Risk based approach to the regulation of small water supplies in scotland
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Risk based approach to the regulation of small water supplies in Scotland. Dr Colette Robertson-Kellie David Williamson Scottish Government. Terminology. In Scotland drinking water supplies are either “public” or “private”

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Risk based approach to the regulation of small water supplies in scotland

Risk based approach to the regulation of small water supplies in Scotland

Dr Colette Robertson-Kellie

David Williamson

Scottish Government


Terminology

Terminology

In Scotland drinking water supplies are either “public” or “private”

  • Public Supplies are the responsibility of Scottish Water, the national water authority

  • Private Supplies, or small community supplies, are the responsibility of owners and users.


Topics

Topics

  • Background

  • Aims, Targets and Consultation

  • The Challenge

  • Water Safety Plan Approach

  • Risk Assessment and case study

  • Analytical results from private supplies

  • Success or not of risk based approach?


Background

Background

  • 1750 samples taken from private water supplies between 1992 and 1998 were analysed.

  • 41% failed for Total coliforms; 30% failed for E.coli.; and 15% failed for nitrate.

  • Combined failure rate was 48%.


Impact on public health

Impact on Public Health

  • Between 1 Jan 2006 and 15 Oct 2008 there were 48 confirmed clinical cases of E.coli.O157 infection where E.coli. O157 contamination of a private water supply was either confirmed or suspected.


Aims targets and consultation

Aims, Targets and Consultation

  • Scottish Government priority - securing longer healthier lives for the people of Scotland

    • Private water supplies to be “clean and wholesome”

    • November 2001: Consulted on future direction of private water supplies regulation.

    • Draft Regulations developed jointly with local authorities (who enforce regulations on behalf of the Scottish Ministers)


Aims targets and consultation cont d

Aims, Targets and Consultation cont’d

  • March 2005: Consultation on draft Private Water Supplies (Scotland) Regulations and proposals for a Grant Scheme.

  • Draft Regulations adjusted in light of responses to consultation

  • July 2006: New Private Water Supplies (Scotland) Regulations 2006

  • Determination of ‘relevant person’


Consultation responses

Consultation responses

  • Widespread support, particularly from health professionals.

  • Criticism from rural communities and businesses about compliance costs.

  • Resource implications for local authorities.

  • Unnecessary and unwelcome interference from government – “supplies have been used for long periods without ill effects”


On going engagement with stakeholders

On-going engagement with Stakeholders

  • Meetings with local authorities

  • Website - www.privatewatersupplies.gov.uk

  • Detailed Technical Manual

  • Scrutiny by Ministers and Parliament

  • Scottish Government engages with members of the public

  • Further research – ‘Getting the message across’


The challenge

The Challenge


Water safety plan approach

Water Safety Plan Approach

“The most effective means of consistently ensuring the safety of a drinking water supply is through the use of a comprehensive risk assessment and risk management approach that encompasses all steps in water supply from catchment to consumer”

WHO 2004


The private water supplies scotland regulations 2006

The Private Water Supplies (Scotland) Regulations 2006

Type A supplies – duties on local authorities to:

  • complete risk assessments (source to tap)

  • undertake compliance monitoring

  • provide advice and guidance

  • ensure remedial works completed


The private water supplies scotland regulations 20061

The Private Water Supplies (Scotland) Regulations 2006

Type B supplies

  • Local authorities have discretionary powers to complete risk assessments / sample / monitor water quality.

  • Subject to a set of nationally set quality parameters.

  • Local authorities must provide owners / users with advice / assistance.


Risk assessment

Risk Assessment


Surface supply risk assessment pro forma

Surface Supply Risk Assessment pro forma

  • Pro forma consists of a series of questions.

  • Sections A to C (questions 1 – 22) common for all 4 risk assessments – basic information about supply / contact details / diagram of supply / water quality issues.

  • Site and supply survey (questions 23 – 49).


Hazard assessment matrix

Hazard Assessment Matrix


Hazard assessment matrix1

Hazard Assessment Matrix


Case study surface water supply

Case StudySurface Water Supply

  • Covered in detail in Technical Manual

  • Dawyck Botanical Gardens

  • 28 miles south of Edinburgh

  • 165 to 250m above sea level

  • Climate

    • temperature range -19 to 29oC

    • annual rainfall between 875mm and 1070mm


Risk based approach to the regulation of small water supplies in scotland

  • Water drawn from Scrape Burn (Stream)

  • Supplies visitor centre and 3 cottages

  • 10 people live in cottages

  • 7 staff work in the centre

  • Site has around 24,000 visitors annually


Risk based approach to the regulation of small water supplies in scotland

Scrape Burn

Dawyck

Botanic Garden


Risk based approach to the regulation of small water supplies in scotland

Dawyck Botanic Garden Supply

Source


Risk based approach to the regulation of small water supplies in scotland

Q23: History of livestock?


