< Previous | Contents | Next >

Investing in Water Services 2006 - 2014

6 DRINKING WATER QUALITY & WATER RESOURCES

Introduction

6.1 The Quality and Standards III Project set up a specialist group led by the Drinking Water Quality Regulator. The Regulator worked in partnership with Scottish Water, the Water Industry Commissioner, the Scottish Executive and the Scottish Environment Protection Agency to establish investment needs in the:

• improvements in drinking water quality;
• protection of the public water supply from accidental/malicious damage (security); and
• the protection of water resources.

Why do we need to invest to improve drinking water quality?

6.2 The Water (Scotland) Act 1980 requires Scottish Water to provide "wholesome" drinking water and the Water Supply (Water Quality) (Scotland) Regulations 2001 define exactly what is meant by "wholesome" ¹⁵. It is Scottish Water’s requirement to meet these standards that "drives" investment.

6.3 Compliance with the prescribed drinking water standards varies across Scotland but particular issues exist in relation to compliance with the standards set for Lead and Trihalomethanes (the latter being disinfection by-products). Other drivers requiring specific attention include the Cryptosporidium (Scottish Water) Directions (issued to Scottish Water in December 2003) and improvements to the public water mains.

6.4 Investment requirements for water resource standards arise mainly from the Water Framework Directive and the Water Environment & Water Services (Scotland) Act 2003. In addition, some water resource investment is required in relation to the Birds and Habitats Directives. The water resource drivers generally aim to limit the removal of water from sources to protect the source and the surrounding area.

What investment is currently underway?

6.5 Of the current Quality and Standards II investment programme, approximately £320 million is being targeted at improving drinking water quality in line with new quality standards. Much of this investment is aimed at meeting standards that came into force at the end of 2003. The investment will result in the building or refurbishment of 371 water treatment works. These include a new treatment works at Milngavie which will serve approximately 700,000 people in and around Glasgow. A major upgrade has also taken place at Invercannie water treatment works which serves Aberdeen. In addition, the capital maintenance programme includes the replacement and/or refurbishment of 3,000 km of water mains.

6.6 Most of the work up until April 06 will be to minimise disinfection by-products known as trihalomethanes. This is achieved by modifications to the disinfection system or by installing treatment to remove the precursors that react with chlorine to form trihalomethanes. Further work will be required in this area during Quality and Standards III because the trihalomethane standard in the Drinking Water Directive is set to tighten further in 2008. The work to minimise disinfection by-products by installing treatment should also reduce problems at customers’ taps in relation to colour, taste and odour. As well as bringing about significant improvements in drinking water quality, this investment will also improve standards of service for Scottish Water customers.

How are the investment requirements for Quality and Standards III derived?

6.7 In conjunction with Scottish Water, the specialist group identified 26 different drivers and identified the required objectives that were to be considered as part of the Quality and Standards III project (Annex B). The outcome of the process, summarised according 4 headings, is discussed below:

• drinking water quality;
• security and emergencies;
• water resources; and
• miscellaneous.

Drinking water quality

6.8 Under this category of investment are a range of investment drivers associated with improving and protecting drinking water quality. These requirements arise mainly from European Community Directive 98/83/EC (the Drinking Water Directive) and cover a range of water quality issues. The minimum regulatory requirements include compliance with a lead standard of 10µg/l by 2013 and a trihalomethane standard of 100µg/l by 2008. Compliance with other standards in Directive 98/83/EC should largely be achieved by the end of the Quality and Standards II period. Other regulatory requirements include compliance with the Scottish Water Cryptosporidium Directions 2003. Much of the investment required by the Directions is required by the end of 2006 but some elements extend out to 2010. Improvements to the aesthetic quality (taste and odour) of drinking water are also sought as part of the Quality and Standards III process through meeting chlorine targets set by the Drinking Water Quality Regulator. These targets are designed to improve control of the disinfection process and limit variations in the amount of residual chlorine in the water when it leaves the treatment works. Compliance with recommendations made in previous water quality incident reports are also regulatory objectives identified for funding in Quality and Standards III. The total cost associated with meeting the minimum regulatory requirement in respect of drinking water quality is approximately £1,270 million over 8 years.

6.9 If it is decided to adopt the absolute statutory minimum scenario then savings are possible in respect of improvements to the aesthetic quality (taste and odour) of drinking water. However, failure to impose targets designed to improve control of the disinfection process and limit variations in the amount of residual chlorine would result in taste and odour complaints and reduced customer service. Non-compliance with recommendations made in previous water quality incident reports could also be removed from the regulatory requirements if the absolute statutory minimum scenario was being considered. However, the risk to public health and the risk to Scottish Water of prosecution following an incident, that could have been prevented, needs to be carefully considered before making judgement on the affordability of not implementing previous recommendations. The saving made to the programme by not including chlorine targets or compliance with incident recommendations is being calculated but it is considered to be approximately £30 million over 8 years.

6.10 It would be possible to invest beyond the minimum regulatory requirement. This would include further investment at water treatment works where the drinking water quality standards are only just being met. Poor weather conditions affect raw water quality at many locations across Scotland and water treatment works that are just meeting the standards in normal conditions are often unable to cope with changes in the raw water due to inclement weather. This can result in drinking water quality failures at customers’ taps, which are often microbiological in nature and can pose a risk to public health.

