Source Water Assessment Guide

Presented by Dan Deere and Karla Billington

Official project title:

Good Practice Guide to Sanitary Surveys and Operational Monitoring to Support the Assessment and Management of

Drinking Water Catchments (WaterRA Project #1109-16)

Project participants

Barwon Water Michael BettaninCentral Coast W Stephen ShinnersColiban Water Raj MahendrarajahDHHS Vic Andrew LanchberyDPIW NSW Christobel Ferguson and Danielle BakerFlinders Uni Craig SimmonsGladstone AWB Sarah LunauGoulburn Valley W Tara CallinghamHunter Water Abigail Morrow, Jordi Bates and Zoe RogersMelbourne Water Melita Stevens and Amanda Hazell NSW Health Katrina WallPower and Water Nadine Riethmuller, Wayne Sharp, Jordan Phasey and Shane PapworthSA Water Jacqueline FrizenschafSeqwater Duncan Middleton, Kate Smolders, Michael Bartkow and Cameron VealTasWater John FawcettWannon Water Catherine HufWater Corp Hew Merrett and Clairly LanceWaterNSW Andrew Ball and Mick BalesWRA researchers Claire McInnes and Kelly HillProject researchers Dan Deere and Karla Billington

Project Advisory Committee

DHHS Vic Andrew LanchberyFlinders Uni Craig SimmonsHunter Water Abigail MorrowMelbourne Water Melita StevensNSW Health Katrina WallSA Water Jacqueline FrizenschafSeqwater Duncan MiddletonWater Corp Hew MerrettWaterNSW Andrew Ball

Brief intro for those new to all this…

Traditional good water supply practice (1854…)

Modern good water supply practice Australian Drinking Water Guidelines (ADWG) (2011 to 2018)

Current international norms and benchmarks (as per US, NZ, WHO, Canada and Australia)• Health-based Treatment Targets (HBT)• Water Services Association of Australia (2015)• Victorian regulations and guidelines (2015)• Revised ADWG Chapter 5.7 (202x)

All explicitly recommend a risk assessment including a system description based on a ‘sanitary survey’ (or equivalent) → but what is a sanitary survey?

Very diverse range of sanitary survey approaches currently described applied…

Drivers for the project

What the layperson might reasonably ask about the quality of their source water:

• “What’s in our water? What contaminants “pollution” does it contain? Show me the test results…”

But for water suppliers and health protection agencies it’s not that simple…

The Australian Drinking Water Guidelines and due diligence call for much more…

How do we assess source waters to determine risk and decide treatment needs?

ADWG “Framework”- a preventive risk management framework

CommitmentE1: Commitment to Drinking Water Quality Management

System Analysis &

Management• E2: Assessment of the Drinking Water

Supply System

• E3: Preventative Measures for Drinking

Water Quality Management

• E4: Operational Procedures & Process

Control

• E5: Verification of Drinking Water Quality

Management

• E6: Incident & Emergency Management

Supporting

Requirements• E7: Employee Awareness &

Training

• E8: Community Awareness

& Involvement

• E9: Research &

Development

• E10: Documentation &

Reporting

Review• E11: Evaluation &

Audit

• E12: Review &

Continual

Improvement

ADWG Framework – risk assessment components and actions in the Framework

Issue #2: timing (image: UQ/IWES) “ambulances at the bottom of the cliff”

Why can’t we just test the water?

Water becomes contaminated

Water consumedWater tested

Test results

Issue #1: sensitivity (image: UQ/IWES)“drop in the ocean”; “needle in the haystack”

Reservoir volume (GL)

Sample volume (L)

Percent sampled(%)

10 0.1 0.000000001%

10 100 0.000001%

Issue #3: variability (image: DES, Qld, 2018)

We need to use source water assessment as an input to our risk assessment

Extracts from NHMRC – ADWG 2018

We need to use source water assessment as an input to our risk assessment

Extracts from © ISO 31000

What we need to ask about the quality of our source water:

• “Where does our water come from, what concentrations of what pollutants could it potentially contain, how would that vary over time, and how confident are we in that assessment?”

