Hello, I have a few questions about septic systems and potentially which backwater valve is better. We had extremely heavy rains in Wisconsin and I have lived here about a year and even with moderate rains this has never happened. But after the 14+ inches in 12 hours the septic system started backing up into the house. So here are the questions: 1.) I had septic pumped after this as I had questions and guy that came out thinks maybe the water came through the "risers" on the first or second tanks since the high water alarm in the third tank did not go off so he said the drain-field probably wasn't the issue (I read that the drain field can be over saturated) . Is a backwater valve the best option. He said they could maybe seal each ring in the riser but they would practically have to dig everything up so probably not worth it. 2.) Does it make sense that only grey water came backup and not actual solid waste? When he was pumping I noticed solid waste was in first tank which is one connected to the house. 3.) Does anyone have a recommend backwater valve. The local plumber quoted this one : Sioux chief Pro , however I saw this one online and it seems like it would give more access if there is an issue with it : Main-Line full port . Is there a benefit to a normally open valve vs the sioux chief which I think is normally closed but opens to let waste through? I have a video if that is of any interest, as I went down there with rubber boots while it was happening and it seems the water just poured out of the drain went to about 3-4 inches in some areas. in retrospect I wish I would have looked in the tanks, but I was a bit stunned as it was happening and trying to make sure as the water encroached that everything was off the ground. The majority of standing water was gone by morning. Obviously the sulfur/sewer smell was not and I had a restoration company come out dry/sanitize everything after I ripped all carpet and 2 feet of drywall out. Thanks for any assistance.