In 1997 I purchased a home built in 1930 . It is a lake-front "cottage" that we are converting into a year-round home. I have had problems with the drywell. The well itself is a steel tank that did not have an access hole. I cut a 2'x2' hole in the top and drained the tank. 

It looks like it hold about 300 gallons. The tank was full and not draining. There was a lot of gray sludge at the bottom. There is also a drain pipe that looks like it empties into the ground. The pipes are ceramic and about a foot long. They were clogged with roots.

My septic system is also archaic. It is two 150 gallon crocks also with the ceramic pipes from the second crock into the ground.

I have experienced backups with both systems. I replaced the ceramice pipes with perforated PVC and added gravel. About a year after this remedy I experienced the same problem with the drywell. When I dug up my newly added PVC outlets I noticed that there was a build up of a black oily substance.

There is talk of sewer sytems for our area within two years. I would like to avoid putting in a whole new system when it will be obsolete in that short of time. Any suggestions???