Eliminating Sewage Pollution from Combined Sewer Overflows (CSO's)

We no longer pile our sewage in our attics or back yards as was common in 19^th century cities. Now we dump it into local waterways. Replacing antiquated combined sewer overflow systems (CSO's) in the U.S. improves public and environmental health, while reducing both sewage treatment and drinking water treatment costs. CSO's are overflow pipes that drain into the river when the sewage, storm water and industrial wastewater become too much for the wastewater treatment plant to handle. There are about 772 cities in the U.S. that with combined systems dumping sewage in our waterways according to the EPA. Eliminating CSO's and sewage pollution is an essential step in protecting our watersheds.

What is being done about CSO's?

Overflow events fall under the EPA's National Pollution Discharge Elimination System (NPDES) laws for point-source water pollution. This is a system where permits are available that allow an entity to pollute our waterways. In the case of CSO's, cities purchase a permit so they can legally dump sewage in a river. As part of the NPDES the EPA set out 9 CSO "minimum controls." These range from maintenance requirements and monitoring to notifying the public of these water pollution events. The EPA provides funds for some projects that help limit overflow events or their impacts
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Improvements on Combined Sewer Systems

An example of EPA funding is the waste-water treatment improvement plans inPennsboro, West Virginia. The city was found to be violating its' NPDES permits. According to the EPA, Pennsboro "will construct a new influent pump station, a new preliminary treatment facility/equalization basin, a new ultraviolet disinfection system, and a metering flume and outfall structure." These improvements are expected to reduce city NPDES violations. A grant of $2,776,000 will pay for about 55% of the project costs; a lot of cash to only limit the problem.

Methods for decreasing urban runoff, which lessen the load on the combined sewer system, are promoted and studied by the EPA. These methods are things such as green roofs, bio-retention areas in parking lots, and other low impact design (LID) considerations.

Separating Combined Systems

While improvements are helpful for lessening water pollution, they can't eliminate problems caused by a CSO. Separating the sewer pipes and eliminating CSO's is the only solution. Cities such as Lansing, Michigan have been doing this. As stated on their website, from 1984 to 1989 4,150 acres of combined sewer were separated and 22 CSO's were eliminated. As of 2010 CSO's have been reduced by 52%. All combined pipes are planned to be separated by 2020. Most funding comes from sewage bill revenue.

Separating sewer pipes and eliminating CSO's is not cheap. The average residential monthly water and sewage bill for Lansing in 2010 is $81.41 according to Delta Townships' website. In my Midwestern hometown we pay this every three months. We also have a horrible stench emanating from the river that runs right through town after every rainfall. Any politician willing to allow rate increases of the sort needed to correct our CSO problem would be looking for a new career.

While separating combined sewers is not cheap we do get taxpayers to foot most of the bill for things such as Indianapolis's $720 million Lucas Oil Stadium. This is in addition to the stadiums 2009 20 million dollar operating deficit which will be made up by taxpayers. There is no debate that eliminating CSO's saves cash in the long term while increasing human and environmental health. It's just not as much fun showing off the cities' new sewer pipes or water treatment plant as watching the team and drinking a beer from box seats.

References

EPA Combined Sewer Overflows in U.S: http//cfpub.epa.gov/npdes/home.cfm?program_id=5

EPA minimum controls:http://cfpub.epa.gov/npdes/cso/ninecontrols.cfm?program_id=5

Lansing Michigan CSO Project: http//lansingmi.gov/pubserv/cso/the_cso_story.jsp

Delta Towship Sewage Bill Prices: http//deltami.gov/?page_id=577