Select Committee on Environmental Audit Appendices to the Minutes of Evidence



APPENDIX 2

Memorandum from the Campaign for the Renewal of Sewerage Systems (CROSS)

1.  INTRODUCTION

  The Campaign for the renewal of Older Sewerage Systems (CROSS) was established at the end of 1997 and is currently chaired by Joan Walley MP. CROSS was set up to campaign for greater investment in the maintenance and renewal of the nation's sewerage systems. Adequate drainage and separation of "clean" from "dirty" water was fundamental to the public health improvements secured by the great Victorian sanitary pioneers. CROSS is concerned not only with how the water and sewerage undertakers operate, but how individual homeowners take private sewers and drains for granted.

  The idea for the campaign came about as the result of research at the Robens Centre for Public and Environmental Health at the University of Surrey, including projects on rat infestations and the environmental health impacts of leaking sewers and drains. Many rat infestations are associated with sewer and drain defects, and raw sewage contains a range of pollutants in addition to faecal bacteria and enteroviruses.

  CROSS aims to increase awareness of the importance of our sewerage infrastructure to public health, the environment and quality of life. Sound sewerage systems make a major contribution to the sustainable use of water, and this needs to be appreciated.

  CROSS is supported by a number of Parliamentarians, local authorities, individuals including householders and academics, Trade Unions, professional bodies and commercial companies in the construction materials sector.

  Whilst there was much debate during the recent review as to how far adequate investment for environmental improvement could be achieved whilst securing lower prices, it is the view of CROSS that the importance of the sewerage infrastructure and its condition was ignored. This was largely because for the general public, the Government, Ofwat and Environment Agency, and the water companies it was too readily a matter of "out of sight, out of mind". An attitude that the House of Lords Select Committee on the European Communities identified in 1991 in its report on Municipal Waste Water Treatment. [1]Those involved in the quadripartite process were thus able to avoid taking responsibility in the absence of any dramatic news headlines, leaving it to each other.

2.  WHY THE SEWERAGE SYSTEM MATTERS

  Water is an essential requirement for life, but we also produce wastewater, and in the UK our sewerage system is a water-borne carriage system that carries our waste products to disposal normally via some treatment. The sewerage system is therefore totally linked to the water supply system. Enteric diseases such as cholera were a problem in the Nineteenth century and were often water-borne; caused by a failure to separate dirty water from the clean water used for human consumption. Unless a community is provided with an effective and adequate system of sewerage it is likely that the water supply system or possible sources of supply will become contaminated. Although relatively rare there have been instances of this occurring more recently than the Victorian era. Effective sewerage and its control is very much part of the management of water systems.

  It should also be noted that the Robens Centre at Surrey University reported in 1998[2] that sewage contains not only faecal bacteria and viruses, but also high levels of inorganic solutes such as ammonium, chlorides and sodium. It also contains organic solutes like benzene and toluene and chlorinated hydrocarbon solvents and all have been found in urban groundwaters. This is not just because of trade effluents, but also reflects a public attitude that any waste liquid (and solid waste whether soluble or not) can be put down drains and sewers. Leakage of sewage into the subsurface must therefore pose a potential threat to environmental health, especially if there is a contamination of actual or potential water sources. With respect to sewerage it appears that the environment has been seen as a free good by the regulator, the companies and the public.

3.  SEWERAGE GIVEN A LOW PRIORITY

  It is clear, and indeed it has been admitted by Environment Minister Michael Meacher, in a meeting with representatives of CROSS, that sewerage was given a low priority in the last periodic review. It is quite apparent that it has been given a low priority in all periodic reviews. Whilst some issues, such as discharges from sewage treatment and leakage from water mains, were given an understandably high priority, this perpetuated the "out of sight, out of mind" attitude to the sewerage infrastructure.

  In September 1998 the Secretary of State provided guidance to the water industry regulator (Ofwat) in "Raising the Quality". This set out the quality obligations facing the water industry in the next five year period and which should be reflected in water companies' investment programmes and price limits. The Environment Agency had set out its National Environment Programme with respect to the water industry in "A Price Worth Paying" published in May 1998. These, documents along with the companies; asset management plans provided the basis for the price regime for 2000-2005. The pipework carrying the sewage to the treatment works (sewerage) was largely ignored in all advice and recommendations to the regulator. Much of the guidance related to the more high profile environmental issues such as the quality of effluents from treatment works, including implementation of the obvious provisions of the Urban Waste Water Treatment Directive, improving the quality of water supplies including reducing the risk from Cryptosporidium, and avoiding leakage from water supplies. The focus was primarily on statutory requirements and obligations with the notion of a reduction in prices. It seemed to be forgotten that leaking sewers allow untreated sewage to pollute the environment and have other adverse impacts.

