The problem of wastewater disposal affects not only third countries, but also world giants such as China or the United States of America. The European Union and the Commonwealth of Independent States are no exception. The increasing use of organophosphate pesticides requires the search for new, more efficient and cheaper ways to dispose of their residual amounts. The existing methods of disposal of toxic waste are costly, ineffective, and environmentally hazardous. The optimal solution can be a chemical system for decontamination of wastewater directly at the place of their origin, for example, at the production of pesticide formulations and agro-industrial facilities. This article presents the results of studying the effectiveness of the chemical system for the destruction of organophosphorus compounds based on hydrogen peroxide and potassium hydroxide in relation to dimethoate. The results of the scaling of the decontamination process are presented and an installation for the technological process of wastewater disposal is proposed. The research results show a high reactivity of the system under study and a high efficiency level of the described technological process.