Grand Rapids sewer system upgrades improve water quality, problems remain for Grand River Watershed
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EmailRecent study of Grand River fecal contamination found ‘no risk’ levels of human sewage in Ottawa County waters. City of Grand Rapids’ CSOs have been all but eliminated, but upstream tributaries continue to contribute fecal contamination to the Grand River.
A recent study found extremely low levels of human fecal bacteria in the Grand River. This is good news, but this was a dry summer. Lack of rain tends to concentrate bacteria from constant sources such as illicit connections and leaky septic fields – so 2012 was a good year to spot problems like these. However, combined sewer overflows (CSOs) only happen during heavy rains and other inputs from agricultural sources are generally lower under dry conditions. Did this year’s drought mask the usual problems from upstream CSOs?
At least as far as Grand Rapids is concerned, probably not. Deputy City Manager Eric DeLong and Environmental Services Manager Mike Lunn gave an overview of the improvements made by the City of Grand Rapids in recent years at the Ottawa County Water Quality Water Quality Forum, which is presented in cooperation with Michigan State University Extension.
Prior to the 1970s, Grand Rapids discharged 8-12 billion gallons of untreated sewage into the Grand, annually. Improvements have brought this down by 99.8 percent. Separation of combined sewers is expensive and time consuming as it requires digging up streets to replace the pipes that run beneath them. To date, the sewer project has fixed CSO problems in 52 of 59 historic CSO areas at a cost of $217 million, with four more slated for completion by 2016.
Grand Rapids contributed 1.7 million gallons of CSO effluent into the Grand River in 2010. Although this is still a lot of water, it pales in comparison to the 337 million gallons contributed by Lansing in the same year. Furthermore, although Grand Rapids CSO effluent is not treated in the same manner as sanitary sewage, much of it is diverted to the Market Avenue Retention Basin, which brings E. coli contamination down below regulatory standards before it discharges to the river.
Lansing historically discharged 1.65 billion gallons of untreated sewage effluent, annually. Progress is being made on CSO separation, as anyone who has encountered construction and “Swish the Fish” signs on Lansing streets can attest. By 2020, sewer upgrades should be completed in Lansing.
For Ottawa County residents, there may be bigger problems closer to home. Source tracking found that bacteria from swine feces were much more prevalent in the Grand River than bacteria from human sewage. The location of origin for that contamination is not precisely known, but two Ottawa County tributaries were found to have extremely high E. coli counts in 2009 (the last year for which data are available). At seven sites on Deer Creek, average E. coli levels in 2009 were two to ten times higher than the worst sample taken during the 2012 sampling of the Grand River.
Becky Huttenga, of the Ottawa County Conservation District, hopes to address fecal contamination of Deer Creek and Bass River by identifying and remediating failing sewage systems and enrolling agricultural producers in programs that reduce fecal contamination of streams. This work could begin in 2013 if the district is awarded a 319 grant it applied for last month.
