Reducing Water Consumption on StFX Campus A proposal by Bramm Systems Engineering brent Brent Doiron, Ross Walker, Andrew Nicholson, Michelle Coleman & Megan Fudge

Introduction Statement of Problem StFX Campus Water is a precious resource Only 3% of the earth’s water is fresh In 2016, 213+ million litres of water used by StFX campus [1] Needs to be protected and conserved StFX Campus Currently: Dual-flush toilets- Schwartz School of Business Low flow toilets- Mount Saint Bernard, Riley and O’Regan Hall Some compressors for cooling the steam boilers were changed from water cooled to air cooled Shower aerators in Riley and O’Regan Hall brent

Project Overview Our project will focus on several steps to conserve water on campus. These steps include: Implementing a retrofitting program Installing low-flow toilets on campus Installing faucet and shower aerators in residences Replacing flushing mechanism in J.B.B. gravity-fed urinals Installing a greywater collection system in MacIsaac Hall Modifying the water-cooled compressor in the Central Heating Plant to recycle its water brent

Retrofitting program Many of the sinks, showers and toilets on campus consume more water than necessary These inefficient appliances can be replaced or modified for decreased campus water consumption To be replaced: 529 toilets 460 shower heads 1088 faucets 4 gravity-fed urinals Andrew

Low-Flow Toilet Glacier Bay 2-Piece 1.28 GPF High Efficiency Toilet 4.8L per flush Current toilet use: 13L per flush Water savings: 63% Unit cost: $100 Andrew [1] 2-Piece 1.28 GPF High Efficiency Single Flush Elongated Toilet in White

[2] Niagara 1.5 gpm Earth Showerhead N2915CH Chrome Shower Head Aerator Niagara 1.5 GPM Earth Showerhead N2915CH 5.7L per minute Currently: 9.5L per minute Water savings: 40% Unit cost: $5.60 [2] Niagara 1.5 gpm Earth Showerhead N2915CH Chrome Andrew

[3] Low Flow Faucet Aerator 0.5 GPM (2-Pack) EarthEasy Low Flow Faucet Aerator 1.9L per minute Currently: 7.57L per minute Water savings: 75% Unit cost: $2.48 [3] Low Flow Faucet Aerator 0.5 GPM (2-Pack) Andrew

J.B.B.’s Gravity-Fed Urinals These four urinals are responsible for 24% of the J. Bruce Brown building’s water consumption (3,250,000L per year, or 2,226L per day) Andrew Siemens Energy Audit (2014), [4]

Low-Flow, Manual-Flush Urinals 1.9 L per flush Flush only when used Significant water savings Cost beneficial Design Decisions: Entirely eliminate urinals from bathrooms? The two stalls in the J.B.B. bathrooms are not sufficient to meet peak demand The urinals are in the bathroom corner; insufficient room for swinging door Decision: Keep urinals in bathroom Replace entire urinal unit, or replace flushing mechanism only? Current flushing mechanism is problematic Urinal bowls are in good shape Decision: Replace flushing mechanism only Automatic or Manual Flush mechanism? StFX has clearly defined peak usage times and downtimes Decision: Manual flushing mechanism andrew

J.B.B.’s Gravity-Fed Urinals Toto TMU1LN#CP 0.5GPF Exposed Manual Flush Valve 1.9L per flush 293 flushes per urinal per day to meet previous water usage; huge savings Unit cost: $152.36 andrew Toto TMU1LN#CP 0.5GPF Exposed Manual Flush Valve [5]

Greywater System Approx. 50% of waste water is Greywater [2] Below: Diagram showing water flow paths, filtration/holding tanks, and vertical height pump requirements. (dimensions in ft) Approx. 50% of waste water is Greywater [2] Scope: sinks and showers, reuse in toilet tanks MacIsaac Hall Location of Washrooms Avoid campus wide transportation Mechanical room: near hot water tank Room: AutoCAD, empty room 21x16x9.67 ft, available enough for tanks Filtration - Holding Tank - Pump Release to drain megan

