Rainwater catchment--First Wash Water trap?

[GoodDaughter]

I am designing a rainwater catchment system for a small house, and plan to use a 'first wash' water trap. The ones I have seen are made from a 4" pvc pipe with a floating ball and seat system, where the pipe fills with the first water to wash off the roof and gutters and as the pipe fills, a ball floats up and is seated against a gasket thing which seals the 4" pipe so the rest of the water flow will be directed into the storage tank. There is a slow release valve at the bottom of the pipe to slowly let the water drip out.

Now here is my question... I have found a couple of places online that sell these kits that are a ball/seat gasket and valve on a pipe, and they are $80 and up.

Can these be reliably made by a DIY'er? I would prefer this ball/seat gasket system because it prevents the dirty 'first wash' water in the pipe from siphoning back out into the rest of the water as it passes by.

[bookwormom]

we have a cistern for laundry and bathing. before the water goes in the cistern it goes through a home made filter, consisting of a five gallon bucket with a grid inside,which holds a few layers of quilt batting. the water off the roof runs through this filter first, in thetop and out the bottom. Of course you have to replace the filter material every so often.

[DavidOH]

I have not seen the type you describe.

This is the only kind I have seen:
http://www.gaiam.com/product/save-the-rain+diverter.do?search=basic&keyword=water+divert er&sortby=bestSellers&page=1

[GoodDaughter]

I tried to look at the link, but it would not finish loading for me. It would start to load and then stop, never getting further than a blank page ???

[hardrock]

GoodDaughter,

I've been designing a catchment system for the shop and house that (hopefully) will get built sometime soon.

My biggest problem so far is the first wash (roof wash).
I've looked at some of the gadgets out there, and none of them look real reliable to me.
I wasn't looking to just collect rain for the garden and livestock, but for the whole house, in lieu of a conventional well.
My approach is a little costly up front, but I believe RW catchment is the only way to insure a safe and reliable source of potable water. (properly treated)
In the long run, it shouldn't cost any more than a regular well, and being isolated from all other water supplies, cross contamination is virtually eliminated.

Assuming your house has good existing guttering that collects at a central point, I'd go with a PVC downspout arrangement that had an oversized resevoir to catch the first roof wash. (the heaviest debris)
Quite a bit larger than 4", say maybe, an 8" piece from eve to just above ground level. You can use a threaded collar/plug at the bottom for a cleanout.
You should be able to find a reducer that will go from 8" to match the standard guttering.
Near the top, you can take off with your 4" out the side and go back down again to your cistern, buried tank, barrel, etc.
If you screen the 4" at the top, as it leaves the resevior, it should hold back anything floating to the top.
Just make "cleanout" a part of your regular chores after a good rain.

From there, I had planned to go into a buried poly tank about 75-100 gal. or so as a secondary settlement tank that overflowed into the main supply tank, that would then overflow back into my old cistern.
This secondary wash tank should go a long time before needing to be accessed for a complete cleaning.
(Probably not as often as the septic system.)
A simple sump pump would keep it emptied between rains, and that can serve livestock, garden, etc....
Anything pulled form the main supply tank, via a regular submersible pump goes to the house for treatment, and I can pull from the pre-tank, or the cistern for non-potable use.
If appearance is a concern, that PVC can be sprayed with enamel (outside surfaces only) to match your trim/gutters. ;)
Hope this gives you some ideas.

[Quietgentleman]

Forget the ball and seal system put yourself a stand pipe with a outlet at the bottom to drain your stand pipe after it quits raining. If you really want clean water you two in series. But make sure you are able to open the bottom up to clean out the stand pipes once in awhile. Then just before it enters your catchment system have a filter to catch the leaves and material that floats.

QGM