water efficiency - cabrillo collegemsoik/6/031512 we ppt.pdfto increase water efficiency within...

Water Efficiency

LEED® Leadership in Energy and Environmental Design

Goals:Reduce the quantity of the water needed for the building.

Reduce municipal water supply and treatment burden.

Water Efficiency

Water EfficiencyCredits

WE Prerequisite 1Water Use Reduction

IntentTo increase water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems.

NC: REQSCHOOLS: REQCS: REQ

WE Credit 3Water Use Reduction

NC: 2-4 ptsSCHOOLS: 2-4 ptsCS: 2-4 pts

RequirementsNC, SCHOOLS & CSReduce building potable water use from the baseline.

WE Prerequisite 1 & WE Credit 3Water Use Reduction

RequirementsThe following fixtures, fittings and appliances are outside the scope of the water use reduction calculation: Commercial Steam Cookers Commercial Dishwashers Automatic Commercial Ice Makers Commercial (family-sized) Clothes Washers Residential Clothes Washers Standard and Compact Residential Dishwashers


Implementation Install flow restrictors and/or reduced flow aerators Install and maintain automatic faucet sensors and

metering controls Install low-flow and low-flush fixtures Install non-water fixtures

Harvest / Collect rainwater


Documentation and CalculationsDetermine the type and number of occupants.

Retain manufacturers’ data showing the water consumption rates, manufacturer, and model of each fixture and fitting.

List plumbing fixtures by usage group, if applicable.Define any usage groups.


Documentation and CalculationsThe calculated water use reduction for the project is the difference between the calculated design case and a baseline case.

Water use calculation is based on fixture and fitting water consumption rates and estimated use by the occupants

Occupants’ estimated use is determined by calculating full-time equivalent (FTE) and transient occupants and applying appropriate fixture use rates to each.


Documentation and CalculationsFixture Usage GroupsFixture usage groups are subsets of washroom facilities used by different types of occupants.


Documentation and CalculationsCalculating OccupancyNC & CSIdentify the number of building occupants by occupancy type. In buildings with multiple shifts, use the number of FTEs from all shifts. Include the followinga. Full-time staffb. Part-time staffc. Transients (students, visitors, retail customers)d. Residents


Documentation and CalculationsSCHOOLSIdentify the total number of building occupants for each occupancy type. In buildings with multiple shifts, use the number of full-time equivalents (FTEs) from all shifts.a. Full-time staffb. Part-time staffc. Studentsd. Transients (volunteers, visitors, etc.)


Documentation and CalculationsNC, SCHOOLS & CSAssume a 1-to-1 gender ratio


Timeline and TeamPredesignDesign Architect / Mechanical EngineerConstructionOccupancy


Referenced StandardsThe Energy Policy Act (EPAct) of 1992 (and as amended)The Energy Policy Act (EPAct) of 2005


Exemplary PerformancePrerequisite – NoneWE Credit 3 – 45%


IntentTo limit or eliminate the use of potable water or other natural surface or subsurface water resources available on or near the project site for landscape irrigation.

WE Credit 1Water Efficient Landscaping


RequirementsNC, SCHOOLS & CSOPTION 1Reduce potable water consumption for irrigation by 50% from a calculated midsummer baseline case.



RequirementsReductions shall be attributed to any combination of the following items: Plant species factor Irrigation efficiency Use of captured rainwater Use of recycled wastewater Use of water treated and conveyed by a public

agency specifically for non-potable uses



RequirementsNC, SCHOOLS & CSOPTION 2Do not use potable water for irrigation

ANDPATH 1Use only captured rainwater, recycled wastewater, recycled graywater or water treated and conveyed by a public agency specifically for nonpotableuses for irrigation.

ORPATH 2Install landscaping that does not require permanent irrigation systems. Temporary irrigation systems used for plant establishment are allowed only if removed within 1 year of installation



ImplementationUse native and drought-tolerant plants that can survive on natural rainfall.

Climate Tolerate PlantsMinimize Turf

Utilize Techniques such as:MulchingAlternative MowingComposting



ImplementationCapture rainwater on-site for irrigation purposes.

