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 CIRIAthe
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 4some
brick loss/badly made connections/moderate loss of level and 2
per cent were categorised as Grade 5collapsed/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
Company | Total 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 viewyears
| Implied asset lifeon 2 year viewyears
|
Anglia | 8,191 | 34
| 29 | 13 | 36 |
16 | 3 | 131 | 61
| 14.56 | 30.5 | 562.57
| 268.56 |
Dwr Cymru | 4,321 | 32
| 8 | 5 | 70 |
8 | 13 | 136 | 34
| 15.11 | 17 | 285.97
| 254.18 |
North West | 10,674 | 127
| 23 | 27 | 120
| 24 | 17 | 338
| 91 | 37.56 | 45.5
| 284.19 | 234.59 |
Northumbrian | 5,982 | 137
| 49 | 57 | 17 |
1 | 1 | 262 | 108
| 29.11 | 54 | 205.49
| 110.78 |
Severn Trent | 7,471 | 95
| 5 | 2 | 265 |
21 | 23 | 411 |
51 | 45.67 | 25.5 |
163.59 | 292.98 |
South West | 1,815 | 32
| 1 | 0 | 17 |
0 | 0 | 50 | 1
| 5.56 | 0.5 | 326.44
| 3,630 |
Southern | 6,460 | 21
| 3 | 1 | 16 |
0 | 0 | 41 | 4
| 4.56 | 2 | 1,416.67
| 3,230 |
Thames | 18,936 | 195
| 35 | 70 | 90 |
14 | 13 | 417 |
132 | 46.33 | 66 |
408.72 | 286.91 |
Wessex | 2,841 | 63
| 6 | 8 | 17 |
1 | 2 | 97 | 17
| 10.78 | 8.5 | 263.54
| 334.24 |
Yorkshire | 6,846 | 23
| 17 | 1 | 11 |
9 | 4 | 65 | 31
| 7.22 | 15.5 | 948.20
| 441.68 |
Total/All | 73,537 | 759
| 176 | 184 | 659
| 94 | 76 | 1,948
| 530 | av 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 lossbadly made connections/moderate
loss of level and 2 per cent were categorised as Grade 5collapsed/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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