Filtration System Currently existing technologies Sand filtration [2] Variety of filtration methods Comparison: Aquacell G Series [4] Sand filtration [2] Initial removal of particles Gradient of grain size Monitored and occasionally cleared Granular Activated carbon [5] Adsorbs organic & odorous compounds Case study: Effective and low cost [7] Changes Eliminated harsh chemicals Chlorination effects Not intended to be potable No long term storage Pump Directly after holding tank Required to transport water back to toilet tanks Outlined in compressor section SAVES: 2.6 million L per year megan

Regulations Health Canada - including flushing and irrigation applications [8] Concern - decomposition of organic materials Previous design Storage tank prior to filtration system Unfiltered storage concern Altered to avoid issue and need for other pump Distribution plumbing pipes/ Outlets Marked in purple to ensure awareness [8] Nova Scotia Greywater cannot be diverted to ditches or woods [9] not an issue within the scope of this project megan

Compressor System Background Information: Two once-through water-cooled compressors (alternating) Located in campus central heating plant Compressors used in heat/energy generation Water used to cool compressor containing hot steam from boiler Uses 25L of water per minute, 24/7/365 Water pumps through once, absorbs heat, goes to drain Temperature increase of only a few degrees Celsius Inlet water is not treated Outlet water still cool enough The Idea: Develop and implement system to use compressor cooling water multiple times. ross

The System to Solve ross

Compressor Design Decisions Justification As compressors tend to have long lifetimes, so too must one’s accompanying water recycling system. Decision Factors: Simple design with few parts Practicality Expense of components ross

Compressor Design Decisions Justification Constant Recycling Volume vs. Variable Recycling Volume Decision: Constant recycling volume Justification: Reduce complexity and expense of system by eliminating need for closed feedback control loop. Mix new incoming water and recycled water, or keep separate? Decision: Keep cycles separate Justification: Deemed necessary once constant recycling volume was decided upon; water temperature would otherwise increase more and more Means of Supplying Pressure: Holding Tank vs. Pump Holding tank was considered to hold water and supply pressure differential; decided against as unnecessary expense due to its location in the system. Pump decided upon to be used in the system. ross

The Proposed System Heat Exchanger Water Source On/Off Valve Drain PLC Water Source On/Off Valve Pipes Used: ½” Type L Copper Piping External Pipe Diameter: ⅝” Internal Pipe Diameter: 0.545” Drain Pump ross 4 Way Valve

The Proposed System: 4-Way Valve PLC alters system between “feed state” and “recycling state”. System state is defined by the state of each of the two valves Feed State Recycling State ross

Programmable Logic Controller (PLC) Processor Selected for its robust design in industrial applications and reliability Programmed with a simple time-based ON/OFF signal controlling both valves simultaneously Loops 2-3 times, but code loops twice for safety margin due to assumptions ross

Compressor Calculations Velocity, Cycle time and Heat Added andrew

Implementation timeline Phase 1: Start: May, 2018 End: August, 2018 Goals: Shower & faucet aerators will be installed in all residences excluding Riley & O’Regan Halls, and Mount St. Bernard Phase 2: Start: May, 2019 End: June, 2019 Goals: - The compressor water-loop system will be installed in the Central Heating Plant - One will be done each month due to the alternating pattern Phase 3: Start: May, 2020 End: August, 2020 Goals: Low-flow toilets will be installed in all buildings except, Riley & O’Regan Halls, Mount St. Bernard, and the Gerald Schwartz School of Business Phase 4: Start: May, 2021 End: August, 2021 Goals: A greywater system will be installed in MacIsaac Hall andrew

Social impacts This project will have several positive impacts on the university. These impacts include: Water savings of approximately 121 million L per year Financial savings of approximately $85 000 per year Improve the reputation of StFX as a leader in the “green movement.” Hope to see increased awareness of saving water on campus brent

Economic analysis (Components) Low flow toilets $200.00 per toilet to remove, dispose and install new 529 to be replaced on campus 64% water savings Shower head aerators $5.60 per showerhead 460 to be replaced on campus 40% water savings Faucet aerators $2.48 per faucet 1088 to be replaced on campus 75% water savings michelle

