engineer research and development center us army corps of engineers water conserving technology...

Engineer Research and Development CenterUS Army Corpsof Engineers

WATER CONSERVING TECHNOLOGY OPTIONS FOR

INSTALLATION USE

Richard Scholze and Annette Stumpf

U.S. Army Corps of Engineers

ERDC-CERL

Champaign, IL

Richard Scholze and Annette Stumpf

U.S. Army Corps of Engineers

ERDC-CERL

Champaign, IL


Water Conservation

Why Do It?

Delay or Avoid Expensive Water Supply and Wastewater Treatment Capital Projects

Helps Protect Fundamental Natural Resources Through Ecosystem Protection, Protect Current Quality of Life and Provide for Future Generations

Minimize Effects of Drought

Why Do It?

Delay or Avoid Expensive Water Supply and Wastewater Treatment Capital Projects

Helps Protect Fundamental Natural Resources Through Ecosystem Protection, Protect Current Quality of Life and Provide for Future Generations

Minimize Effects of Drought


Federal Sector

Executive Order 13123

Requirements

Water Management Plan

Implementation of FEMP BMPs

Executive Order 13123

Requirements

Water Management Plan

Implementation of FEMP BMPs


Selected Conservation Opportunities

• Domestic Use

• Administrative/Commercial/Institutional

• Domestic Use

• Administrative/Commercial/Institutional


Toilets

Current Lowflow Designs Much Better

Dual Flush Toilets

Waterless Urinals

Current Lowflow Designs Much Better

Dual Flush Toilets

Waterless Urinals


Dual Flush Toilet


Dual Flush Toilet Fixtures

Only Recently Actively Marketed in U.S.4 New Manufacturers in 2004, Others Watching MarketplaceCosts Becoming CompetitiveDo They Save water?3 Study Summary

20-30% Savings in WaterWeighted Average Flush 1.1 to 1.3 gpf vs 1.6Customer Satisfaction Positive, Liked OptionAdvantage – Seldom ClogsDisadvantage – Smaller Water Spot, Possible StreakingPayback - 8.5 Years for $300 Toilet, 10 Flushes/day,

Combined W/WW Cost of $3.79/1000 gallons

Only Recently Actively Marketed in U.S.4 New Manufacturers in 2004, Others Watching MarketplaceCosts Becoming CompetitiveDo They Save water?3 Study Summary

20-30% Savings in WaterWeighted Average Flush 1.1 to 1.3 gpf vs 1.6Customer Satisfaction Positive, Liked OptionAdvantage – Seldom ClogsDisadvantage – Smaller Water Spot, Possible StreakingPayback - 8.5 Years for $300 Toilet, 10 Flushes/day,

Combined W/WW Cost of $3.79/1000 gallons


Waterless Urinals


Waterless Urinals

Becoming Widespread (Thousands in Use)

Several Manufacturers

Focus on Non-Residential Installations

Concern Over Proper Maintenance

Ex. Presidio of Monterey

173 Urinals Replaced – Classrooms, Administrative and Recreational Facilities in 48 Buildings

Expected Savings - 11,500 gal/day or 3 million gallons per year

Becoming Widespread (Thousands in Use)

Several Manufacturers

Focus on Non-Residential Installations

Concern Over Proper Maintenance

Ex. Presidio of Monterey

173 Urinals Replaced – Classrooms, Administrative and Recreational Facilities in 48 Buildings

Expected Savings - 11,500 gal/day or 3 million gallons per year


Food Service

• Pre-Rinse Spray Valves

• SOMAT System

• Boilerless Food Steamers

• Air-cooled Icemakers

• Water Conserving Dishwashers

• Pre-Rinse Spray Valves

• SOMAT System

• Boilerless Food Steamers

• Air-cooled Icemakers

• Water Conserving Dishwashers


Pre-Rinse Spray ValvesTypical Restaurant/Food Service – Up to 50% of Dishwashing

Water Consumed by Pre-rinse Spray Valve to Remove Food From Dishware, Utensils and Pans

Newer Units 1.6 gpmOver 3.0 for Non-efficient ValvesUsually Use Heated WaterTraditional “Showerhead” Type Spray PatternOrifices Become Restricted with TimeNew “Knife-like” Continuous Spray – More Efficient, Less

