Geography Reference
In-Depth Information
For some time, companies have been anxious to
differentiate between the leaks from pipes for
which they have responsibility and those that
belong to the customer. Today, the approach to
leakage reduction has been integrated with water
quality improvement and customer satisfaction.
Many companies now offer customers free
repairs to their installations and are also replacing
service pipes, which may leak or contaminate
potable water through, for example, dissolved
lead.
Service reservoirs provide a 'local' supply of
treated water and serve to balance the supply and
demand and to provide an emergency reserve of
water. Service reservoirs also have negative
characteristics. They allow chlorine to decay; they
are a focus for microbial growth; they act as
chemical reactors for disinfection by-products; and
they leak. Management will seek to minimise
residence time by maximising turnover; to ensure
internal circulation and to monitor chlorine levels
and chlorine decay products such as
trihalomethanes. Researchers will provide
technology and systems to optimise this
management. Social and computational scientists
will have the opportunity to contribute to the
most worrying problem: that of risk of deliberate
contamination as a result of vandalism, extortion
or terrorism. Risk analysis and vulnerability
assessments to address these issues are becoming a
part of management planning.
Distribution systems are complex spatially
organised systems. To optimise the performance
of these assets and to achieve the tightening
performance standards in the face of stringent
cost constraint requires improved monitoring,
data transfer, modelling and communication to
identify trends in performance and to indicate
potential problems and network sensitivities. It
also allows operational staff to be trained in 'what
if' scenario planning. Such network models have
been credited with the success ofYorkshire Water
in delivering uninterrupted water to all
customers in the face of a 1 in 600-year drought.
It could do nothing to address the PR failures in
that situation.
MAINTAINING AND IMPROVING
DRINKING WATER QUALITY
From the privatisation of the water industry in
1989 until the drought of 1995, the quality of
drinking and environmental waters was at the top
of the political, public and company agendas. It
remains near the top of the agenda today. Drinking
water must be 'wholesome' and fit for human
consumption. In practical terms, these very
positive objectives are interpreted through the
negatives: (1) that the water does not contain
anything detrimental to public health; and (2) it
does not exceed defined standards. Examples of
the key prescribed standards and values (PSVs) are
given in Table 10.2.
The standards set have a mixed pedigree. They
are growing in number and are becoming more
stringent. They often lack a scientific basis, and
the significance of non-compliance (an
understanding of the dose-response relationship)
is infrequently addressed. In most cases, a wide
safety margin is incorporated into the individual
standards implicitly to compensate for increases
in toxicity associated with aggregate element
effects. Drinking water quality is assessed through
the analysis of random water samples from the
households served. While the individual
companies review the results against the
prevailing standards and take action if
appropriate, the results also go to the Drinking
Water Inspectorate to assess compliance and
trends in compliance.
Research challenges are of two types: those that
relate to the composition of the PSVs and those
that relate to the sampling and interpretation of
the PSVs. In both cases, researchers must be aware
of the sensitivity of the research topic and results.
Table 10.3 suggests key research areas.
FORECASTING AND PRICING
Forecasting and the research needs associated with
that practice have increased in importance in the
last ten years. At a time of population, demand and
climate stability, it could be assumed that the water
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