DIY first flush diverter provides cleaner roof water

I have part one of the video on the diverter up on YouTube. It is here:

Some questions included how does the pipe seal if there is only glue on one part? How long are the pieces? The friction fit is enough to seal the parts that are not glued. Some pvc pipe does not fit exactly like the ones here so be aware of that. The od and id dimensions of all pvc are not identical. The video should give a good idea of how long to make the pieces. The inch and a quarter pipe (the one with the bevel is 2 inches long and the inch and a half pipe (the one on the bottom that will get holes drilled in it) is 10 inches long.

This entry was posted in slow sand water filter study and construction. Bookmark the permalink.

3 Responses to DIY first flush diverter provides cleaner roof water

  1. Matt says:

    So confused on how this works. Hope you don’t mind if I post a few random questions and thoughts here – I currently have a rain collections system that holds up to 165 gallons.
    Is rainwater collected from slate roof fairly safe – I understand things like air pollution may change that, but in general, is it basically safe?
    That leads me to the first flush diverter – should I be using one to help decrease contaminates? Should I go whole hog and create a slow sand filter? If so, how would I integrate that into my current system without doing a lot of dismantling of the current system?
    Also, how does the first flush work – is there a part 2 on this video? Is there a filter or screen in there? I’d love to see a super simple walk through on the whole thing from top to bottom.
    Thanks, I know that’s a lot to throw at you. Love what I’ve seen so far!

  2. Jason Perez says:

    Hello. I have built the first flush diverter, following your diagram for the most part. But since my diverter is connected to the gutter directly there is no air break between the gutter and the diverter opening. I have a LeafBeater screen at the gutter opening to screen out debris so I did not use any screens in the diverter input. Also since it has to be watertight I cemented it all together except for the last two outside pieces (2″ mpt and 2″-1.5″ adapter). I did use a 2″ union between the 4″ diverter input and the 4″ gutter pipe (in retrospect I should have not even used the 4″ input and gone straight from the union output to the diverter). I did not have much luck finding a 2+” o-ring so I just put silicone caulk around the 2″ mpt piece.

    Haven’t fully tested it yet since there has been no rain but I believe it will work fine.

    However, looking back on this, instead of drilling a hole in the top of the barrel for the 2″ mpt, why not just use one of the 2″ bung openings in the barrel (already threaded)?


  3. admin says:

    In response to both comments: I have not done any tests on water from a “slate” roof. Some of the articles I have read indicate that type of a surface may be better than composition (tar) roofing, or cedar roofing. It is important to know that contamination in roof water also originates from the surrounding area. The newest diverter/slow sand filter system here uses a leaf filter on the gutter and and two screens in the diverter. Tests have yet to go in (as of December 8, 2011 the filter has been operating for 15 days. Part 2 is on YouTube now with an explanation of how it works.

    As for the threaded top in the barrel, yes that works on some barrels – the threads match up exactly with the 2 inch adapter – on other barrels the threads don’t match. The newest diverter here uses the existing threaded hole, it does lean a bit to the side though.

Leave a Reply

Your email address will not be published. Required fields are marked *

28 + = thirty one