River Pollution
In spite of considerable money having been spent over the last decade on improvements to sewerage systems in the UK there is still a huge problem with effluent entering rivers. A quick search of the BBC news web site for ’sewage discharge’ brings up about 100 quite recent articles on the subject. This one puts the problem in the European context. The problem exists for several reasons:
- some of the systems are still old or inadequate for increasing population densities.
- In some cases, discharges are deliberately allowed to happen. For instance many streams and rivers are licensed to receive overflow from drains a certain number of times per year, often during periods of high rainfall when surface water runoff overwhelms the drainage system. This is often abused
- In other cases the problem is chemicals which do not break down properly in the sewage works. Typical of this problem are hormones in the sewage, such as those produced by the female contraceptive pill. They damage fish populations by feminising the male fish as in this article.
- sometimes it is by accident like when 100 million litres of sewage leaked into the Firth of Forth in 2008
Handling waste water and sewage locally on site by means of composting toilets and grey water treatment can remove this problem. See Waste recycling
The other important way of preventing drains and sewers overflowing is SUDS
