• CHAPTER6
    WATER USE EFFICIENCY

    601.1 (6.1)Scope.

    This section specifies requirements for potable water and nonpotable water use efficiency, both for the site and for the building, and water monitoring.

    601.2 (6.2)Compliance.

    All provisions of Section 6 are mandatory provisions.

    601.3 (6.3)Mandatory Provisions.

    601.3.1 (6.3.1)Site Water Use Reduction.

    601.3.1.1 (6.3.1.1)Landscape Design.

    A minimum of 60% of the area of the improved landscape shall be in biodiverse planting of native plants and rainfall-ETc compatible plants.

    Exceptions:

    1. 1.The area of dedicated athletic fields, golf courses, driving ranges, and areas dedicated for production of food for human consumption, shall be excluded from the calculation of the improved landscape for schools, residential common areas, or public recreational facilities.

    2. 2.Landscape areas irrigated solely with alternate on-site sources of water shall be exempt from these requirements.

    3. 3.Where average annual rainfall is less than 12 in. (300 mm), plants other than turfgrass, with an annual ETc of 15 in. (380 mm) or less, shall be deemed equivalent to rainfall-ETc compatible plants.

    601.3.1.2 (6.3.1.2)Irrigation.

    For golf courses and driving ranges, only municipally reclaimed water or alternate on-site sources of water shall be used to irrigate the landscape. For other landscaped areas, not greater than one-third of improved landscape area is allowed to be irrigated with potable water. The area of dedicated athletic fields shall be excluded from the calculation of the improved landscape for schools, residential common areas, and public recreational facilities. All other irrigation shall be provided from alternate on-site sources of water or municipally reclaimed water.

    Exception: Potable water is allowed to be temporarily used on such newly installed landscape for the landscape establishment period. The amount of potable water allowed to be applied to the newly planted areas during the temporary landscape establishment period shall not exceed 70% of ETo for turfgrass and 55% of ETo for other plantings. Where municipally reclaimed water is available at a water main within 200 ft (60 m) of the project site, such water shall be used instead of potable water during the landscape establishment period. After the landscape establishment period has expired, all irrigation water use shall comply with the requirements established elsewhere in this code.

    601.3.1.2.1 (6.3.1.2.1)Irrigation System Design.

    The design of the irrigation system shall be performed by an accredited or certified irrigation professional and shall be in accordance with the following:

    1. a.Irrigation systems:

      1. 1.Shall be based on hydrozones. Turfgrass areas shall be on their own irrigation stations.

      2. 2.Shall have backflow prevention in accordance with the plumbing code (Informative note: e.g., International Plumbing Code).

      3. 3.Shall have a master valve on municipally supplied water sources that allows pressurization of the irrigation mainline only when irrigation is scheduled.

      4. 4.Shall have a flow sensor and monitoring equipment that will shut off the control valve if the flow exceeds normal flow from an irrigation station.

      5. 5.Shall prevent piping from draining between irrigation events.

    2. b.Irrigation emission devices shall comply with ASABE/ICC 802, Landscape Irrigation Sprinkler and Emitter Standard.

    3. c.Irrigation sprinklers:

      1. 1.Shall not spray water directly on buildings or hardscape area.

      2. 2.Shall have matched precipitation rate nozzles within an irrigation station.

      3. 3.Shall be prohibited on landscape areas having any dimension less than 4 ft (1220 mm).

      4. 4.Shall have an application rate less than or equal to 0.75 in. (19 mm) per hour on slopes greater than 1 unit vertical in 4 units horizontal.

      5. 5.Shall be limited to use with turfgrass or ground cover areas with vegetation maintained at 8 in. (203 mm) or less in height.

      6. 6.Where of the pop-up configuration, shall have a pop-up height of not less than 4 in (100 mm).

    4. d.Microirrigation zones:

      1. 1.Shall be equipped with pressure regulators, filters, and flush assemblies.

      2. 2.Shall have indicators that allow confirmation of operation by visual inspection.

    601.3.1.2.2 (6.3.1.2.2)Controls.

