1. Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com1

2. Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com2

3. Water Efficiency (WE)
Overview
The Water Efficiency (WE) category addresses efficiency and reduction of potable water for:
Indoor use
Outdoor use
Specialized uses
Metering
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4. Water Efficiency (WE)
Overview
Potable Water - water that meets or exceeds U.S. Environmental Protection Agency drinking water quality standards (or a local equivalent outside the U.S.) and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems.
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5. On-site Non-potable Water Use
Water Efficiency (WE)
Overview
On-site Non-potable Water Use
Collection, treatment, and reuse of alternative water supplies.
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6. Alternative Water Sources Available On-site
Water Efficiency (WE)
Overview
Alternative Water Sources Available On-site
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7. Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com7

8. Key Water Quality Parameters
Water Efficiency (WE)
Overview
Key Water Quality Parameters
pH is a measure of the acidic or basic (alkaline) nature of a solution. pH can be used to gauge wastewater treatment efficacy and the corrosion potential of the water in the distribution system.
Total Suspended Solids (TSS) is a measurement of total solid materials, both organic and inorganic, that are suspended in water and one of the main indicators of the quantity of pollutants present.
Volatile Organic Compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects.
Total Coliform or E. Coli are indicators of microbial contamination (bacteria and viruses). UV, chlorine, and ozone disinfection are highly effective at removing microbes and the associated public health risk.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 8

9. Key Water Quality Parameters
Water Efficiency (WE)
Overview
Key Water Quality Parameters
Carbonaceous biochemical oxygen demand (CBOD) is the amount of dissolved oxygen needed by biological organisms in a body of water in which the contribution from nitrogenous bacteria has been suppressed. CBOD can be used to gauge the effectiveness of biological wastewater treatment.
Turbidity is a measure of water clarity and is a useful indicator of the likelihood that the water may be contaminated with pathogens. Filtration processes are highly effective at removing turbidity.
Chlorine residual in the water indicates that:
1) a sufficient amount of chlorine was added to inactivate bacteria and some viruses; and,
2) the water is protected from recontamination during storage.
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10. Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com10

11. Water Efficiency Goals
Water Efficiency (WE)
Overview
Water Efficiency Goals
Infiltrate rainwater on site to recharge the local aquifer.
Use water more efficiently.
Reduce the buildings water demand from indoor water (used by fixtures, appliances, and processes, such as cooling), and irrigation water.
Install building level water meter and submeters to track consumption and identify issues.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 11

12. Helpful Documentation
Water Efficiency (WE)
Overview
Helpful Documentation
Site plans: Plans are used to document the location and size of vegetated areas and the locations of meters and submeters. Within the building, floorplans show the location of fixtures, appliances, and process water equipment (e.g., cooling towers, evaporative condensers), as well as indoor submeters.
The same documentation can be used in credits in the Sustainable Sites category.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 12

13. Water Efficiency (WE)
Overview
Fixture cutsheets: Projects must document their fixtures (and appliances as applicable) using fixture cutsheets or manufacturers’ literature. This documentation is used in the Indoor Water Use Reduction prerequisite and credit.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 13

14. Water Efficiency (WE)
Overview
Alternative water sources: A project that includes graywater reuse, rainwater harvesting, municipally supplied wastewater (purple pipe water), or other reused sources is eligible to earn credit in:
WE Credit Outdoor Water Use Reduction
WE Credit Indoor Water Use Reduction
WE Credit Cooling Tower Water Use, and
WE Credit Water Metering.
But the team cannot apply the same water to multiple credits unless the water source has sufficient volume to cover the demand of all the uses (e.g., irrigation plus toilet-flushing demand).
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 14

15. Water Efficiency (WE)
Overview
Occupancy calculations: The Indoor Water Use Reduction prerequisite and credit require projections based on occupants’ usage.
The Location and Transportation and Sustainable Sites categories also use project occupancy calculations.
Review the occupancy section in Getting Started to understand how occupants are classified and counted. Also see WE Prerequisite Indoor Water Use Reduction for additional guidance specific to the WE section.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 15

