You may also want to think about reducing the amount of water your putting into your septic system. For me, the biggest contributor was the washing machine. We ended up buying a new front loading washer. It uses, I'm guessing, 80% less water to run. It's amazing how much water it DOESN'T use. I also installed a dual flush kit on our 3 toilets. They have been working great and are saving a decent amount of water. You can also save water with low flow faucets and shower heads.