Abstract: A subsurface flow constructed wetland treats a variety of flowing wastewater effluents, provides pre-treatment clog-reducing wastewater sludge disintegration, and adds pre-treatment nutrients to wastewater so as to enhance microbial growth therein for improving the effectiveness and efficiency of wastewater treatment. The constructed wetland includes a wastewater treatment system having a flow intake, a pre-treatment nutrient addition chamber, and a wastewater flow divider. The flow divider further has a compressed air aerator in the bottom thereof. The constructed wetland includes one or more treatment cells having a soil, fine stone, organic and/or synthetic material substrate cap covering a further substrate media accommodating the wastewater to be treated. The substrate cap is populated by natural plants having root systems extending within the substrate.