks shall be in accordance with Table U 9.2.3(2) or Equation U 9.2.3(2).

Equation U 9.2.3(1)

Vt(forced type) =

Equation U 9.2.3(2)

Vt(diaphragm) =

Where:

C 1 = 0.00041

C 2 = 0.0466

Vt = Minimum volume of expansion tank, gallons (L)

Vs = Volume of system, not including expansion tank, gallons (L)

t = Average operating temperature, °F (°C).

Pa = Atmospheric pressure, pounds per square inch (kPa)

Pf = Fill pressure, pounds per square inch (kPa)

Po = Maximum operating pressure, pounds per square inch (kPa)

For SI units: C 1 = 0.000738, C 2 = 0.03348, 1 gallon = 3.785 L, °C = (°F-32)/1.8, 1 pound per square inch = 6.8947 kPa

TABLE U 9.2.3(1) EXPANSION TANK CAPACITIES FOR GRAVITY HOT WATER SYSTEMS1

For SI units: 1 gallon = 3.785 L, 1 square foot = 0.0929 m 2

Notes:

1 Based on a two-pipe system with an average operating water temperature of 170°F (77°C), using cast-iron column radiation with a heat emission rate of 150 British thermal units per square foot hour [Btu/(ft 2 •h)] (473 W/m 2 ) equivalent direct radiation.

2 For systems exceeding 2400 square feet (222.9 m 2 ) of installed equivalent direct water radiation, the required capacity of the cushion tank shall be increased on the basis of 1 gallon (4 L) tank capacity per 33 square feet (3.1 m 2 ) of additional equivalent direct radiation.

TABLE U 9.2.3(2) EXPANSION TANK CAPACITIES FOR FORCED WATER SYSTEMS1

For SI units: 1 gallon = 3.785 L

Notes:

1 Based on an average operating water temperature of 195°F (91°C), a fill pressure of 12 psig (83 kPa), and an operating pressure of not more than 30 psig (207 kPa).

2 Includes volume of water in boiler, radiation, and piping, not including expansion tank.

(Ord. 2025-0049 § 28, 2025.)

U 10.0 - Solar Collectors.

U 10.1   General.

Frames and braces exposed to the weather shall be constructed of materials for exterior locations, and protected from corrosion or deterioration, in accordance with the requirements of the Authority Having Jurisdiction.

U 10.1.1   Construction.

Collectors shall be designed and constructed to prevent interior condensation, out-gassing, or other processes that will reduce the transmission properties of the glazing, reduce the efficiency of the insulation, or otherwise adversely affect the performance of the collector.

U 10.1.2   Flat Plate Collector Glass.

Flat plate collector glass shall be tempered.

U 10.1.3   Plastic.

Plastic used in collector and other parts of the solar thermal energy system construction shall be installed in accordance with the manufacturer's installation instructions.

U 10.1.4   Listing.

Collectors that are manufactured as a complete component shall be listed or labeled by an approved listing agency in accordance with ICC 901/SRCC 100, UL 1279, or equivalent standard.

U 10.1.5   Air Collectors.

Materials exposed within air collectors shall be noncombustible or shall have a flame spread index not to exceed 25 and a smoke developed index not to exceed 50 where tested as a composite product in accordance with ASTM E 84 or UL 723.

U 10.1.5.1   Testing.

Materials used within an air collector shall not smoke, smolder, glow, or flame where tested in accordance with ASTM C 411 at temperatures exposed to in service. In no case shall the test temperature be less than 250°F (121°C).

U 10.2   Solar Collector Installation.

U 10.2.1   General.

Solar collectors shall be ballasted or anchored to roof structures or other surfaces in accordance with the manufacturer's installation instructions and Title 26 — Building Code — of Los Angeles County. Collectors shall be mounted to minimize the accumulation of debris. Connecting pipes shall not be used to provide support for a solar collector.

U 10.2.2   Roof Installations.

Anchors secured to and through a roofing material shall be made to maintain the water integrity of the roof covering. Roof drainage shall not be impaired by the installation of collectors. Solar collectors that are not an integral part of the roofing system shall be installed to preserve the integrity of the roof surface.

U 10.2.3   Protection Against Decay.

Wood shall not be used in the construction of collector or system mounting.

U 10.2.4   Above Or On The Roof.

Collectors located above or on roofs, and functioning as building components, shall not reduce the required fire-resistance and fire-retardance classification of the roof covering materials.

Exceptions:

(1)

Collectors located on one- and two-family dwellings.

(2)

Collectors located on buildings not exceeding three stories in height or 9,000 square feet (836.13 m 2 ) total floor area, or both, provided:

(a)

The collectors are noncombustible.

(b)

Collectors with plastic covers have noncombustible sides and bottoms, and the total area covered and the collector shall not exceed the following:

(i)

Plastic CC1 — 33⅓ percent of the roof area;

(ii)

Plastic CC2 — 25 percent of the roof area; and

(c)

Collectors with plastic film covers having a thickness of not more than 0.010 of an inch (0.25 mm) shall have noncombustible sides and bottoms, and the total area covered by the collector shall not exceed 33⅓ percent of the roof area.