    Where any irrigation system for the project site uses an automatic controller, the system shall be controlled by a qualifying smart controller that uses evapotranspiration (ET) and weather data to adjust irrigation schedules and that complies with the minimum requirements. Alternatively, the system shall be controlled by an on-site rain or moisture sensor that automatically shuts off the system after a predetermined amount of rainfall or sensed moisture in the soil. Qualifying smart controllers shall be labeled according to USEPA WaterSense Specification for Weather-Based Irrigation Controllers or tested in accordance with Irrigation Association SWAT Climatologically Based Controllers, 8th Testing Protocol. Smart controllers that use ET data shall provide the following irrigation amounts:

    1. a.Irrigation adequacy— 80% minimum ETc.

    2. b.Irrigation excess— not to exceed 10% of ETc.

    Exception: A temporary irrigation system used exclusively for the establishment of new landscape shall be exempt from this requirement. Temporary irrigation systems shall be removed or permanently disabled at such time as the landscape establishment period has expired.

    601.3.1.2.2.1 (6.3.1.2.2.1).

    The following settings and schedule for the irrigation control system shall be posted on or adjacent to the controller:

    1. a.Precipitation rate of each irrigation station.

    2. b.Plant factors for each hydrozone.

    3. c.Soil type.

    4. d.Rain sensor settings.

    5. e.Soil moisture sensor settings, where installed.

    6. f.Peak demand schedule, including run times, cycle starts, and soak times.

    7. g.Maximum runtimes to prevent water runoff.

    601.3.1.2.3 (6.3.1.2.3)Irrigation of Rainfall-ETc Compatible Plants.

    The use of potable water or reclaimed water for irrigation of adapted plants is prohibited after the landscape establishment period. In-ground irrigation systems for rainfall-ETc compatible plants using potable or off-site treated reclaimed water are prohibited. After the landscape establishment period of adapted plants, the irrigation system using potable water or reclaimed water shall be permanently disabled or removed from site.

    Exception: Plants deemed equivalent to rainfall-ETc compatible plants by Section 601.3.1.1 (6.3.1.1), Exception 3, shall be exempt from the requirements of Section 601.3.1.3 (6.3.1.3).

    601.3.2 (6.3.2)Building Water Use Reduction.

    601.3.2.1 (6.3.2.1)Plumbing Fixtures and Fittings.

    Plumbing fixtures (water closets and urinals) and fittings (faucets and showerheads) shall comply with the following requirements, as shown in Table 601.3.2.1 (6.3.2.1):

    1. a.Water closets (toilets)—flushometer valve type. For single-flush, maximum flush volume shall be determined in accordance with ASME A112.19.2/CSA B45.1 and shall not exceed 1.28 gal (4.8 L). For dual-flush, the full-flush volume shall not exceed 1.28 gal (4.8 L) per flush. Dualflush fixtures shall also comply with the provisions of ASME A112.19.14.

    2. b.Water closets (toilets)—tank-type. Tank-type water closets shall be certified to the performance criteria of the USEPA WaterSense Tank-Type High-Efficiency Toilet Specification and shall have a maximum full-flush volume of 1.28 gal (4.8 L). Dual-flush fixtures shall also comply with the provisions of ASME A112.19.14.

    3. c.Urinals. Maximum flush volume, when determined in accordance with ASME A112.19.2/CSA B45.1, shall not exceed 0.5 gal (1.9 L). Flushing urinals shall comply with the performance criteria of the USEPA WaterSense Specification for Flushing Urinals. Nonwater urinals shall comply with ASME A112.19.19 (vitreous china) or IAPMO Z124.9 (plastic) as appropriate.

    4. d.Public lavatory faucets. Maximum flow rate shall not exceed 0.5 gpm (1.9 L/min) when tested in accordance with ASME A112.18.1/CSA B125.1.

    5. e.Public metering self-closing faucet. Maximum water use shall not exceed 0.25 gal (1.0 L) per metering cycle when tested in accordance with ASME A112.18.1/CSA B125.1.

    6. f.Residential bathroom lavatory sink faucets. Maximum flow rate shall not exceed 1.5 gpm (5.7 L/min) when tested in accordance with ASME A112.18.1/CSA B125.1. Residential bathroom lavatory sink faucets shall comply with the performance criteria of the USEPA WaterSense High-Efficiency Lavatory Faucet Specification.