Consider using for Irrigation: Stormwater Graywater Condensate Water

Minimize the amount of turf and use only where needed for recreational or pedestrian use. Turf typically requires irrigation and creates a monoculture that does not encourage biodiversity.



ImplementationSpecify high-efficiency irrigation systems, such as, drip irrigation which delivers water to plant roots so less water is lost to evaporation.



ImplementationRegularly monitor irrigation systems to ensure that they are watering on desired schedules.

Do not irrigate plants during winter months.

Mulch landscaped areas to assist with water retention.



ImplementationGood Approaches:

High-Efficiency Irrigation StrategiesMicro-irrigation systemsMoisture sensorsRain shut-offsWeather-based evapotranspiration controllersDrip systems – use 30% - 50% less water than sprinklers




Rainwater CollectionCisternsUnderground TanksPondsRain Barrels




Rainwater CollectionRoofsPlazasPaved Areas




Wastewater RecoveryOn-siteMunicipal

On-Site:GraywaterWastewater Treatment







Graywater:Wastewater from:SinksShowersWashing MachinesCooling TowerCondensation from AC Systems






Graywater:Wastewater from:SinksShowersWashing MachinesCooling TowerCondensation from AC Systems

No Human Waste or Food Processing


Documentation and CalculationsPerform calculations of the baseline and design case to show the percentage reduction in water demand, and report what portion of irrigation will come from each nonpotable source (if any).

Prepare a landscape plan showing a planting schedule and irrigation system.



Documentation and CalculationsBaseline Case vs Design CaseFor each Landscape Area:Calculate KL KL = Ks x Kd x KmcDetermine ET0 for your region (July)

Calculate ETL ETL [in] = ET0 x KL

KL – Landscape CoefficientKs – Species FactorKd – Density FactorKmc – Microclimate Factor




KL = Ks x Kd x Kmc

ETL = ET0 X KL

KL = Ks x Kd x Kmc

ETL = ET0 X KL

BLDG

Which two variables remain constant when calculating the design and baseline cases?



KL = Ks x Kd x Kmc

ETL = ET0 X KL

KL = Ks x Kd x Kmc

ETL = ET0 X KL

BLDG

Which two variables remain constant when calculating the design and baseline cases?

Kmc & ET0



Baseline Case TWA [gal]Design Case TWA [gal]

Percent Reduction of Potable Water

Baseline H20% Reduction

% Reduction = 100 x [1 – Design H20 /Baseline H20]

Design H20


Timeline and TeamPredesignDesign Architect / Mechanical Engineer / Civil Engineer

ConstructionOccupancy



Referenced StandardsNone



Exemplary PerformanceNone



IntentTo reduce wastewater generation and potable water demand while increasing the local aquiferrecharge.

WE Credit 2Innovative Wastewater Technologies

NC: 2 pointsSCHOOLS: 2 pointsCS: 2 points

RequirementsOPTION 1Reduce potable water use for sewage conveyance by 50%through water conserving fixtures (water closets, urinals) or non-potable water (captured rainwater, recycled graywater, and on-site or municipally treated wastewater).

OR

OPTION 2Treat 50% of wastewater on-site to tertiary standards. Treated water must be used on-site or infiltrated.



ImplementationSpecify:

High Efficiency Fixtureslow flowdual flush

Dry Fixturescomposting toiletsnon-water urinals



ImplementationReuse for sewage conveyance:StormwaterGraywater



ImplementationConsider:On-site wastewater treatment



ImplementationConsider:Constructed Wetlands



ImplementationConsider:High-efficiency Filtration Systems



Documentation and CalculationsOption 1:Using the WE Prerequisite 1 calculations, determine the baseline and design case of only the flush fixtures, to determine whether potable water consumption is reduced by 50%.

Option 2:Determine the amount of wastewater compared with the capacity of the wastewater treatment system available.

Compile information about system schematics and the capacity of any rainwater of graywater systems.



