RSC Water Forum: Flow Cytometry Day

Using Flow Cytometry as a Process Diagnostic Tool In Drinking Water Treatment

Claire Thom

Water Science Team Leader

Scottish Water

1. Background to Scottish Water2. Our Flow Cytometry Journey

3. Initial Work4. Expanding the Project

5. Using Big Data6. Online FCM7. Next Steps

Outline

Scottish Water

West:

Upland peat moor –humic and infertile in nature, granite rock

High rainfall (western highlands one of the highest rainfall areas in Europe.

Raw Waters with seasonally high organic content, low alkalinity and typically very flashy

East:Limestone sandstone/clays, soil, grassland –fertile

Relatively lower rainfall

Water bodies:Relatively more stable and of lower organic content

c.50% of Scotland’s WTW’s<5% of the population

Drinking Water Treatment In Scotland

Scottish Water’s Flow Cytometry Journey so Far….Initial

Intact/Total Cell method

development (MSc)

Trialled on 3 systems using

traditional coagulation/filt

ration treatment

Inter-stage Sampling Protocol

Developed

16 systems selected for in-depth analysis-

Expanded by another 20

sites in 2017.

Collation of Lessons learnt,

informing Business

strategy for the next regulatory

period.

Development of Online Flow

Cytometry Protocol. Trials at sites across

Scotland

2013 2014 2016 20172015 2018

Initial Method Development: 2013

• MRes Project

• Sample stability study – effect of sample age on cell count with storage at different temperatures

• Daily monitoring of regulatory microbiology samples taken from Mannofield/Invercannie, Glendevon and Roberton supplies.

• Samples taken from the residual volume left after routine microbiology testing – only around 2ml required.

Risk reduced through optimisation

Lintrathen WTW

Balmashanner

(188h)

Baggerton

(145h)Muirheads

(219h)

Burghill

New (97h)

Maisondieu (140)

Hillhead

(254h)

West Ballochry (56)

Wuddy

Law (104)

Balkiellie New (243h)

Rossie (72h) Dickmontlaw

(112h)46h

46h

46h

72h

97h46h 46h

??h 46h

46h

46h

2015: Initial 3 Systems Work Lintrathen WTW

Expanding the Project: 2015-17

• On- site inter stage sampling at 14 works

• Assessing 4 aspects of works performance:

» Coagulation/Clarification

» Filtration

» Disinfection

» System legs- network regrowth

• Production of a site specific report on WTW and Network bacto performance, with recommendations for improvements.

• On site- analysis for c.1 week to 2 weeks at each site throughout 2016

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Log

Ce

ll R

em

ova

l

Log removal TCC Log removal ICC

0

20000

40000

60000

80000

100000

120000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct

2015 2016

Ce

lls/m

l

Average of Old Total Average of New Total

Old tank averages 37% higher total

cells.

3 ColiformFailures.

Total Cells 80% greater

Example: Using FCM to Assess Tank Condition

• Repeat Coliform failures from WTW.

• Isolated to the old Clean Water Tank.

• Cell counts in the preceding months showed marked increases.

2018: Big Data

Online Flow Cytometry: On Cyt

Next Steps…

• Apply new process control technology and learning to a pilot system.

• RT Coliform/E.coli monitoring.

• Online Flow Cytometry

• ATP

• Next Gen Sequencing

• Identify any relationships between pathogen loading and Coliform failures.

• Carry out sampling across pilot plant under optimal and suboptimal conditions.

• Identify impacts of process failure.

• Apply knowledge to live systems to understand failure implications and inform QMRA processes.

Enhancing Process Control

Source Coagulation/Flocculat

ion

2nd Stage

filtration

Disinfection Storage1st Stage

filtration

Collaborate with SLM Team to ensure Catchment ‘character’ is assessed, quantified &linked into process performance conclusions

Investigate & create optimal Coagulation Control systems for Scottish Waters based around Zeta, S.C & UV abs / Fluorescence

Build ‘smart’ measurement tool to allow for clear measurement & performance monitoring

Build & test enhanced inter-stage Laboratory analysis suite of traditional & novel techniques to test value & quantify hazard loadings / process unit performance

Fully test & report on the impacts of returning wash-water to the headworks and value of filter slow start

Utilise FCM alongside, advancedlaboratory techniques and on-line coliform analysis to measure & assess microbial loadings, their fate through the process and the significance of process control (QMRA)

Utilise R&I Filter column and CCT pilot plants to test and evidence the various enhancement scenarios inclusive of media choices, backwash operation, disinfection configurations.

Collaborate with Asset Capability Team to ensure rounded site assessment

PhD Project: Improving Measures of Pathogens and Health Risk in Drinking Water

1. Identify new potential indicators.

2. Develop new molecular analyses for identification.

3. Analyse on TEP pilot system during routine and abnormal operations.

4. Combine real time cell count/coliform/e.coli monitoring to analyse risks.

5. Use to develop risk-based system of drinking water quality.