One year ago, a municipality banned dishwasher detergents containing phosphates  Anecdotal evidence indicates that many residents continued to use detergents containing phosphates; they just purchased them from out-of-town stores
However, it is clear that some residents did switch to phosphate-free detergents, since phosphate pollution from the municipal wastewater treatment plant decreased significantly in the past year
What pollutants, if any, are present in phosphate-free dishwashing detergents.