Regional planning in the past 30 years and more ignored the dynamics of intensified development of suburban regions. So, with increasing urbanization of the region the objects of disposal of solid household wastes containing toxic garbage gases capable of inflicting harm to the environment and human health became a part of the urban environment. This article reports the results of study of the component composition of the gases of the garbage dumping ground located in the Leningrad Oblast (region) and discusses the problems of monitoring gas emissions and possible cryptic ecological risks of formation of methylmercury as a constituent of the emitted garbage biogas.