Using State water withdrawals and parameters defining industrial activity, estimates were made of the total self-supplied industrial withdrawal in each Standard Metropolitan Statistical Area (SMSA) across the nation. A SMSA is an area delineated to include at least one city of 50,000 or more inhabitants. Self-supplied SMSA industrial withdrawals (other than for thermoelectric power) in 1964 were at least 63% of the combined public plus self-supplied non-thermoelectric power industrial withdrawals in SMSA's. Public-controlled water supplies appear to account for a relatively small portion of the water withdrawn in metropolitan USA. The findings lead to the suggestion that at least half of the national water pollution problem originates in SMSA's, and to the conclusion that schemes for improving the management of water resources in metropolitan areas that do not take into account the significant role of private interests must be regarded as only partial potential remedies. There is a clear need for quantification of industrial water withdrawals and industrial wastewater volumes and effluent qualities in metropolitan areas.