workshop on small water supplies warsaw 18-19 th june 2009 risk based approach to the regulation of...

Workshop on Small Water Supplies

Warsaw18-19th June 2009

Risk based approach to the regulation of small water supplies in

Scotland

Dr Colette Robertson-KellieDavid Williamson

Scottish Government



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

• 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

• 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

• 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

• 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

– 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

• 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

• 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



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

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 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



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

Likelihood

Severity of consequences

Insignificant Minor Moderate Major Catastrophic

Almost certain 16 32 64 128 256

Likely 8 16 32 64 128

Moderately Likely 4 8 16 32 64

Unlikely 2 4 8 16 32

Rare 1 2 4 8 16



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



• 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



DawyckBotanic Garden

Scrape Burn



Dawyck Botanic Garden Supply

Source



Q23: History of livestock?



Scrape Burn catchment showing signs of erosion on heather grouse moor at source of the burn

Q24: Evidence of Wildlife?Source



Oil on track

Found after forestry operations

Scrape Burn is down the slope on the right of the picture - just out of shot

Q30: Forestry activity?



Air vent and tanks at Dawyck Botanic Garden

Tanks

Air Vent

Q40: Supply network constructed frommaterial liable to fracture?



Overflow Pipe

drain pipe from tanks

Q41: Intermediate tanks adequately protected?



Scrape Burn showing wind fallen logscarried by the burn when in spate

Pond formed from Scrape Burnused as source of drinkingwater supply at Dawyck Garden

(Note gravel deposits washedinto the pond during spate flows)



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



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)

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 (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

• 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

• 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

• 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

• 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

• 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 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

Perception: private water supplies are of poorer

microbiological quality than public supplies



E. Coli Samples taken in Public Supplies in 2008

% Failures from public supplies

Samples taken in private water supplies in 2008

% Failures from private water supplies

14,473 0.01 2,651 22.48



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

• 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+])

• 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)

• 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)

• 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)

• 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• 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 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

Supplies Samples % Compliance

Total 17,040 41,267 90.77

Type A 1,972 29,781 93.01

Type B 15,068 11,485 84.97



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

• 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

• 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 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• 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?

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