    7. g.Residential kitchen faucets. Maximum flow rate shall not exceed 1.8 gpm (6.8 L/min) when tested in accordance with ASME A112.18.1/CSA B125.1. Kitchen faucets shall be permitted to temporarily increase the flow greater than 1.8 gpm (6.8 L/min) but shall not exceed 2.2 gpm (8.3 L/min) and must automatically revert to the established maximum flow rate of 1.8 gpm (6.8 L/min) upon physical release of the activation mechanism or closure of the faucet valve.

    8. h.Residential showerheads. Maximum flow rate shall not exceed 2.0 gpm (7.6 L/min) when tested in accordance with ASME A112.18.1/CSA B125.1. Residential showerheads shall comply with the performance requirements of the USEPA WaterSense Specification for Showerheads.

    9. i.Residential shower compartment (stall) in dwelling units and guest rooms. The allowable flow rate from all shower outlets (including rain systems, waterfalls, bodysprays, and jets) that can operate simultaneously shall be limited to a total of 2.0 gpm (7.6 L/min).

      Exception: Where the area of a shower compartment exceeds 2600 in.2 (1.7 m2), an additional flow of 2.0 gpm (7.6 L/min) shall be permitted for each multiple of 2600 in.2 (1.7 m2) of floor area or fraction thereof.

    10. j.Water-bottle filling stations. Water-bottle filling stations shall be an integral part of, or shall be installed adjacent to, not less than 50% of all drinking fountains installed indoors on the premises.

    TABLE 601.3.2.1 (TABLE 6.3.2.1)

    PLUMBING FIXTURES AND FITTINGS REQUIREMENTS

    PLUMBING FIXTUREMAXIMUM
    Water closets (toilets)—flushometer single-flush valve typeSingle-flush volume of 1.28 gal (4.8 L)
    Water closets (toilets)—flushometer dual-flush valve typeFull-flush volume of 1.28 gal (4.8 L)
    Water closets (toilets)—single-flush tank-typeSingle-flush volume of 1.28 gal (4.8 L)
    Water closets (toilets)—dual-flush tank-typeFull-flush volume of 1.28 gal (4.8 L)
    UrinalsFlush volume 0.5 gal (1.9 L)
    Public lavatory faucetsFlow rate—0.5 gpm (1.9 L/min)
    Public metering self-closing faucet0.25 gal (1.0 L) per metering cycle
    Residential bathroom lavatory sink faucetsFlow rate—1.5 gpm (5.7 L/min)
    Residential kitchen faucetsFlow rate—1.8 gpm (6.8 L/min)a
    Residential showerheadsFlow rate—2.0 gpm (7.6 L/min)
    Residential shower compartment (stall) in dwelling units and guest roomsFlow rate from all shower outlets total of 2.0 gpm (7.6 L/min)
    1. a.With provision for a temporary override to 2.2 gpm (8.3 L/min) as specified in Section 601.3.2(g) [6.3.2.1(g)].

    601.3.2.2 (6.3.2.2)Appliances.

    1. a. Clothes washers and dishwashers installed within dwelling units shall comply with the ENERGY STAR® Program Requirements for Clothes Washers and ENERGY STAR Program Requirements for Dishwashers. Maximum water use shall be as follows:

      1. 1. Clothes washers—Maximum water factor (WF) of 5.4 gal/ft3 of drum capacity (0.72 L/L of drum capacity).

      2. 2.Dishwashers—Standard-size dishwashers shall have a maximum WF of 3.8 gal/full operating cycle (14.3 L/full operating cycle). Compact sizes shall have a maximum WF of 3.5 gal/full operating cycle (13.2 L/full operating cycle). Standard and compact size shall be defined by ENERGY STAR criteria.

        [See also the energy efficiency requirements in Section 701.4.7.3 (7.4.7.3).]

    2. b.Clothes washers installed in publicly accessible spaces (Informative Note: e.g., multifamily and hotel common areas), and coin- and card-operated clothes washers of any size used in laundromats, shall have a maximum WF of 4.0 gal/ft3 of drum capacity normal cycle (0.53 L/L of drum capacity normal cycle). [See also the energy efficiency requirements in Sections 701.4.7.3 (7.4.7.3).]

    3. c.Commercial dishwashers in commercial foodservice facilities shall meet all ENERGY STAR requirements as listed in the ENERGY STAR Program Requirements for Commercial Dishwashers, Version 2.0.

