Eleven home water systems were tested representing six different types of filtering systems. Tests were made for Sulfates, Nitrates, Phosphate, Iron and Escherichia coli and Enterobacter aerogenes before and after passing through a home treatment system. All of the systems removed iron adequately but had little effect on the removal of nitrates, phosphates, sulfates or control of pH. Since none of the ground waters was contaminated by coli- forms, nothing was established regarding the effectiveness of bacterial removal by these systems