Documentation and CalculationsPlumbing Drawings of on-site wastewater treatment facilities□ Calculated occupants [ Default 1 to 1]□ Calculated Baseline Water usage□ Calculated Design Water Usage

Provide:Fixture ManufacturerFixture ModelFlush Rate in gallons per flush [GPF]



Documentation and CalculationsTotal non-potable water for sewage conveyance [gal] (if using)

□ If treating wastewater provide the annual quantity (gal) of:Water treatedTreated water infiltratedTreated water that is re-used on site

□ Narrative describing potable water reduction strategies employed by the project.



Documentation and CalculationsOPTION 1Full Time Equivalent - FTETransient Building Occupants – daily average

Baseline CaseUse Energy Policy Act of 1992 for Fixture Flush Rates

Design CaseActual WC & Urinals Specified



Documentation and CalculationsAssumptions50% males & 50% females

Daily Uses:MalesWC 1 useUrinal 2 uses

FemalesWC 3 uses



Documentation and CalculationsEnergy Policy Act of 1992

Flush Rate for Fixtures:Conventional Water Closet 1.6 GPFConventional Urinal 1.0 GPF



Documentation and CalculationsCommercial Building - 14 FTEBaselineWC, Women 3 x 1.6 GPF x 7 = 33.6 galWC, Men 1 x 1.6 GPF x 7 = 11.2 galUrinal, Men 2 x 1.0 GPF x 7 = 14.0 gal

TPW daily = 58.8 galDesignWC, Women 3 x 1.1 GPF x 7 = 23.1 galWC, Men 1 x 1.1 GPF x 7 = 7.7 galUrinal, Men 2 x 0.0 GPF x 7 = 0.0 gal

TPW daily = 30.8 gal



Documentation and CalculationsCommercial Building - 14 FTEBaselineWC, Women 3 x 1.6 GPF x 7 = 33.6 galWC, Men 1 x 1.6 GPF x 7 = 11.2 galUrinal, Men 2 x 1.0 GPF x 7 = 14.0 gal

TPW daily = 58.8 galDesignWC, Women 3 x 1.1 GPF x 7 = 23.1 galWC, Men 1 x 1.1 GPF x 7 = 7.7 galUrinal, Men 2 x 0.0 GPF x 7 = 0.0 gal

TPW daily = 30.8 gal


% Reduction

= 100 x (1 – 30.8/58.8)

= 47.6%


Documentation and CalculationsOPTION 2

Annual Volume of Sewage GeneratedAnnual Volume of Wastewater Treated and Reused and/or infiltrated On-Site

Calculate the percent reduction of wastewater that is released into the municipal sewer system.



Timeline and TeamPredesignDesign Architect /Mechanical Engineer / Civil Engineer

ConstructionOccupancy



Referenced StandardsThe Energy Policy Act (EPAct) of 1992 (and as amended)

The Energy Policy Act (EPAct) of 2005

The 2006 editions of the Uniform Plumbing Code or International Plumbing Code



Exemplary Performance100% reduction in potable water use for sewage conveyance

OR

On-site treatment and re-use/infiltration of 100% of generated wastewater



IntentTo maximize water efficiency within buildings to reduce the burden on municipal water supplyand wastewater systems.

WE Credit 4Process Water Use Reduction

NC: NASCHOOLS: 1 pointCS: NA

RequirementsSCHOOLSTo receive this credit, buildings must have the following:

No refrigeration equipment using once-through cooling with potable water

No garbage disposals


X


RequirementsAt least 4 process items where water use is at or below the levels shown in the table below. Inclusion of any equipment not listed in the table below must be supported by documentation showing a 20% reduction in water use from a benchmark or industry standard.



ImplementationAssess all water-using process equipment within the school and select water-efficient options.



Documentation and CalculationsRetain manufacturers' data showing the water consumption rates, manufacturer, and model of each appliance.

Assemble information about the baseline water use based on industry standards for any equipment that is not listed in the credit requirements.



Timeline and TeamPredesignDesign Architect /Mechanical Engineer / Project OwnerConstructionOccupancy



Referenced StandardsNone



Exemplary PerformanceProjects may earn an innovation credit for exemplary performance by demonstrating a projected process water saving of 40%.



water efficiency - cabrillo collegemsoik/6/031512 we ppt.pdfto increase water efficiency within...

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