Sampling/testing is useful for verification and helps understand steady state concentrations (e.g. in deep groundwater) but is of decreasing value as water quality varies.

Risk assessment is about "the effect of uncertainty on objectives" and is primarily about assessing potential causes and consequences.

How should we assess source waters to determine risk and decide treatment needs?

Principles of risk management

Extracts from © ISO 31000

Principles of risk management

Extracts from © ISO 31000

Review of current practice

Review of existing practice - approach aligned with WHO and NHMRC processes

Scoping the systematic review

Evidence retrieval

Evidence quality assessment and grading

Development of recommendations

Defining topics and questions to be considered

Search of academic publications, search of practitioner non-academic publications

and interviews with stakeholders

Transparent quality assessment and grading process with the PAC and using

workshops

Development of recommendations

• Guidelines for Drinking-water Quality (GDWQ; WHO, 2008 and 2011).• Protecting Groundwater for Health, (WHO, 2006).• Protecting Surface Water for Health (WHO, 2016).• Australian Drinking Water Guidelines (ADWG), (NHMRC, 2011), as amended, including the

Framework for the Management of Drinking Water Quality (ADWG Framework). • ADWG Chapter 5.7 ‘health-based targets’ (HBT) guidance (in preparation). • Drinking Water Source Assessment and Treatment Requirements, Manual for the Application of

Health-Based Treatment Targets, WSA 202—2015-1.2, (WSAA, 2015) (WSAA HBT Manual).• Catchment Management Practical Guidance, Water Industry Operators Association (WIOA,

2008).• Practical utility case studies of sanitary survey guidance from Seqwater, Qld (Baker et al., 2016).• Observational monitoring for drinking water catchments from Water Corporation, WA (Lance,

2016).

Examples of existing practices examined and presented in detail

Comparison of existing approaches

Existing approach Includes tables and/or checklists of information to consider

Supports discrimination between source categories at the broad level

Supports discrimination between source categories that translates into quantified treatment needs

Provides support for qualitative assessment of mitigation of source controls

Provides support for quantitative assessment of mitigation of source controls

Includes a verification check based on microbial monitoring data

WHO GDWQ (2011)

Yes No No No No No

WHO Groundwater Monograph (2006)

Yes Yes No Yes No No

WHO Surface Water Monograph (2016)

Yes Yes No Yes No No

USEPA (1999) Yes Yes No Yes No No

USEPA SWTR (1996 to 2006)

Yes Yes Yes Yes Yes Yes

WSDH (2010) Yes Yes No Yes Yes No

DWSNZ (2008) Yes Yes Yes Yes No Yes

ADWG (2011; 2018 draft)

Yes Yes Yes Yes Yes Yes

SDWR (2015) No No No No No No

WSAA (2015) Yes Yes Yes Yes Yes Yes

WSAA HBT Manual (used by almost all utilities in Australia)

The basics of a source water assessmentPathogen shedding

Transport and attenuation pathways and barriers

Catchment export and barriers

Source challenge

Storage inputs and barriers

Differences are orders of magnitude between water sources…

Differences are orders of magnitude between water sources…

Log reduction values (LRVs):• Logarithms to base 10

• 1 log = 90%

• 2 log = 99%

• 3 log =99.9% etc…

• Derived from starting concentrations

• e.g. start with 10,000

• 1 LR = 1,000

• 2 LR = 100

• 3 LR = 10 etc…

The variation is so great, treatment needs are expressed in log reduction values

Target health outcome is “one disability-adjusted life year” (a universal disease burden metric)This translates into an acceptable pathogen concentration in treated waterThe treatment needs are then estimated from there

Treatment needs are directly related to potential source water pathogen concentrations

Cunliffe et al., NHMRC 2009

WSAA HBT Manual (used by almost all utilities in Australia)