Economic analysis (Components) Compressor 50 psi pump: $57.23 $90.00 for four-way and single on/off valve $500.00 for basic PLC $29.00 for copper piping 50% water savings Greywater system $147 193.40 for piping infrastructure $750 for pump cost $156.25 maintenance every 6 months Water savings: no new water needed for flushing michelle

Economic analysis (Net) Element Capital cost Annual savings Payback period (i=8%) Low flow toilets $132 500.00 $32 357.98 5 years Faucet aerators $4 874.24 $22 351.14 <1 year Shower head aerators $4 876.00 $26 105.42 Compressor $676.23 $3 547.80 Greywater system $147 943.40 $ 1 262.87 29 years Totals $290 869.87 $85 625.21 4 years michelle

Conclusions and recommendations The overall goal for the project was to reduce water consumption on campus. This was achieved, implementation would result in 121 406 800 litres of water saved annually (56.9% of 2016 StFX water usage). The project will also save the university $85 625.21 annually. Possible steps to expand on this project: Investigation of other buildings where it could be beneficial to install a greywater recycling system Modification and implementation of the compressor recycling system in other areas on campus, such as the growth chambers in J Bruce Brown Investigation into other campuses to implement a retrofitting program michelle

Project Timeline michelle

Acknowledgements & Special Thanks We would like to thank the following people for assisting us in our project: Kevin Latimer; ET, CEM, LEED AP, Energy & Utilities Supervisor, StFX Facilities Management Brittany MacDonald; EIT, PhD (CHEE Candidate), PhD Candidate, Port Hawkesbury Paper LP Jude Rankin; PE, Chief Power Engineer, StFX Brian Doiron; P.Eng, Project Manager, StFX Facilities Management Dr. Frank Comeau; Ph.D, P.Eng, Chair of Engineering Department, StFX Dr. Emeka Oguejiofor; Ph.D, FEC, P.Eng, Engineering Professor, StFX Paul Doiron; P.Eng, Senior Electrical Engineer, A.H. Roy & Associates Ltd. megan

References [1] Latimer, Kevin. “StFX Water,” Saint Francis Xavier University [2] https://wrrc.arizona.edu/sites/wrrc.arizona.edu/files/pdfs/Greywater_Filtration_sustainable_water_11_2011.pdf [3] https://www.engineeringtoolbox.com/pumps-power-d_505.html [4] “Water Recycling,” Greywater System & Greywater Recycling | PHOENIX Process Equipment Company. [Online]. Available: http://www.dewater.com/water_recycling/greywater.html. [Accessed: 30-Mar-2018]. [5] “Water Treatability Database,” EPA, 05-Feb-2007. [Online]. Available: https://iaspub.epa.gov/tdb/pages/treatment/treatmentOverview.do?treatmentProcessId=2074826383. [Accessed: 30-Mar-2018]. [6] “Adsorption,” Adsorption - an overview | ScienceDirect Topics. [Online]. Available: https://www.sciencedirect.com/topics/immunology-and-microbiology/adsorption. [Accessed: 30-Mar-2018]. [7] “Low-Cost Methods to Treat Greywater: A Case Study from Oman,” Middle East Institute. [Online]. Available: http://www.mei.edu/content/low-cost-methods-treat-greywater-case-study-oman. [Accessed: 30-Mar-2018]. [8] “What is Chlorination?,” Safe Drinking Water Foundation. [Online]. Available: https://www.safewater.org/fact-sheets-1/2017/1/23/what-is-chlorination. [Accessed: 30-Mar-2018]. [9] Wong, Kevin. “Greywater Strategies,” Ground Water Canada. [Online]. Available: https://www.groundwatercanada.com/geothermal/greywater-strategies-1540. [Accessed: 30-Mar-2018]. [10] “Regulations and Technical Guidelines | Wastewater | Nova Scotia Environment,” Government of Nova Scotia, 01-Apr-2009. [Online]. Available: https://novascotia.ca/nse/wastewater/regulations.tech.guidelines.asp. [Accessed: 30-Mar-2018]. megan

Questions? Bramm Systems Engineering megan