The city of Ann Arbor has reported that on the evening of Sept. 20, 2013, it discovered that sewage was coming to the surface and flowing into a drainage swale that leads to First Sister Lake on the city’s west side, and ultimately to the Huron River. According to the city’s press release, the discharge was attributed to an infiltration of tree roots and debris that had caused a sanitary sewer line to clog.
In the description provided in the press release, city crews were notified around 6:30 p.m. Friday evening that a strong smell was coming from behind a shopping complex at Jackson Road and I-94. The amount of the flow was estimated to be comparable to about half the flow of a garden hose. The time to clear the obstruction, according to the city, was under an hour.
The city’s press release indicates that the amount of sewage that overflowed is not known, nor is it known how long the clog had existed.
According to the press release, the city has notified the Michigan Dept. of Environmental Quality to inform the state agency about the incident. It’s the third similar incident, in different parts of the city, which has been reported since the end of August.
The Chronicle has inquired with the city if the three incidents reflect an increase in frequency of such events, or a decision to adopt a new practice of issuing press releases for every incident.
Updated Sept. 23, 2013 3:30 p.m:
According to a statement from city of Ann Arbor water quality manager Jennifer Lawson, the change in standard operating procedure was to begin notifying all media outlets of such incidents, not just The Ann Arbor News. According to the statement, sent to media on Sept. 23, 2013, the city maintains almost 400 miles of sanitary sewer pipe, 68% of which was built in the 1960s or earlier.
The statement from Lawson also indicates that for the 2013 reporting period (October 2012 – September 2013) the following sanitary sewer overflows were documented:
- 12-19-2012 Maple Village (privately owned sewer backup in parking lot of Maple Village – washed into stormwater system, ultimately to the Huron River)
- 12-24-2012 Nichols Arboretum (did not reach Waters of the State)
- 06-27-2013 237 Pineview Court (minimal amount – washed into stormwater system, ultimately to the Huron River)
- 06-27-2013 WWTP (10,000 gallons – Huron River)
- 08-29-2013 Nichols Arboretum (unknown amount – discharged to the Huron River)
- 09-16-2013 Pauline/Maple (minimal amount – washed into stormwater system, ultimately to the Huron River)
- 09-20-2013 Fuller Court (did not reach Waters of the State)
- 09-20-2013 Jackson/I-94 (unknown amount – discharged to the Huron River)