Mineral Buildup

Ex. Water savings 77,050 gal/yearGas Savings 335 therms/year; 7600 kWh

Typical Restaurant/Food Service – Up to 50% of Dishwashing Water Consumed by Pre-rinse Spray Valve to Remove Food From Dishware, Utensils and Pans

Newer Units 1.6 gpmOver 3.0 for Non-efficient ValvesUsually Use Heated WaterTraditional “Showerhead” Type Spray PatternOrifices Become Restricted with TimeNew “Knife-like” Continuous Spray – More Efficient, Less

Mineral Buildup

Ex. Water savings 77,050 gal/yearGas Savings 335 therms/year; 7600 kWh


SOMAT Disposal System

What is It? Food Waste Pulping and Dewatering System to Replace Scraping Trough and Garbage Disposal System in Kitchens

Uses Water to Move Material Scraped Off Plates to a Pulper Which Cuts Solid Waste into a Slurry

Slurry Flows From Pulper to Water Extractor Unit Which Removes Water to Produce Odor-Free, Semi-dry pulp

Extracted Water Returned to Feed Tray to Complete Closed-loop CycleWater Level Automatically ControlledSmall Amount 1-3 gpm Bled Off and ReplacedSystem Eliminates Need to Separate Food Scraps, Paper and Plastic WasteReduces Staff Time by HalfEx. POM 2 Systems, 2 Bldgs. – Cuts Daily Water Consumption from 9,240 to

1680 gallonsSavings 2.76 Million gal/year

What is It? Food Waste Pulping and Dewatering System to Replace Scraping Trough and Garbage Disposal System in Kitchens

Uses Water to Move Material Scraped Off Plates to a Pulper Which Cuts Solid Waste into a Slurry

Slurry Flows From Pulper to Water Extractor Unit Which Removes Water to Produce Odor-Free, Semi-dry pulp

Extracted Water Returned to Feed Tray to Complete Closed-loop CycleWater Level Automatically ControlledSmall Amount 1-3 gpm Bled Off and ReplacedSystem Eliminates Need to Separate Food Scraps, Paper and Plastic WasteReduces Staff Time by HalfEx. POM 2 Systems, 2 Bldgs. – Cuts Daily Water Consumption from 9,240 to

1680 gallonsSavings 2.76 Million gal/year


SOMAT SystemPulper and Hydra-Extractor


Boilerless Food Steamers

• Atmospheric Compartment Food Steamers – Connected to an Incoming water Line and Utilize a Steam Boiler or Generator That Injects Steam at a Constant Rate During the Cooking Event

• To Maintain Atmospheric Pressure, Rejected Steam Goes into Drain Requiring Additional Cooling Water

• Boilerless Steamers Use a Water Reservoir in Bottom of Cooking Compartment in Lieu of a water Connection – Manual Fill and Drain. No Steam Leaves.

• Better Energy Performance and Water Efficiency• Easier Cleaning• Now About 10 Different Manufacturers• Estimate of Savings – 500-1000 gallons per day plus Energy

Savings, 3 gph vs. 20 to 40 gph

• Atmospheric Compartment Food Steamers – Connected to an Incoming water Line and Utilize a Steam Boiler or Generator That Injects Steam at a Constant Rate During the Cooking Event

• To Maintain Atmospheric Pressure, Rejected Steam Goes into Drain Requiring Additional Cooling Water

• Boilerless Steamers Use a Water Reservoir in Bottom of Cooking Compartment in Lieu of a water Connection – Manual Fill and Drain. No Steam Leaves.

• Better Energy Performance and Water Efficiency• Easier Cleaning• Now About 10 Different Manufacturers• Estimate of Savings – 500-1000 gallons per day plus Energy

Savings, 3 gph vs. 20 to 40 gph


Boilerless Food Steamer


High Efficiency Washers

• Most Are Front – Loaders

• A Few Top Loaders Marginally Meet Standard CEE (Consortium for Energy Efficiency)

• Toploaders ½ to 1/3 Price of Front Loaders

• 36% Less Water

• 60% Less Energy

• Most Are Front – Loaders

• A Few Top Loaders Marginally Meet Standard CEE (Consortium for Energy Efficiency)

