The entrance of untreated wastewater or disposal leachate to water resources such as surface water, groundwater or irrigation water increases the risk of contaminant accumulation. Removal or deduction of water contaminant concentration is then crucial before entering water to the natural resources or its transfusion directly to the soil as irrigation water. Four studies were carried out in a pilot plant to evaluate the effect of natural zeolite to decrease chemical and biological index of compost factory leachate. Land treatment was considered as the main strategy; however, some pounding and column experiment was implemented as well. Wastewater chemical and biological indexes were analyzed. These indexes consisted of Na, K, Mg, Ca, Co₃, HCO₃, Ni, Cd, Pb, Cr, chemical oxygen demand (COD), fecal coliform and total coliform (TC). In addition, soil was analyzed for EC, pH …