AWWA ACE62954

This slide presentation outlines a project to treat waste filter backwash and sedimentation/coagulation sludges to meet NPDES permit limits at one of Detroit's water treatment plants (WTPs). Project drivers included: need to increase state approved plant capacity rating from 300 mgd to 400 mgd; change to Modified Direct Filtration Operation; MDEQ concerns over recycle of contaminants through waste backwash water; and, improved raw water quality by eliminating recycled filter backwash water. Design challenges included: meet DWSD's requirements for fail safe operation/redundancy; design and construct a low maintenance facility that essentially runs itself, so staff can focus more on treating drinking water than wastewater; and, regulatory agency reviewing project as a drinking water facility rather than the wastewater project. Beneficial features included: reduced solids loading to sedimentation basins resulting in less material to manually clean (O&M Cost Savings); simple, easy to operate system; redundancy; and, fail safe operation. Includes figures.