No special backfill or water filling required during installation;May be pumped dry during pump-outs;May be installed with 6" to 36" of cover;Suitable for use as a septic tank or pump tank and may also be used for non-potable water;Access openings and lids accept NexGenD2 manhole extension, double wall corrugated pipe, and ribbed PVC pipe;Tanks are available with PVC tees and gaskets supplied;Available in the sizes you need, 750, 1000, 1250, and 1500 gallon capacity