Hi:

I created a gravity flow leach bed in my backyard last summer to replace the existing unsightly raised bed that is eating up a majority of the yard. I kept the raised bed in place until I was sure the new bed functioned properly. With a recent thaw and large amount of rain, the new bed started backflowing back into the pump chamber, so I started using the raised bed again. Here's my question: Could the backflow issue be caused by 1. water flowing down from the raised bed 2. by poor landscaping ( I noticed that the earth used to backfill the new tile-bed runs has compacted, created ruts where the runs are, leaving water to pool there).
FYI, the soil is clay. I created three, 70 foot runs of perforated pipe, with used plenty of "clean" grave as backfill for about 18 inches of coverage under and over the pipes.