Gypsum

Once upon a time, all the gypsum used for building materials in the UK was mined here, with obvious environemtnal effects on the landscape. At the same time, power stations were burning fossil fuels, whic resulted in a lot of sulphur oxides being pumped into the atmosphere, causing acidification of the ecosystems from the resultant acid rain.

Sulphur scrubbers were added to power stations to improve their environmental effectiveness. However, the power stations had a problem in that the process produced a lot of solid waste which needed to be dumped. However, this solid waste is more or less the same as the gypsum being mined, so the power stations decided to sell it in place of mined gypsum. The output from all UK power stations supplied most of the UK's building needs, with the following results:

1. power stations no longer produce so much acid rain;
2. gypsum mines are no longer needed;
3. the power stations' environmental processes became financially self-supporting;
4. power costs were reduced in the long term as the power companies had an extra source of income.

A superb example of "win-win" environmental practices. It also shows that everyone's waste is valuable to someone else, with some ingenuity!