sustainex 2013 - water efficiency richard barnard (pdf)

Water Efficiency

Richard Barnard

WHY LOOK AT WATER?

• Water availability – it is a finite resource and we don’t want to run out.

• Costs – water costs money – often much more than we think.

• Legal and regulatory reasons – eg Pollution Prevention and Control (Industrial Emissions) Regulations (Northern Ireland) 2012, The Water Supply (Water Fittings) Regulations (Northern Ireland), etc.

• Corporate requirements (eg CSR Reporting); and

• Good business sense !

WATER AVAILABILITY

Rainfall in Northern Ireland is very varied.

Wettest:

Killeter Forest - 1950 mm

Driest:

Lough Neagh - 800 mm

Source: Met office

To compare:

Khartoum, Sudan - 155 mm

Tripoli, Libya - 271 mm

Athens, Greece - 371 mm

Paris, France - 607 mm

Rome, Italy - 802 mm

Sydney, Australia - 1222 mm

Source: worldweather.com

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Incoming water meter

48956.8

Water supply: - standing charge £ - volumetric charge £/m3

Wastewater disposal: - standing charge £ - sewerage volumetric charge £/m3

- trade effluent charges £/m3

water in

WHERE DO COSTS ARISE?

added value

wastewater out

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48956.8




water in


wastewater out

MAINS WATER CHARGES

2012/13 tariffs Northern Ireland Water

Supply Pipe Size Water Up to 20mm £70 Over 20mm up to 25mm £117 Over 25mm up to 40mm £213 Over 40mm up to 50mm £335 Over 50mm up to 75mm £660 Over 75mm up to 100mm £1,195 Over 100mm £1,697

Standing charges

MAINS WATER CHARGES


Discount Water Standard volumetric charge per m3 107.8p

Large user volumetric charges: (100,000 – 250,000m3) 20% 86.2p (250,000 – 500,000m3) 25% 80.9p (Over 500,000m3) 30% 75.5p

Variable charges

WASTEWATER ?

Usually either to:

• Foul sewer (regulated by NIW) - Domestic wastewater (Sewerage charges) - Trade effluent (TE consent and Trade Effluent Charges)

• Waterways or underground strata Under the Water (Northern Ireland) Order 1999, the consent of the Department of Environment is required to discharge any trade or sewage effluent into waterways or underground strata.

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48956.8




water in

wastewater out


SEWERAGE CHARGES


Supply Pipe Size Sewerage Up to 20mm £80 Over 20mm up to 25mm £134 Over 25mm up to 40mm £243 Over 40mm up to 50mm £383 Over 50mm up to 75mm £755 Over 75mm up to 100mm £1,366 Over 100mm £1,942

Standing charges

SEWERAGE CHARGES

Remember: non-return to sewer allowance. It will be 5% unless it has been agreed with NIW that a different allowance will be applied


Sewerage Standard volumetric charge per m3 173.3p

Variable charges

Charge (p/m3) = R + V + B x Ot + S x St Os Ss

R = reception and conveyance (20.78 p/m3)

V = primary treatment (23.43 p/m3)

B = biological oxidation settled sewage (15.52 p/m3)

S = treatment & disposal of primary sludge (18.09 p/m3)

Os = COD crude sewage settled 1 hr (332 mg/l)

Ss = total suspended solids crude sewage (247 mg/l)

Ot = COD of trade effluent (mg/l)

St = Suspended solids of trade effluent (SS) (mg/l)

TRADE EFFLUENT CHARGES

= 77.82 p/m3


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48956.8




water in

wastewater out


added value

Easily Identified Costs

Hidden Costs or Added Value

Cost of water treatment Loss of product/in sales value

Cost of raw materials in effluent Cost of effluent treatment

Cost of wasted energy, eg heating, pumping

Water Charges Sewerage Charges

Trade Effluent Charges

WHAT OTHER COSTS?

m3/min x head (m) kW = 6.1 x pump efficiency

With an overuse of water of, say,100 m3/h used on first floor of a building then unnecessary power consumed through pumping may be given from:

= 1.66 x 15 6.1 x 0.6

= 7 kW

At 7.0p/kWh and 16h/d operation, 5d/week, 48week/year = £1,881/y

ADDED VALUE COSTS?