U 10.2.5   Ground Installations.

Solar collectors shall terminate above finished grade to avoid obstruction by vegetation, snow, or ice. The supporting columns shall extend below the frost line.

U 10.2.6   Wall Mounted.

Solar collectors mounted on a wall shall be secured and fastened in accordance with Section 313.0 of this Code.

U 10.2.7   Access.

Access shall be provided to collectors and components in an approved manner. A work space adjacent to collectors for maintenance and repair shall be provided in accordance with requirements of the Authority Having Jurisdiction.

U 10.2.8   Stagnation Condition.

The collector and other parts of the solar thermal assembly shall be capable of withstanding stagnant conditions in accordance with the manufacturer's instructions where high solar flux and no flow occurs.

U 10.2.9   Waterproofing.

Joints between structural supports and buildings or dwellings, including penetrations made by bolts or other means of fastening, shall be made watertight with approved material.

U 10.2.10   Fasteners.

Mountings and fasteners shall be made of corrosion-resistant materials. Carbon steel mountings and fasteners shall be classified as noncorrosive in accordance with ASME SA194.

U 10.2.11   Combustible Materials.

Solar thermal energy systems constructed with combustible materials shall not be located on or adjacent to construction required to be of noncombustible materials or in Very High Fire Hazard Severity Zone as defined in Title 32 — Fire Code — of the Los Angeles County Code, unless approved by the Authority Having Jurisdiction.

U 10.2.12   Orientation.

Collectors shall be located and oriented in accordance with the manufacturer's installation instructions.

U 10.3   Fire Safety Requirements.

U 10.3.1   Building Components.

Collectors that function as building components shall be in compliance with Title 26 — Building Code — of the Los Angeles County Code and Title 32 — Fire Code — of the Los Angeles County Code.

(Ord. 2025-0049 § 28, 2025.)

U 11.0 - Hazardous Heat Transfer Medium for Solar Thermal Energy Systems.

Heat-transfer mediums that are hazardous shall not be used in solar thermal energy systems, except where approved by the Authority Having Jurisdiction.

U 11.1   Flash Points.

The flash point of a heat-transfer medium shall be 50°F (10°C) or more above the design maximum temperature.

U 11.2   Discharge.

The collector, collector manifold, and manifold relief valve shall not discharge directly or indirectly into the building or toward an open flame or other source of ignition.

(Ord. 2025-0049 § 28, 2025.)

U 12.0 - Heat Exchangers.

U 12.1   General.

Solar thermal energy systems utilizing heat exchangers shall protect the potable water system from being contaminated by the heat transfer medium. Systems that incorporate a single-wall heat exchanger to separate potable water from the heat transfer fluid shall meet all of the following requirements:

(1)

The heat transfer medium is either potable water or contains fluids recognized as safe by the Food and Drug Administration (FDA) as food grade.

(2)

A tag or label shall be securely affixed to the heat source with the word "CAUTION" and the following statements:

(a)

The heat transfer medium shall be water or other nontoxic fluid recognized as safe by the FDA.

(b)

The maximum operating pressure of the heat exchanger shall not exceed the maximum operating pressure of the potable water supply.

(3)

The word "CAUTION" and the statements listed above shall have an uppercase height of not less than 0.120 of an inch (3.048 mm). The vertical spacing between lines of type shall be not less than 0.046 of an inch (1.168 mm). Lowercase letters shall be not less than compatible with the uppercase letter size specification.

Systems that do not comply with the requirements for a single-wall heat exchanger shall install a double-wall heat exchanger. Double-wall heat exchangers shall separate the potable water from the heat transfer medium by providing a space between the two walls vented to the atmosphere.

(Ord. 2025-0049 § 28, 2025.)

U 13.0 - Valves.

U 13.1   General.

Valves shall be rated for the operating temperature and pressures of the solar thermal energy system and shall be compatible with the type of heat transfer medium and piping materials. Valves shall be installed in accordance with this Section.

U 13.2   Heat Exchanger.

Shutoff valves and isolation valves shall be installed on the supply and return side of the heat exchanger.

Exception: Where a heat exchanger is an integral part of a boiler or is a part of a manufactured boiler and heat exchanger packaged unit, and is capable of being isolated from the hydronic system by supply and return valves.

U 13.3   Pressure Vessels.

Isolation valves shall be installed on connections to pressure vessels.

U 13.4   Pressure Reducing Valves.

Isolation valves shall be installed on both sides of a pressure reducing valve.

U 13.5   Equipment, Components, and Appliances.

Serviceable equipment, components, and appliances within the system shall have isolation valves installed upstream and downstream of such devices.

U 13.6   Expansion Tanks.

Isolation valves shall be installed at connections to non-diaphragm-type expansions tanks.

U 13.7   Flow Balancing Valves.

Where flow balancing valves are installed, such valves shall be capable of increasing or decreasing the amount of flow by means of adjustment.

U 13.7.1   Location.

Balancing valves shall be installed at the outlet of each group of collectors.

U 13.8   Control Valves.

