Scottish Water's Circular Economy Exploits

Scottish Water, which provides water and wastewater services to 2.49 million households and 152,000 businesses across Scotland, is contributing towards the development of a circular economy.

In the circular economy, products and materials are kept in a high-value state for as long as possible, then recovered and regenerated at the end of each service life. This ‘reduce, reuse, recycle’ (3R) model contrasts with our current linear economy (take-make-use-dispose) which is placing a strain on raw materials and leading to environmental degradation.

Reduce: Water savings calculator

Scottish Water provides customers with an online Water Savings Calculator to determine their actual water usage. At the start, customers get to personalize the questions to suit their homes, so if they do not have a car the customer will not be asked how often do they clean it. Once completed – it takes around 5 mins – the user is provided with their own personalized water, energy and spend profile, a number of free water saving products that are easy to install, along with a series of tips on what can be done to save water. For example:

• Fixing a dripping tap can save as much as 48 liters of water a day, or 17,500 liters of water a year
• Shaving 1 minute off your shower could save £15 in energy bills and a further £15 in water bills per year or £120 saved a year for an average 4-person household

Scottish Water's 3Rs

Reuse: Sludge-to-energy

Scottish Water directly, or under Private Finance Initiative Contracts (PFI), treats sludge by anaerobic digestion, liming or drying to create biosolids. Biosolids is an extremely valuable source of fertilizer on agricultural land, reducing fertilizer costs to farmers, increasing crop-yields and reducing the farmers’ carbon footprint. In addition, the treated sludge is used to generate renewable energy, with 48% of sludge treated by PFI operators used as a fuel substitute in the cement manufacturing industry; reducing the use of virgin raw materials in that sector.

Recycle: Waste oil recycling

Scottish Water is partnering with Sainsbury’s to provide recycling facilities for waste cooking fat and oil, which is a major cause of sewer blockages and flooding: Fat, oil, and grease (FOG) cause 20% of the nearly 37,000 sewer blockages reported per year. Sainsbury’s is trialing dedicated FOG collection points at 7 store car parks located in Edinburgh, West Lothian, and Fife, where customers can drop off containers of waste oil in an easy and clean way. So far almost 5,000 liters of waste oil has been collected and recycled. Olleco – a resource recovery company – transports the waste oil to one of its processing centers where FOG is removed from its containers, heated, cleaned and filtered before it is converted into biodiesel for use in road vehicles. The US EPA estimates that biodiesel made from FOG has greenhouse gas emissions 86% lower than petroleum-based diesel.

The take-out

In the circular economy, water utilities can make a significant contribution including reducing resource usage and recovering and recycling materials for productive use.

*Robert C. Brears is the author of  Urban Water Security  (Wiley), and of the forthcoming titles  Blue and Green Cities  (Palgrave Macmillan) and  The Green Economy and the Water-Energy-Food Nexus  (Palgrave Macmillan). He is Founder of Mitidaption, which consults on climate change risks to business, governance and society.

Facebook: UrbanH20

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Taxonomy

• Nutrients Recovery
• Sludge Management
• Sludge Drying
• Governance
• Solid Wastes & Wastewater Recycling
• Conservation
• Governance & Planning
• Renewable Energy
• Waste to Energy
• Renewable Energy
• Recycling
• Nutrient Recovery & Reuse
• Sludge Treatment & Management
• Conservation
• Water Conservation
• circular economy