water resource efficiency gerard enright stem project
TRANSCRIPT
Water Resource Efficiency
Gerard Enright STEM Project
Why is Water Important?
• Water availability – it is a finite resource and we might not always have the supply we need.
• Water costs money – often much more than we think.
• Carbon footprint of water
• Corporate requirements (e.g. CSR reporting).
• Good business sense !
The Cost of Water
What we knowWater ChargesSewerage ChargesTrade Effluent Charges
What We Don’t KnowWater Treatment CostsCost of Raw Materials in the EffluentCost of Wasted Energy (Heating, Pumping)Cost of Maintenance
Standing Charges 2014 / 15
Supply Pipe Size Water Sewerage
Up to 20mm £66 £76
Over 20mm up to 25mm £110 £126
Over 25mm up to 40mm £202 £230
Over 40mm up to 50mm £316 £362
Over 50mm up to 75mm £624 £714
Over 75mm up to 100mm £1,130 £1,291
Over 100mm £1,605 £1,837
Volumetric Charges
Discount
Water Sewerage
Standard volumetric charge per m3
102p £1.638
Large user volumetric charges:
(100,000 – 250,000m3) 20% 81.6p
(250,000 – 500,000m3) 25% 76.5p
(Over 500,000m3) 30% 75.5p
Unmeasured Charges
Unmeasured Tariff Water Sewerage
Standing Charge £25.85 £36.15
Variable Charge per each £1,000 NAV
£9.93 £13.61
Charge Cap £405 £430
Trade Effluent Charges
Charge (p/m3) = R + V + B x Ot + S x St Os Ss
R = reception and conveyance (19.03 p/m3)
V = primary treatment (21.46 p/m3)
B = biological oxidation settled sewage (14.21 p/m3)
S = treatment & disposal of primary sludge (16.57 p/m3)
Os = COD crude sewage settled 1 hr (285 mg/l)
Ss = total suspended solids crude sewage (225 mg/l)
Ot = COD of trade effluent (mg/l)
St = Suspended solids of trade effluent (SS) (mg/l)
The Hidden Cost of Water – Raw Materials Excessive product / raw materials in effluent streams
cost you money.
Increase water consumption to during wash-down.
Do you have a wash-down procedure
Dry cleaning of floors, equipment and drains prior to wash down/disinfection.
Increased effluent strength = higher trade effluent costs.
The Hidden Cost of Water - Heating
You Pay 3 times for Hot Water 120 Ltr Hot Water Cylinder will take 2.3 Hours to heat
from 12 Degrees to 65 Degrees with a 3.2 kW Immersion Heater.
The energy needed to heat water is given by:
Energy required (kWh) = V x (T2 – T1)
860
An Action Plan to Improve Water Efficiency
1 Find Your Water Bill What is it telling you?
Are you getting a domestic allowance
Are you getting a rateable allowance
Are you details correct (NAV, supply pipe size, septic tank,)
Is the meter reading correct
Is there non return to sewer.
Would you benefit from a metered supply
Find Your Water Meter
Start to Take Water Readings
Take regular readingsGive someone responsibilityMost meters measure in M3 = 1000 litres
Mind the Spiders…….
Find Out When You Use Water
Water profile Night-time usage Weekend usage Holiday usage Usage during lunch breaks Are there spikes in usage High staff numbers
Find Out Where You Use Water
Identify areas of high usage. Use sub meters. Manufacturers guidelines Bucket test (30 seconds)
The Bucket Test
Find The Leaks And Overflows
• Locate and check all overflows
• Check for leaks – particularly if water balance doesn’t balance!
• Remember a leak may cost more than it looks…
Check Water Pressures
• 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?
Increased Pressure = Increased Usage
Ensure Pipes are Lagged
Keeps hot pipes hot and cold pipes from freezing in winter
How long does the water take to heat up.
What is the water usage after a freeze
Not all Taps are EqualCheck Taps, Springs, Triggers and Washers
Tap 1 – 8 Litres / MinTap 2 – 12 Litres / MinTap 3 – 7 Litres / Min
The Bucket Test…..
Water Saving Devices
Sensors on Urinals
Coke Bottle / Hippo Bag
Low Volume Shower head
Tap aerator
What can I do about my Water Usage?
Monitor, Monitor, and Monitor Again……… Weekends, Evening, Holidays.
Make sure your bill is right. Standing Charges
Rateable Allowances
Non Return to Sewer
Identify What is Costing You. Find an alternative that is cheaper to run
Improve your controls
Find that leak
Give People Responsibility Communicate and Train
