There is are two ways to avoid the SCAM of a new drinfield. Both are detailed in my special report.
Your problem is caused by clogged up drain field pipes. The pipes get so clogged up that they block the flow of water.
1) There are companies in business that specialize in using a high pressure water pump to blast out the drain field pipes, then they use air pressure to "crack" the field. I have videos & details of this in my file. You can add chemicals to the drainfield ( Not the tank )
2) Add a LOT of worms to your drainfield. Australia uses worms extensively for drainfield clearing.