An approved three-way valve shall be permitted to be installed for manual control systems. An approved electric control valve shall be permitted to be installed for automatic control systems. The installation and operation of automatic control valves shall comply with the manufacturer's instructions.

U 13.8.1   Mixing or Temperature Control Valves.

Where mixing or temperature control valves are installed, such valves shall be capable of obtaining the design water temperature and design flow requirements.

U 13.9   Thermosiphoning.

An approved type check valve shall be installed on liquid heat transfer piping to control thermosiphoning of heated liquids.

U 13.10   Air Removal Device or Air Vents.

Isolation valves shall be installed where air removal devices or automatic air vents are utilized to permit cleaning, inspection, or repair without shutting the system down.

U 13.11   Closed Loop Systems.

Closed loop systems, where hose bibbs or similar valves are used to charge or drain the system, shall be of loose key type; have valve outlets capped; or have handles removed where the system is operational.

U 13.12   Fullway Valves.

A fullway valve shall be installed in the following locations:

(1)

On the water supply to a solar thermal energy system.

(2)

On the water supply pipe to a gravity or pressurized water tank.

(3)

On the water supply pipe to a water heater.

U 13.13   Accessible.

Required fullway or shutoff valves shall be accessible.

(Ord. 2025-0049 § 28, 2025.)

U 14.0 - Piping and Cross-connection Control For Solar Thermal Energy Systems.

U 14.1   Cross Connection Control.

No piping installation, 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 the potable water system from a pipe, tank, receptor, or any other equipment by reason of backsiphonage, suction, or any other cause, either during normal use and operation thereof, or where such pipe, tank, receptor, or equipment is subject to pressure exceeding the operating pressure in the potable water system.

U 14.2   Materials.

U 14.2.1   Piping Materials.

Piping, tubing, and fittings materials shall comply with Table U 14.2. Joining methods shall be in accordance with Section 605.0. Materials in contact with the heat transfer medium shall be approved for such use. Galvanized steel shall not be used for solar thermal piping systems containing antifreeze. Black steel shall not be used in systems with entrapped or entrained air. Unions between dissimilar metals shall comply with Sections 310.6 and 605.15. The material used shall be capable of withstanding the maximum temperature and pressure of the system.

U 14.2.1.1   Plastic.

Plastic used in the construction of a solar thermal system shall be installed in accordance with the manufacturer's installation instructions.

U 14.2.1.2   Combustible Materials.

Combustible materials shall not be located on or adjacent to construction required to be of noncombustible materials or in fire areas, unless approved by the Authority Having Jurisdiction.

U 14.2.1.3   Adhesives.

Adhesives used in a solar collector shall not vaporize at the design temperature and shall be identified and approved for the intended use.

U 14.2.1.4   Potable Water.

Materials in contact with potable water shall comply with NSF 61/ANSI/CAN 61. Piping in solar thermal systems designed to convey potable water shall be flushed and disinfected in accordance with this Code.

U 14.2.1.5   Racks.

Dissimilar metals used for racking shall be isolated to prevent galvanic corrosion. Paint shall not be used as a method of isolation.

U 14.2.1.6   Fasteners.

Mountings and fasteners shall be made of corrosion-resistant materials. Carbon steel mountings and fasteners shall be classified as noncorrosive in accordance with ASME SA194.

U 14.2.2   Storage Tank Connectors.

Flexible metallic storage tank connectors or reinforced flexible storage tank connectors connecting a storage tank to the piping system shall be in accordance with the applicable standards referenced in Table U 18.1. Copper or stainless steel flexible connectors shall not exceed 24 inches (610 mm). PEX, PE-AL-PE, or PE-RT tubing shall not be installed within the first 18 inches (457 mm) of piping connected to a storage tank.

U 14.2.2.1   Flexible Connectors.

Listed flexible connectors shall be installed in readily accessible locations, unless otherwise indicated in the listing.

U 14.3   Safety Devices.

U 14.3.1   Pressure Relief Valves.

Solar thermal energy system components containing pressurized fluids shall be protected against pressures exceeding design limitations with a pressure relief valve. Each section of the system in which excessive pressures are capable of developing shall have a relief device located so that a section cannot be isolated from a relief device. Pressure and temperature relief valves shall be installed in accordance with the terms of their listing and the manufacturer's installation instructions.

TABLE U 14.2 MATERIALS FOR SOLAR THERMAL SYSTEM, PIPING, TUBING, AND FITTINGS

MATERIAL STANDARDS PIPING/TUBING FITTINGS

Notes:

1 Ductile and gray iron.

2 Only Type K, L, or M shall be permitted to be installed.

U 14.3.2   Pressurized Vessels.

Pressurized vessels shall be provided with overpressure protection by means of a listed pressure relief valve installed in accordance with the manufacturer's installation instructions.

U 14.3.3   Discharge Piping.

The discharge piping serving a temperature relief valve, pressure relief valve, or combination of both shall have no valves, obstructions, or means of isolation and comply with the following:

(1)

The discharge pipe shall equal the size of the valve outlet and shall discharge full size to the flood level of the area receiving the discharge and pointing down.

