Reactive Nitrogent (Nr) is produced from natural and for human activity, the use of fuel, the activities of industry, and agriculture. Nr from agriculture is used to produce food crops, but excess Nr will have an impact on the surrounding land. Landfill also generates Nr from the decomposition of waste which then releases leachate containing Nr. This study aims to determine the value of Nr generated by landfills, the effect of Nr on the environment, and the performance of Nr when used in CW. Review papers are collected from several studies and publications that have been conducted or published. Nr commonly found in leachate landfills are NH4, NH3, NO2, and NO3. The performance Nr present in landfill leachate at CW can be used for proper plant development and growth, which significantly increases and enhances its quality and yield by playing an important role in the biochemical and physiological functions of plants. In addition, the content of hazardous substances in landfill leachate can also be processed using CW. This review paper discusses the effects of Nr from human activities ending up in landfills. Landfill leachate with Nr content can be used in CW for plant growth.