4.  STANDARD OF SERVICEABILITY

  Currently the standard of serviceability of sewers is based on whether they collapse, cause flooding of sewage, or are associated with pollution incidents. Such events are the end of a substantial period of deterioration and are hardly adequate for the protection of the environment and public health. Indeed the Water companies seem to assume their sewers are operating adequately so long as the flows to treatment works confirm to their expected pattern and level. They are not concerned with leakage into the environment, nor infiltration of groundwater into sewers.

  New sewers can be accepted even if they are known to leak, with the allowable leakage assuming all sewers in an "as new" condition could amount to 2.1 million m3/day. [3]Allowable leakage from "new" sewers is 12,000 times that allowed for the same size "new" water mains.

  In "Raising the Quality" the Government said that it believed water and sewerage companies should maintain their assets so they can deliver a high absolute standard of serviceability to customers and the environment. Encouragingly it said that it would not be enough simply to maintain the current levels where they are inadequate. The Government said that Ofwat should therefore develop absolute standards for the serviceability of water distribution and sewerage networks. CROSS believes however that Ofwat was supposed to have developed such standards some time ago.

  A paper (based on a study for CIRIA—the Construction Industry Research and Information Association) in Water and Environmental Management in June 1998[4], examined the impact of sewers on groundwater quality. It concluded that age is the most significant characteristic governing leakage from sewers that affects abstracted groundwater. Although further research has shown that age is not as significant when looking at leakage from sewers generally, this paper recommended strategies for reducing groundwater contamination. These included modification of existing criteria for service performance (more than whether they flood or collapse), and improved construction of sewers with increased groundwater monitoring. Nothing has yet been done.

5.  ENVIRONMENTAL HEALTH IMPACTS OF LEAKING SEWERS AND THE ROLE OF THE ENVIRONMENT AGENCY

  Infiltration is the passage of groundwater into leaking sewers and will occur where the sewer is below the water table. Exfiltration occurs when sewage passes out of the sewer into the ground and ground water. The two issues cannot be divorced from each other. As public sewers are usually installed between the maximum and minimum levels of the water table, fluctuations in this position may cause reversals of infiltration and exfiltration with consequent contamination of groundwater.

  Geology, sewer condition and the relative level of the water table control the rate of infiltration. It leads to:

    —  increased operational costs, including additional pumping costs;

    —  overloading of sewage treatment works;

    —  reduction of capacity and more frequent operation of combined sewer overflows (CSOs) (an issue that was addressed in raising the quality without acknowledging the role of infiltration); and

    —  increased incidence of flooding and pollution.

  Infiltration also causes fine material from the surrounding area to be washed into the sewer causing silting which in turn increases cleaning costs. Additionally there is a loss of supporting material from around the sewer, which has implications for the integrity of the pipeline, leading to collapse. Infiltration can also lead to loss of groundwater. Some 9 per cent of the UK catchments have been shown to have infiltration rates greater than 50 per cent and 28 per cent of catchments have infiltration rates of more than 25 per cent. That is more than 50 per cent and 25 per cent of the sewer flow respectively are derived from infiltrating groundwater.

  In the Lambourn Valley it was found that infiltration rates as high as 75-82 per cent occurred and investment in a sewer sealing programme costing £180,000 reduced pumping hours reduced to between 21 per cent and 31 per cent of the long term averages. As the leaking sewers were contributing to the flooding of properties and overloading of the treatment works, the saving of £1,800 on pumping costs was considered to be reasonable although this was only 1 per cent of capital investment. The alternative solutions would have been more expensive, and would not have dealt with the costs to the environment of infiltration. Costs, which were not taken into account in the analysis of options.

  Exfiltration leads to pollution of the unsaturated zone and groundwater. Pollution of the unsaturated zone is a potential hazard for sub-surface workers such as cable and pipe layers. Exfiltration can also lead to pollution of the groundwater in a number of scenarios:

    —  where the pipe is in close proximity to the water table;

    —  there are leaking water mains in the vicinity which act as a source of recharge water; or

    —  indirectly from the unsaturated zone where it is washed down to the water table during recharge precipitation.

  Such pollution will pose a problem if the groundwater is being abstracted for drinking water. Even where that is not the case the EC Directive on Groundwater requires the protection of groundwater irrespective of use. Such pollution will make the use of new groundwater sources problematic.

