This article examines the industrial wastes and environmental effects of Soviet technological development through the history of the Karelian Isthmus, a border territory that had previously been Finnish. Focusing primarily on the history of two large enterprises – the Svetogorskii (former Enso) and Sovetskii (former Johannes) pulp and paper making plants, the authors illustrate the polluting nature of the Soviet economy in the 1940s-1980s. We contend that from the very beginning, important as they were for the USSR, the enterprises of the Isthmus were built into a system of shortages of techniques and materials that contributed to the hectic fulfillment of the plan. Producing pulp and pulp-based products remained a priority during the whole Soviet period. On the level of industrial enterprises, the Soviet system revealed itself as incapable of solving the problem of pollution and wasting. After waste treatment facilities developed by Soviet engineers in the 1960s turned out to be inadequate for dealing with increasing pollution, the Soviet authorities called on Finnish companies to carry out substantial modernization of a few enterprises on the Isthmus. This helped the modernized plants remain functioning in the age of economic crisis at the end of the Soviet epoch. Old problems, however, such as shortages and lack of expertise, remained pivotal, while new sources of pollution, such as carbon emissions, appeared. As a result, the level of contamination was still high and led to negative environmental impacts.