Ecosystem survey finds 20 Great Lakes cities dump over 90 billion litres of untreated sewage yearly
Peel Region and Thunder Bay were among the top-rated Great Lakes communities for their management of municipal sewage, as assessed by Sierra Legal in its first Great Lakes Sewage Report Card. By contrast, Windsor was among the worst performers, with Toronto, Hamilton, Sarnia, Kingston and Sudbury each receiving below-average grades.
The investigative report represents the first-ever ecosystem-based survey and analysis of municipal sewage treatment and sewage discharges in the Great Lakes basin, says Sierra Legal. It analyzes 20 cities in the Great Lakes basin - 11 Canadian and nine U.S. - and grades them on the basis of how well they manage their sewage. The study takes into account issues such as collection, treatment and disposal of sewage based on information provided by each municipality.
Sierra Legal unequivocally calls the results appalling. Many cities in the region have antiquated systems for collecting and treating sewage and regularly release untreated sewage into local waterways. It is estimated that the 20 cities evaluated, whose total population makes up one-third of the region's 35 million people, dump more than 90 billion litres of untreated sewage into the Great Lakes each year. Although many cities have made efforts to clean up their act, waters surrounding urban areas throughout the Great Lakes are still commonly unsafe for recreational use and many parts of the vast freshwater ecosystem are in peril.
"The Great Lakes basin is one of the most important freshwater ecosystems on the planet - holding one fifth of the world's freshwater," said report author Dr Elaine MacDonald. "Yet, the twenty cities we evaluated are dumping the equivalent of more than 100 Olympic swimming pools full of raw sewage directly into the Great Lakes every single day."
Peel Region was second only to Green Bay, Wisconsin and came in just ahead of Duluth, Minnesota. The study found that all three cities generally have more advanced treatment processes and permit little, if any, sewage to escape into the environment through combined sewer overflows, spills or bypasses. Thunder Bay ranked fourth, providing secondary treatment and having invested in extensive upgrading, with plans in the works for UV disinfection.
The report deemed the results for cities like Toronto and Hamilton disappointing and said Detroit, Cleveland and Windsor performed abysmally and are at the bottom of the class. The cities that fared poorly typically have serious problems related to their combined sewers, antiquated systems that combine storm water and sanitary sewers into a single pipe and are prone to releasing raw sewage during wet weather.
Toronto, for example, reported nine billion litres per year of combined sewer overflows (CSOs) and 900 million litres of sewage bypasses in 2004. The city did, however, report having plans for UV disinfection and has the most comprehensive final effluent testing, says the report.
The study also found that:
*the 20 cities produce and treat more than three trillion litres of sewage per year;
*all the cities provide at least secondary treatment except for Kingston, Sault Ste Marie and Windsor, all of which intend to upgrade to secondary treatment;
*only London, Ont and Duluth provide tertiary treatment;
*nine cities have phosphorus removal technology, three in Ontario (Peel, Toronto and Hamilton);
*four cities (all U.S.) use dechlorination;
*four cities use UV disinfection, two in Ontario (London and Sarnia), with Toronto and Thunder Bay reporting plans to upgrade to this level; and
*only four cities have no combined sewers, including Peel Region, Sault Ste Marie, Duluth and Green Bay.
In addition to grading the cities, the report provides an analysis of the region's patchwork of sewage treatment laws and policies. "Although it would be easy to point the finger at municipalities, the Great Lakes basin is a political quagmire that includes two countries, eight states, a province, dozens of tribes and First Nations and hundreds of local municipal and regional governments," Dr MacDonald stated, adding, "The only way out of this mess is to have all levels of government make a renewed commitment to upgrade our aging sewage systems and conserve our precious freshwater resources."
Finally, the Great Lakes Sewage Report Card offers several recommendations for reducing sewage discharges and protecting water quality in the Great Lakes. Water conservation, says the report, would not only preserve freshwater resources, it would also reduce the volumes flowing into outdated, overloaded treatment facilities.
Secondly, the report calls for "keeping rain out of the drain," i.e. minimizing the amount of stormwater entering sanitary and combined sewer systems. Cities need programs to encourage the disconnection of residential downspouts and footing drains from municipal sewer systems. Physically separating stormwater and sewage streams in combined sewer systems, although initially costly, would also greatly reduce CSOs and the overall volumes flowing into wastewater treatment plants, adds the report.
Keeping toxic substances out of treatment facilities is also essential, as these plants are not capable of treating many of these substances. The report recommends enactment and enforcement of strict sewer use bylaws to limit or ban specific toxic pollutants.
Also recommended is wastewater reclamation and re-use, a common practice in many areas of the world where clean, fresh water is in short supply. New technologies can make reclaimed wastewater a viable resource for uses such as irrigation, non-potable industrial processes, surface water replenishment and groundwater recharge.
Finally, the report calls for adequate funding from all levels of government to ensure adequate treatment facilities and sewer infrastructure throughout the Great Lakes basin. The development and use of alternative, more cost-effective sewage treatment technologies should be encouraged as well.
The full report may be viewed on the Sierra Legal Web site, www.sierralegal.org. more information is also available from Dr Elaine MacDonald, Sierra Legal staff scientist, 416/368-7533, ext 27.