My understanding is that shallow-rooted perennials are considered safe to plant over the leach field; any plant which does not extend its root systems more than a maximum of about 15" inches downward. So why not cover the pipe with a fake rock, and then put in a group of plants, a vignette to enjoy. How to arrange the vignette depends on where the pipe is -- if it's right in the middle of the lawn, make an island bed: surround the pipe with taller perennials such as JoePye weed and then encircle with perennials, bulbs and annuals of decreasing height. By using those which bloom at different times, and mixing in differing plant shapes and leaf forms you can turn an eyesore into eye candy for much of the year. Check with your local nursery, but I think some of the very dwarf evergreens are sufficiently shallow-rooted. If so, do use one or two to provide winter color and concealment. Also, check and see if you are permitted to paint the pipe; a dark green would be easier to ignore.

You could also fake the eye: Put a birdbath very close to the pipe and plant short vines [such as mandevilla or nasturtiums or morning glories] to climb both pipe and birdbath support; or, if the pipe is short enough, surround with daylilies. Just don't forget to put in a stepping-stone path so you can keep the birdbath filled!

Ah.. good ideas. You've got me thinking now!!!!

I had posted in an other forum about planting some Love-Lies-Bleeding around it, but I love your ideas to. And you know what, I never even thought of painting the ugly thing! I live wayyy out in the country and you can't even see my house from the road, so zoning issues is not a problem! I can paint it bright orange if I wanted to... but I wont. I'll do the green like you say.

Thanks for the help!