    601.3.2.3 (6.3.2.3)HVAC Systems and Equipment.

    1. a.Once-through cooling with potable water is prohibited.

    2. b.The water being discharged from cooling towers for air-conditioning systems such as chilledwater systems shall be limited in accordance with method (1) or (2):

      1. 1.For makeup waters having less than 200 ppm (200 mg/L) of total hardness expressed as calcium carbonate, by achieving a minimum of 5 cycles of concentration.

      2. 2.For makeup waters with more than 200 ppm (200 mg/L) of total hardness expressed as calcium carbonate, by achieving a minimum of 3.5 cycles of concentration.

      Exception: Where the total dissolved solids concentration of the discharge water exceeds 1500 mg (1500 ppm/L) or the silica exceeds 150 ppm (150 mg/L) measured as silicon dioxide before the above cycles of concentration are reached.

    3. c.Cooling towers and evaporative coolers shall be equipped with makeup and blowdown meters, conductivity controllers, and overflow alarms in accordance with the thresholds listed in Table 601.3.4.1B (6.3.4.1B). Cooling towers shall be equipped with efficient drift eliminators that achieve drift reduction to a maximum of 0.002% of the recirculated water volume for counterflow towers and 0.005% of the recirculated water flow for cross-flow towers.

    4. d. Building projects located in regions where the ambient mean coincident wet-bulb temperature at 1% design cooling conditions is greater than or equal to 72°F (22°C) shall have a system for collecting condensate from air-conditioning units with a capacity greater than 65,000 Btu/h (19 kW), and the condensate shall be recovered for reuse.

    601.3.2.4 (6.3.2.4)Roofs.

    1. a.The use of potable water or reclaimed water for roof spray systems to thermally condition the roof shall be prohibited.

      Exception: Where approved by the authority having jurisdiction (AHJ), on-site treated reclaimed water may be used for roof spray systems.

    2. b.In-ground irrigation systems on vegetated roofs using potable or off-site treated reclaimed water shall be prohibited.

    3. c.The use of potable water or reclaimed water for irrigation of vegetated (green) roofs is prohibited after the vegetation establishment period or 18 month after the initial installation, whichever is less. After the landscape plants are established, the irrigation system using potable water or reclaimed water shall be removed from site.

      Exception: Where approved by the AHJ, onsite treated reclaimed water may be used for vegetated roof irrigation systems during and after the vegetation establishment period.

    601.3.2.5 (6.3.2.5)Commercial Food Service Operations.

    Commercial food service operations (Informative Note: e.g., restaurants, cafeterias, food preparation kitchens, caterers, etc.):

    1. a.Shall use high-efficiency prerinse spray valves (i.e., valves that function at 1.3 gpm [4.9 L/min] or less and comply with a 26 second performance requirement when tested in accordance with ASTM F2324),

    2. b.Shall use dishwashers that comply with the requirements of the ENERGY STAR Program for Commercial Dishwashers,

    3. c.Shall use boilerless/connectionless food steamers that consume no more than 2.0 gal/h (7.5 L/h) in the full operational mode,

    4. d.Shall use combination ovens that consume not more than 10 gal/h (38 L/h) in the full operational mode,

    5. e.Shall use air-cooled ice machines that comply with the requirements of the ENERGY STAR Program for Commercial Ice Machines, and

    6. f.Shall be equipped with hands-free faucet controllers (foot controllers, sensor activated, or other) for all faucet fittings within the food preparation area of the kitchen and the dish room, including pot sinks and washing sinks.

    601.3.2.6 (6.3.2.6)Medical and Laboratory Facilities.

    Medical and laboratory facilities, including clinics, hospitals, medical centers, physician and dental offices, and medical and nonmedical laboratories of all types shall:

    1. a.Use only water-efficient steam sterilizers equipped with (1) water-tempering devices that allow water to flow only when the discharge of condensate or hot water from the sterilizer exceeds 140°F (60°C) and (2) mechanical vacuum equipment in place of venturi-type vacuum systems for vacuum sterilizers.

    2. b.Use film processor water-recycling units where large-frame x-ray films of more than 6 in. (150 mm) in either length or width are processed. Small dental x-ray equipment is exempt from this requirement.

