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SECTION 5.303 INDOOR WATER USE


5.303.1 Meters.
Separate submeters or metering devices shall be installed for the uses described in Sections 5303.1.1 and 5303.1.2.

5.303.1.1 Buildings in excess of 50,000 square feet (4645 m2). Separate submeters shall be installed as follows:
1. For each individual leased, rented, or other tenant space within the building projected to consume more than 100 gal/day (380 L/day), including, but not limited to, spaces used for laundry or cleaners, restaurant or food service, medical or dental office, laboratory, or beauty salon or barber shop.
2. Where separate submeters for individual building tenants are unfeasible, for water supplied to the following subsystems:
a. Makeup water for cooling towers where flow through is greater than 500 gpm (30 L/s)
b. Makeup water for evaporative coolers greater than 6 gpm (0.04 L/s)
c. Steam and hot-water boilers with energy input more than 500,000 Btu/h (147 kW)
5.303.1.2 Excess consumption. Any building or a space within a building that is projected to consume more than 1,000 gal/day (3800 L/day).
5.303.2 Twenty percent savings. A schedule of plumbing fixtures and fixture fittings that will reduce the overall use of potable water within the building by 20 percent shall be provided. The reduction shall be based on the maximum allowable water use per plumbing fixture and fittings as required by the California Building Standards Code. The 20 percent reduction in potable water use shall be demonstrated by one of the following methods:

1. Prescriptive method. Each plumbing fixture and fitting shall not exceed the maximum flow rate at ≥ 20 percent reduction as specified in Table 5.303.2.3, or
2. Performance method. A calculation demonstrating a 20% reduction in the building "water use baseline" as established in Table 5.303.2.2 shall be provided.
5.303.2.1 Multiple showerheads serving one shower.

When a shower is served by more than one showerhead, the combined flow rate of all the showerheads controlled by a single valve shall not exceed the maximum flow rate at ≥ 20 percent reduction contained in Table 5.303.2.2 or the shower shall be designed to only allow one showerhead to be in operation at a time.

Exception:
The maximum flow rate for shower heads when using the performance method specified in Section 5.303.2, Item 2 is 2.5 gpm @ 80 psi.

TABLE 5.303.2.2 INDOOR WATER USE BASELINE4


FIXTURE TYPE

BASELINE FLOW RATE

DURATION

DAILY USES

OCCUPANTS2

Showerheads

2.5 gpm @ 80 psi

5 min.

1

X2a

Lavatory faucets residential

2.2 gpm @ 60 psi

.25 min.

3

X

Lavatory faucets nonresidential

0.5 gpm @ 60 psi

.25 min.

3

X2b

Kitchen faucets

2.2 gpm @ 60 psi

4 min.

1

X

Replacement aerators

2.2 gpm @ 60 psi

 

 

X

Wash fountains

2.2 [rim space (in.)/20 gpm @ 60 psi]

 

 

X

Metering faucets

0.25 gallons/cycle

.25 min.

3

X

Metering faucets for wash fountains

.25 [rim space (in.)/20 gpm @ 60 psi]

.25 min.

 

X

Gravity tank type water closets

1.6 gallons/flush

1 flush

1 male1
3 female

X

Flushometer tank water closets

1.6 gallons/flush

1 flush

1 male1
3 female

X

Flushometer valve water closets

1.6 gallons/flush

1 flush

1 male1
3 female

X

Electromechanical hydraulic water closets

1.6 gallons/flush

1 flush

1 male1
3 female

X

Urinals

1.0 gallons/flush

1 flush

2 male

X



Fixture "Water Use" = Flow rate × Duration × Occupants × Daily uses

1. The daily use number shall be increased to three if urinals are not installed in the room.

2. Refer to Table A, Chapter 4, California Plumbing Code, for occupant load factors.

a. Shower use by occupants depends on the type of use of a building or portion of a building, e.g., total occupant load for a health club, but only a fraction of the occupants in an office building as determined by the anticipated number of users.

b. Nonresidential kitchen faucet use is determined by the occupant load of the area served by the fixture.

