large Septic Tank installation specifications

[bbakk]

can anyone give me a good specification for the installation of a 10,000 gallon septic tank ... i.e. what type of backfill should I spec out and or any instructions to give to the contractor to make sure it is installed correctly (the septic tank will be part of a STEP system) ... thank you in advance ...

BRB

 

[CarlB]

This size is similar to many UST's (underground storage tanks) for fuel. You could look at spec's available from the Steel Tank Institute website (don't know it off-hand). The beeding they spec may be finer than you need as protection of coatings is important. I would think you want a granular material, maybe 3" max, bring up backfill uniformly. If not in a load bearing area, 90% of modified proctor sufficient. And consider a hold-down if you have a shallow water table.