I have a septic system that has gone into partial failure. The piping coming out of my tank goes into a distribution box that separates the leach field into two halves. When switching to one half, it only takes about 24 - 36 hours for it to back up into the distribution box. I am using the "good" half the majority of the time but I'm worried about over use. Is there any way I can bring the poor flowing side back to life? Are there additives or treatments known to be effective in this situation? The system itself was installed in 1987 for a three bedroom home occupied by three people. I have always pumped out every 1 1/2 to 2 years. Thank you.