6.11 Another area where it would be possible to invest beyond the minimum regulatory requirement is in relation to compliance with the iron and manganese standards. Bursts and other unplanned interruptions often lead to dirty water complaints and failure to comply with standards for iron and manganese. A reduction in the number of bursts and unplanned interruptions would reduce the number of dirty water complaints. The European Commission is also currently reviewing the standards set in Directive 98/83/EC and it is clear that the standard for trihalomethanes is set to tighten further. It would be possible to start to move towards compliance with a tighter standard now rather than await its formal introduction.

6.12 However, if expenditure beyond the regulatory minimum is to be considered, the most beneficial area for spend would be the production of Drinking Water Safety Plans. Drinking Water Safety Plans are being promoted by the World Health Organisation as best practice for the protection of drinking water quality and public health. Drinking Water Safety Plans are being adopted internationally and there is a danger that Scotland will fall behind the rest of the world in applying recognised best practice. There are also clear indications that the next revision of the Drinking Water Directive will incorporate a requirement for Drinking Water Safety Plans. The cost of meeting all of the additional aspirations identified by the specialist group (including delivering the regulatory minimum) is approximately £2,600 million over 8 years.

Security and emergencies

6.13 In this category, the basic regulatory requirements arising under the Security and Emergency Measures Direction will cost approximately £120 million over 8 years. There is not considered to be any scope for reducing the basic security and emergency measures requirements on the grounds of affordability.

6.14 It is considered that it is a reasonable aspiration for Scottish Water to reduce its reliance on other utilities during emergencies. By "engineering" its distribution system, Scottish Water could reduce the maximum number of people affected by a single event to 250,000. The cost of such works, including the basic regulatory requirements under the Security and Emergency Measures Direction, would be approximately £260 million over 8 years.

Water resources

6.15 The Water Environment and Water Services (Scotland) Act 2003 and Water Framework Directive (WFD) will, from 2005, place requirements upon Scottish Water to control and manage the amount of water it extracts from watercourses. The statutory minimum includes compliance with SEPA guidelines for water abstractions and impoundments (at Natura 2000 sites) by 2007 and compliance with the Water Framework Directive (WFD). The WFD requires controls on abstractions and impoundments, and the restoration of abandoned engineering works where the economic investment required is proportionate to the benefits of the improvements. The WFD also requires the production of catchment protection plans for drinking water sources supplying greater than 10m³ per day and new licensing regimes at all sites with abstractions greater than 30m³ per day. The total cost of carrying out the regulatory minimum is estimated to be approximately £260 million over 8 years.

6.16 The absolute statutory minimum position in relation to water resource requirements is still being investigated.

6.17 It would be possible to go beyond the regulatory minimum in terms of water resources and invest to ensure that Scottish Water customers are provided with a sufficient supply of water for domestic purposes with a likelihood of failure of providing this level of service of no more than once in thirty years. Equally, it could be considered reasonable that Scottish Water should be compliant with the new licensing regime required under the Water Framework Directive at all identified sites and not just those with abstractions greater than 30m³ per day. The cost of meeting these aspirations, including to the regulatory minimum requirements, is estimated to be approximately £540 million over 8 years.

Miscellaneous

6.18 There are regulatory requirements in relation to inspections carried out under the Reservoirs Act because new methods for calculating rainfall depths generally require the spillway capacity of reservoirs to be increased. The regulatory minimum considered to be necessary during the Quality and Standards III period is for a flood study to be carried out on a dam following its inspection under the Reservoirs Act and for the appropriate remedial works to be carried out. The cost of this work is approximately £2 million over 8 years.

6.19 If it is decided to adopt the absolute statutory minimum position in relation to spillway capacity of reservoirs then this item could be dropped from Quality and Standards III and reconsidered as part of Quality and Standards IV.

6.20 Reasonable aspirations beyond the statutory minimum that fall into the miscellaneous category include: the expansion of Scottish Water’s telemetry (remote monitoring) system at water treatment works and service reservoirs to cover all operational and customer service needs and the extension of the flood study remedial work identified above to include all category B dams. The cost of meeting these reasonable aspirations is approximately £7 million over 8 years.

6.21 The extension of the public water network to include people on a private water supply was also considered by the specialist group but the costs associated with undertaking the work were considered to be very high and beyond reasonable aspiration.

What are the costs associated with these requirements?

6.22 The total cost of dealing with all of the regulatory minimum requirements for drinking water quality and water resources identified above amounts to approximately £1,650 million over 8 years. If it is decided to adopt the absolute statutory minimum position, then savings over 8 years of approximately £30 million have been identified in relation to drinking water quality, and savings of approximately £2 million in relation to the miscellaneous items. These savings would deliver the absolute statutory minimum, but by not adopting the regulatory minimum position, it would involve acceptance of the risks identified above. Any savings that would accrue from adopting the absolute statutory minimum position in relation to the Water Framework Directive and water resources have still to be identified. There are not considered to be any savings available in relation to security and emergency measures.

6.23 The regulatory minimum cost of approximately £1,650 million over 8 years compares with a cost of approximately £3,400 million over the same period for meeting the reasonable aspirations identified by the specialist group. These aspirations exceed the regulatory minimum but provide greater public health protection and reduced environmental risk.

How the decision will be taken on the investment requirements

6.24 The costs associated with investing in improvements in drinking water quality, while not as large as for the environment, do represent a significant investment requirement. As discussed in Chapter 2, a key element in the next phase of the work is for work packages to consider the emerging requirements against the global constraints: cost effectiveness; deliverability; affordability; and sustainability (see Chapter 1). It is clearly important that the required programme of works is carried out at the minimum costs to customers.

< Previous | Contents | Next >