Wastewater & Trade effluent Wastewater is generally charged at 95% • There are allowances (e.g. swimming pool, water in • product) Significant trade effluent requires a licence. Charging is based on the Mogden Formula which considers: Total dissolved solids (TDS) Top Tip - • Check that your bill allows for Biochemical Oxygen Demand (BOD) • any water not entering the public sewerage system. Chemical Oxygen Demand (COD) • Maximum Daily Volume • WRAP Mogden Formula Tool http://www.wrap.org.uk/content/mogden-formula-tool-0
Regular monitoring Identify leaks / irregularities • Unauthorised use • Take meter readings regularly • Time periods should be consistent • Look at sub-metering if appropriate • Set individual responsibility • Track progress using appropriate • benchmark(s) Zero Waste Scotland tracking spread sheet •
Data Collection - Reading & interpreting a water meter Locate water meter • Information on its location is often outlined on the • water bill Check serial number • Not all sites have a water meter • Hundredths m 3 of m 3 Top Tips Record meter readings regularly (consistent • timescale) Measure water use during shutdown period • Check meter is the correct size (mm) • Consider Automated Meter Reading technology • Sub-meter high water using processes •
Your water bill Exercise – Question 1 15 minutes
Planning for water efficiency
Gain senior management commitment Objective: to get buy-in to investigate Resources required • Personnel required • Agree objectives and targets • Meter / Bill data to hand • Consider wider benefits • ─ Energy (hot water) ─ Carbon ─ Corporate Social Responsibility (CSR) ─ Environmental Management Systems (EMS) ─ Added value…
Planning for water efficiency
Build a water mass balance This works on the principle that • what comes in, must go out. Taking time to develop a water mass balance helps an organisation: understand where water is used, • what activities are producing • wastewater; identify areas with the greatest • cost saving potential; and detect leaks. • A typical business uses around 25 litres per person per day (40 litres with a canteen)
Water Mass Balance Wastewater (?? Supplied (?? m 3 ) m 3 ) Water bills? Meter readings? Meter readings? Water bills? …95% assumption correct? Need more information
Water mass balance
Conduct a site walk around What do you need? Notebook & pen • Camera • Personal Protective Equipment • Bucket / bottle & stopwatch • Site layout plan • Prior to walk around Ensure key colleagues are • available Use a site layout plan to make • notes on potential improvements
Conduct a site walk around What do you need? Notebook & pen • Camera • Personal Protective Equipment • Bucket / bottle & stopwatch • Site layout plan • Prior to walk around Ensure key colleagues are • available Use a site layout plan to make • notes on potential improvements
Conduct a site walk around During the site visit On site layout plan note: Water use including toilets and canteen areas • Potential improvements • Actions and follow-up questions • Evaporation • Drains (Foul sewer / effluent) • Fixture and fitting numbers • (toilet/taps/showers etc.) Ask questions • Take photos • Measure flow rates – bucket & stopwatch • Collect equipment manufacturer and model • numbers
Planning for water efficiency
Review - What have you got? Meter data / Bill data • Flow rates • A site plan and notes on water use • Sub-meter data (if applicable) • Information from colleagues • Anecdotal information from observation •
What are you looking for? General Areas of high water use to target effort • Areas where water use appears excessive • Dripping taps / leaks • Domestic Cisterns larger than 6 litres • Un-controlled urinals • Taps with flow rates in excess of 6 litres per minute • Cleaning No trigger spray guns on hoses • Excessive water use • Process Areas where water is only used once and can be used • elsewhere (especially hot water)
Assembly • Significant process water use (Paint Shop) • Cleaning activities (uncontrolled) • Sub-metering shows high water use
Canteen • Tap left running • Tap flow rate of 12 litres/min • Food defrosted under running tap • Plates rinsed under running tap (no plugs)
General Domestic • Lots of dripping taps and flow rates in excess of 10 litres/min • No controls on urinals • A mix of toilet cisterns, most in excess of 6 litres.
