E.coli bacteria and reed bed

Dear Permaculturalists,

I suppose many of you already knew the panic in Japan caused by a colon
bacillus "O-157". In Sakai City, Osaka area, more than 6,000 pupils
and teachers have been infected with it and more than 70 are still seriously
ill. Nearly 10 people have been killed by it all over Japan.
In the case of Sakai City, it had beenspread by school lunch service.

Some past reports written in the united states had indicated
swimming is also dangerous under some conditions.
So many kindergartens and some local governments have closed their
swimming pools. And I heard yesterday on radio, a local government
discharged water from ponds in a city park not to spread further infection
by swimming. What a hot summer in Japan!

By the way, if you have "Permaculture Designers* Manual" by Bill Mollison,
please open page 179 and see Figure 7.38.

You can find a description about NATURAL SWIMMING POOLS.

> Slow flow through reed bed is essential,
> as are tests for the presence of E. Coli bacteria. 

I want to know more about this point.
If you know something about the effect of reed bed,
please post your knowledge or experience here.
Both scientific and non-scientific explanations are welcomed.
Reed bed may be more effective than chlorine.


Hiko Yamashita
1-45-11 Kamo, Sawara-ku, Fukuoka 814-01, Japan
Email: TBC03531@niftyserve.or.jp