16. Water Efficiency (WE) Indoor Water Use
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 16

17. Water Efficiency (WE) Outdoor Water Use
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 17

18. Water Efficiency (WE) 30% 20% 50% 100% Overview 25% 30% 35% 40% 45%
≥55%
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19. Intent WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Intent
To reduce outdoor water consumption.
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20. Requirements WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Requirements
Reduce outdoor water use through one of the following options.
Exclude - non-vegetated surfaces, including permeable and impermeable pavement.
Include - vegetated playgrounds, athletic fields, food gardens, and urban agricultural areas at project’s discretion.
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21. Option 1. No Irrigation Required
WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Option 1. No Irrigation Required
Permanent irrigation not required beyond a maximum two-year establishment period.
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22. Option 2. Reduced Irrigation
WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Option 2. Reduced Irrigation
30% reduction from baseline for site’s peak watering month.
Reduction attributed to:
Plant species selection
Irrigation system efficiency
Environmental Protection Agency (EPA) WaterSense Water Budget Tool.
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23. Additional Information to Consider
WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Native, adapted, drought-tolerate plants. Require less fertilizer and fewer chemical pesticides.
Projects with no landscape area are exempt from this prerequisite.
WaterSense Water Budget Tool automatically derives rainfall and evapotranspiration (ETo) in inches per month for the critical month of the year, based on the project’s zip code.
Minimize the use of turf (athletic playing fields).
Artificial turf may not count.
No credit is given for alternative water sources in this prerequisite.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 23

24. xeriscaping landscaping that does not require routine irrigation.
WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
xeriscaping landscaping that does not require routine irrigation.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 24

25. WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
ETo, a measurement of water lost from a well maintained expanse of average-height green grass and the surrounding soil, varies with a location’s sunshine, wind, humidity, and temperature.
Hot, dry, and windy locations have higher ETo values than cool, humid locations.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 25

26. WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Cooling tower blowdown the water discharged from a cooling tower typically because increased salinity or alkalinity has caused scaling.
Cooling tower blowdown may be too saline for use in landscape irrigation.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 26

27. Example: Rockville, Maryland
WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Example: Rockville, Maryland
The location is a typical suburban community in Maryland. Its zip code is
The team uses the EPA WaterSense Water Budget Data Finder:
Enter Zip Code: 20852
Peak Month: Jun
ETo Value: 6.27 inches/month
Rainfall: 3.10 inches/month
Access the EPA Interactive Water Budget Tool:
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 27

28. WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 28

29. WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 29

30. WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 30

31. WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 31

32. Example: Rockville, Maryland
WE Prerequisite Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Example: Rockville, Maryland
The landscape water allowance (30% below baseline minimum) equals 43,771 gallons a month.
The LWR for this design in this location is 16,873 gallons a month.
The total savings from the baseline amounts to 73%.
Since only 30% is required to meet the prerequisite, the project easily achieves compliance.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 32

33. Intent WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Intent
To reduce indoor water consumption.
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34. Requirements WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Requirements
Building Water Use
20% reduction from baseline for fixtures and fitting shown in Table 1.
All newly installed toilets, urinals, private lavatory faucets, and showerheads that are eligible for labeling must be WaterSense labeled.
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35. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Table 1. Baseline water consumption of fixtures and fittings
Fixture or fitting
Baseline (IP units)
Toilet (water closet)*
1.6 gpf
Urinal*
1.0 gpf
Public lavatory (restroom) faucet
0.5 gpm at 60 psi all others except private applications
Private lavatory faucet
2.2 gpm at 60 psi
Kitchen faucet (excluding faucets used exclusively for filling operations)
Showerhead*
2.5 gpm at 80 psi per shower stall
*WaterSense label available for this product type
gpf = gallons per flush gpm = gallons per minute psi = pounds per square inch
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 35

36. Appliance and Process Water Use
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Appliance and Process Water Use
Install appliances, equipment, and processes within the project scope that meet the requirements listed in the tables below.
Table 2. Standards for appliances
Appliance
Requirement
Residential Clothes Washer
ENERGY STAR or performance equivalent
Commercial Clothes Washer
CEE Tier 3A
Residential Dishwasher (standard and compact)
Prerinse spray valve
 ≤ 1.3 gpm
Ice machine
ENERGY STAR or performance equivalent and use either air-cooled or closed-loop cooling, such as chilled or condenser water system
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 36

37. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Table 3. Standards for processes
Process
Requirement
Heat rejection and cooling
No once-through cooling with potable water for any equipment or appliances that reject heat
Cooling towers and evaporative condensers
Equip with
makeup water meters
conductivity controllers and overflow alarms
efficient drift eliminators that reduce drift to maximum of 0.002% of recirculated water volume for counterflow towers and 0.005% of recirculated water flow for cross-flow towers
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38. Healthcare, Retail, Schools, and Hospitality Only
WE Prerequisite Indoor Water Use Reduction
S, R, HOS, HC
Healthcare, Retail, Schools, and Hospitality Only
In addition, water-consuming appliances, equipment, and processes must meet the requirements listed in Tables 4 and 5.
Table 4. Standards for appliances
Kitchen equipment
Requirement (IP units)
 Dishwasher
Undercounter
≤ 1.6 gal/rack
Stationary, single tank, door
≤ 1.4 gal/rack
Single tank, conveyor
≤ 1.0 gal/rack
Multiple tank, conveyor
≤ 0.9 gal/rack
Flight machine
≤ 180 gal/hour
 Food Steamer
Batch
≤ 6 gal/hour/pan
Cook-to-order
≤ 10 gal/hour/pan
 Combination Oven
Countertop or stand
≤ 3.5 gal/hour/pan
Roll-in
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39. WE Prerequisite Indoor Water Use Reduction
S, R, HOS, HC
Table 5. Process requirements
Process
Requirement
Discharge water temperature tempering
Where local requirements limit discharge temperature of fluids into drainage system, use tempering device that runs water only when equipment discharges hot water OR
Provide thermal recovery heat exchanger that cools drained discharge water below code-required maximum discharge temperatures while simultaneously preheating inlet makeup water
If fluid is steam condensate, return it to boiler
Venturi-type flow-through vacuum generators or aspirators
Use no device that generates vacuum by means of water flow through device into drain
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 39

40. Additional Information to Consider
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
The WaterSense label was developed by the U.S. Environmental Protection Agency to identify these efficient fixtures and ensure that higher efficiency does not come at the cost of performance.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 40

41. Additional Information to Consider
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Alternative or nonpotable water sources that offset potable water demand are addressed in the corresponding credit.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 41

42. Additional Information to Consider
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Using aerators is an acceptable water savings strategy. Newly installed aerators or flow restrictors added to private lavatories or showers must be WaterSense labeled.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 42

43. Additional Information to Consider
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Duration-based savings from autocontrol faucets with automatic fixture sensors or metering controls are no longer allowed in the design case. Studies have shown that autocontrol faucets do not save water because users frequently reactivate the faucet after initial use or stop washing before the cycle ends.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 43

44. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Sinks can be defined as public, private, kitchen, or process, depending on use and location.
Ice machines that are ineligible for the ENERGY STAR label—for example, ice machines within refrigerators—do not need to comply with the prerequisite requirement.
Describe the cooling tower or evaporative condenser system, and address the meters, controllers, alarms, and features indicated in the credit requirements.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 44

45. Compliance Path 1 WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Compliance Path 1
Compliance is documented through product cutsheets or fixture schedules.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 45

46. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Table 6. Maximum installed flush or flow rates for prescriptive path
Fixture or fitting
Maximum installed flush or flow rate
Threshold below code baseline
Toilet (water closet)*
1.28 gpf
20%
Urinal*
0.50 gpf
50%
Public lavatory (restroom) faucet
0.40 gpm
Private lavatory faucets*
1.50 gpm
32%
Kitchen faucet
1.75 gpm
Showerhead
2.00 gpm
* The WaterSense label is available for this fixture type.
**The average flush rate for dual-flush toilets must be calculated as the average flush volume of one full flush and two reduced flushes, using a 1:2 (high flush:low flush) ratio.
gpf = gallons per flush gpm = gallons per minute
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 46