Assumptions • Daily occupancy – consider annual leave, remote workers, part time staff, off-site working • Tap operation time - 0.33 minutes per use • Number of uses per person - (Men 2 / women 3) • Urinals – operate 24/7/365? 4 flushes per hour • Showers – number of uses per day? Will depend on number of cyclists / runners etc. 1-5% of staff
Typical expected usage Water use activity Typical expected usage Overall employee water use (canteen 40 litres / day on site) Overall employee water use (no 25 litres / day canteen on site) Conventional urinal (no control device 540 - 864 litres / day / cistern fitted) Toilet 6 - 13 litres / flush Showers (no control device fitted) 8 - 12 litres / min Tap (no control device fitted) 6 - 12 litres / min Dripping tap ~ 14 litres / day
Your water bill Exercise – Questions 2 & 3 15 minutes
Break
Water saving devices & techniques
Water saving devices & techniques Simple water saving measures can be applied on most sites. • Increasing Staff awareness • Domestic water reduction • Pipework & overflows • Kitchen & canteen • Common process improvements
Staff awareness Get buy-in from staff to help implement a water efficiency programme. Liaise with the Green Team • Identify staff willing to help • Provide training where appropriate • Ensure staff are aware of how to report leaks • Encourage water minimisation ideas • Inform staff about what you are trying to achieve • Keep staff updated on progress and how they can help •
Common opportunities
Example savings Office with 100 staff daily • 50:50 Men and Women • Men use facilities once per day • Women use facilities twice per day • 3 urinal cisterns at 9 litres per flush (4 times per hour) • Tap is operated for 0.33 minutes per use • Site is operational 8 hours per day, 250 days per year • £2.20 per m 3 supply and sewerage • 4p/kWh energy •
Domestic water reduction Toilets Particularly where cisterns are larger than 6 litres in size consider: installing cistern volume adjusters (1 • litre) Low flush / dual flush toilets • Ensure leaking toilets are reported, • and inspected as part of on-going maintenance
Domestic water reduction Toilets Particularly where cisterns are larger than 6 litres in size consider: installing cistern volume adjusters (1 • litre) Low flush / dual flush toilets • Savings 62,500 litres per year Ensure leaking toilets are reported, • £138 per year and inspected as part of on-going ~£20 to implement (£2 per maintenance device)
Domestic water reduction Urinals Uncontrolled urinals will flush 24 hours per day, 7 days per week. Install control devices to save up to 70% of flush. Passive Infra-Red sensors to detect • presence (PIR) will reduce flush frequency out of hours and during quiet periods . Flush timers can be installed so that urinals • only flush during certain times. Particularly useful for a 9am – 5pm operation. Pressure sensitive hydraulic valves • triggers the urinal cistern to fill when pressure drops (e.g. someone washing their hands)
Domestic water reduction Urinals Uncontrolled urinals will flush 24 hours per day, 7 days per week. Install control devices to save up to 70% of flush. Passive Infra-Red sensors to detect • presence (PIR) will reduce flush frequency out of hours and during quiet periods . Flush timers can be installed so that urinals • only flush during certain times. Particularly useful for a 9am – 5pm operation. Pressure sensitive hydraulic valves • Savings triggers the urinal cistern to fill when 730,080 litres per year pressure drops (e.g. someone washing their £1,606 per year hands) ~£450 to implement (£150 per device)
Domestic water reduction Taps Best practice flow rate for taps is 4 litres per minute. Many taps far exceed this. To control this consider the following technologies. • Flow regulators can be retrofitted to some taps or alternatively may be included in a new tap. These reduce the flow rate of the water to a pre-determined level. • Tap aerators may be retrofitted to taps to maintain pressure while reducing water use through displacement of water with air. • Water efficient taps including automatic, spray or percussion (push) taps • Foam soaps can be used to reduce water used when washing hands
Domestic water reduction Taps Best practice flow rate for taps is 4 litres per minute. Many taps far exceed this. To control this consider the following technologies. • Flow regulators can be retrofitted to some taps or alternatively may be included in a new tap. These reduce the flow rate of the water to a pre-determined level. • Tap aerators may be retrofitted to taps to maintain Assuming a flow rate reduction of 4 litres pressure while reducing water use through displacement of per minute. water with air. Savings • Water efficient taps including automatic, spray or 82,500 litres per year percussion (push) taps £252 per year (including energy) £100 (10 sets of taps, £5 per device) • Foam soaps can be used to reduce water used when implementation cost washing hands
Domestic water reduction Showers Best practice for showers is 6 litres per minute. Performance need not be affected by reduced flow rates. install flow regulators, • aerating showerheads and/or push button • controls.
