An initial analysis of the economic impact of proposed water effluent guidelines upon the organic chemicals industry (SIC 2815/2865 and 2818/2869) was performed based on abatement cost data supplied by the EPA. In view of limited cost data available, the impact was based on best practicable control technology currently available. On this basis, with 75% coverage of the industry, the following specific chemicals appear to face significant water pollution control problems: ethylene glycol, caprolactam, methanol, acetic acid, acetone, phenol, aniline, coal tar products, ethyl cellulose, dyes and pigments, and unformulated pesticides. Extrapolating to the entire industry, minimum total annual cost by 1977 would be an estimated $194 million with the maximum cost $590 million. On the basis of maximum cost, a very severe fixed capital requirement of $576 million per annum over the period 1973-1977 would be imposed on the industry. This is about 72% of the 1972 capital investment by the industry. On the minimum impact basis, prices would rise by 1.6% over the five-year period and profits after taxes in years of full compliance depressed by 8% below that of the 1972 base year.