  In a study in Nottingham it was found that pollution of the shallow aquifer was the result of exfiltration. Detailed monitoring of a housing estate constructed in the 1970s revealed widespread pollution. The most likely source was considered not to be the trunk sewers which were below the water table, but the lateral connecting pipes (drains and shallower sewers). Most of the emphasis of repairs, such as it is, is on repairing the strategically "critical" sewers. As is known from the evidence from the Water Services Association (now Water UK) to the Environment, Transport and Regional Affairs Committee that water companies make no effort to inspect or repair nine-tenths of the public sewer network not considered as strategically "critical"[5].

  The issue of investment in these "critical" sewers is dealt with below.

  Most monitoring of leaking sewers in the past has been passive, in that existing water abstraction points have been monitored. This is inadequate to quantify the scale of sewer related pollution problems, and will only reveal extensive contamination. This approach has led to the view that contamination of groundwater by leaking sewers is not widespread. However, more recent studies (of which the Environment Agency is aware) carried out in the UK and Germany using "active" monitoring (purpose installed monitoring points around sewers) has revealed more widespread pollution that is not necessarily linked to the age of the sewer. Such monitoring should be part of the assessment of serviceability whether undertaken by the undertakers or the Environment Agency under the Groundwater Regulations.

  There was little or no reference to these potential problems by Ofwat, the DETR or the Environment Agency in the last price round. In these circumstances it seems difficult to understand how asset management plans can be properly assessed.

6.  PRIVATE SEWERS

  Although there are 300,000km of public sewer, there is approximately 200,000km of sewers that are not vested in the sewerage undertakers. Some of these are in very poor condition, and contribute to the environmental problems. Whilst not strictly part of this inquiry, there is no doubt that some private sewers would be best renovated by a strategic authority rather than by the individual owners. Furthermore, records of sewers have been sometimes lost or are unclear so that there may be no certainty whether or not they are public or private. The sewerage companies always place the onus to prove they are public sewers elsewhere and disclaim responsibility. This is an issue that has not been addressed by the Government, regulator or Environment Agency. It could have been addressed by some allowance for companies to take over unsatisfactory private sewers where there is environmental justification. This is an issue outside the provisions within section 101A of the 1991 Act.

7.  IMPLIED ASSET LIFE AND CURRENT RATE OF INVESTMENT

  CROSS has examined the figure published by Ofwat for investment in the so-called "critical sewers". However there is some confusion as to what is considered "critical". In a Parliamentary Answer to a question from Dr Alan Whitehead MP, the then Environment Minister, Alan Meale said that "critical sewers" are those which are either costly or difficult to repair, and/or are important to the performance of the network. This definition is given in the sewerage rehabilitation manual (Water Research Council adopted by the industry in 1983). This seems to be two different things, and when CROSS has tried to obtain information directly from different water companies it appears they have chosen different arms of the definition by which to define their own "critical" sewers.

  Yet in a meeting with the then Water Services Association, CROSS representatives were told by an official of the WSA that "critical" was not a description of their condition, but that they were strategically important. It is about time that this definition was clarified after all the reports from the companies to Ofwat may well be using the same term to consider different things.

  Nevertheless the Table at Appendix 1 reveals the implied asset life of these sewers given the rate of investment from recent years. It should be noted that these represent less than a quarter of the whole public sewerage network. At best the implied average asset life of these sewers is nearly 280 years and on one calculation could be nearly a thousand years. Few if any sewers ever built have had to last that long. Even Water UK argued last autumn that it was unreasonable to expect an asset-life of more than 100 years.

  If "critical" sewers have to last anything from 110 years to 3,630 years for the different companies, how much longer will the remainder of the network have to last? With no significant increase in investment allowed for in the latest round, then it will be the public health and environment that will pay the price. Expecting an asset to last 100 years is unreasonable. Even the great engineering masterpieces of the Victorian public health engineers have required some renovation and many sewers installed since then have not been built to those same standards. Indeed there is some dispute as to whether some of the newer materials used are sufficiently durable.

8.  ACCOUNTABILITY (OR LACK) IN THE REGULATORY PROCESS

  Dr Jean Shaoul of Manchester University has undertaken a study of the effectiveness of Ofwat's regulation of the water industry[6]. She concluded that in the past Ofwat has made little effort to ensure money was spent on the purposes for which investment was allowed. Thus it is not clear whether individual companies have under-spent or whether those sewers which were renovated or replaced were those most in need or those for which the company had claimed it needed investment. It is apparent that expenditure on sewers is largely driven by companies' operational and business requirements. Most of the work relating to the sewerage system is seen by Ofwat as activities not outputs and is therefore not reported despite the obvious importance for public health. As Dr Shaoul has pointed out, at privatisation Ofwat stated its intention to develop new levels of service indicators but has not yet done so.

