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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. 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

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  1. Risk based approach to the regulation of small water supplies in Scotland Dr Colette Robertson-Kellie David Williamson Scottish Government

  2. 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.

  3. 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?

  4. 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%.

  5. 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.

  6. 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)

  7. 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’

  8. 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”

  9. 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’

  10. The Challenge

  11. 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

  12. 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

  13. 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.

  14. Risk Assessment

  15. 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).

  16. Hazard Assessment Matrix

  17. Hazard Assessment Matrix

  18. 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

  19. 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

  20. Scrape Burn Dawyck Botanic Garden

  21. Dawyck Botanic Garden Supply Source

  22. Q23: History of livestock?

  23. Q24: Evidence of Wildlife? Source Scrape Burn catchment showing signs of erosion on heather grouse moor at source of the burn

  24. 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

  25. Q40: Supply network constructed from material liable to fracture? Tanks Air Vent Air vent and tanks at Dawyck Botanic Garden

  26. Overflow Pipe drain pipe from tanks Q41: Intermediate tanks adequately protected?

  27. 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)

  28. 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

  29. The Implementation of the Private Water Supplies Regulations

  30. 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)

  31. 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

  32. 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

  33. 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

  34. 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

  35. 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

  36. 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%

  37. 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)

  38. 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?

  39. Microbiology Perception: private water supplies are of poorer microbiological quality than public supplies

  40. E. Coli

  41. 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

  42. 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

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