Keep an eye on performance
Legislative drivers are putting pressure on water companies to monitor CSO performance, so in a bid to demonstrate compliance, they are now exploring a new system called HawkEyeWater companies within the UK are facing increased pressure from legislative drivers, such as the European Water Framework Directive (WFD), which is adding to the timescale imperatives at the end of AMP3. The UK water companies have done much to reduce the impact of unsatisfactory intermittent discharges (UIDs) from combined sewer outfalls (CSOs) but to demonstrate compliance some form of monitoring is required.
The performance of the water industry has come into sharp focus recently, following the publication of the Environment Agency's (EA) spotlight report, which shows water companies are improving the performance of CSOs.
The EA reports that the water industry is now responsible for one in six of the 1,468 serious pollution incidents reported in 2002.
The fines that result represent only a small proportion of costs. The public relations implications are also significant within an increasingly socially responsible culture and water companies are aware of these drivers. Water utilities have spent vast amounts of money on improvements to the water infrastructure and assets.
They have a better understanding of the implications of pollution incidents from innovative and comprehensive monitoring programmes implemented during AMP3, but there is still much work to be done.
Overflow compliance monitoring is a significant part of the remaining AMP3 period and the water companies are facing an uphill struggle.
It is estimated that within AMP3, up to 3,000 of the UK's 4,700 CSOs will either need to be re-designed, upgraded or replaced by the end of 2005. Schemes are gathering pace but the scale of the programmes will continue to place significant pressure on existing operational work schedules. Some of the EA CSO discharge consents actually specify the frequency and duration of sewage spills.
The demonstration of compliance is a difficult problem given the hazards and hydraulic nature of CSO chambers. If that was not enough, there is usually no power supply and the end of pipe structures are well away from telecomm or Scada systems. On a strategic level, compliance monitoring has moved away from monitoring the performance of CSOs during storm events. It is generally accepted that during certain rainfall periods CSOs are going to spill - that is what they are designed for.
Of more significance are discharges during dry periods. Constant monitoring of CSOs, and in particular, during dry periods, allows water companies to identify problem areas.
Spills could indicate problems associated with the catchment area, blinding of screens, the performance of particular WwTW or bottlenecks within the network.
Added to the programme pressures to meet the end of AMP3 are the implications of preparation for AMP4 and the WFD. The WFD provides a framework, on a strategic basis, for the effective management of the water environment and provides an integrated approach, mainly to the management of river basins.
The EC legislation comes into force in December with implementation taking place for the UK over the next two AMP periods. To meet the requirements of the WFD, water companies will have had to establish and maintain appropriate monitoring networks within river basins.
Solutions that provide continuous monitoring capabilities are essential within each of these drivers but they must also provide significant cost and operational benefits to make them a viable proposition. IETG, which provides a comprehensive asset data collection and management service, believes it has developed the first fully integrated measurement and telemetry system specifically designed to monitor the performance of CSOs. The HawkEye CSO monitor is the first device of its type to be fully safety tested and certified to the new ATEX standards for installation in the potentially explosive environment of a CSO chamber. Using HawkEye reduces civils costs as it requires no additional power or telecommunication connections, road cuts, pavement-mounted pillars or cabinets.
In addition, the use of a non-contact ultrasonic sensor means maintenance visits and fouling problems are minimised. HawkEye's communication structure has been designed to integrate with already established asset monitoring and alarm systems in place within the corporate Scada system. Using the integral GSM modem, CSO performance data can be interrogated through the existing system. Parallel data management streams and operational alarm handling logistics have been avoided because water companies have existing systems to manage their assets.
IETG has gone one step further by offering a comprehensive, guaranteed data provision service.
IETG managing director Neil Scarlett said: "We will gladly sell Hawkeye monitors to anybody and all indications show they are in demand right now, but we are not 'box shifters' and I believe this is all about the possession of asset data and not about owning instrumentation.
"Rather than buying the kit and having the overhead of ownership, maintenance and replacement, we are offering the water companies the opportunity to buy the data stream. IETG will retain ownership of the instruments and provide the data, straight to desk-top, at guaranteed service levels and performance."
It is a bold step and one that is yet to have an impact, but some water companies have taken note and are exploring the potential cost savings.