The thesis analyzed the evolution of the environmental parameters of the surface water of the Nanay River, as an effect related to the Construction of the Nanay Bridge and Access Viaducts, in the district of Punchana, province of Maynas. The study is quantitative of the observational, descriptive, analytical type. The information was obtained from the quarterly environmental monitoring of 2018 - 2021 expressed in the results of the physicochemical, microbiological, total metal analyzes and direct field measurements of the most important environmental parameters of the water carried out by the Construction Company Consorcio Puentes de Loreto. The physicochemical results show that in the concentration parameters of oils and fats, nitrates (NO3), hydrocarbons in surface water, their concentration levels are below the Environmental Quality Standards for water in each parameter evaluated. Whi...