• Toploaders ½ to 1/3 Price of Front Loaders

• 36% Less Water

• 60% Less Energy


Common Area Laundry Rooms

Study

– In-Unit Washer – 11,800 gal/year

– Common Area Laundry Rooms 3600 gal/year per Apartment

– 3.3 Times as Much Water

Why? Residents with In-Unit Washers Tend to Operate Equipment More Often and Less Efficiently

Advantages – Savings in Gas, Electricity and Sewage, Reduced Construction Expense, Increased Space in Units

Study

– In-Unit Washer – 11,800 gal/year

– Common Area Laundry Rooms 3600 gal/year per Apartment

– 3.3 Times as Much Water

Why? Residents with In-Unit Washers Tend to Operate Equipment More Often and Less Efficiently

Advantages – Savings in Gas, Electricity and Sewage, Reduced Construction Expense, Increased Space in Units


Hospitals

• Steam Sterilizers• Example – University of Washington• Why – Steam Sterilizers Use Cold Water to Temper

Condensate from Steam (212 F) to Keep Water Entering Drain at or Below 140 F

• Older Units – Constant Bleed of 1 gpm to Mix While Unit is Hot Including Idle Time

• Install Water Saving Kit – Device or Components That Sense Effluent Temperature and Only Apply Water When Necessary to Reduce Effluent Temperature

• Evaluation – Payback Less Than 3 months• Tests Resulted in 68 to 98% Reduction

• Steam Sterilizers• Example – University of Washington• Why – Steam Sterilizers Use Cold Water to Temper

Condensate from Steam (212 F) to Keep Water Entering Drain at or Below 140 F

• Older Units – Constant Bleed of 1 gpm to Mix While Unit is Hot Including Idle Time

• Install Water Saving Kit – Device or Components That Sense Effluent Temperature and Only Apply Water When Necessary to Reduce Effluent Temperature

• Evaluation – Payback Less Than 3 months• Tests Resulted in 68 to 98% Reduction


Condensate

Local Example – San Antonio

Use Air Conditioning Condensate

Free Resource – High Quality, Distilled Water

If You Can Get to the Pipe, Catch It

Typical Home 5-10 gal/day

Larger Buildings Rule of Thumb 0.1 to 0.3 gallon per ton-hour

Collect – Residential Bucket Under Drain Line

Rout to Rain Barrel or Other Collection System

Use Gravity flow

Local Example – San Antonio

Use Air Conditioning Condensate

Free Resource – High Quality, Distilled Water

If You Can Get to the Pipe, Catch It

Typical Home 5-10 gal/day

Larger Buildings Rule of Thumb 0.1 to 0.3 gallon per ton-hour

Collect – Residential Bucket Under Drain Line

Rout to Rain Barrel or Other Collection System

Use Gravity flow


Condensate – Cont.

• Other Buildings• Ex. 500 ton System @ 80 % Load (0.2 Factor) Produces 1.3

gpm or 56,000 Gal/Month• Case Study- San Antonio Library• Produce 1 gpm (43,200 gal/month)• Garden 26,000 square feet• Collection System – 3 Interconnected Concrete Cisterns

(8400 gal capacity)• Collect from Sump Gravity Fed into Irrigation System• Total Cost $21,500, 1/3 that of Rainwater Harvest System• Another Example - River Center Mall – 12 MG of

Condensate Used for Cooling Tower Makeup

• Other Buildings• Ex. 500 ton System @ 80 % Load (0.2 Factor) Produces 1.3

gpm or 56,000 Gal/Month• Case Study- San Antonio Library• Produce 1 gpm (43,200 gal/month)• Garden 26,000 square feet• Collection System – 3 Interconnected Concrete Cisterns

(8400 gal capacity)• Collect from Sump Gravity Fed into Irrigation System• Total Cost $21,500, 1/3 that of Rainwater Harvest System• Another Example - River Center Mall – 12 MG of

Condensate Used for Cooling Tower Makeup


Condensate – Cont.

