IMPACTS OF SEWERS ON GROUNDWATER QUALITY

This paper summarizes the findings of a recent research project on gro undwater contamination from leaking sewers, which was completed for th e Construction Industry Research and Information Association. Fifty-fo ur incidents were identified in England and Wales from a combined ques tionnaire survey and literature review. In addition to recorded incide nts, the poor quality of many urban groundwaters suggests some effects from leaking sewers, Age is considered to be the most significant cha racteristic governing leakage from sewers; ground conditions (predomin antly aquifer vulnerability) and usage (private versus public ownershi p) are also important factors relating to the likelihood of groundwate r pollution from leaking sewers. Recommended strategies for reducing g roundwater contamination include (a) modification of existing criteria for the sen ice performance grading of existing sewers, (b) improved construction of new sewers in appropriate areas, (c) increased groundw ater monitoring, and (d) risk assessments for new groundwater sources.