At its Jan. 3, 2011 meeting, the Ann Arbor city council approved a $1,384,350 amendment to its contract with CDM Michigan, Inc. for its work on the city’s footing drain disconnection (FDD) program. The FDD program was put in place in the early 2000s as a strategy for mitigating against sanitary sewer backups in some residents’ basements during heavy rains. Part of the load on the sanitary sewer system is due to storm water from footing drains that is led into the sanitary system. The aim of the FDD program is to disconnect these footing drains from the sanitary system, because the water does not need treatment and adds needlessly to the volume of water in the sanitary system.
To help fund the FDD program, the city requires that builders of projects adding to the sanitary sewage volume balance out that additional volume by removing the equivalent of 1.2 times their additional volume from elsewhere in the system – through footing drain disconnects.
Recent renovations to the University of Michigan football stadium added to the load on the sanitary sewage system. So the university paid the city for the equivalent of 140 disconnections at $10,040 per disconnection for a total of $1,405,600. The city is using $1,275,080 of that sum for the current contract amendment and appropriating $109,270 from its capital budget. The balance of the UM money – the equivalent of 13 disconnections – can be used at the city council’s discretion.
Some of the work to be funded by this amendment will be undertaken along Iroquois Place, where several homes had sewage backups during the June 6, 2010 heavy rains.
This brief was filed from the boardroom in the Washtenaw County administration building, where the council is meeting due to renovations in the city hall building. A more detailed report will follow: [link]