The research attempts to answer the question whether enough trained men will be available who are willing to work in the waste water treatment industry under present and projected economic conditions. The quantity of waste water treatment plant operators was postulated to be a function of wages, alternative wages, population, unemployment, and recent hirings. Simple equation, linear regression procedures based on cross sectional data, were used to estimate the operator supply functions. The analysis involves two variables that appear to be significant in explaining the quantity of operators supplied, that is, wages and population. Projections for two regions in Indiana and for the State as a whole for 1972 suggest managers have several alternatives to insure that enough skilled and trained operators will be available. (WRSIC abstract)