This inventory updates a long list of earlier inventories by other regulatory agencies to chronicle the deep waste-injection well situation. As the effects of subsurface pollution are not well understood, it was necessary to gather all data possible regarding practices which may introduce materials to the subsurface. Information was collected for industrial and municipal deep well-injection systems using saline aquifers. Excluded from the inventory were oil field brine injection wells, storage wells and private domestic sewage wells. Comprehensive geologic settings, technical specifications, and operating procedures were recorded and stored in the STORET computer file. The collected data was assessed to determine current trends. A wide variety of waste waters are injected, including chemicals, petrochemicals, pharmaceutical products, hydrocarbon refining by-products, metal manufacturing wastes, and municipal sewage.