Risk based approach to the regulation of small water supplies in scotland

Q24: Evidence of Wildlife?

Source

Scrape Burn catchment showing signs of erosion on

heather grouse moor at source of the burn


Risk based approach to the regulation of small water supplies in scotland

Q30: Forestry activity?

Oil on track

Found after forestry operations

Scrape Burn is down the slope on the

right of the picture - just out of shot


Risk based approach to the regulation of small water supplies in scotland

Q40: Supply network constructed from

material liable to fracture?

Tanks

Air Vent

Air vent and tanks at Dawyck Botanic Garden


Risk based approach to the regulation of small water supplies in scotland

Overflow Pipe

drain pipe from tanks

Q41: Intermediate tanks adequately protected?


Risk based approach to the regulation of small water supplies in scotland

Scrape Burn showing wind fallen logs

carried by the burn when in spate

Pond formed from Scrape Burn

used as source of drinking

water supply at Dawyck Garden

(Note gravel deposits washed

into the pond during spate flows)


Case study conclusions

Case Study - Conclusions

  • Overall risk HIGH

  • Interventions/action plan to include

    • Restrict access of animals to burn

    • Control forestry activity

    • Protect overflow and drain lines

    • Identify pipe materials

    • Be aware that heavy rainfall can have detrimental effects on water quality in this system


The implementation of the private water supplies regulations

The Implementation of the Private Water Supplies Regulations


Drinking water in scotland

Drinking Water in Scotland

In Scotland

  • Public water supplies

    • 97% of supplies

    • Managed entirely by Scottish Water

      • Publicly owned company

      • Regulated by Drinking Water Quality Regulator

  • Private water supplies

    • 3% of supplies

    • Responsibility of owners and users of supplies

    • Regulated by local authorities (councils)


Role of drinking water quality regulator dwqr

Role of Drinking Water Quality Regulator (DWQR)

Public Supplies

  • Responsible for enforcing Water Quality Regulations

  • Independent from Scottish Government

  • Powers:

    • Power to obtain information

    • Power of entry or inspection

    • Power of enforcement


Role of drinking water quality regulator dwqr1

Role of Drinking Water Quality Regulator (DWQR)

Private Supplies

  • Regulated by local authorities

    • Local authorities must report annually on individual supplies to DWQR

  • DWQR has independent role in verifying that Regulations are complied with

  • Reports on compliance with private water supplies to European Commission

  • NO powers of enforcement


Sampling and analysis of private water supplies

Sampling and Analysis of Private Water Supplies

  • Revised private water supplies Regulations came into force in June 2006

  • Analytical data from 2008

    • First time most Local Authorities reported on sample results from new Regulations

    • Large increase in sampling from previous Regulations

    • First time that analysis could be carried out on sample data from new Regulations

    • Two out of 32 local authorities did not provide required analytical data


Risk based approach to the regulation of small water supplies in scotland

Data

  • Data required by end March

  • In 2009, last of the data received at the beginning of June

  • Not yet published in Scotland

  • This presentation – initial analysis of data

    • Further analysis to be carried out


Risk assessments

Risk Assessments

  • 1,972 Risk Assessments required

    • Based on identified private water supplies

  • 1,332 Risk Assessments produced

    • 68%

  • DWQR to contact local authorities who have not completed risk assessments


Range of sampling

Range of Sampling

  • 41,267 samples taken in total

  • 29,781 samples from Type A supplies

    • 72%

  • 11,485 samples from Type B supplies

    • 28%


Categories and sizes of type a supplies

Categories and Sizes of Type A Supplies

  • DWQR requested volume and population supplied

  • Large private water supply users

    • Poultry slaughter/processing (1,500m3/day)

    • Hotels (200m3/day)


Data on volumes and populations supplied

Data on Volumes and populations supplied

  • Data on volumes supplied unreliable

  • For example:

    • Holiday home

      • Volume supplied = 0.50m3/day

      • Population supplied 39,968

      • How big is this holiday home?

    • Fish farm

      • Volume supplied 0.50m3/day

      • Population supplied 39,175

      • Have the fish been counted?


