Fed II Star - February 5, 2006

REAL LIFE NEWS: MAKE A GARDEN AND DEAL WITH POLLUTION

A new study by US researchers has discovered that "rain gardens" can dramatically cut the amount of pollution in storm water in cities.

Most of the rain that falls on cities lands on hard surfaces such as roads, where it absorbs pollutants before it finally drains away. But a shallow depression in a garden containing bark mulch and shrubs can remove up to 99% of toxins. Researchers from the University of Connecticut found that the gardens significantly reduced the concentrations of fertilisers, oil and particulates that reach storm drains. They can also help reduce localised flooding by absorbing the rain water from heavy downpours. This reduces the risk of the drains becoming overloaded.

Michael Dietz, one of the authors of the study, explained why they carried out the research. "The concept of rain gardens has been around for 10 to 15 years but there has not been a lot of research. A lot of places are hesitant to use something that has not been verified, so we felt it was an important step to bridge that gap."

For the study, two rain gardens were planted and frequently monitored over a two-year period to see how effectively they absorbed a range of pollutants. It looks like the answer is: very well indeed! Given that the percentage of the world's population living in cities continues to grow, the problems of flooding and pollution are set to increase, so this research points to a tool that could help considerably.