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 supplies in Scotland

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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

Water safety plan approach
Water Safety Plan Approach supplies in Scotland

“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 supplies in Scotland

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 supplies in Scotland

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 supplies in Scotland

Surface supply risk assessment pro forma
Surface Supply Risk Assessment supplies in Scotlandpro 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 supplies in Scotland

Hazard assessment matrix1
Hazard Assessment Matrix supplies in Scotland

Case study surface water supply
Case Study supplies in ScotlandSurface 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

  • Water drawn from Scrape Burn (Stream) supplies in Scotland

  • Supplies visitor centre and 3 cottages

  • 10 people live in cottages

  • 7 staff work in the centre

  • Site has around 24,000 visitors annually

Scrape Burn supplies in Scotland


Botanic Garden

Dawyck Botanic Garden Supply supplies in Scotland


Q23: History of livestock? supplies in Scotland

Q24: Evidence of Wildlife? supplies in Scotland


Scrape Burn catchment showing signs of erosion on

heather grouse moor at source of the burn

Q30: Forestry activity? supplies in Scotland

Oil on track

Found after forestry operations

Scrape Burn is down the slope on the

right of the picture - just out of shot

Q40: Supply network constructed from supplies in Scotland

material liable to fracture?


Air Vent

Air vent and tanks at Dawyck Botanic Garden

Overflow Pipe supplies in Scotland

drain pipe from tanks

Q41: Intermediate tanks adequately protected?

Scrape Burn showing wind fallen logs supplies in Scotland

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 supplies in Scotland

  • 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

Drinking water in scotland
Drinking Water in Scotland supplies 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) supplies in Scotland

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) supplies in Scotland

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 supplies in Scotland

  • 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

Data supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland


private water supplies are of poorer microbiological quality than public supplies

E coli
E. Coli supplies in Scotland

Maintenance of disinfection systems
Maintenance of Disinfection Systems supplies in Scotland

  • 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 supplies in Scotland

  • 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

pH ([H supplies in Scotland+])

  • 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) supplies in Scotland

  • 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) supplies in Scotland

  • 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) supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

  • 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 supplies in Scotland

Grants supplies in Scotland

  • 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 supplies in Scotland

  • 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


  • 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