Reed bed sewage treatment

[Mary Fisher]

What actually happens in such a system?

Mary

[John Borman]

In my understanding (And this comes from my own research as were looking at having one) Sewage is 1st separated from solids in a settling tank the resulting liquid is passed through the roots of reed, whereby Nitrogen fixation takes place in root nodules of the reeds (Same process as clover and any legumes) the water then passes out the other side clean and free from excessive nutrients and pollutants. The water is meant to be suitable for drinking, but cant say I would trust it. But it is suitable for discharge into water courses.

[Mary Fisher]

Thanks for that - but what happens to the solids?

I didn't realise there was a separate settling tank.

You say you were looking into it - any suggestions of where to look?

Mary

[Huge]

Shitty Mick comes and takes them away every April.

:o)

[Mary Fisher]

I Googled, it seems it's not really suitable for an inner-city semi ...

Pity, but it's very interesting anyway.

More than one system too. With tank, without tank. On one level, on more than one level. Permanent and semi-permanent. Pumped and not pumped.

Unless some things aren't mentioned until after one's got starry-eyed ...

:-)

Mary

[Andrew Gabriel]

I used to work at a small software company in Wheathampstead Herts. We were in what were once the offices of Murphy's Chemicals, who used to do insecticide R&D. Next to us was a large area of waste ground, which was apparently where Murphy's used to do their chemical processes. Sainsbury's bought this to build a large supermarket, but then failed to get planning permission. Then it was discovered this site was extremely badly contaminated and was contaminating an underground aquifer which had been detected tens of miles away. Sainsbury's now had to foot the bill for decontaminating the site, being the current owners. Strangely, the local council could find no connection between the company called Murphy's Chemicals in the insecticide business which occupied an office on part of the former site and the Murphy's Chemicals which had badly poluted the ground there, so it was not possible to get them to clean up the site.

Analysis of the contaminants revealed many known insecticides such as DDT, but also a lot of unknown chemicals, presumably things which were not developed through to being products due to some problem with them. The council tried to find former workers who might be able to shed some light, but strangely couldn't find any who were still alive -- it was not so long ago that they would have expected them all to be dead by then. Many local residents recalled a large fire at the factory in the 1950's or 1960's which lasted some time (days I think), and many chemical drums were bulldozed into large holes in the ground to prevent them exploding in the fire.

Anyway, to clean the site up, all the topsoil was removed and taken somewhere miles away where it was incinerated at very high temperatures. The lorries leaving the site had to be cleaned down just like in the foot'n'mouth era to prevent any of the contaminated soil dropping outside the site. Then large amounts of lime were ploughed into the remaining soil. Half of the site was then sold off for housing development (I bet they don't get any insects in their vegetable patches;-), and the other half was turned into a giant reed bed with pumps drawing up the contaminated water from deep wells, and letting it filter back through the reeds which apparently were chosen for their ability to absorb all the nasty chemical contaminants. It was expected this would have to operate for at least 25 years.

Just when the reed bed was finished being constructed (late

1990's), there was a change in the law that forbid discharging contaminated water into an underground aquifer. Since the reeds don't completely decontaminate the water in one pass, the discharge counts as contaminated water and would thus become illegal, even though the water originally came from the aquifer and the discharge was less contaminated that the original. This ended up putting the whole project on hold, but they did somehow get around this restriction, and I believe the reed bed has been operating for a few years now.

[John Borman]

Yeah I believe you need to pass th ewater through two separate reed beds to allow discharge into a water course

[Howard Neil]

See:-

[Rick]

You need an environment agency licence to discharge from one of these things, and you won't get one if mains sewage is avaiable.

The stuff is sort-of drinkable, my packaged treatment unit discharges directly into a river (I have a licencce), where the water board pump water out of the river, and give it to the scousers .........

The "solids" need to be pumped out every year, and the "mummies nappies" really are a bit of a nightmare........

Rick

[Mary Fisher]

?

Mary

[Pete C]

Hi,

Willow beds are another alternative, the willow can be harvested and also attracts bees.

cheers, Pete.

[Andy Hall]

Vampire's teabags, jammers,.......

[Mary Fisher]

... ?

Nope ...

[Mary Fisher]

I'm all for that. But not all willow produces pollen attractive to bees.

Willow - most varieties - are wonderful plants.

Mary

[Andrew Chesters]

Sanitary towels

[Mary Fisher]

Oh. I'd forgotten.

Why do they go into reed beds?

Mary

[Rick]

They go down the loo - they shouln't but they doo, and whatever treatment system there is has to deal with them. So these dicussions about people leaving the private sewage treatment systems years between pump outs seem a bit mad, these things do not appear to be very treatable.

Rick

[Dave Liquorice]

Female sanitory products, internal or external. Though they should not be ending up in the septic tank...

"Do not flush anything down this toilet that has not passed through you first (other than toilet paper)."

[Mary Fisher]

That's irresponsible and stupid. surely people who are caring enough to have reed beds wouldn't? Oh, there are commercial systmes toowhere the public uses them. Surely there are notices?

Mind you, there are no-smoking notices, no speeding notices ...

Yes. I'm very sorry to read that.

Mary

[Mary Fisher]

I'm way past using those things ... sphagnum moss was good enough in my day and is fully biodegradable ... but a daughter has a septic tank and we're not even allowed to use washing up liquid ...

Mary