Another Bldg. Captures 6.2 million gallons per year

Used for Boiler Feed Makeup water

Cost $19,000 Installed

Savings $26,000 / year

Payback – 11 Months

IOI – Possible Ordinance Mandating Collection System in New Large Buildings

Another Bldg. Captures 6.2 million gallons per year

Used for Boiler Feed Makeup water

Cost $19,000 Installed

Savings $26,000 / year

Payback – 11 Months

IOI – Possible Ordinance Mandating Collection System in New Large Buildings


Example Supermarket (CA)

Focus on CoolingAverage Concentration Ratio 2.45 BaselineCycles of Concentration – Approach 6, Water Reduction NegligibleProblems Scale Prevention in Condensers

Wide Range of Scale Forming MineralsCalcium Carbonate, Calcium Sulfate, Calcium Phosphate, Magnesium Silicate

Biological FoulingCorrosionTested 3 ProcessesOnly Effective Process was Alkalinity ControlOperated at 5.5 Cycles of Concentration

Focus on CoolingAverage Concentration Ratio 2.45 BaselineCycles of Concentration – Approach 6, Water Reduction NegligibleProblems Scale Prevention in Condensers

Wide Range of Scale Forming MineralsCalcium Carbonate, Calcium Sulfate, Calcium Phosphate, Magnesium Silicate

Biological FoulingCorrosionTested 3 ProcessesOnly Effective Process was Alkalinity ControlOperated at 5.5 Cycles of Concentration


Supermarket Cont.

BenefitsReduced Water Use, Lower Water and Wastewater ChargesReduced Electrical UseReduced Acid Washing, Life Extension of Cooling TubesB/C Ratio 2 to 4 for Water and WastewaterOther Water SavingsUse High Efficiency Spray Nozzles and Aerators on All Hand

Sinks and Spray TablesEliminate Garbage GrindersReplace Low Pressure Hoses with High Pressure Sprayers for

Washing

BenefitsReduced Water Use, Lower Water and Wastewater ChargesReduced Electrical UseReduced Acid Washing, Life Extension of Cooling TubesB/C Ratio 2 to 4 for Water and WastewaterOther Water SavingsUse High Efficiency Spray Nozzles and Aerators on All Hand

Sinks and Spray TablesEliminate Garbage GrindersReplace Low Pressure Hoses with High Pressure Sprayers for

Washing


Options for the Reduction of Outdoor Garden/Landscape Water

UseManagement Options Potential Savings (Percent)Turf maintenance 10Turf maintenance, irrigation system 20Maintenance, Irrigation Scheduling Mulching in Ornamental Gardens 20Soil Amendments (Compost) 20Irrigation Scheduling 25 Irrigation/Soil maintenance 65 to 75Lawn to go Dormant 90

Hardware OptionsAutoRain Shut Off 10Soil Moisture Sensors; Soil Probes 10 to 30Improve Performance 40Drip/Bubbler Irrigation 50Gray Water Up to 100Rain Barrel Catchment Up to 100

Landscape Design OptionsLandscape Design 19 to 55Turf Reduction 19 to 35Choice of Plants 30 to 80

From Gleick et al.

Management Options Potential Savings (Percent)Turf maintenance 10Turf maintenance, irrigation system 20Maintenance, Irrigation Scheduling Mulching in Ornamental Gardens 20Soil Amendments (Compost) 20Irrigation Scheduling 25 Irrigation/Soil maintenance 65 to 75Lawn to go Dormant 90

Hardware OptionsAutoRain Shut Off 10Soil Moisture Sensors; Soil Probes 10 to 30Improve Performance 40Drip/Bubbler Irrigation 50Gray Water Up to 100Rain Barrel Catchment Up to 100

Landscape Design OptionsLandscape Design 19 to 55Turf Reduction 19 to 35Choice of Plants 30 to 80

From Gleick et al.


New Faucet Developments

Hydropower Generator to Recharge Battery

Uses PV Cell to Power Optical Sensor


Summary

• Variety of Technologies and Techniques to Reduce Water Consumption

• New Resource Soon Available

– Army Water Conservation Website

– Information on Policies, Technical Guidance, Case Studies, Best Practices Within Army and Other Sectors

– Links to Information Sources

– Further Information Contact Author at 217-398-5590 or email [email protected]

• Variety of Technologies and Techniques to Reduce Water Consumption

• New Resource Soon Available

– Army Water Conservation Website

– Information on Policies, Technical Guidance, Case Studies, Best Practices Within Army and Other Sectors

– Links to Information Sources

– Further Information Contact Author at 217-398-5590 or email [email protected]

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