(2)

Materials shall be rated at not less than the operating temperature of the system and approved for such use or shall comply with ASME A112.4.1.

(3)

The discharge pipe shall discharge independently by gravity through an air gap into the drainage system or outside of the building with the end of the pipe not exceeding 2 feet (610 mm) and not less than 6 inches (152 mm) above the ground and pointing downwards.

(4)

The discharge pipe shall discharge in such a manner that does not cause personal injury or structural damage.

(5)

No part of such discharge pipe shall be trapped or subject to freezing.

(6)

The terminal end of the pipe shall not be threaded.

(7)

Discharge from a relief valve into a water heater pan is prohibited.

(8)

The discharge termination point shall be readily observable.

U 14.3.4   Vacuum Relief Valves.

System components that are subjected to a vacuum while in operation or during shutdown shall be protected with vacuum relief valves. Where the piping configuration, equipment location, and valve outlets are located below the storage tank elevation, the system shall be equipped with a vacuum relief valve at the highest point.

U 14.3.5   Temperature Regulation.

Where a system is capable of providing potable water at temperatures that exceed 140°F (60°C), a thermostatic mixing valve that is in accordance with ASSE 1017 shall be provided to limit the water supplied to the potable hot water distribution system to a temperature of 140°F (60°C) or less.

U 14.4   Protection of System Components.

U 14.4.1   Materials.

System components in contact with heat-transfer mediums shall be approved for such use. Components installed outdoors shall be resistant to ultraviolet radiation.

U 14.4.2   Corrosion.

Solar thermal energy systems and components subject to corrosion shall be protected in an approved manner. Metal parts exposed to atmospheric conditions shall be of corrosion-resistant material.

U 14.4.3   Mechanical Damage.

Portions of a solar thermal energy system installed where subjected to mechanical damage shall be guarded against such damage by being installed behind approved barriers or, where located within a garage, be elevated or located out of the

normal path of a vehicle, defined as a line perpendicular to the garage vehicle opening to the back wall extending 36 inches (914 mm) to either side along the back wall and to a height of 48 inches (1219 mm). Protective barriers for energy storage systems (ESS) shall be designed to resist, deflect, or visually deter vehicle impact in accordance with Section U 14.4.3.1 through Section U 14.4.3.3. (See Figure U 14.4.3).

Exception: Where the clear height of the vehicle garage opening is equal to or less than 90 inches (2286 mm), ESS installed at least 36 inches (914 mm) above the finished floor shall not be subject to vehicle impact protection requirements.

U 14.4.3.1   Bollards.

Where installed, construction of bollards shall be in accordance with one of the following:

(1)

48 inches (1219 mm) in length by 3 inches (76 mm) in diameter, Schedule 80 steel pipe embedded in a concrete pier 12 inches (305 mm) deep and 6 inches (152 mm) in diameter, with 36 inches (914 mm) of pipe exposed, filled with concrete, and spaced at intervals not exceeding 60 inches (1524 mm). Each bollard shall be located not less than 6 inches (152 mm) from an ESS.

(2)

36 inches (914 mm) in height by 3 inches (76 mm)?in diameter, Schedule 80 steel pipe fully welded to an 8 inch (203 mm) by 8 inch (203 mm) by 1?4 of an inch (6.4 mm) thick steel plate and bolted to a concrete floor by means of four ½ inch (12.7 mm) concrete anchors with not less than 3 inches (76 mm) of embedment. Spacing shall not exceed 60 inches (1524 mm), and each bollard shall be located not less than 6 inches (152 mm) from the ESS.

(3)

Pre-manufactured steel pipe bollards shall be filled with concrete and anchored in accordance with the manufacturer's installation instructions. Spacing between bollards shall not exceed 60 inches (1524 mm). Each bollard shall be located not less than 6 inches (152 mm) from the ESS.

U 14.4.3.2   Wheel Barriers.

Where installed, construction of wheel barriers shall be in accordance with one of the following:

(1)

6 inches (152 mm) in height by 6 inches (152 mm) in width, wheel stop made of concrete or polymer, anchored to the concrete floor at intervals of not less than 36 inches (914 mm) and located not less than 54 inches (1372 mm) from the ESS. Not less than two ½ inch (12.7 mm) diameter concrete anchors with 3 inches (76 mm) of embedment per wheel stop shall be used. Spacing between wheel stops shall not exceed 36 inches (914 mm).

(2)

Pre-manufactured wheel stops shall be anchored in accordance with the manufacturer's installation instructions.

U 14.4.3.3   Other Approved Methods.

Protective barriers installed 24 inches (610 mm) above grade and designed to resist a 2000 pound-force (8896 N) impact in the direction of vehicle travel shall be permitted.

FIGURE U 14.4.3 PROTECTIVE BARRIERS FOR ESS

U 14.4.4   Freeze Protection.

Unless designed for such conditions, solar thermal energy systems and components that contain liquid as the heat transfer medium shall be protected from freezing, by means of fail-safe freeze protection in accordance with this Section, where the ambient temperature may be less than 46°F (8°C).

