Water and wastewater services for Kent, Sussex, Hampshire and the Isle of Wight
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Our carbon footprint

We're working hard to minimise our carbon production by investing in our current operations and in renewable forms of energy.

Southern Water - pumping station in Brighton

We're one of the largest users of energy in the South East due to the significant amounts of energy needed to pump water and wastewater around the region and treat it to the high standards for our customers.

During 2016–17, we produced 245 kilotonnes of carbon dioxide and other greenhouse gases. This is our lowest level in 5 consecutive years and is due to:

  • Our energy efficiency measures,
  • The generation of renewable energy on our sites for our use  
  • Cleaner power from the National Grid 

Our carbon emissions target for 2015 to 2020 is, as a minimum, not to exceed 2015 emission levels despite population growth and increased treatment standards.

This target was developed after listening to what our customers wanted in our 2015-20 business plan.

Our approach is to counteract increases in energy demand by focusing on energy efficiency and increasing renewable energy generation. Our 2015 emissions were 281 kilotonnes of CO2e (carbon dioxide equivalent). The chart below shows a breakdown of our emissions for 2016-17. The reported emissions covers all our offices and operational sites in Kent, Sussex, Hampshire and the Isle of Wight for the 12 months from April 2016 to March 2017.

Emission source

Kilotonnes CO2e (carbon dioxide equivalent)

On site fossil fuel combustion


Process emissions


Owned transport


Grid electricity


Business travel


Outsourced activities


Gross emissions


Renewable energy exported to grid

-                             6

Net emissions


Reducing our footprint

We are undertaking multi-million pound investments in carbon offsetting and energy efficiency schemes between 2015 and 2020 to help manage our carbon footprint.

CHP units take biogas created during the digestion stage of the wastewater treatment process and use it to provide 80 per cent of the power used on site. Any surplus is exported to the National Grid.

We have replaced 3 CHP units with larger more efficient ones and added 2 new CHP engines in 2017. This allows us to generate more renewable energy and use less electricity from the National Grid.

As a result, we now produce approximately 75 million kilowatt hours of electricity and save approximately 33,000 tonnes of carbon dioxide equivalent each year.

We're increasing our generation of renewable energy and recoverable energy to offset our overall energy use

In 2016-17 we generated 17% of our power from renewable energy by using gas generated from wastewater treatment.

This meant we have met and exceeded our customer promise and target of 16.3% renewables for the year.

Southern Water - pumping station in Brighton

Solar Power

This year we have installed solar power at 3 of our large water treatment centres. The power we generate from our new solar panels will be used on site in Southern Water's treatment processes. The capacity from all three sites equates to 4 megawatts - the equivalent to providing power for 1,000 homes for an entire year. This will save over 1,900 tonnes of carbon dioxide equivalent each year.

We're being more efficient in how we use energy, and embracing innovative technology solutions

We’re proud to run an annual site energy optimisation programme. Each year we conduct detailed energy assessments at our key energy consuming sites. This process yields fantastic energy saving opportunities: like limiting the run times of certain items of non-critical plant, and identifying where small operational changes can result in big energy savings.

A concentrated effort since 2014 has meant that we have been able to reduce energy consumption at our high consuming sites by an average of 13GWh per year, that’s an energy equivalent of 26 trips to the international space station!

We are also working with our supply chain and infrastructure partners to incorporate more innovative energy-efficient technologies into our business, including increasing biogas and renewable energy yields through additional treatment processes, and using our own assets to help balance the demand on the national grid helping to ensure that our region maintains a reliable and efficient source of power.

We’re reducing our heavy vehicle movements

A key component of waste water treatment is removing solid material from sewage. We transport separated solids from rural Waste Water Treatment Works to regional Recycling Centres by road, where they are processed to release methane gas which we use as a renewable energy source. Moving solids around the Southern Water region is one of our core business activities and results in numerous heavy vehicle movements.

We take every opportunity to increase the dry solid content of transported material by optimising processes at source – this in turn reduces the volume of material that requires transportation. Successful thickening schemes in 2016 helped to avoid 22,000 miles of heavy vehicle movements across our region. This is equivalent to approximately 30 tonnes of CO2 and has the same greenhouse emissions impact of an average UK passenger vehicle driving for 69,000 miles.

Please email us at optimisation@southernwater.co.uk to find out more about how we’re putting our ongoing commitment to sustainability into practice.

Carbon Trust Standard

We were awarded the Carbon Trust Standard in November 2017, acknowledging our achievement in reducing our carbon emissions.

Southern Water - Carbon Trust Standard awardWe've earned the Carbon Trust Standard four times, recognising our on-going efforts to reduce our impact on the environment.

The Carbon Trust Standard certifies that an organisation has genuinely reduced its carbon emissions and is committed to making further reductions year on year.

Reporting emissions

We are a participant in the CRC Energy Efficiency Scheme, a government initiative which encourages industry in the UK to cut emissions and reduce energy consumption.

In total, 2,800 companies are part of the scheme. These organisations are responsible for around 10 per cent of the UK's carbon emissions.

Each year, we report our emissions from fossil fuels to government and purchase around £3.5 million of allowances to cover our emissions. You can find out more about the scheme on the Department for Energy and Climate Change website.

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