I received another interesting letter concerning the deterioration of concrete septic tanks, particularly compartmented tanks. The letter from Lupe De la Garza of Texas may explain the reason for some of the concrete tank deterioration. He sent along a diagram that I’ve included here, with the following comments:
“This tank (of concrete construction, shown in the accompanying diagram) is what I use in Texas. I use the No. 1 tee fitting allowing air to flow from one chamber to another. We have no troubles with these tanks, but if you build a tank and use the No. 2 fitting and not
