Data is not the full measure

Michael Scott of SWIG describes steps being taken to improve the reliability of operator self-monitoring in order to establish regulator and public confidence in measurement data

The regulators are moving towards self-monitoring as a means for showing that

regulations are being met as the public becomes more sophisticated in its demand

for information. Self-monitoring will mean an increasing number of people will

need to use measurement data. Most of them will have little understanding or

interest in its source, but may take far-reaching business or personal decisions

based on the data available. Thus, it is increasingly important to find some

way of demonstrating the quality and validity of the data.

Measurement data

The problem is that measurement data can come from a wide range of sources and

each might use one of several technologies or methods. The data may be validated,

if at all, by a wide range of standards, procedures or reference points. Furthermore

the quality of the data is dependent on people-skills related issues such as:

  • measurement selection,
  • sampling considerations,
  • installation design,
  • installation, calibration and maintenance.

In the water and wastewater treatment and environmental industries data is

sparse, both spatially and temporally. Two reports have shown that confidence

is not only low in measurement data but, because of a lack of standards and

agreement on how to express it, there little or no comparability between member

states in the EU:

  • pre-normative research for ISO TC147 and an EU report by Anders Lynggaard

    Jensen concluded that comparability of data between member states is not possible.

    This was one of the inputs to ISO/TC 147/WG2 for ISO/CD 15839 Water quality

    – On-line Sensors/Analysing Equipment for Water Specifications and Performance

    Tests of which the author has seen version N29 and suspects this is now out

    of date. The number of versions seems to demonstrate the difficulty of defining

    specifications and performance tests for the wide range of measurements needed

    in the water and wastewater treatment industry and also the application sensitivity

    of their use,

  • a 1999 UKWIR report, On-line Instrumentation Standards & Practices,

    concluded there is a wide spread lack of confidence in on-line measurements.

    Measurement is multi-discipline and multi-cultural because of the need to


  • measurement device/methodology design – the rapidity of technology change,
  • business support – the speed of business change,
  • application design,
  • data transmission,
  • data use,
  • data storage,
  • standards/best practice support.

In addition, Glen Harvey, chief executive officer of the Instrumentation, Systems,

and Automation Society (ISA) has just reported on a year-long USA industrial

tour. He concludes that process control data and control techniques are more

important than ever, but instrument engineering disciplines have all but disappeared.

Many observers consider the picture is similar in the UK and

the rest of Europe.

Regulation needs

The monitoring of process effluents and wastewater discharges and their impact

on receiving environments is a key element of regulation under environmental

protection legislation, and of the provision of information to the public on

pollution control.

Historically, the majority of effluent and wastewater monitoring was undertaken

by the appropriate regulatory authorities. In the years following the introduction

of the Environmental Protection Act 1990, industrial process operators have

been required by conditions in environmental permits to carry out compliance

monitoring programmes and report the results to the Environment Agency (EA).

This has become known as operator self-monitoring. Particular emphasis has been

placed on the use of continuous monitoring systems. This approach is being extended

through implementation of the Pollution Prevention and Control Regulations and

the Urban Waste Water Treatment Directive.

In order to ensure this approach commands the confidence of both the regulator

and the public, the EA is pursuing several initiatives to help improve the quality

and reliability of operator self-monitoring. The self-monitoring of flow initiative

started with the issue of P150 Flow Monitoring of Discharges: An audit Manual.

As part of the development of the monitoring certification scheme (MCERTS)

the EA is in the process of extending the scheme to continuous water monitoring

systems (CWMS). These monitors are often used for the monitoring of discharges

of process effluents and wastewaters (for example from industrial processes

and sewage treatment works) and of receiving waters (for example rivers, lakes

and reservoirs). The MCERTS’s performance standards and conformity testing requirements

were published for an eight-week consultation period on January 7, 2002.

The EA’s key drivers for the scheme are to:

  • monitor wastewater discharges and receiving water quality in order to assess

    the environmental impact of the industries it regulates,

  • ensure the EA’s performance requirements for water monitors are clearly


  • improve the reliability of monitoring results.

It is believed the MCERTS will ensure instrument manufacturers will demonstrate

the manufacturing process is controlled under a quality management system to

produce instruments that deliver consistent performance. Both the EA and the

industrial process will then have mutual confidence and the surveillance costs

will be reduced.


Data used for establishing that regulations and consents have been met is almost

all derived from samples taken from the point of measurement and subsequently

analysed in a laboratory. It is no surprise that automatic samplers are already

regulated under the EA’s E32 document against which a number of samplers have

been approved and are in use. There are a number of detail questions yet be

resolved on the transition from the E32 approval to MCERTS accreditation. Even

with samplers there are application issues. Tests are done on clean water and

yet some samplers will be used on dirty water. Dirty water must be defined.The

point at which the sample is taken must be demonstrably representative. Some

commentators point out that each application has quirks and that reliability

and maintenance problems will take a number of years to appear. One of the major

suppliers is convinced the only way forward is for the supplier to monitor the

sampler remotely and take care of application and maintenance issues as they



Monitoring and process measurement is certainly less than 1% of capital investment

so senior management can be forgiven for not considering it to be a strategic

issue. However self-monitoring will mean investment in measurement will become

an important senior management consideration. The water industry must, for Ofwat

reasons, make plans for at least five years, but realistically needs to take

10 and 20 year decisions on its asset investments. Careful selection and use

of process and monitoring equipment and support services can have a disproportionately

beneficial or detrimental affect on capital and revenue budgets. The footprint

of a new plant and existing plant capacities and/or output qualities can be

increased and hence civil engineering costs significantly reduced with the application

of new monitoring and control technologies. The costs of demonstrating compliance

with regulations and directives could be reduced and the risks of adverse publicity

also reduced with a broader look at the monitoring assets and the support costs


Business would benefit if:

  • the net present value of each measurement was compared with the business

    value of that measurement,

  • a very strong case was made for measurements for which the above is not


  • the quality of measurement data were an integral part of the use of the


The problem with the introduction of new approval/accreditation demands is

there are inevitably going to be significant costs and this may well inhibit

the introduction of new products and technologies. There are many important

small suppliers in this market sector and the accreditation costs might be prohibitive

in a market noted for small margins.

work to be done

The EA and the trade association for instrumentation, control, automation and

laboratory technology in the UK – GAMBICA, has made a good start with draft

standards and an accreditation facility for monitoring, but further work needs

to be done on the people-skills part of the uncertainty equation. While data

quality will certainly benefit from the EA’s MCERTS initiative much more work

needs to done on design and application practices and on the all-important business

analysis of support costs and comparison with the business benefits.

The recently reported work on auditing flow metering systems carried out by

the national engineering laboratory (NEL) on behalf of six UK water companies

is also encouraging but not extensive enough.

The water and wastewater treatment monitoring market is not large and is highly

fragmented by application, with a significant number of suppliers. All these

needs and concerns are becoming apparent at a time when it is becoming extremely

difficult for companies to spare the appropriately skilled and experienced managers

to work on the consensus specification and best practice document generation.

It is suggested that to help deal with both the above challenges it would make

good business sense to organise some pre-competitive co-operation to generate:

  • updated/new standards,
  • accreditation of instruments, design practices and people,
  • best practice guides.

The views expressed in this article are those of the author and must not

be taken as policy statements by, in particular, SWIG or the EA

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