Your description is of the classic symptons of a failing drainfield due to buildup of anaerobic sludge. This is the situation Septic-Scrub can help. Look at the addition directions on this WEB page. 

Your field is saturated with water and the water is ponding at the point of least resistence, the septic tank. The most important point to help ensure a successful treatment is to dewater the field first. If you live in an urban area, this can be economically done by having your septic tank pumped and then pumping the water from the field back into the spetic tank.

Please call if you have any questions.