Service contracts may be key to wastewater treatment cost control in UK

Mar. 30, 2009 -- Across all UK water regions, maintenance requirements for existing and often ageing waste treatment plant are causing budget concerns, especially with keen government scrutiny of the utility charges and the need to limit increases for the credit squeezed householder.

Recently, several utility companies have looked to increase the practice of external contracts for regular and preventative maintenance on specific equipment. The advantages include excellent cost control, easier budget planning and reduced emergency outages and associated costs.

For example, Southern Water operates nearly 60 Hydro SludgeScreen™s at 30 waste treatment sites across the region. These comprise 19 older chain driven machines (originally Picatec) and 37 modern, direct drive Hydro units, all on sludge dewatering duties.

A two-year (2008 to 2010, plus optional third year) service agreement was recently concluded with Hydro Wastewater Division's Spares and Service. It removes the main responsibility for the SludgeScreen™s from the site maintenance teams who are required to complete the lubrication and visual inspection duties.

"Efficiency and reliability of operation are critical to wastewater treatment works," comments Frank Baker, Supplier Agreement Leader for Southern Water. "With this contract we can now predict our costs much more tightly, and reduce the cost provision we might have to make for reactive maintenance if the screens go down, with all the associated additional costs.

"This approach provides Southern Water with a contract that enables an efficient method of managing our asset and ensuring we maximize their efficiency, an important part of Southern Water's approach to managing its assets.

Neil Hobbs, Sales and Service Manager for Hydro Wastewater Division, adds: "Equipment such as the SludgeScreen™ responds to regular servicing to maintain its effectiveness.

"When a site only has one machine, with no back-up, it is essential that it doesn't break down, otherwise the sludge may have to be tankered off site for processing, with heavy extra costs. We can maintain them with minimum downtime at low flow times, reducing any disruption to treatment.

"There is also the element of predictive maintenance and condition monitoring. We are able to spot wearing components, and suggest how soon they might need replacement, so identifying a problem before it becomes a crisis. It also improves the SludgeScreen™'s efficiency and economy of running, helping reduce Southern Water's carbon footprint."

The Hydro service includes an annual major strip down, clean and component assessment, and a six monthly adjustment and check of any potential problems noted at the last visit.

"The visiting engineer has to be sure that the unit will continue to operate for the next six months without major breakdown, " continues Neil Hobbs. "In this way, Southern Water have a very clear idea of their potential repair bills at any one time."

The Hydro International SludgeScreen™ has a small footprint and low running costs. It provides screening, dewatering and coarse material discharge in one operation without requiring washwater. It is suitable for automatic continuous or intermittent operation and sludges of varying dry solids content and will accept any combination of tanker delivery or pumped feed; it is thus ideal for works where there are considerable differences between sources. As a totally enclosed system it is a low odor process.

Hydro International, which has offices in the UK, USA and Ireland, provides cost‑effective solutions for controlling the quantity and improving the quality of water with minimal maintenance.

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