47. Compliance Path 2 WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Compliance Path 2
Usage-Based Calculation is for projects that cannot demonstrate the 20% reduction for each fixture, based on manufacturers’ documentation.
Using the indoor water use calculator provided by USGBC, the project team must perform calculations to show that, in aggregate, the fixtures comply with prerequisite requirements.
Projects pursuing points under WE Credit Indoor Water Use Reduction must use this compliance path.
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48. Indoor Water Use Calculator Requires:
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Indoor Water Use Calculator Requires:
Project occupancy - Count occupants consistently across all LEED credits.
Gender ratio - The default gender mix is half male and half female (50:50).
Days of operation - The default number of days of operation per year is 365.
Fixture types used in the project.
Note: Gender ratio affects water usage only when urinals are installed.
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49. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 49

50. Excluded Water-Using Equipment
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Excluded Water-Using Equipment
Appliances and equipment that use water on materials intended for human consumption may be excluded:
Bread and produce misters
Soda machines
Coffee-making machines
Fixtures used to fill sinks for washing produce
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51. Process water sink fixtures that are excluded:
WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Process water sink fixtures that are excluded:
Specialized
Janitor sinks
Laboratory sinks regulated for medical or industrial purposes
Commercial kitchens (food service)
Commercial kitchen (food service) sinks and prep sinks, including pot filling sinks, wash-down, and cleaning sinks
Health care
Surgical scrub sinks
Exam or procedure room sinks for clinical use
Medication room sinks
General
Janitor closet sinks
Soiled utility room flushing rim sinks
Soiled utility room hand-washing sinks
Clean utility room hand-washing sinks
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52. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 52

53. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 53

54. Project Variations WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Project Variations
Core and Shell
Include only plumbing fixtures, appliances, and process water installed as a part of the Core and Shell project’s scope of work.
If no eligible plumbing fixtures, appliances, and process water are installed as part of the Core and Shell project scope of work, the project automatically achieves this prerequisite.
Schools
For K–12 schools that close on weekends, holidays, and for eight weeks of school vacation, assume 195 days of operation.
Mixed-Use
Separate calculation if the spaces use different fixtures or have dramatically different patterns of occupancy.
Additions
Include all fixtures within the project boundary
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55. WE Prerequisite Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 55

56. Intent WE Prerequisite Building-Level Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Intent
To support water management and identify opportunities for additional water savings by tracking water consumption.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 56

57. Requirements WE Prerequisite Building-Level Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Requirements
Building Water Use
Install permanent water meters that measure the total potable water use for the building and associated grounds.
Meter data must be compiled into monthly and annual summaries; meter readings can be manual or automated.
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58. WE Prerequisite Building-Level Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Commit to sharing with USGBC the resulting whole-project water usage data for a five-year period beginning on the date the project accepts LEED certification or typical occupancy, whichever comes first.
This commitment must carry forward for five years or until the building changes ownership or lessee.
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59. Additional Information to Consider
WE Prerequisite Building-Level Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Potable water end uses:
Plumbing fixtures
Cooling towers and evaporative condensers
Laundering
Dishwashing
Indoor and outdoor water features
Irrigation
Exterior cleaning
Manufacturing processes
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60. Potable water sources that must be metered:
WE Prerequisite Building-Level Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Potable water sources that must be metered:
Public water supply
On-site well
On-site potable water treatment system
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61. WE Prerequisite Building-Level Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
If all water comes from a public water supply and the utility’s water meter provides monthly consumption data, that system’s meter meets the prerequisite requirements.
Project team may meet the prerequisite requirement by tracking water usage through monthly billing.
Begin tracking water use when the project achieves LEED certification or at occupancy, whichever occurs first.
Metering and data collection are the same for Core and Shell projects.
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62. Multifamily Residential
WE Prerequisite Building-Level Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Multifamily Residential
Either use a whole-building meter or, provided all potable water uses are accounted for, aggregate data from submeters for each unit and common spaces.
Additions
A single meter that covers both old and new portions of the building may be installed, but submetering for the addition is encouraged.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 62

63. Intent WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Intent
To reduce outdoor water consumption.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 63

64. Requirements WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Requirements
Reduce outdoor water use through one of the following options.
Nonvegetated surfaces, such as permeable or impermeable pavement, should be excluded from landscape area calculations.
Athletic fields and playgrounds (if vegetated) and food gardens may be included or excluded at the project team’s discretion.
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65. Option 1. No Irrigation Required
WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Option 1. No Irrigation Required
Permanent irrigation not required beyond a maximum two-year establishment period.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 65