    3. c.Use digital imaging and radiography systems where the digital networks are installed.

    4. d.Use a dry-hood scrubber system or, if the applicant determines that a wet-hood scrubber system is required, the scrubber shall be equipped with a water recirculation system. For perchlorate hoods and other applications where a hood wash-down system is required, the hood shall be equipped with self-closing valves on those wash-down systems.

    5. e.Use only dry vacuum pumps unless fire and safety codes (Informative Note: e.g., International Fire Code) for explosive, corrosive, or oxidative gases require a liquid ring pump.

    6. f.Use only efficient water treatment systems that comply with the following criteria:

      1. 1.For all filtration processes, pressure gages shall determine and display when to backwash or change cartridges.

      2. 2.For all ion exchange and softening processes, recharge cycles shall be set by volume of water treated or based on conductivity or hardness.

      3. 3.For reverse osmosis and nanofiltration equipment with capacity greater than 27 gal/h (100 L/h), reject water shall not exceed 60% of the feed water and shall be used as scrubber feed water or for other beneficial uses on the project site.

      4. 4.Simple distillation is not acceptable as a means of water purification.

    7. g.With regard to food service operations within medical facilities, comply with Section 601.3.2.5 (6.3.2.5).

    601.3.3 (6.3.3)Special Water Features.

    Water use shall comply with the following:

    1. a.Ornamental fountains and other ornamental water features shall be supplied either by alternate on-site sources of water or by municipally reclaimed water delivered by the local water utility acceptable to the AHJ. Fountains and other features equipped with automatic water refilling valves shall be equipped with (1) makeup water meters (2) leak detection devices that shut off water flow if a leak of more than 1.0 gal/h (3.8 L/h) is detected, and (3) equipment to recirculate, filter, and treat all water for reuse within the system.

      Exception: Where alternate on-site sources of water or municipally reclaimed water are not available within 500 ft (150 m) of the building project site, potable water is allowed to be used for water features with less than 10,000 gal (38,000 L) capacity.

    2. b.Pools and spas:

      1. 1.Recover filter backwash water for reuse on landscaping or other applications, or treat and reuse backwash water within the system.

      2. 2.For filters with removable cartridges, only reusable cartridges and systems shall be used. For filters with backwash capability, use only pool filter equipment that includes a pressure drop gage to determine when the filter needs to be backwashed and a sight glass enabling the operator to determine when to stop the backwash cycle.

      3. 3.Pool splash troughs, if provided, shall drain back into the pool system.

    601.3.4 (6.3.4)Water Consumption Measurement.

    601.3.4.1 (6.3.4.1)Consumption Management.

    Measurement devices with remote communication capability shall be provided to collect water consumption data for the domestic water supply to the building. Both potable and reclaimed water entering the building project shall be monitored or submetered. In addition, for individual leased, rented, or other tenant or subtenant space within any building totaling in excess of 50,000 ft2 (5000 m2), separate submeters shall be provided. For subsystems with multiple similar units, such as multicell cooling towers, only one measurement device is required for the subsystem. Any project or building, or tenant or subtenant space within a project or building, such as a commercial car wash or aquarium, shall be submetered where consumption is projected to exceed 1000 gal/day (3800 L/day).

    Measurement devices with remote capability shall be provided to collect water use data for each water supply source (Informative Note: e.g., potable water, reclaimed water, rainwater) to the building project that exceeds the thresholds listed in Table 601.3.4.1A (6.3.4.1A). Utility company service entrance/interval meters are allowed to be used.

    Provide submetering with remote communication measurement to collect water use data for each of the building subsystems if such subsystems are sized above the threshold levels listed in Table 601.3.4.1B (6.3.4.1B).

