Fiji installation of TJ3357 Treatment tank. Septic Treatment Tank in Auckland fabricated from 12 mm HMWPE and shipped to the beautiful Pacific Islands. This Auckland fabricated septic treatment tank is couple to a standard 4,500 ltr single stage septic tank with the highest output effluent quality which is used for irrigation of plants and gardens. These units come complete with irrigation field, filters, control box, high level alarm, 2 x isolation switches, aeration unit, clarification unit with sludge return and pump out unit. Inlets, outlets and are ready to plug in and go.