Domestic water reduction Showers Best practice for showers is 6 litres per minute. Performance need not be affected by reduced flow rates. install flow regulators, • aerating showerheads and/or push button • controls. Assuming a flow rate reduction of 4 litres per minute and 10 staff uses per day for 10 minutes per use. Savings 100,000 litres per year £303 per year (including energy savings) £25 (5 showers, £5 per device) implementation cost
Savings summary Improvement Device No. of Cost Total Water Cost Payback units per unit cost of savings (l) savings devices Reduce WC Cistern volume 10 £2 £20 62,500 £138 2 months flush volume adjuster Reduce urinal Flush timer 3 £150 £450 730,080 £1,606 3 months flush volume Reduce tap flow Flow regulators 20 £5 £100 82,500 £252 5 months rate Reduce shower Flow regulators 5 £5 £25 100,000 £303 1 month flow rate Total £595 975,080 £2,299
Pipework & overflows Check pipe work, tanks and • overflows and look for leaks Leaks beyond the meter are the • organisation’s responsibility Ensure flow control mechanisms • are working correctly Consider the water pressure • required and identify any areas where pressure could be reduced by installing a pressure reducing valve or flow regulator. Top tip – listen for Employ a regular check and • water flowing during maintain programme a period of shut down
Kitchen / Canteen • Don’t defrost under running water • Trigger-activated spray guns • Remove macerators • Ensure dishwashers are full • Purchase water saving equipment • Use eco-settings where available • Make sure plugs are available
Common process areas Review current cleaning practices Introduce dry cleaning techniques • (scrapers/squeegees/brushes) Look at automated cleaning systems (cleaning in place) • Trigger activated spray guns with different settings •
Common process areas Water re-use Consider where water (and or heat) can be recycled elsewhere. Look into water treatment & • recycling systems Alternative water sources • ─ rainwater harvesting ─ grey-water harvesting Look at where value is being • added to the water (e.g. heating, softening, de-ionisation etc.)
Water efficient technologies Exercise 2: 30 minutes
Developing and implementing an action plan
Identifying specific improvements What further information do you need to collect in order to prioritise your list of improvements? • Review your notes from your site walk around • Consult with colleagues Estimate: • How much will the improvement cost? • How much will the improvement save? • What payback can be achieved? • What are the wider benefits?
Identifying specific improvements Prioritise your actions and plan for their implementation. Legal compliance Highest cost saving Highest water Also consider: use saving Quick Strategic Conducting a site walk around • importance payback trialling different devices; • communicating with staff to encourage behaviour change; and • consulting with key managers to check that the implementation of • your plans will not adversely affect other business activities.
Implementing specific improvements Use targets to plan & monitor progress Specific Well defined to all of your colleagues; Measurable Know when the target is achieved; Achievable Resource / knowledge available; Relevant The goal is sensible and attainable; Time bound Completion within a given timescale.
Implementing your action plan Communicate in the context of progress towards objectives • and targets. Senior management will expect you to monitor progress • against targets. Any changes will need to be communicated to staff. In particular you should look to: raise awareness of the programme • provide information on why change is important • give instructions and a clear call to action • communicate relevant messages to all staff in different parts of the • organisation The graph on the next page provides an example of how progress against a set target can be assessed.
Conclusion • Drivers for change • Building an understanding of your water use, and where you use it • How to identify appropriate efficiency opportunities • Water saving technologies and techniques • Developing an action plan
Best practice case studies
HM Revenue & Customs Greening Government commitment to significantly reduce the impact government has on the environment East Kilbride • ─ The review identified total potential water savings of up to 28,241m 3 (77%) per year and estimated cost savings of up to £47,669.
HM Revenue & Customs Reduce flow rate of taps to bring in line with best practice • ─ Saving 4% of annual water use (2 month payback) Carry out an overnight water reading and instigate leak detection • activities if appropriate ─ Estimated saving of up to 49% of annual water use Consider installing a rainwater harvesting system to flush toilets • within the site Further improve communications between HMRC and their facilities • management
Case Study - Natural Fruit & Beverage Company Worked closely with Zero Waste Scotland in 2009 • Manufacture fruit purees and bottle drinks • Installed sub-meter to help construct a mass • balance Identified Top 3 water using activities • ─ Product cooling baths (35%) ─ Other tenants on site (25%) ─ Product sterilising tunnels (10%) 16,600m 3 reduction in cooling baths (£12,000) • 4,100m 3 reduction in sterilising tunnels (£3,000) • Gas & electricity savings of £15,000 •
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