A subsurface drip wastewater disposal system and method are disclosed that eliminate the need for headworks, reduce the risk of damage to the system, and permit optimal pump sizing by simultaneously dosing, flushing the pipe network and flushing the filter. A tank and pump package provide effluent under pressure to the field piping network comprising a supply manifold, a return manifold, and a plurality of emitter lines. A discharge filter that is capable of simultaneous filtering and flushing is provided on the discharge line, and a first flow restrictor is provided on the filter flush return line. Effluent is discharged at a rate and pressure that permits simultaneous pipe flushing and dosing, with the return manifold returning to the tank through a field return line having a second flow restrictor. The size of the first and second flow restrictors is selected to provide the desired flow splits.