66. Option 2. Reduced Irrigation
WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Option 2. Reduced Irrigation
50% reduction (1 point) or
100% reduction (2 points) from baseline for site’s peak watering month.
Additional reductions beyond 30% may be achieved using any combination of:
Efficiency
Alternative water sources
Smart scheduling technologies (WaterSense labeled automatic 15% reduction)
Environmental Protection Agency (EPA) WaterSense Water Budget Tool.
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67. Additional Information to Consider
WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Rainwater Harvesting from Roof
Gallons per 1 inch of rain = Roof area in ft2 x 0.6
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68. Additional Reduction from Baseline for Smart Irrigation Controls
WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Reduction from Baseline for Smart Irrigation Controls
Count only irrigation controls whose smart-sensor technology meets the WaterSense criteria.
These controls result in an additional 15% reduction that project teams can take from the baseline.
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69. Alternative Water Sources
WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Alternative Water Sources
Reclaimed wastewater
Graywater
Swimming pool backwash filter
Refrigeration system condensate
Captured rainwater
Stormwater and foundation drain water
Steam system condensate
Fluid cooler discharge
Food steamer discharge
Combination oven discharge
Industrial process water
Fire pump test water
Municipally supplied treated wastewater
Ice machine condensate
Condensate and cooling tower blowdown in particular may have salinity levels precluding use for irrigation.
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70. Graywater WE Credit Outdoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Graywater
Untreated household wastewater from:
Bathtubs
Showers
Bathroom wash basins
Clothes-washers and
Laundry tubs
No Human Waste or Food Processing
i.e. kitchen sinks and dishwashers
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71. Intent WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Intent
To reduce indoor water consumption.
Lori A. Brown, LEED AP BD+C – Power Jam Study! Lorisweb.com 71

