Water & Wastewater Treatment Magazine
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Top Tips for… System Totex Ofwat's decision to move to investment decisions based on Totex has caused a radical shi in strategy for the water sector. Capital expenditure and operational cost are now part of a greater whole, and both the shorter and longer life cycle cost impacts of procurement decisions is under scrutiny. System Totex is key to employing this approach for inlet works, and these tips around the example of debris, screenings and grit removal provide guidance on applying it. The Knowledge 1 Establish a case for shorter-term investment Ofwat's new emphasis on Totex requires an understanding of how decisions are made on inlet works investment, not just in terms of a set of parameters, but in achieving much wider customer-focused deliverables. The new thinking provides the flexibility to move from the traditional 20-year whole life cost, output-focused investment approach to a shorter term, five-year horizon that addresses the levels of service customers believe are important to them, and which are a significant element in Ofwat's thinking. Creating a solid case for this type of short-term investment, which resonates with the five-year AMP cycle, means shi ing the focus from long-term Capex to Opex or short-term Capex to meet the required outcomes more closely. The approach focuses on the system in its entirety, which involves assessing many factors that affect Totex cost as well as the usual capital costs. 2 Assess the indirect costs of gaps in maintenance A comprehensive system Totex strategy must include consideration of the benefits of proactive maintenance for inlet works, for example, by protecting pumps ahead of and throughout the treatment process. Effective screening removes debris that can affect the efficiency of downstream equipment and processes and ensures that downstream operational and maintenance costs are minimised. Debris, either from storms or dumped material, is a well-known cause of damage and blockage to critical pumps, leading to long periods of down time for repairs. And, as pumps are o en very significant in terms of both capital and operational investment costs, protecting 6 TOP TIPS www.wwtonline.co.uk | WWT | NOVEMBER 2017 | 25 Alex Lloyd Managing Director Jacopa A worn bearing next to a new bearing