    TABLE 601.3.4.1A (TABLE 6.3.4.1A)

    WATER SUPPLY SOURCE MEASUREMENT THRESHOLDS

    WATER SOURCEMAIN MEASUREMENT THRESHOLD
    Potable water1000 gal/day (3800 L/day)
    Municipally reclaimed water1000 gal/day (3800 L/day)
    Alternate sources of water500 gal/day (1900 L/day)

    TABLE 601.3.4.1B (TABLE 6.3.4.1B)

    SUBSYSTEM WATER MEASUREMENT THRESHOLDS

    SUBSYSTEMSUBMETERING THRESHOLD
    Cooling towers (meter on makeup water and blowdown)Cooling tower flow through tower > 500 gpm (30 L/s)
    Evaporative coolersMakeup water > 0.6 gpm (0.04 L/s)
    Steam and hot-water boilers> 500,000 Btu/h (150 kW) input
    Total irrigated landscape area with controllers> 25,000 ft2 (2500 m2)
    Separate campus or project buildingsConsumption > 1000 gal/day (3800 L/day)
    Separately leased or rental spaceConsumption > 1000 gal/day (3800 L/day)
    Any large water-using processConsumption > 1000 gal/day (3800 L/day)

    601.3.4.2 (6.3.4.2)Consumption Data Collection.

    All building measurement devices, monitoring systems, and submeters installed to comply with the threshold limits in Section 601.3.4.1 (6.3.4.1) shall be configured to communicate water consumption data to a meter data management system. At a minimum, meters shall provide daily data and shall record hourly consumption of water.

    601.3.4.3 (6.3.4.3)Data Storage and Retrieval.

    The meter data management system shall be capable of electronically storing water meter, monitoring systems, and submeter data and creating user reports showing calculated hourly, daily, monthly, and annual water consumption for each measurement device and submeter and provide alarm notification capabilities as needed to support the requirements of the water user efficiency plan for operation in Section 1001.3.2.1.2 (10.3.2.1.2).

    601.3.5 (6.3.5)Water Softeners.

    Water softeners shall comply with Sections 601.3.5.1 (6.3.5.1) through 601.3.5.4 (6.3.5.4).

    601.3.5.1 (6.3.5.1)Demand-Initiated Regeneration.

    Water softeners shall be equipped with demand-initiated regeneration control systems. Timer-based control systems shall be prohibited.

    601.3.5.2 (6.3.5.2)Water Consumption.

    During regeneration, water softeners shall have a maximum water consumption of 4 gal (15.1 L) per 1000 grains (17.1 g/L) of hardness removed, as measured in accordance with NSF 44.

    601.3.5.3 (6.3.5.3)Waste Connections.

    Waste water from water softener regeneration shall not discharge to reclaimed water collection systems and shall discharge in accordance with the International Plumbing Code.

    601.3.5.4 (6.3.5.4)Efficiency and Listing.

    Water softeners that regenerate in place, that are connected to the water system they serve by piping not exceeding 11/4 in. (31.8 mm) in diameter, or that have a volume of 3 ft3 (0.085 m3) or more of cation exchange media shall have a rated salt efficiency of not less than 4000 grains of total hardness exchange per pound of salt (571 grams of total hardness exchange per kilogram of salt), based on sodium chloride equivalency, and shall be listed and labeled in accordance with NSF 44. All other water softeners shall have a rated salt efficiency of not less than 3500 grains of total hardness exchange per pound of salt (500 grams of total hardness exchange per kilogram of salt), based on sodium chloride equivalency.

    601.3.6 (6.3.6)Reverse Osmosis Water Treatment Systems.

    Reverse osmosis systems shall be equipped with an automatic shutoff valve that prevents the production of reject water when there is no demand for treated water. Point-of-use reverse osmosis treatment systems for drinking water shall be listed and labeled in accordance with NSF 58.

    601.3.7 (6.3.7)On-Site Reclaimed Water Treatment Systems.

    On-site reclaimed water treatment systems, including grey water reuse treatment systems and waste water treatment systems, used to produce nonpotable water for use in water closet and urinal flushing, surface irrigation, and similar applications shall be listed and labeled in accordance with NSF 350.

    601.3.8 (6.3.8)Dual Water Supply Plumbing.

    601.3.8.1 (6.3.8.1)

    Where sufficient supply of reclaimed water or alternate on-site sources of water is available, or planned to be available, within five years of completed building construction, the water supply system within the building shall be installed to allow the supply of reclaimed or alternative water to all urinals and water closets.

    Exceptions:

    1. 1.Existing buildings under renovation, where the water supply to the urinals and water closets within the building is to remain intact, shall not be required to supply nonpotable water to urinals and water closets.

    2. 2.Urinals and water closets designed to operate without the use of water shall not be required to have alternate or reclaimed water supply to the fixture.

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