72. Requirements WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Requirements
Further reduce fixture and fitting water use from the calculated baseline in WE Prerequisite Indoor Water Use Reduction.
Additional potable water savings can be earned above the prerequisite level using alternative water sources.
Include fixtures and fittings necessary to meet the needs of the occupants.
Some of these fittings and fixtures may be outside the project boundary.
Points are awarded according to Table 1.
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73. WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Table 1. Points for reducing water use
Percentage reduction
Points (NC, CS, DC, WDC)
Points (S, R, HOS, HC)
25% 1
30% 2
35% 3
40% 4
45% 5
50% 6
---
Exemplary performance: Achieve ≥55% water use reduction.
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74. Schools, Retail, Hospitality, and Healthcare only
WE Credit Indoor Water Use Reduction
S, R, HOS, HC
Schools, Retail, Hospitality, and Healthcare only
Meet the percentage reduction requirements shown in Table 1.
AND
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75. Appliance and Process Water
WE Credit Indoor Water Use Reduction
S, R, HOS, HC
Appliance and Process Water
Install equipment within the project scope that meets the minimum requirements in Table 2, 3, 4, or 5 .
One point is awarded for meeting all applicable requirements in any one table. All applicable equipment listed in each table must meet the standard.
Schools, Retail, and Healthcare projects can earn a second point for meeting the requirements of two tables.
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76. WE Credit Indoor Water Use Reduction
S, R, HOS, HC
To use Table 2, the project must process at least 120,000 lbs of laundry per year.
* Based on equal quantities of heavy, medium, and light soil laundry.
Table 2. Compliant commercial washing machines
Washing machine
Requirements (IP)
On-premise, minimum capacity 2,400 lbs per 8-hour shift
Maximum 1.8 gals per pound*
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77. Requirement (IP units)
WE Credit Indoor Water Use Reduction
S, R, HOS, HC
To use Table 3, the project must serve at least 100 meals per day of operation.
Table 3. Standards for commercial kitchen equipment
Kitchen equipment
Requirement (IP units)
Dishwasher
Undercounter
ENERGY STAR
Stationary, single tank, door
Single tank, conveyor
Multiple tank, conveyor
Flight machine
Food Steamer
Batch (no drain connection)
≤ 2 gal/hour/pan including condensate cooling water
Cook-to-order (with drain connection)
≤ 5 gal/hour/pan including condensate cooling water
Combination oven
Countertop or stand
≤ 1.5 gal/hour/pan including condensate cooling water
Roll-in
Food waste disposer
Disposer
3-8 gpm, full load condition, 10 minute automatic shutoff; or 1 gpm, no-load condition
Scrap collector
Maximum 2 gpm makeup water
Pulper
Strainer basket
No additional water usage
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78. To use Table 4, the project must be a medical or laboratory facility.
WE Credit Indoor Water Use Reduction
S, R, HOS, HC
To use Table 4, the project must be a medical or laboratory facility.
Table 4. Compliant laboratory and medical equipment
Lab equipment
Requirement (IP)
Reverse-osmosis water purifier
75% recovery
Steam sterilizer
For 60-inch sterilizer, 6.3 gal/U.S. tray
For 48-inch sterilizer, 7.5 gal/U.S. tray
Sterile process washer
0.35 gal/US tray
X-ray processor, 150 mm or more in any dimension
Film processor water recycling unit
Digital imager, all sizes
No water use
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79. WE Credit Indoor Water Use Reduction
S, R, HOS, HC
To use Table 5, the project must be connected to a municipal or district steam system that does not allow the return of steam condensate.
Table 5. Compliant municipal steam systems
Steam system
Standard
Steam condensate disposal
Cool municipally supplied steam condensate (no return) to drainage system with heat recovery system or reclaimed water OR
Reclaim and use steam condensate
100% recovery and reuse
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80. Additional Information to Consider
WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Alternatives to Potable Water:
Municipally supplied reclaimed water (“purple pipe” water)
Graywater
Rainwater
Stormwater
Treated seawater
Condensate
Foundation dewatering water
Used process water
Reverse osmosis reject water
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81. Untreated Water Sources Ineligible
WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Untreated Water Sources Ineligible
Raw water from naturally occurring surface bodies of water:
Streams
Rivers
Groundwater
Well water
Water discharged from an open-loop geothermal system
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82. WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
When choosing alternative sources of water, target the uses that require the least treatment first.
In most cases, water can be reused outside the building (for irrigation) or inside (for toilet flushing) with minimal treatment, but other uses will require more energy-intensive treatment.
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83. WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
process water water that is used for industrial processes and building systems, such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making.
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84. Core and Shell WE Credit Indoor Water Use Reduction
NC, CS, S, R, DC, WDC, HOS, HC
Core and Shell
Include in the credit documentation all plumbing fixtures necessary to meet the occupants’ needs whether they will be installed as part of the project’s scope of work or not.
A project team may earn credit for the efficiency of not-yet-installed future plumbing fixtures by submitting a legally binding tenant sales or lease agreement.
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85. Intent WE Credit Cooling Tower Water Use
NC, CS, S, R, DC, WDC, HOS, HC
Intent
To conserve water used for cooling tower makeup while controlling
microbes, corrosion, and scale in the condenser water system.
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86. Requirements WE Credit Cooling Tower Water Use
NC, CS, S, R, DC, WDC, HOS, HC
Requirements
