, how can I construct a 3x3x4 septic tank in an area that is fully water logged.the sewage tank always fills every 2days and we have spent a lot of money evacuating and we are about giving up. Thanks for your help

Better find another location. If ground is water logged the drain field will never work. I take it that you mean the hole for the tank fills up with water in two days. If so, it ain't going to to work.

A tank 3x3x4 will hold approximately 270 gallons. The standard size septic tank for a single family residence is 1000 gallons.

All tanks and fields should first pass a perc test. Every place I have worked required that the county building department view the perc test results and approve the plan. Where are you located?