I have been told a water treatment plant - I don't really know what that is, could anyone elaborate?

Also would to cost of collecting & storing rain water or waste water to flush five toilets be practical? - baring in mind I would have to dig soak-aways if I don't re-use it

<<sorry don't know if baring is spelt right....I struggle with spellings>>

They are most likely thinking of something like a Klargester or Acorn:

http://www.ohel.co.uk/products/biodisc_ba-bax-bb.html?gclid=CJumxra8mpMCFQyD1Qodsm91ng
http://www.acornsystems.com/

You would need to get one of the correct size and also pay attention to servicing and de-sludging frequency as well as the energy input required.

Sizing looks difficult
30 children - 10 of whom will be in nappies (n average)
6 staff
Washing machine & dishwasher
No shower or bath

That won't be easy to work out

Katymac - has the existing nursery got a water meter? Check water consumption as that will roughly equal the waste you have to dispose of. Plus rainwater if you don't harvest it.

Katymac, how much land is there available?

Richardt,

Thanks for the information on the reed bed option.... I have been looking into this and think we may head this way. How did you get it sized by the way? We have the space, but glad for any anecdotes,

Neil

Oh dear - that sounds bad

Can I flush the toilets with it?

Will grey water & rainwater recycling help this or not?

Umm I'm about 1/4 mile from a river

That's next door

Mine will be day-care - I just don't have access to an existing one (iyswim)

I think I will have to do some careful research

If I have a water treatment plant or a septic tank will the water coming out of either would be good enough to flush the toilet with?

If I recycle rainwater & flush the toilet with this water will I still need soakaways?

You'll need soakaways as it would be impractical/costly to size the rainwater tanks to be large enough never to overflow.

The calculation is pretty simple:

for every 1mm of rainfall each square meter of roof collects 1 liter of rainwater.

So if your average annual rainfall is, say, 1200mm and you have 30m2 of roof area to collect from then you have:

1200 x 30 = 36,000 liters of potential water to collect each year.

If a thunderstorm dumps 50mm of rain in one hour on the same size roof you will have:

50 x 30 = 1500 liters to handle. That's a lot of water and if this happens when your tanks are already full then it will all have to overflow to a soakaway.

The Met Office website has details of average rainfall for different parts of the UK with monthly figures too.

You'll probably need to decide how many days without rain you can afford to size the tank to support you through, although cost will be a factor that will require you to compromise and switch to mains water to cover short periods of drought.

You might find that what they suggest is a little impractical.

The outlet from a treatment plant will be at least 750mm below ground level. To get this to gravity feed into the rainwater tank will mean having an inlet lower than this (how far below depends on how far apart the two will be). This means a deeper hole than otherwise required for the rainwater tank plus, maybe, concrete rings for manhole access, etc.

You can get pumped outlet treatment plants, so you're not relying on gravity, but they cost more to buy and to run - consuming electricity which isn't what we want.