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