U 14.4.4.1   Antifreeze.

Antifreeze shall be used in accordance with the solar thermal system manufacturer's instructions.

U 14.4.4.2   Drainback.

Drainback systems shall drain by gravity and shall be permitted to be installed in applications where the ambient temperature may not be less than -60°F (-51°C).

U 14.4.4.3   Integral Collector Storage.

Integral collector storage systems shall be permitted to be installed in applications where the ambient temperature may not be less than 23°F (-5°C) and the duration of below-freezing episodes exceeding 18 hours. Exposed piping in a solar thermal energy system shall be protected with insulation having a thermal resistance of not less than R-5.0.

U 14.4.4.4   Indirect Thermosiphon.

Indirect thermosiphon systems shall be permitted to be installed in applications where the ambient temperature may not be less than 23°F (-5°C). Exposed piping in a solar thermal energy system shall be protected with insulation having a thermal

resistance of not less than R-5.

U 14.4.4.5   Air Heating Systems.

Air solar heating systems shall be permitted to be used in accordance with the manufacturer's instructions.

U 14.4.4.6   Labeling.

A label indicating the method of freeze protection for the system shall be attached to the system in a visible location.

U 14.4.4.7   Piping.

Fittings, pipe slope, and collector shall be designed to allow for manual gravity draining and air filling of solar thermal energy system components and piping. Pipe slope for gravity draining shall be not less than ¼ inch per foot (20.8 mm/m) of horizontal length. Collector header pipes or absorber plate riser tubes internal to the collector shall be sloped in accordance with the manufacturer's instructions. Where a means to drain the system is provided, a drain valve shall be installed.

U 14.4.5   Water Hammer Protection.

The flow of the hydronic piping system shall be designed to prevent water hammer.

U 14.4.6   Heat Transfer Fluid Quality.

Heat transfer fluids used in closed-loop hydronic systems shall be in accordance with IAPMO/ANSI H1001.1.

U 14.4.6.1   Ethylene Glycol.

Ethylene glycol shall not be used in one- and two-unit residential systems. In existing systems, where ethylene glycol is used, there shall be no direct or permanent potable water connections. Where a temporary potable water connection is required, a backflow preventer shall be installed.

U 14.4.7   Heat Transfer Fluid.

Solar thermal piping shall be identified with an orange background with black uppercase lettering, with the words "CAUTION: HEAT TRANSFER FLUID, DO NOT DRINK." Each solar thermal energy system shall be identified to designate the medium being conveyed. The minimum size of the letters and length of the color field shall comply with Table U 14.4.7.

Each outlet on the solar thermal piping system shall be posted with black uppercase lettering as follows:

"CAUTION: HEAT TRANSFER FLUID, DO NOT DRINK."

TABLE U 14.4.7 MINIMUM LENGTH OF COLOR FIELD AND SIZE OF LETTERS

OUTSIDE DIAMETER OF PIPE OR COVERING MINIMUM LENGTH OF COLOR FIELD MINIMUM SIZE OF LETTERS (inches) (inches) (inches)

½ to 1¼ 8 ½

1½ to 2 8 ¾

2½ to 6 12 1¼

8 to 10 24 2½

Over 10 32 3½

For SI units: 1 inch = 25.4 mm

U 14.4.8   Identification of Chemical Additives.

In systems where chemical additives are used, documentation including the following information shall be readily accessible and maintained onsite:

(1)

Concentrations

(2)

Maintenance requirements

(3)

Maintenance log

(4)

Safety data sheet (SDS)

U 14.4.9   Insulation.

U 14.4.9.1   General.

The temperature of surfaces within reach of building occupants shall not exceed 140°F (60°C) unless the surfaces are protected by insulation. Where sleeves are installed, the insulation shall continue full size through them. Coverings and insulation used for piping shall be of material approved for the operating temperature of the system and the installation environment. Where installed in a plenum, the insulation, jackets and lap-seal adhesives, including pipe coverings and linings, shall have a flame spread index not to exceed 25 and a smoke-developed index not to exceed 50 where tested in accordance with ASTM E84 or UL 723.

U 14.4.9.2   Heat Loss.

Insulation shall be installed on interconnecting solar and hot water piping. The final 5 feet (1524 mm) of the cold water supply line, or the entire length where less than 5 feet (1524 mm), shall be insulated. The insulation shall have an R-value of not less than R-2.6 degree Fahrenheit hour square foot per British thermal unit (°F•h•ft 2 /Btu) (R-0.46 m 2 •K/W). Piping, storage tanks, and circulating air ductwork shall be insulated. Ductwork and piping shall be permitted to not be insulated where exposed in conditioned spaces, and the heat loss from such ducts or piping does not otherwise contribute to the heating or cooling load within such space.

Exception: Low temperature, aboveground piping installed for swimming pools, spas, and hot tubs in accordance with the manufacturer's installation instructions unless such piping is located within a building.

U 14.4.9.3   Piping.

Pipes and fittings, other than unions, flanges, or valves, shall be insulated. Insulation material shall be approved for continuous operating temperatures of not less than 220°F (104°C).