  She concluded that the regulators have not released information that enables the performance of the water and sewerage undertakers to be properly monitored. There is no public scrutiny of the regulators. It is quite conceivable that companies have submitted plans for investment in some sewers that have been included in previous rounds. For instance in setting the prices for Yorkshire Water at privatisation they were expected to improve 380km of sewers, 82km immediately, according to the prospectus, but between 1990-91 and 1994-95 only 17km were renovated. By 1999 only 65km had been renovated or replaced. On this basis it is clear that environmental improvements could have been achieved under the 1999-2005 price round without an increase in price.

9.  INADEQUACY OF INFORMATION ON THE STATE OF THE NETWORK

  Although the companies submit audited reports on the state of the sewerage network vested in them, this information is not in the public domain. Indeed there is no publicly available, reliable or comprehensive information about the underground network from which to monitor maintenance expenditure systematically. There is no publicly available comprehensive and authoritative data on the state of the sewer network, for instance on the amount of infiltration and exfiltration. This must be so if the sewerage undertakers actually inspect so little. The national method of assessment includes hydraulic capacity and structural conditions but not leak tightness. A detailed analysis of sewer survey results showed that 56 per cent of all joints in public sewers were faulty[7]. The published information is general and is more related to business-case investment and the companies' own desires rather than any environmental criteria. In the absence of monitoring other than of flow rates, it is hard to see how decisions on investment that lead to adequate protection of the environment can be made.

  Such information as Ofwat makes available does not relate to specific companies or specific catchments. Ofwat has said that 40 per cent of sewers have structural defects that could cause leakage.

  As the table at Annex 1 shows, in 1997, 8 per cent of critical sewers were categorised as Grade 4—some brick loss/badly made connections/moderate loss of level and 2 per cent were categorised as Grade 5—collapsed/severely deformed/missing inverts/extensive areas of missing fabric or bricks. That is 7,350km (4,560 miles) were in the two worst categories.

  For non-critical sewers, 9 per cent of the total length of 232,264km were categorised as in Grades 4 and 5, that is 20,900km (12,980 miles). This is insufficiently detailed to make an assessment as to whether investment is adequate for individual companies. What is more there is no information as to the environmental impact of this decaying asset.

10.  OFWAT'S REMIT AND THE ENVIRONMENT AGENCY

  Ofwat sets the price limits at the end of the periodic review. Part of this review is an assessment of the asset management plans of the water companies. Comment has already been made that in the absence of detailed information about the state of the sewerage network, and the low standard of serviceability it is difficult to see how these asset management plans can be adequate from an environmental perspective.

  Furthermore, Ofwat publishes water industry outputs in a way that uncouples them from targets, prices and expenditure agreed at privatisation. The regulator has a role that is limited to that of economic regulator. Even though companies have not met targets originally agreed, the regulator has not taken any action to make them comply.

  The Environment Agency, although aware of the research on leaking sewers, including that in Nottingham, made little effort to ensure that the latest periodic review allowed for increased investment in the sewerage system. Thus Ofwat could put downward pressure on prices as a punitive measure for profits made previously and possibly previous failure to meet targets. However that does not force the companies to increase the rate of investment in the sewerage infrastructure.

  Leaking sewers lead to pollution of groundwater. The Environment Agency could therefore prosecute for an offence under the Water Resources Act 1991 or else use powers under the Groundwater Regulations to ensure work is carried out to prevent such pollution. The Agency has not used any of its powers with respect to leaking sewers, and until it does so, it will be easy for the issue to be ignored when price limits are set. It also must be said that regardless of price limits the Agency can still use these powers to protect the environment and the cost of compliance will have to be borne by the companies from their own resources.

  In effect to CROSS it seems the attitudes of the Ofwat, the Government and the Environment Agency, have so far led to investment in the sewerage infrastructure being squeezed to allow for price reductions.

11.  CONCLUSION

  The sewerage infrastructure has been largely taken for granted. In the former Federal Republic of Germany, with a similar sewerage system to the UK in terms of size, age and methods of construction, in 1991 it was estimated that 300 million m3 of waste water entered the ground each year from leaking sewers (equivalent to 1 litre/day per metre of sewer)[8]. There is no reason to believe the situation is not similar in the UK, but the Periodic Review has taken little or no account of the environmental and potential public health impacts of a deteriorating sewerage network.

