Philippa Clark, of our sponsors Northumbrian Water, explains how the company makes power from poo, and how you can save water – and energy

THE theme for the 2014 World Environment Day is "Small islands and climate change", a theme chosen to highlight low-lying, vulnerable areas that face the impact of climate change.

Barbados, for example, is a small nation that is taking big steps to reduce its climate footprint and to provide clean, renewable energy and opportunities for economic growth.

A little closer to home, in our region, our local water company is taking big steps too. In fact, Northumbrian Water is an industry leader in advanced anaerobic digestion – or "making power from poo", as they call it.

Historically, sewage was taken out to sea and dumped. As well as having adverse affects on the environment, this was a huge waste of what is now a valuable commodity.

In 1991, a shift in legislation required waste water to be collected and treated before its disposal. Until 2007, the treatment of sludge (the residual, semi-solid material left from industrial waste water, or sewage treatment processes) focussed on sludge-drying – or "dewatering" – with lime stabilisation. As well as being expensive, it was highly energy and carbon intensive.

Recognising the impact it had on the environment, and taking its responsibility to protect and enhance the environment now and in the future, Northumbrian Water invested in leading edge technology to clean up its waste, and become the first water company in the UK to turn 100 per cent of its sewage sludge into renewable energy. In addition, it cut its carbon footprint by 20 per cent.

This is an example of first class environmental innovation, right on our doorstep. But how is it done?

The process is called advanced anaerobic digestion (AAD). And at Teesport and at Howdon on Tyneside, we have the biggest plants in the UK. Conventional anaerobic digestion is used widely throughout the water industry to treat sewage sludge but the "advanced" element of AAD is the key to its high green credentials.

Sludge is loaded into pressurised reactors and heated at 165 degrees. This stage of the process can be compared to pressure cookers found in domestic kitchens. It is then depressurised and cooled before being fed into large concrete tanks for the bacterial process to start. Methane given off by the bugs that digest the waste is collected in 11 metre diameter storage bags before being used to fuel gas engines that generate four mega watts of electricity. In short, the methane and carbon dioxide released by bacteria digesting the sludge is used in gas engines to create electricity.

In 2009, the first of two AAD plants, built by Northumbrian Water costing £75m, opened. The second, a five acre sewage treatment works in Howdon on Tyneside, followed suit in 2012.

And now in another innovative move to maximise energy production, the biogas is going to be upgraded to remove the carbon dioxide so that the purified gas can be directly injected into the gas grid.

Having pioneered power from poo, the company is now leading the industry again in another sustainable alternative energy production. A successful small trial of a hydrogen Microbial Electrolysis Cell (MEC) reactor at a waste water treatment works on Tyneside has lead Northumbrian Water to try to scale up this form of energy production to fully assess its viability. The company is the first water company in the UK to take the lead on detailed studies of MEC potential, the next generation of microbial fuel cells.

In 2013 Newcastle University and Northumbrian Water collaborated to install a pilot at Howdon sewage treatment works. It was the first working MEC reactor fed on real waste water in the world.

As we celebrate World Environment Day 2014, the biggest day for positive environmental action, it’s true meaning is to serve as the "people’s day" for doing something positive for the environment. So how can you make a difference?

The average person in the region uses around 140 litres of water a day but on a warm sunny day it can be as much as 170 litres. In a household with two adults and two children this is the equivalent of 985 pints of milk per day.

Northumbrian Water uses lots of energy to treat and pump water and to take it away and clean it. The company’s 2.7 million customers across the North-East can each do their bit to make every drop count by using water wisely in the home and garden. Small changes to daily habits can make a big difference to the way you use water, such as turning off the tap when brushing your teeth and repairing dripping taps.

And if you have a meter fitted in your home it can save you money, too. Reducing water use can help to reduce your carbon footprint.

Change of habit - Saving per property per day

Turn off the tap when brushing your teeth - 30.7 litres

Shower rather than bathe - 25 litres

Use a bowl when hand washing dishes - 17.5 litres

Take shorter showers - 17 litres

Use a bowl when personal washing - 11.8 litres

Repair dripping taps - 8.9 litres

Use full loads in washing machines - 8.3 litres

Use a bowl when washing food - 6.5 litres

Use water resourcefully in the garden - 2 litres

Use full loads in dishwashers - 3.8 litres