U 14.4.9.4   Fittings.

Fittings shall be insulated with mitered sections, molded fittings, insulating cement, or flexible insulation.

U 14.4.9.5   Installation.

Insulation shall be finished with a jacket or facing with the laps sealed with adhesives or staples so as to secure the insulation on the pipe. Insulation jacket seams shall be on the underside of the piping and shall overlap in accordance with the manufacturer's installation instructions. Joints and seams shall be sealed with a sealant that is approved for both the material and environmental conditions. In lieu of jackets, molded insulation shall be permitted to be secured with 16 gauge galvanized wire ties not exceeding 9 inches (229 mm) on center.

U 14.4.9.5.1   Exterior Applications.

Insulation for exterior applications shall be finished with an approved jacket, coating, or facing with the surfaces and laps sealed. Jacketing, coating, facing, and tape used for exterior applications shall be designed for such use. Where flexible insulation is used, it shall be wrapped and sealed against water penetration. Insulation used for exterior applications shall be resistant to extreme temperatures, UV exposure, and moisture.

(Ord. 2025-0049 § 28, 2025.)

U 15.0 - Specific Requirements.

U 15.1   Electrical.

U 15.1.1   Wiring.

Electrical connections, wiring, and devices shall be installed in accordance with NFPA 70. Electrical equipment, appliances, and devices installed in areas that contain flammable vapors or dusts shall be of a type approved for such environment.

U 15.1.2   Controls.

Required electrical, mechanical, safety, and operating controls shall be listed or labeled by a listing agency. Electrical controls shall be of such design and construction as to be suitable for installation in the environment in which they are located.

U 15.2   Flow Directions.

Flow directions shall be permanently affixed on the solar thermal energy system.

U 15.3   Attic Installations.

An attic space in which solar energy system components are installed shall comply with Section 508.4 of this Code.

U 15.4   Connections to Drainage System Required.

Receptors, drains, appurtenances, and appliances, used to receive or discharge liquid waste, shall be connected to the drainage system of the building or premises in accordance with the requirements of this Code.

U 15.5   Dry Storage Systems.

U 15.5.1   Waterproofing.

The containment structure for dry thermal storage systems shall be constructed in an approved manner to prevent the infiltration of water or moisture.

U 15.5.2   Detecting Water Intrusion.

The containment structure shall be capable of fully containing spillage or moisture accumulation that occurs. The structure shall have a means, such as a sight glass, to detect spillage or moisture accumulation, and shall be fitted with a drainage device to eliminate spillage.

U 15.5.3   Rock as Storage Material.

Systems utilizing rock as the thermal storage material shall use clean, washed rock that is free of organic material.

U 15.5.4   Odor and Particulate Control.

Thermal storage materials and containment structures, including interior protective coating, shall not impart toxic elements, particulate matter, or odor to areas of human occupancy.

U 15.6   Heat Pumps.

Heat pumps shall comply with UL 1995 or UL 60335-2-40. Air-source heat pumps shall also comply with AHRI 210/240. In addition, ground-source heat pumps shall comply with AHRI/ASHRAE/ISO 13256-1 for water-to-air heat pumps and AHRI/ASHRAE/ISO 13256-2 for water-to-water heat pumps. Heat pumps shall be fitted with a means to indicate that the compressor is locked out.

(Ord. 2025-0049 § 28, 2025.)

U 16.0 - Solar Thermal Energy Systems for Swimming Pool, Spas, and Hot Tubs.

U 16.1   Water Chemistry.

Where water from a swimming pool, spa, or hot tub is heated by way of circulation through solar collectors, the chemistry of such water shall comply with the requirements of Section U 16.2 and shall be filtered in accordance with Section U 16.3 and Section U 16.3.1 of this Code.

U 16.2   Parameters.

Parameters for chemicals used within a swimming pool, spa, or hot tub shall be in accordance with Table U 16.2.

TABLE U 16.2 WATER CHEMISTRY

For SI Units: 1 part per million = 1 mg/L

U 16.3   Filter.

A filter shall be provided to remove debris from the water entering the solar loop.

Exception: A solar swimming pool, spa, or hot tub heating system with a heat exchanger.

U 16.3.1   Location.

A filter shall be located upstream of a pump used to direct water to solar collectors.

U 16.4   Corrosion Resistant.

Glazed solar collectors made of copper shall not be used for solar pool, spa, or hot tub heating.

Exception: Where a heat exchanger is provided between the collector circuit and the swimming pool, spa, or hot tub water.

(Ord. 2025-0049 § 28, 2025.)

U 17.0 - Certificate of Compliance.

Upon completion of the solar thermal energy system, the permittee shall sign a Certificate of Compliance with this Code. The Certificate of Compliance shall also list the following information:

(1)

Type of freeze protection;

(2)

Mixing valve setting degrees Fahrenheit (° F);

(3)

Subsystem working pressure (if applicable) pounds per square inch;

(4)

Subsystem test pressure (if applicable) pounds per square inch;

(5)

Heat exchanger make and model number (if applicable);

(6)

Circulating pump over temperature protection shut-off setting degrees Fahrenheit (° F) for one-tank systems where the water heater controls utilize fusible-link type over temperature protection.

