The Environment Agency doesn't just take responsibility for its own impact on the planet, it is doing its bit to reduce our impact too. "It's our job to look after your environment and make it a better place," the organisation says. This is an everyday consideration, according to staff, who give this question a green score of 92%.

Winner of our award for the best big company for employee engagement, the agency's staff are aware of the environmental implications of the work they do (87%) and say that the environment is a top priority for their bosses (82%).

"We're here to protect and enhance the environment. It's very important that we get it right and lead by example," says Lucy Smith, regional environmental management adviser. "If we can't do it, we can't expect others to."

With 11,921 employees, 252 sites (ranging from listed buildings to vehicle depots and offices), and the taxpayer's money to spend, the public sector agency's remit isn't without its challenges.

"We don't have an advantage because we're the Environment Agency — we have all the problems any other organisation has," says Graham Ledward, director of resources.

Staff say its environmental commitments are serious, giving this a 92% score. They believe the organisation doesn't choose the cheapest option rather than the most ecofriendly (80%) and the workforce tends to think green (91%).

Three years into a five-year plan to reduce carbon emissions, waste, mileage and energy and water consumption, Ledward believes that setting goals is the key to turning the organisation greener. "It's a combination of setting stretching but not unattainable targets, breaking them down over the five-year strategy and getting as many staff engaged as possible."

Testament to this engagement is a cut in business mileage of 8.9m miles over two years, which earned the organisation the Energy Saving Trust's Fleet Hero award in 2008. This massive reduction and the corresponding cut in emissions was achieved primarily through replacing face-to-face meetings with telephone conversations, and where travelling was unavoidable, by using public transport, car sharing and low-emission pool cars.

Two top five green scores of 86% show staff are encouraged to use public transport or to share their car, and they consider the environmental impact of their work-related travel.

The Environment Agency is keen to get to the root of its 65,000-ton carbon footprint with its carbon reduction fund (CRF), rather than offset the emissions. "We are really proud of the CRF," says Simon Dawes, manager of the internal environmental management team. "A lot of companies offset. It's very easy to write a cheque and say, we're carbon neutral. We take that money and spend it internally on CO2 reduction."

Employees from all areas of the business can bid for a portion of the fund to implement green initiatives. The CRF for 2009-10 stands at £400,000. Bids for funding to the value of £1.7m were put forward by members of staff, indicating their support for the scheme. "It is indicative of how enthusiastic people are and how much they want to do," says Dawes. Employees don't think environmental initiatives are a waste of money (92%) and believe their bosses are committed to the environment (84%).

One initiative made possible by the CRF involves a project on the River Towy in Wales. The agency is responsible for adding lime to the water, to make it a more suitable breeding ground for salmon. This required staff to travel long distances to refuel the petrol generators powering the equipment which added the lime.

On the suggestion of an employee, the two petrol generators were replaced with a micro hydro generator which uses water to produce the power needed for the equipment. A remote monitoring system has also made it possible to keep an eye on the equipment from the office rather than travelling to check it is working properly, reducing mileage and man hours needed for this project.

An 86% score shows Environment Agency bosses are open to suggestions for environmental improvements. They don't drive gas-guzzling cars while expecting the rest of the workforce to save the planet (85%) and they keep staff up to date on the latest green issues with regular communication (88%).

An ecofriendly head office in Bristol is due to be completed next year, joining the organisation's office in Oxfordshire, which opened in 1993, as an example of sustainable development.

There are plans to fit speed limiters to company vehicles, reducing their emissions by capping speed at 62mph. Smart metering is also due to be installed across all sites, making it easier to monitor the use of gas, electricity and water.

With these kind of initiatives, the Environment Agency's reputation remains intact — the friends and family of staff think the organisation is green (87%).