This 525 gallon septic pump tank is constructed with rotationally molded polyethylene resin. It's seamless construction makes it durable and resistant to cracks, chips, and ruptures. The poly tank was made with FDA approved resin that complies with FDA standards 21 CFR 177.1520 (1) 3.1 and 3.2 for waste water storage.The 525 gallon septic pump tank features one 20" gasketed manway. Installation requires no backfill.Norwesco provides a 3 year manufacturer warranty to their septic tanks. There are additional options available for risers and septic tank sizes (ranging from 200 to 3,525 gallon).