This Certificate shall be posted in a conspicuous location at or near the water heater.

(Ord. 2025-0049 § 28, 2025.)

U 18.0 - General.

U 18.1   Referenced Standards.

The standards listed in Table U 18.1 are referenced in various sections of this Appendix and shall be considered part of the requirements of this Code. The standards are listed herein by the standard number and effective date, the title and application. The application of the referenced standard(s) shall be as specified in Section U 5.2.

(Ord. 2025-0049 § 28, 2025.)

TABLE U 18.1 REFERENCED STANDARDS

(Ord. 2025-0049 § 29, 2025.)

TABLE U 18.2 STANDARDS, PUBLICATIONS, PRACTICES, AND GUIDES

(Ord. 2025-0049 § 30, 2025.)

ABBREVIATIONS IN TABLE U 18.1 AND TABLE U 18.2

(Ord. 2025-0049 § 31, 2025.)

APPENDIX 1 - Legislative History for Ordinance 2269.

Ordinance 2269, the Plumbing Code for Los Angeles County, was originally adopted on May 29, 1933. Ordinance 2269 was kept up to date by frequent amendments until the entire Plumbing Code was repealed and replaced by Ordinance 95-0068. Major amendments, each amending Ordinance 2269 in its entirety or adopting the current edition of the Uniform Plumbing Code, are listed and briefly described in Table A below; amending ordinances are also listed.

Table B covers the legislative history of the county's own Plumbing Code provisions before Ordinance 95-0068 was passed, and gives the specific legislative history for each section. Some repealed material is included for continuity.

Table C shows the correspondence between sections of the 1991 Uniform Plumbing Code and the 1994 Uniform Plumbing Code. The 1991 Uniform Plumbing Code was extensively revised and renumbered to create the 1994 Uniform Plumbing Code.

Provisions of Ordinance 95-0068 and its amendments now comprise Title 28 of the Los Angeles County Code.

Table A

For later amendments, see the Ordinance List and Disposition Table in Volume 8 of this code, and legislative history notes following individual sections in Title 28.

Table B

Ord. 2269 Amending Ordinances

Article 1 Added by 9543 § 3 (part), 1968 (§§ 1—5).

1 See Art. 1 entry; renumbered to be 1.5; new § 1 added by 84-0210 § 2, 1984; amended by 12339 § 1, 1981; 84-0210 § 2, 1984; 87-0178 § 1, 1987; 90-0046 § 1, 1990; 91-0088 § 1, 1991; 92-0115 § 1, 1992.

1.5 Renumbered from § 1 by 84-0210 § 1, 1984.

2 See Art. 1 entry; amended by 10325 § 3, 1971; 90-0046 § 2, 1990.

3 See Art. 1 entry; amended by 10325 § 4, 1971.

4 See Art. 1 entry; amended by 10325 § 5, 1971; 90-0046 § 3, 1990.

5 See Art. 1 entry; amended by 10325 § 6, 1971.

6 Added by 10325 § 7, 1971.

Article 2 Added by 9543 § 3 (part), 1968 (§§ 21—32).

21—32 See Art. 2 entry.

33 Added by 10325 § 8, 1971; amended by 87-0178 § 3, 1987.

Article 3 Added by 9543 § 3 (part), 1968 (§§ 51—66).

51 See Art. 3 entry; amended by 11243 § 1 (part), 1975; 12270 § 1, 1980.

52 See Art. 3 entry; amended by 11098 § 3, 1975; 82-0090 § 1, 1982.

53 See Art. 3 entry.

54 See Art. 3 entry.

55 See Art. 3 entry.

55.5 Added by 10803 § 1, 1973 and 11098 § 4, 1975.

56 See Art. 3 entry.

57 See Art. 3 entry; amended by 10325 § 9, 1971; 11098 § 5, 1975.

58 See Art. 3 entry; amended by 11576 § 2, 1977.

59 See Art. 3 entry; includes Tables I and II; Table 1, amended by 10207 § 1 (part), 1971; 10325 § 10, 1971; 11098 § 6, 1975; 11243 § 1 (part), 1975; 11576 § 3 (part), 1977; 12270 § 2, 1980.

Table 2, amended by 10207 § 1 (part), 1971; 11243 § 1 (part), 1975; 11576 § 3, 1977; 12270 § 2, 1980.

Amended by 82-0101 § 1, 1982; 82-0104 § 1, 1982; 89-0058 § 1, 1989; 90-0128 § 1, 1990; 91-0088 § 2, 1991.

60 See Art. 3 entry; amended by 10325 § 11, 1971; 11098 § 7, 1975; 11576 § 4, 1977; 12270 § 3, 1980; 82- 0104 § 2, 1982; 89-0058 § 2, 1989; 90-0128 § 2, 1990; 91-0088 § 3, 1991.