HOT WATER – ENERGY

The energy needed to heat water is given by: Energy required (kWh) = V x (T2 – T1) 860 Where V = volume of water heated (in litres) T1 = temperature of water to be heated (if unknown, assume 12°C) T2 = temperature water is heated to (°C) 860 = conversion factor to convert kcal to kWh (860 kcal/kWh)

Hot water tank

Water heater

Added value

Water Maintenance

Energy

Energy Labour

Chemicals Maintenance

Energy Labour

Maintenance

Raw water tank Softener

Mains water

Hot (65oC) softened water to supply

107.8p/m3 100 m3 per day 500 W UV light

= 0.8p/m3

1 m3 15 » 65oC 2.9 p/kWh

= 187.3 p/m3

1 m3 Salt and

regen water = 46.4 p/m3

Value of hot water = 342.3 p/m3

ADDED VALUE COSTS?


TRUE VALUE OF WATER

Type Typical cost 1

Mains supply £1.078/m3 (std) Chlorinated water3 £1.098/m3

Softened water £1.548/m3

Demineralised/Deionised water £3.028/m3

Hot water (65°C) – gas heated2 £3.068/m3

Hot water (65°C) – electrically heated2 £5.868/m3 Steam – gas heated2 £24.888/tonne Ice (-7oC) £11.358/tonne

1 – approximate, based on 12/13 costs excluding capital costs and renewals and excluding disposal costs 2 – heating 12 to 65oC; energy costs at 2.9p/kWh for gas and 7.0p/kWh electricity and boiler 90% efficient 3 – Simple sodium hypochlorite addition


SO, WHAT DOES IT COST?

EXERCISE: Judge the flow and what this running tap would cost:

3 mm stream = m3/year

Cold water cost = £ /year

Hot water cost (gas) = £ /year

Hot water cost (elec) = £ /year

394

1,107

1,816

2,817

SO WHAT DO WE DO?

We’ll go through 12 key actions frequently identified that can improve water efficiency…..

1 - WATER BALANCE

Get a good understanding of water use on your site by using a water balance. It’s based on a very simple concept: what goes in must come out (somewhere). Draw a simple block diagram…

Source: Envirowise GG152

KEEP IT SIMPLE !

ESTIMATE WATER USE

Use sub-meter data or estimate water use if no data is available:

• ‘Domestic’ component from the number of people on site per day Staff / delegates 25 – 45 litres/person/day no canteen 50 – 90 litres/person/day canteen

• For plant and process use volumes, rated capacities of equipment/how long they operate for, etc

• If all fails - bucket and stopwatch!

2 - FIND YOUR MAIN METER !

TAKE READINGS !

• Locate and check all overflows

• Check for leaks – particularly if water balance doesn’t balance!

• Remember leaks of raw material or product – it may cost more than it looks…

3 – OVERFLOWS AND LEAKS

4 – DISTRIBUTION PRESSURE

• How is your hot and cold water distributed around your site?

• Is it off mains supply pressure, gravity supply or is it pumped?

• What pressure is the hot and cold supply operating at?

• Is the pressure too high?

Water tank

Third floor

Ground floor

Hand washing: 500 uses, 20 sec/use, 260 day/year Overuse 780 m3/year - £2,968/year

10 litres/min

28 litres/min

• Fit a pressure reducing valve or • Reduce the booster pump

pressure control setting

PRESSURE CONTROL

Do you need 10 bar or will 2 bar (or less) do?

PRESSURE – THE SAVINGS

Source: Envirowise GG522

5 - LAGGING

• Lagging – hot or cold it can save water (and energy!)

6 – TURN IT OFF !

• Once through pump seal water?

• Does flow stop if the unit is not working?

7 – PROCESS TANKS

• Does the tank overflow?

• Is the tank difficult to clean?

• Is there any unnecessary water use?

8 – HOSES

• Diameter of hose – 25mm or 15mm? • Trigger operated?

