A liquid treatment system is provided having a vault that contains a treatment chamber and an outflow chamber. The treatment chamber may have a filtration media layer containing media that treats liquid as it descends through the filtration media layer, where it will accumulate in a porous layer or open space. The liquid will then be directed through the plurality of pipes to the outflow chamber, where the treated liquid is further directed to outside the system. Accumulated debris settled at the bottom of the treatment chamber may be flushed out by a spray bar.