3. Use Worksheet WS-1 to calculate base line water use.

TABLE 5.303.2.3 FIXTURE FLOW RATES


FIXTURE TYPE

BASELINE FLOW RATE

MAXIMUM FLOW RATE AT 20 PERCENT REDUCTION

Showerheads

2.5 gpm @ 80 psi

2 gpm @ 80 psi

Lavatory faucets—residential

2.2 gpm @ 60 psi

1.5 gpm @ 60 psi1

Lavatory faucets—nonresidential

0.5 gpm @ 60 psi

0.4 gpm @ 60 psi3

Kitchen faucets

2.2 gpm @ 60 psi

1.8 gpm @ 60 psi2

Wash fountains

2.2 [rim space (in.)/20 gpm @ 60 psi]

1.8 [rim space (in.)/20 gpm @ 60 psi]

Metering faucets

0.25 gallons/cycle

0.2 gallons/cycle

Metering faucets for wash fountains

.25 [rim space (in.)/20 gpm @ 60 psi]

.20 [rim space (in.)/20 gpm @ 60 psi]

Gravity tank type water closets

1.6 gallons/flush

1.28 gallons/flush1

Flushometer tank water closets

1.6 gallons/flush

1.28 gallons/flush1

Flushometer valve water closets

1.6 gallons/flush

1.28 gallons/flush1

Electromechanical hydraulic water closets

1.6 gallons/flush

1.28 gallons/flush1

Urinals

1.0 gallons/flush

.5 gallons/flush


1. Lavatory Faucets Residential shall not have a flow rate less than 0.8 gpm at 20 psi.

2. Kitchen faucets may temporarily increase flow above the maximum rate, but not above 2.2 gpm @ 60 psi and must default to a maximum flow rate of 1.8 gpm @ 60psi.

3. Where complying faucets are unavailable, aerators rated at .35 gpm or other means may be used to achieve reduction.

4. Includes single and dual flush water closets with an effective flush of 1.28 gallons or less:

Single flush toilets—The effective flush volume shall not exceed 1.28 gallons (4.8 liters). The effective flush volume is the average flush volume when tested in accordance with ASME A 112.19.233.2.

Dual flush toilets—The effective flush volume shall not exceed 1.28 gallons (4.8 liters). The effective flush volume is defined as the composite, average flush volume of two reduced flushes and one full flush. Flush volumes will be tested in accordance with ASME A 112.19.2 and ASME A 112.19.14.

5.303.4 Wastewater reduction. Each building shall reduce by 20 percent wastewater by one of the following methods:

1. [DSA-SS] The installation of water-conserving fixtures (water closets, urinals) meeting the criteria established in Section 5.303.2 or
2. Utilizing nonpotable water systems [captured rainwater, graywater, and municipally treated wastewater (recycled water) complying with the current edition of the California Plumbing Code or other methods described in Section A5.304].
5.303.6 Plumbing fixtures and fittings. Plumbing fixtures (water closets and urinals) and fittings (faucets and showerheads) shall meet the standards referenced in Table 5.503.6.

TABLE 5.303.6 STANDARDS FOR PLUMBING FIXTURES AND FIXTURE FITTINGS



REQUIRED STANDARDS

Water closets (toilets) –
flushometer valve type single flush,
maximum flush volume

ASME A 112.19.2/
CSA B45.1 – 1.28 gal (4.8 L)

Water closets (toilets) –
flushometer valve type dual flush,
maximum flush volume

ASME A 112.19.14 and
 USEPA WaterSense Tank-type
High-efficiency Toilet Specification – 1.28 gal (4.8 L)

Water closets (toilets) – tank-type

U.S. EPA WaterSense Tank-type
High-efficiency Toilet Specification

Urinals, maximum flush volume

ASME A 112.19.2/
CSA B45.1 – 0.5 gal (1.9 L)

Urinals, nonwater urinals

ASME A 112.19.19 (vitreous china)
ANSI Z124.9-2004 or IAPMO
Z124.9 (plastic)

Public lavatory faucets: Maximum
flow rate – 0.5 gpm (1.9 L/min)

ASME A 112.18.1/CSA B125.1

Public metering self-closing
faucets: Maximum water use –
0.25 gal (1.0 L) per metering cycle

ASME A 112.18.1/CSA B125.1

Residential bathroom lavatory
sink faucets: Maximum flow rate –
1.5 gpm (5.7 L/min)1

ASME A 112.18.1/CSA B125.1

Showerheads: Maximum flow
rate – 2.5 gal (9.5 l/min)

ASME A112.18.1/CSA B125.1