Microbiology

Microbiology

Perception:

private water supplies are of poorer microbiological quality than public supplies


E coli

E. Coli


Maintenance of disinfection systems

Maintenance of Disinfection Systems

  • 28.62% of E.Coli failures came from disinfected supplies

  • Concern over installation, operation and maintenance of disinfection

  • To be raised with local authorities


Chemistry

Chemistry

  • Not all parameters in the Regulations need to be sampled for each site

    • Dependent on Risk Assessment

    • Dependent on history of site

    • First sample from site may be analysed for more parameters than subsequent samples

  • Parameters are those dictated by the EU Drinking Water Directive


Risk based approach to the regulation of small water supplies in scotland

pH ([H+])

  • The pH standard is 6.5 – 9.5

  • 2,066 samples taken

  • 572 (27.83%) failed the pH standard

    • 475 (83.04%) < 6.5

    • 97 (16.96%) > 9.5

  • Public supply 0.51% failed

  • Increased risk of plumbing material metals dissolving into water


Copper cu

Copper (Cu)

  • 642 copper samples were taken

  • 77 (11.99%) failed

  • 68 properties or businesses had copper failures

    • 21 (30.88%) had pH failures

    • 19 with pH <6.5

    • 2 with pH >9.5

  • Public supply 0.06% failed


Iron and manganese fe and mn

Iron and Manganese (Fe and Mn)

  • Fe and Mn are naturally occurring metals in the environment

  • Fe can also come from Fe pipework

  • Compliance with the Fe and Mn standards was relatively poor

    • Fe: 1,339 Samples taken

      • 163 (12.17%) samples failed

    • Mn: 1,190 samples taken

      • 112 (9.41%) samples failed

    • Public supply

      • Fe: 1.37% failed

      • Mn: 0.78% failed


Lead pb

Lead (Pb)

  • 1,564 samples taken

    • 101 samples failed

    • 6.46% samples failed

  • Highest recorded value 18,000 µg/l

    • (PCV = 25 µg/l

  • Public supply 0.83% failed


Other parameters

Other Parameters

  • Arsenic (As)

    • 620 samples

    • 10 failures (1.61%)

    • Highest recorded 42.90µg/l (PCV = 10 µg/l)

    • Public supply 0% failed

  • Fluoride (F)

    • 493 samples

    • 31 failures (6.29%)

    • Highest recorded 1105mg/l (PCV = 1.5mg/l)

    • Public supply 0% failed


Other parameters1

Other Parameters

  • Nitrate (NO3)

    • 1494 samples

    • 84 failures (5.62%)

    • Highest recorded 118.80mg/l (PCV 50mgNO3/l)

    • Public supply 0% failed


Summary of analytical results

Summary of Analytical Results


Grants

Grants

  • The Scottish Government has set up a grants system – financial assistance

    • To encourage improvement of private water supplies

    • Available for domestic and commercial supplies

  • Maximum grant available £800 (~€910)

    • If more than one property supplied from a single source, all properties can apply for grants


Benefit of grants

Benefit of Grants

  • In 2009 total cost of grants £1,221,890 (~€1.39m)

  • Scottish Government now needs to quantify improvements

  • Should be possible as further data is made available


Issues and challenges with regulating private water supplies

Issues and Challenges With Regulating Private Water Supplies

  • Large number

  • Control and surveillance difficult

    • Many supplies very rural

    • Many are large distances from local authority offices

  • No clear responsibility for small supplies

    • Type B – some owner/users are reluctant to take responsibility

  • The Regulations focus only on quality

  • Drought starting to become an issue


Issues and challenges with regulating private water supplies1

Issues and Challenges With Regulating Private Water Supplies

  • Gathering data from 32 Local Authorities has been onerous

    • All submitted some data

    • Two did not submit analytical data

      • One had IT issues

  • Some data incorrect

    • e.g. reported µg/l as mg/l

    • Volume/population problems

  • Some very late in returning data

  • Additional support needs to be given to some local authorities

    • Interpretation of Regulations

    • Water Quality/science

  • Further analysis needs to be carried out on data

  • Not all Risk Assessments completed

  • Strongly suspect that frequency of sampling not always adequate

  • DWQR does not have power of enforcement over local authorities


Conclusions

Conclusions

  • Private water supplies

    • Significantly poorer microbiological quality than public supplies

    • Some chemical parameters problematic

    • However, not all samples taken

  • New Regulations increasingly successful for private water supplies

    • Raising awareness of risks

    • Looking at drinking water quality

    • Improving of supplies

  • Ultimate aim – to minimise risk to public health


Questions

Questions?


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