put a clean out right before that turn so when it plugs you just open the clean out and shove a hose in there with a fire nozzle stand back and turn it on, or cut new hole in tank its easy take a drill make bunch small holes chisel it out put elbow on inside and cement up. takes about and hour.
Here is trick to make your drain field last forever on the outlet side of the tank in the distribution box cut hole in the top and bring a piece of 1.5 tubing straight up with loose cap on top every 6 month put in a pound of copper sulfate like you buy at the feed stores blue stuff, it will prevent roots from clogging the drain field, I've got fields 40 years old and still working.
Also don't use lots of bleach and a running toilet will screw up the tanks bio digestion, add bio agent down the toilet regularly also. The way tank works is the solids have be digested and output line is below the surface level so only liquids reach the field, Have pulled the lid on many a tank and pumped them out you be surprised what you find on the bottom.
Never pay to have your field dug up, most times it roots in the distribution box, dig it up yourself cut roots out and maybe three feet of field replaced pour a lot copper sulfate in the fields. Go to the rental place rent a ground water pump and extra long discharge hose and pump it into the flowers. They will bloom like crazy, don't tell the rental place what your doing they won't rent it you. In some places pumping out the tank might be a rule breaker. In that case wait till dark and run the pump.