companies to gaze deeply into their crystal balls to prepare for AMP5, believes Watson Marlow

Now the dust of the AMP4 has settled, water and sewerage companies have begun making plans to maintain, upgrade and develop their asset base over the next five years.

It is probably true to say that uncertainty and risk have played a greater role than in any of the previous AMP planning processes – a trend that is now set to continue for some considerable time.

The previously risk-averse water and sewerage companies now have to build risk and uncertainty into their planning, investment and business processes. However, while they have a greater ability to understand their asset base and analyse data to make more informed predictions, two issues in particular are currently turning this into crystal-ball gazing. These are the upcoming Water Framework Directive (WFD) and the wildcard of climate change.

Water companies are already taking climate change into account, with various scenarios forming a key part of AMP business-plan submissions to the water industry regulator, Ofwat, and the long-term water resources planning process. However, despite the fact that the WFD (likely to be the most significant piece of legislation ever to impact on the sector) is now looming large, Ofwat did not allow any WFD-related expenditure in AMP4.

It is clear that AMP5 will have to address this but if, as in previous planning rounds, draft business plans have to be in by March 2008, this only leaves a relatively short period of time to quantify the impact of WFD on their business operations. Some serious crystal-ball gazing will be necessary if the sector is to adequately plan to meet

its likely requirements.

One of the key areas of concern is the directive’s aim of reducing or phasing out emissions of Priority Hazardous Substances (PHS) and Priority Substances (PS) that enter WwTWs.

The WFD establishes a list of priority substances, 33 of which have been shown to be of major concern to European waters, requiring environmental quality standards and emissions controls. Within this list, 11 have been identified as priority hazardous substances to be subject to cessation or phasing out of discharges, emissions and

losses within a maximum of 20 years. Another 14 are candidates for consideration as priority hazardous and are subject to further scrutiny.

At the moment, there are considerable variations on cost estimates for the further treatment required. The Department for Environment, Food and Rural Affairs (DEFRA), for example, quotes a figure of between £450M and £630M per annum. A UK Water Industry Research study suggests, however, that extra treatment for the removal of priority substances would be required at half of all WwTWs in England and Wales at a cost of some £6B. This would be on top of the £7B Ofwat says should be invested in maintaining and improving sewerage in 2005-10.

Given that achieving the proposed stringent standards for the PHS and PS in the sewage-effluent discharges is likely to require huge investment at WwTWs, running into billions of pounds for the water industry, water companies are being urged to take action now by reviewing their waste water treatment systems.

Key to this process will be the extent to which the water and sewerage companies can future-proof their existing wastewater treatment systems. But is it possible in practical terms to future-proof complex systems in such a way to cope with as yet unspecified requirements?

In one key area, the wider opportunities offered by an existing process are increasingly being viewed in the light of its significant future-proofing capabilities.

The WFD may well require water companies to look at additional

dosing systems for other priority substances. This is an area where

peristaltic pumping technology is now being seen by a growing number of water and sewerage companies as not only ideally suited to meeting existing legislative and quality requirements but also capable of meeting potentially major additional WFD requirements.

Peristaltic pumps are already used for a wide range of applications in WwTWs and WTWs – for example, dosing and metering ferric chloride to ensure phosphorus removal (meeting Habitats Directive requirements), sampling raw water and final potable water, and transfer of settled sludge.

Philip Bolton, from pump manufacturer Watson-Marlow Bredel, says a growing number of water companies are approaching them to discuss how they can incorporate the technology in their wastewater treatment. According to Bolton, peristaltic technology provides water and sewerage companies with a future-proofing process which no other pumping technology is currently capable of delivering.

“Peristaltics are ideally suited to WwTWs – they can cope with harsh environments and corrosive materials. They are also outstandingly accurate, delivering a teaspoonful of chemicals or a tanker-load and at variable rates. The key benefit is its flexibility. The Watson-Marlow Bredel 520 series, for example, enables operators to use up to eight different diameters of tubing in one pump.

“It’s like having eight different pumps in one. Add in the ability to cope with a flow range from 3000:1, and you’ve got a system that can cope with significant increases without any need to upgrade, let alone replace or retrofit.”

DEFRA guidance on PRO4 stated that it would expect companies to “consider whether current solutions can be designed to facilitate later upgrading to meet any changes that can be reasonably anticipated”. As the water and sewerage companies get closer to the realities of implementing the WFD, they will increasingly be looking for this level of future-proofing capabilities across a wide range of technologies.

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