For cooling towers and evaporative condensers, conduct a one-time potable water analysis, measuring at least the five control parameters listed in Table 1.
Calculate the number of cooling tower cycles by dividing the maximum allowed concentration level of each parameter by the actual concentration level of each parameter found in the potable makeup water. Limit cooling tower cycles to avoid exceeding maximum values for any of these parameters.
Table 1. Maximum concentrations for parameters in condenser water
Parameter
Maximum level
Ca (as CaCO3)
1000 ppm
Total alkalinity
SiO2
100 ppm
Cl-
250 ppm
Conductivity
2000 μS/cm
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87. WE Credit Cooling Tower Water Use
NC, CS, S, R, DC, WDC, HOS, HC
Table 2. Points for cooling tower cycles
Parameter
Points
Maximum number of cycles achieved without exceeding any filtration levels or affecting operation of condenser water system
(up to maximum of 10 cycles) 1 
Achieve a minimum 10 cycles by increasing the level of treatment in condenser or make-up water OR
Meet the minimum number of cycles to earn 1 point and
use a minimum 20% recycled nonpotable water 2
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88. Additional Information to Considerb
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
To prevent buildup of deposits, cooling tower and evaporative condenser systems remove a portion of the water through a process called blowdown.
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89. WE Credit Cooling Tower Water Use
NC, CS, S, R, DC, WDC, HOS, HC
Makeup water is then added to replace evaporative losses and blowdown volume.
Cooling towers can therefore account for large portions of a building’s total water use.
Increasing the number of cycles can save thousands of gallons of potable water during a building’s peak cooling periods.
Only projects served by cooling towers or evaporative condensers are eligible for this credit.
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90. Equation 1. Cooling tower cycles
WE Credit Cooling Tower Water Use
NC, CS, S, R, DC, WDC, HOS, HC
Equation 1. Cooling tower cycles
Cycles of concentration = Acceptable maximum concentrations in condenser water
Parameter concentrations in makeup water
Limiting factor: Identify which concentration parameter has the fewest calculated cycles before it exceeds the maximum concentration.
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91. Cycles of Concentration
WE Credit Cooling Tower Water Use
NC, CS, S, R, DC, WDC, HOS, HC
Cycles of Concentration
Cycles of concentration are the number of times that a volume of water can circulate through a cooling tower system before dissolved minerals become so concentrated (as water is lost to evaporation) that they precipitate and cause scaling—deposits that reduce the efficiency of the cooling system.
A higher number of cycles indicates better water efficiency because less makeup water is required.
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92. Nonpotable Sources should have low levels of dissolved solids.
WE Credit Cooling Tower Water Use
NC, CS, S, R, DC, WDC, HOS, HC
Nonpotable Sources should have low levels of dissolved solids.
Good nonpotable water sources include the following:
Air-conditioner condensate
Rainwater
Steam system condensate
Food steamer discharge water
Fire pump test water
Ice machine condensate
Other factors to consider are ease of transport to the cooling tower and required volume of makeup water.
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93. Intent WE Credit Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Intent
To support water management and identify opportunities for additional water savings by tracking water consumption.
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94. Requirements WE Credit Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Requirements
Install permanent water meters for two or more of the following water subsystems, as applicable to the project:
Irrigation
Meter water systems serving at least 80% of the irrigated landscaped area. Calculate the percentage of irrigated landscape area served as the total metered irrigated landscape area divided by the total irrigated landscape area. Landscape areas fully covered with xeriscaping or native vegetation that requires no routine irrigation may be excluded from the calculation.
Indoor plumbing fixtures and fittings
Meter water systems serving at least 80% of the indoor fixtures and fitting described in WE Prerequisite Indoor Water Use Reduction, either directly or by deducting all other measured water use from the measured total water consumption of the building and grounds.
Domestic hot water
Meter water use of at least 80% of the installed domestic hot water heating capacity (including both tanks and on-demand heaters).
Boiler with aggregated projected annual water use of 100,000 gallons or more, or boiler of more than 500,000 Btuh
A single makeup meter may record flows for multiple boilers.
Reclaimed water
Meter reclaimed water, regardless of rate. A reclaimed water system with a makeup water connection must also be metered so that the true reclaimed water component can be determined.
Other process water
Meter at least 80% of expected daily water consumption for process end uses, such as humidification systems, dishwashers, clothes washers, pools, and other subsystems using process water.
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95. Healthcare Projects only
WE Credit Water Metering HC
Healthcare Projects only
In addition to the requirements above, install water meters in any five of the following:
purified water systems (reverse-osmosis, de-ionized);
filter backwash water;
water use in dietary department;
water use in laundry;
water use in laboratory;
water use in central sterile and processing department;
water use in physiotherapy and hydrotherapy and treatment areas;
water use in surgical suite;
closed-looped hydronic system makeup water; and
cold-water makeup for domestic hot water systems.
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96. Additional Information to Consider
WE Credit Water Metering
NC, CS, S, R, DC, WDC, HOS, HC
Additional Information to Consider
Metering water usage by subsystem helps facilities managers better gauge a building’s water efficiency.
Cooling tower submeters are addressed separately, under WE Prerequisite Indoor Water Use Reduction.
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