  These sewers will have to last many hundreds of years at the present rate of investment. Whilst Ofwat sets the price limits on the basis of mandatory environmental investment programme set by the DETR, Environment Agency and the DWI, none of these have pushed the matter of sewerage investment adequately. Furthermore, the Environment Agency could take action to protect groundwater from leaking sewers regardless of the periodic review but has so far not done so. CROSS believes that ignoring the need for increased investment in sewerage has enabled the price reductions to be made.

  CROSS will be happy to give oral evidence should the Committee so wish.

May 2000

ANNEX 1

CompanyTotal length of critical sewers,1 km Critical sewers renovated 1990-97,2 km Critical sewers renovated 1997-98,2 km Critical sewers renovated 1998-99, km Critical sewers replaced 1990-97,2 km Critical sewers replaced 1997-98,2 km Critical sewers replaced 1998-99,2 km Total critical sewers renovated or replaced 1990-99, km Total critical sewers renovated or replaced 1997-99, km Average p/a sewers renovated/replaced 1990-99, km Average p/a sewers renovated/replaced 1997-99, km Implied asset lifeon 9 year view—years Implied asset lifeon 2 year view—years
Anglia8,19134 291336 16313161 14.5630.5562.57 268.56
Dwr Cymru4,32132 8570 81313634 15.1117 285.97 254.18
North West10,674127 2327120 2417338 9137.5645.5 284.19234.59
Northumbrian5,982137 495717 11262108 29.1154 205.49 110.78
Severn Trent7,47195 52265 2123411 5145.6725.5 163.59292.98
South West1,81532 1017 00501 5.560.5326.44 3,630
Southern6,46021 3116 00414 4.562 1,416.67 3,230
Thames18,936195 357090 1413417 13246.3366 408.72286.91
Wessex2,84163 6817 129717 10.788.5263.54 334.24
Yorkshire6,84623 17111 946531 7.2215.5948.20 441.68
Total/All73,537759 176184659 94761,948 530av p/a per co
21.646
av p/a per co
26.5
overall av
486.54 years
overall av
908.39 years
av p/a total
216.44 km pa
av p/a total
265.00 km pa
av p/a total
216.46 km pa
av. p/a total
265.00 km pa
or taking av p/a total ren/reps
339.73
years
or taking av p/a total ren/reps
277.5
years

  1 Reported in 1999; source OFWAT W2000 JR-T-16 included in private correspondence.
  2 Source: Reports on the financial performance and capital investment of water companies in England and Wales, 1995-96 to 1998-99, OFWAT, Birmingham.

  Note:
  In 1997, 8 per cent of critical sewers were categorised as Grade 4Í some brick loss—badly made connections/moderate loss of level and 2 per cent were categorised as Grade 5—collapsed/severely deformed/missing inverts/extensive areas of missing fabric or bricks ie 7,350 kilometres (4,560 miles) in the two worst categories.
  For non-critical sewers, 9 per cent of the total length of 232,264 kilometres were categorised as in Grades 4 and 5, that is 20,900 kilometres (2,980 miles).


1  10th Report, 1990-91 HL 50-1. Back
2  Barrett Mike, Lynch Jennie, Pond Kathy, Environmental health impacts of infiltration and exfiltration connected with underground drainage systems. Report prepared for CROSS, RCPEH, Surrey University, Guildford. Back
3  WSA/WRc, Civil Engineering Specification for the Water Industry, 4th Edition. Back
4  Bishop, P K, Misstear, B D, White, M, and Harding, N J, Impacts of Sewers on Groundwater Quality, Water and Environmental Management, JCWIM, 1998, 12 June. Back
5  Second Report, Session 1997-98, HC 266-1. Back
6   Shaoul, Jean, Water Clean Up and Transparency: The Accountability of the Regulatory Process in the Water Industry-A Public Interest Report, Dept of Accounting and Finance, Manchester University, 1998. Back
7   Transport and Road Research Laboratory Research Report 172, Analysis of Defects in 180km of Pipe Sewer in Southern Water Authority, 1989. Back
8   Schleyer R et al, Institute of Water Soil and Air Hygiene of the Federal Health Office, Germany. Development of Aquifer Protection Policy in Germany, IWEM Annual Symposium 1991, Groundwater Pollution and Aquifer Protection in Europe. Back

 
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