61 See Art. 3 entry; amended by 91-0088 § 4, 1991.

62 See Art. 3 entry.

63 See Art. 3 entry.

64 See Art. 3 entry.

65 See Art. 3 entry.

66 See Art. 3 entry; amended by 10110 § 1, 1970; 10518 § 1, 1972.

67 Added by 91-0088 § 5, 1991.

68 Added by 91-0088 § 6, 1991.

Article 4 Added by 9543 § 3 (part), 1968 (§§ 71—85).

71 See Art. 4 entry; amended by 10325 § 12, 1971; 11098 § 8, 1975.

72 See Art. 4 entry; amended by 11098 § 9, 1975.

73 See Art. 4 entry; amended by 11098 § 10, 1975; 90-0086 § 29(a), 1990.

74 See Art. 4 entry; amended by 12299 § 13, 1981; 90-0086 § 29(b), 1990.

75 See Art. 4 entry.

76 See Art. 4 entry.

77 See Art. 4 entry; amended by 87-0178 § 4, 1987; 91-0088 § 7, 1991.

78 See Art. 4 entry; amended by 11098 § 11, 1975.

79 See Art. 4 entry.

80 See Art. 4 entry; amended by 11098 § 12, 1975.

81 See Art. 4 entry; amended by 11098 § 13, 1975; 11243 § 2, 1975; 12339 § 2, 1981; 91-0088 § 8, 1991.

82 See Art. 4 entry.

83 See Art. 4 entry; amended by 11098 § 14, 1975.

84 See Art. 4 entry.

85 See Art. 4 entry; amended by 11098 § 15, 1975; 11243 § 3, 1975; 82-0090 § 2, 1982; 91-0088 § 9, 1991.

Article 5 Added by 89-0003 § 1 (part), 1989.

91—94 See Art. 5 entry.

Chapter 1

113 Amended by 90-0046 § 4, 1990.

117 Amended by 90-0046 § 5, 1990.

121 Amended by 90-0046 § 1, 1990; 92-0115 § 3, 1992.

122 Amended by 90-0046 § 7, 1990; 92-0115 §§ 4, 5, 1992.

124 Amended by 90-0046 § 8, 1990.

Chapter 2

201(e) Amended by 91-0088 § 10, 1991.

201(k) Added by 92-0115 § 6, 1992.

208(c), (d) Added by 90-0046 § 9, 1990.

Table A Amended by 90-0046 §§ 10, 11, 1990.

Chapter 3

307(a) Amended by 87-0178 § 6, 1987.

310(h), (i) Added by 92-0115 § 8, 1992.

314(a) Amended by 90-0046 § 12, 1990.

314(b) Amended by 90-0046 § 13, 1990.

315(b) Amended by 84-0210 § 4, 1984.

315(f)

318(a)(1) Amended by 92-0115 § 10, 1992.

323

324

Chapter 4

401(a) Amended by 84-0210 § 5, 1984; 92-0115 § 11, 1992.

Chapter 5

503(a) Amended by 84-0210 § 6, 1984; 92-0115 § 12, 1992.

Chapter 6

615(g)

Chapter 8

802(a) Amended by 92-0115 § 13, 1992.

803(g) Added by 90-0046 § 14, 1990.

804(g) Added by 92-0115 § 14, 1992.

Chapter 9

906(c) Added by 92-0115 § 15, 1992.

913 Added by 91-0097U § 1, 1991.

Chapter 10

1001 Amended by 90-0046 § 16, 1990; 92-0115 § 17, 1992.

1004(a) Amended by 84-0210 § 7, 1984; 87-0178 § 8, 1987.

1007(e) Amended by 90-0046 § 17, 1990.

1010 Added by 92-0115 § 18, 1992.

Chapter 11

1102(c) Amended by 89-0006 § 1, 1989.

1105 Amended by 87-0178 § 9, 1987.

1107(b) Amended by 87-0178 § 10, 1987.

1110(a) Amended by 87-0178 § 11, 1987.

1110(b)(2) Amended by 92-0115 § 21, 1992.

1110(c), (d)

1119(b), (c)

1119(d) Amended by 90-0046 § 18, 1990.

119(f)

Chapter 12

1203 Added by 90-0046 § 19, 1990.

1213(c) Amended by 90-0046 § 20, 1990; 92-0115 §§ 23, 24, 1992.

1213(o) Amended by 87-0178 § 12, 1987.

Chapter 13

1310(a), (e) Amended by 87-0178 § 15, 1987; 92-0115 § 27, 1992.

Chapter 14 Added by 91-0116 § 1 (part), 1991.

1401 See Ch. 14 entry.

1402 See Ch. 14 entry.

1403 See Ch. 14 entry.

1404 See Ch. 14 entry.

Table C

This table shows changes to Sections of Title 28 made by Ordinance 95-0068 to incorporate provisions of the Los Angeles County Plumbing Code as they appeared prior to Ordinance 95-0068.

Use this table to find the location of a particular section of Ordinance 2269 in Title 28. Consult Tables A and B and the history notes following each section for a complete legislative history. This table will show where sections of the County's own Plumbing Code and its amendments to the Uniform Plumbing Code were located prior to the adoption of Ordinance 95-0068.