Implementing Water Reuse
Transcript of Implementing Water Reuse
Implementing Water Reuse
Martyn TupperSenior Research Scientist
April 2014
Water Consumption - Facts and Figures
• UK : we each use 150 litres per day • 2013 Thames Region: 160 litres per day. (In 1977 this was 125)• Only 2% of water through tap is drunk; 33% Flushes Toilets
Thames Water Resource Challenge
1.7 million more people predicted over next 25 years and climate change will restrict future resources
Thames Water Resource Solution Options
• Leak Less from our Networks• Install Meters – real time meter data (tracks leaks)• Encourage our customers to use less• Bulk Transfer from wetter parts of UK• Build Large Strategic Reservoir• Create water resources – reuse of sewage effluents
─ Termed Planned Indirect Potable Reuse• Thames has investigated 2 technologies
─ Non-Potable Reuse
Indirect Potable Reuse
IPR Pilot Plant - Deephams STW
Creating additional Resource
Deephams IPR Pilot plant overview• A 600 m3/d pilot plant trialling current “state-of-the-art” in IPR
technology─ Multi barrier approach / membrane approach based on
existing worldwide schemes
Old Ford Water Recycling PlantCreating an alternative product
• Plant creates reclaimed water from raw sewage used for irrigation (mainly) and toilet flushing. 570m3/day production rate.
• 3.65km separate water main network, 10 metered connections• On-line Feb 2012. More than 50 million litres of drinking water saved (at Dec 2012). • Avoided drought impact on wild flower meadows
Process Treatment Steps
• Half waste water treatment plant• Half water treatment • 10 hours final storage capacity• Key biological parameters - MLSS 7-8g/l, sludge age 27 days• Designed to meet 0.1mg/l ammonia, <5 SS, <5 BOD + US
EPA unrestricted use standards (modified)
When was the 50 million litres saved?
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1 2 3 4 5 6 Usage:Irrigation (84%)Toilet flushing (1.7%)Other (14.8%)
Peak demand in Spring & Summer months
Irrigation demand profile relatively stable
During games irrigators avoided periods when park was occupied
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Pre-OlympicsOlympicsBetween Olympics and ParalympicsParalympicsTransition periodLegacy period
Lessons Learnt• Customer Engagement
─ Consult from the start• Regulation & Guidance
─ Labelling & Pipework─ Water Quality
• Special Requirements─ Dye Testing
• Reclaimed water systems need demand!─ Prolonged periods of low demand = poor biological system aeration and lack of
denitrification─ Difficult to maintain chlorine residuals in network under low demand
• Water and Wastewater treatment plant designers don’t always speak common language─ Units megalitres or population equivalent; mg/l as N or NO3─ Hypochlorite for disinfection vs. chloraminated potable water back up
Old Ford WRP as a research facilityOngoing research
• Customer Education & Engagement with Regulators• Improved Uptake of Reclaimed Water on Park• Carbon Impact of Reclaimed Water • MBR and GAC system treating sewage to generate new
water resources─ Analysing lots of chemicals to compare with RO system─ Improve understanding of the microbiological barrier
offered by MBR
Virus Monitoring at Old Ford WRPProject Aim
How effective is an MBR system as a barrier to Viruses?• RO systems considered an effective barrier• Real world knowledge gap surrounding MBR treatment• 3 indicator species monitored
Mean numbers of bacteriophages through the Old Ford WRP.(Outliers represented by *)
Bacteriophage Log Removal across MBR
Somatic Coliphage 5.34
F-RNA 3.12
GB124 3.63
Virus Monitoring at Old Ford WRPConclusions and Ongoing research
• Removal is consistent with bench scale studies• High association of phage's with solids
─ Resulting size exclusion principle method of removal• Increasing our understanding of the Health Risks associated
with MBRs
The project is ongoing• Further seasonal monitoring• Monitoring of pathogenic viruses
Thank you for listening