Water & Wastewater Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/863631
Alternative Water The Works JAmes Brockett Editor, WWt Thames Water has started to use a flexible, modular system of temporary tanks and digitally controlled pumps to keep water flowing through customers' taps during short-term supply interruptions. The Always in Supply (AiS) system, which the utility helped develop in partnership with liquid handling company Arlington, consists of boxed tanks and pumps with their own power source, which can be delivered from the back of a van and placed in the street near where required work is taking place. Water (whether it is taken from the main When compared to the distribution of bottled water, it is significantly cheaper and more sustainable – particularly since the tanks can be refilled if a shut-off takes longer than expected. A€er the success of an initial trial, Thames is now using the system across its region, where it is used to attend to 2 or 3 incidents a week. The utility owns more than 150 Arlington AEWT tanks, which it can deploy for incidents of all sizes, but hires the AiS pumping units from the Pewsey-based supplier in order to benefit from its expertise with the equipment. Because the number of tanks and pumping units can be tailored to fit each situation, the system provides for a flexible approach to alternative water which could mean water companies can join up their response to notifiable, unplanned events with the way that they treat smaller, planned shutdowns. 20 | SEPtEMBEr 2017 | WWt | www.wwtonline.co.uk prior to shut off, or a mobile tanker lorry) is then stored in the temporary tanks and pumped directly into customers' pipes for the duration of the incident. Thames is using the system both for small-scale planned work and for unplanned incidents such as burst mains, when they affect areas of up to a few hundred properties. The water company has a 'SI4' regulatory threshold agreed with Ofwat, which means that any supply interruption over 4 hours is counted towards its performance total and could contribute to an incentive or penalty from the regulator at the end of the year. Because the system supplies water to individual household taps, its operation means that an incident need not be counted as a supply interruption at all – in fact, most customers do not notice that anything has occurred. Water companies' response to a short-term supply disruption is o en to distribute bottled water, but Thames is now using a different approach which is more sustainable and cost-effective The AEWT tank is a 'bag in a box' alternative water solution the AiS intelligent pumping system links the water sources, and a power source is supplied