Developing Industrial Water Pollution Control Programs

FROM THE INTRODUCTION Over the past decade, industrial water pollution control has undergone vast changes. Public Law 92-500 passed in 1972 primarily targeted conventional pollutants such as Biochemical Oxygen Demand (BOD) and suspended solids and as a result wastewater treatment plants were designed to meet these objectives. In recent years volatile organics, priority pollutants, aquatic toxicity and some heavy metals have received attention in specific industrial effluents. In some cases nitrogen and phosphorus will have specific effluent limitations. If the wastewater contains volatile organics such as benzene or toluene, these organics must be removed prior to biological treatment or basins must be covered with off-gas treatment. The technology choice to meet these objectives in a cost-effective manner will be site specific. In 1976 EPA established effluent limitations for priority pollutants in the organic chemicals, plastics and synthetic fibre industries (OCPSF). These are pollutant specific guidelines expressed as an effluent concentration. Depending on the specific chemical involved, the biological treatment process or a source treatment technology may provide the most economical solution. Aquatic toxicity poses a major problem in industrial water pollution control. Because it is frequently non-specific it is difficult to identify appropriate cost effective technologies. As a general rule, biological treatment should be the first option with more costly physical chemical technologies employed only in cases where the toxicity-causing chemicals are non-biodegradable.