In practice we typically only need four source water categories…

…because most treatment trains falls into one of four categories

Requirements for the guidance

Project participants wanted this guidance to fit in…

ADWG Chapter 5.7 Guideline values for enteric pathogens to meet a HBT of

1 µDALY and overview of source water assessment, log reduction values and treatment validation

WQRA Project 1004In depth study setting out a

1 µDALY HBT for microbial

water quality in the Australian context

WRA Project 1036In depth analysis of

pathogen concentrations in Australian source waters and implications for meeting HBT

WSAA HBT Manual

In depth industry guidance on practical aspects of HBT source water assessments, treatment

needs assessments and log credits

Treatment validationIn depth sector guidance on

validation of pathogen log reduction values for treatment

technologies (USEPA, WaterVal, WRA, DVGW, ONORM, etc.)

WRA Project 1109

In depth sector guidance on practical aspects of source water sanitary surveys and operational

monitoring

Project participants emphasised the need for direct compatibility: • WSAA HBT Manual 2015• NHMRC ADWG Ch 5.7

Project participants emphasised the need for a flexible and non-prescriptive body of guidance • Allowed for qualitative assessments and quantitative estimations • Fit-for-purpose tools aligned with the water source manager’s capacity, scale and needs

Finding the right balance for a national guideline…

Standard Flexible

Proportionate

Customisable

Dynamic

Integrated

Comparable

Structured

Contemporary needs of water utilities include: • baseline assessment of catchment condition (completed 5 yearly)• feed into, semi-quantitative, and qualitative assessment of risk as part of

the ADWG ‘Framework’ approach to risk assessment• accounting for benefits and relative effectiveness of preventive measures

across all areas of source protection• evidence bases for investment in preventative barriers and

compliance/enforcement actions• defining drinking water treatment requirement categories• routine operational monitoring against benchmarks and performance

targets

This guidance needs to meet current needs

Current technologies that are being utilised include: • geospatial databases and linked survey applications • high resolution aerial photography, satellite imagery and

drone surveillance• electronic on ground surveillance tools such as cameras,

movement sensors and counters

This guidance needs to draw in current technologies

The guidance

Three enteric pathogen groups• Protozoa (from human and livestock sources)• Viruses (from human sources)• Bacteria (from human, livestock and wildlife sources)

Aligned with WSAA and NHMRC

Intrinsic vulnerability• What is the relative vulnerability of the catchment or aquifer before human impacs

are included ( e.g. climate, soil type, terrain or size of storages)

Anthropogenic pathogen sources and risk

Discounting• Considers tailored mitigation actions (planning and policy, catchment actions, or

compliance and enforcement)• Current and future mitigation actions are accounted for separately• If validated, credible and reliable

Covers multiple stages of assessment

1. Desktop analysis • GIS landuse information• Maps• Zoning and planning information• Aerial photography• Descriptions

2. Ground-truthing and gap-filling• Physical on-ground inspection• Drones• Interviews

A step-wise analysis of the intrinsic source vulnerability

Source water risk mitigation and treatment discounting includes:• full protection and exclusion• partial protection and exclusion• selective abstraction• environmental mitigation (land, water and aquifer)

The processes need validating with the operational monitoring program

Discounting for source protection

Pathogens often behave very differently from:• solutes• solvents• volatiles• algae• one anotherPathogens:• are colloidal particles• amplify • grow• die• stick • detach• clump• evolveThey need to be considered in their own right

Understanding discounting for source protection

Surface water summary

Ground water summary

Discounting summary

Improvement needs are driven by the assessments

Research needs

• Quantifying and understanding the efficacy of source protection barriers

• Expressing pathogen log reduction values for source protection barriers and controls

• Providing ‘lines in the sand’ benchmarks for scale and frequency of barrier/controls

• Tools to assess sources and protection barriers at the whole of catchment scale

Research Needs

Thank you

To all of you for listening today

To those participating in previous workshops

For the PAC for providing case studies and advice

For the PAC and WaterRA team for review, comment and feedback