9 – CLEANING

Tunnel or tray washers:

• Make sure all nozzles are present

• Make sure discharge is visible

10 - CLEANING - CIP

Advantages:

• Water efficient

• Recover cleaning chemicals

• Repeatability of clean

• Automatic

Bottle washer

Washwater tank

Mains supply

Overflow to drain

Hot water from cooling

Hot water supply

High-level top up valve

11 - PROCESS CONTROL

Bottle washer

Mains supply

Little overflow to drain

Hot water from cooling

Hot water supply

Low-level top up valve

Water source controlled

Washwater tank

Savings: £15,000 p.a water/effluent/energy

Costs: £2,000 Savings: £5,000 p.a water/effluent/energy

11 - PROCESS CONTROL

12 - RECOVER AND REUSE

Condensate recovery

• Why not collect it?

• Value around £4.37/m3

OTHER WATER SOURCES

• Rainwater harvesting

WATER USE QUALITY REQUIRED TREATMENT OPTIONS Nurseries, sports grounds,

gardens Toilet flushing Cooling (boilers) General cleaning Filter backwashing

LOW: Water is not used for consumption, and there is a very low risk of contact. Water should look clean and be odour free

First flush diverted Coarse filter

Laundry Cleaning of equipment or

process cleaning

MEDIUM: Water is not used for consumption, and there is a low risk of contact. Water must be clean and odour free, but not necessarily sterile

All of the above, plus Fine filter (possibly

membrane filter)

Food processing Cleaning food processing

equipment Substitute potable supply

HIGH: Water may be used for consumption, water must be clean, odour free and sterile

All of the above, plus Pathogen removal and/or

inactivation (e.g. UV treatment)

Source: Envirowise EN896 ‘Reducing mains water use through rainwater harvesting’

OTHER WATER SOURCES

• Borehole supply

TYPICAL WATER USE ADVANTAGES DISADVANTAGES Nurseries, sports grounds,

gardens Toilet flushing Cooling (boilers) General cleaning Filter backwashing

Low cost supply No reliance on third parties No licence (up to 20m3/d)

Reliant on groundwater availability (quantity and quality)

Borehole construction required

Laundry Cleaning of equipment or

process cleaning

All of the above, plus May need storage May need treatment

Food processing Cleaning food processing

equipment Substitute potable supply

All of the above, plus May fall under Private Water

Supplies Regulations (Northern Ireland) 2009

Increasing quality requirem

ent

OTHER WATER SOURCES

Borehole supply also:

• Need to notify NIEA Water Management Unit, Lisburn

• Over 20m3/d will need a licence

• Fees may apply (>20m3/d)

The legislation can be viewed at: http://www.ni-environment.gov.uk/water/water_resources.htm

OTHER BENEFITS

Impact on carbon emissions as:

• greenhouse gas emissions emitted in supply of 1Ml water (1,000 m3) is 0.34 tonnes CO2 equivalent (= 0.34kg CO2/m3)

• greenhouse gas emissions emitted in treating 1Ml sewage (1,000 m3) is 0.71 tonnes CO2 equivalent (= 0.71kg CO2/m3)

Adapted from Water UK Sustainability Report 2010/11.

The Consumer Council, with the support of Invest NI and NI Water, is launching “Water Champions”, an award for businesses that have taken steps to reduce their environmental impact and save money by reducing their water use. The awards are free to enter and open to all businesses across Northern Ireland.

OTHER BENEFITS

FURTHER ASSISTANCE

If you would like further assistance you may find: • Invest NI

Maximising efficiencies (inc water) see • http://www.investni.com/index/already/maximising.htm Cut water costs information resources (inc on-site reviews) • http://www.nibusinessinfo.co.uk/content/cut-water-costs

• NI Water • http://www.niwater.com/waterefficiencybusiness.asp

• WRAP • http://www.wrap.org.uk/

• Enhanced Capital Allowance (ECA) scheme • http://www.nibusinessinfo.co.uk/content/first-year-allowances-water-efficient-

technologies

QUESTIONS, ANSWERS AND DISCUSSION

sustainex 2013 - water efficiency richard barnard (pdf)

Business

standing charges

charge pm3

water availabilityrainfall

pvariable charges

trade orsewage effluent

costs water costs money

water northern ireland

plarge user volumetric