Castle Moffat Water Treatment Works

Business • East Lothian

Castle Moffat Water Treatment Works in East Lothian is one of Scottish Water's most environmentally friendly sites and is the first site to use hydropower generated on site to run itself.

  • Castle Douglas Water Treatment Works.
  • Generator at Castle Douglas Water Treatment Works.

Scottish Water's Story

Castle Moffat WTW provides on average 21 Ml/day of clean, fresh drinking water to approximately 47,000 customers across all of East Lothian. The original hydro turbine that powered the site was more than 50 years old – installed in 1992, so it was in need of refurbishment. Scottish Water took action to invest £200,000 and use innovative technology to best adapt to Scotland's topography, to build a site that best serves its customers and the environment.

This project reflects our commitment to reducing our carbon footprint and trying to reduce the amount of electricity we use. Using renewable technology like hydro and getting greater value from our day-to-day practices is helping us play our part in tackling the climate change emergency.

Treating water is an energy-intensive process and with Scottish Water's carbon footprint dominated by electricity at around 69%, natural resources are being put to good use at Castle Moffat works and off-setting the site's power consumption.

A range of renewable initiatives like at Castle Moffat are helping Scottish Water make a significant contribution to Scotland's national economic, carbon and renewable energy targets.

More than 70 of Scottish Waters' water and wastewater treatment works are either self-sufficient or partly sufficient in their power requirements, leading to lower operating costs and a more sustainable business.

We aim to continue to reduce the amount of energy we consume to deliver our vital water and wastewater services and grow new capabilities by changing behaviours and influencing others to change. We are committed to getting to net zero by eliminating all emissions associated with our activities by 2040 - whilst delivering excellent service and great value to our customers.

Useful Learnings from Scottish Water

The work at Castle Moffat and other sites in the last few years demonstrates how we have significantly expanded our renewables programme.

We would advise other organisations to retrofit renewables to existing assets, or if there is a need to invest in new assets then consider whether there are opportunities to include renewables in the design.

Scottish Water has set a goal to increase on-site generation of renewables to 90GWh by 2030. During 2020-21 Scottish Water assessed the renewables potential at 500 assets and is upping its rate of delivery each year across these assets to achieve the goal.

Scottish Water's Metrics

kWh generated per annum (750,000).

Feeling inspired? Discover more about this story...

Action Area

Renewable Energy

Positive Impacts

Clean Air


East Lothian

Response to climate crisis





Business, 250 to 10,000 people

Shared by

Carbon Copy

Updated Feb, 2024

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