What is the procedure with installing new leach lines on a existing septic system. My leach lines are some 35 years old and in need of replacement and extended. The original lines aren't very long. We don't even have all the house hooked up to it due to not having enough leach line to take on the extra water usage. When the house was built it was only designed for 1 bathroom and a kitchen sink. Since then, we have added a utility room with a washer and since the original leach line is only about 20 - 30 ft. we figure it wouldn't handle all the extra water we use in the washer. So ever since we have had the washer and the kitchen sink drain out back directly onto the ground. The septic tank is plenty big enough, I'm just needing to replace the existing clay pipe with new and make the drainage ditch some 300' long so I can hook the washer, kitchen sink, and hopefully a new bathroom addition some day. I was going to have this done by a professional but after 2 months of promises I'm giving up hope on him. I'm thinking since I glue a lot of pvc together in my electrical trade then the task should be quit similar. As far as the gluing peaces together. But just what is the procedure? Does the ditch need to be at least 2 feet deep, or deeper? How many inches of rock gravel do I place in the bottom of the ditch? After placing the leach lines on top of the gravel, do I place something on top of the lines before filling in with dirt? Any help will be appreciated. Thankyou.