Peace and Environment News* April 1996
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Peace and Environment News * April 1996 |
by Heather Burke
(with files from Peggy Land)
Sewage sludge may not be the black gold people think it is. The City of Gloucester is reconsidering its use. Gloucester Parks and Operations has already decided against spreading biosolids in public parks and is considering a more widespread ban on their use.
Biosolids are a nutrient-rich organic byproduct of the wastewater treatment process. The spreading of biosolids onto agricultural land is often seen as the answer to two problems. Farmers need cheap sources of nutrients and organic matter, and sewage treatment plants need to dispose of sewage sludge. In this way, the product is recycled instead of being trucked to landfill sites.
Dioxin contamination
The problem with biosolids is that they do not contain just organic matter and nutrients. They also contain heavy metals, dioxins and furans.
Dioxins are highly toxic organochlorines connected with breast cancer and birth defects. They are fat soluble and notoriously slow to degrade. They are in the food we eat and the air we breath. Although our environment only contains a small amount of dioxins, a steady exposure combined with slow breakdown allows them to accumulate in our bodies. They are excreted in feces (as well as in breast milk and sperm) and thus enter the sewer system. It is suspected that more dioxins form in the sewer system through the combination of chlorine from our drinking water and other organics.
Recently, the Regional Government developed a Biosolids Management Plan which included a fairly extensive public consultation. Pamphlets explained that biosolids contain some metals and chemicals, but no specifics were given. Although 70 percent of the public stated that environmental impact was their primary concern, the recommendations were to expand biosolids use on agricultural land and build storage facilities rather than truck the sludge to landfill sites. If the public had been more clearly informed about what is actually in biosolids, the recommendations might have been different.
Zero release
Sludge from several wastewater treatment plants in Canada was analyzed in a February 1995 study by Webber and Nichols. The study found that "dioxins and furans in Canadian municipal sludges and composts may represent a risk to agriculture and the environment." Several samples exceeded the maximum amount suggested by the U.S. Environmental Protection Agency. Despite these results, the study concluded that "many Canadian sludges and sludge composts represent no significant risk to agriculture and the environment."
In later comments at a Public Biosolids Workshop held in September 1995, co-author Mel Webber explained that the Canadian Environmental Protection Act (CEPA) did not set guidelines for allowable limits of toxic substances in soils. He stated further that local concentrations of dioxins and furans in sludges were within provincial guidelines for clean-up of contaminated sites.
Falling back on a lack of guidelines will no longer work under the revised CEPA. In June 1995, Environment Canada outlined proposed guidelines for toxic waste management designed to eliminate substances such as dioxins which are persistent and bio-accumulative. These guidelines will mandate against any release of these toxic substances into the environment.
Local use undecided
The R.O. Picard Environmental Centre in Gloucester produces 33,000 tons of biosolids per year. This amounts to one tenth of Canada's total biosolids production. As a pilot project, ten farmers have agreed to try the free "soil conditioner" from the Centre on their fields. The agreement is that no crops can be grown on the fields for a year after the application, and the soil cannot be too acidic, as this would lead to the leaching out of metals into the groundwater.
The Gloucester Environmental Advisory Committee (EAC) has become concerned about the possible toxicity of biosolids and has made presentations to the Regional Planning and Environment Committee and to Gloucester City Council. Gloucester Mayor Claudette Cain is concerned about possible further contamination of well water in the Carlsbad Springs area, where farmers have asked for biosolids for their fields.
The Gloucester EAC is also voicing concern about the lack of openness regarding the contaminants and the lack of monitoring of the soils after biosolids application for dioxin and furan contamination as well as soil acidity.
The public consultation process is in effect until Regional government makes its final decision whether to expand its biosolids application program. This should be by early May. Gloucester City Council will decide on April 9 what message it will send to Regional government regarding the biosolids plans.
Interested people can contact the Regional Planning and Environment Committee at 560-1242.
Converted April 11, 2000 - Lg
To follow up on this article, contact the author or the organizations/individuals mentioned; do not contact the Peace and Environment Resource Centre - we cannot provide follow up or contact information. This article is an archival copy of the printed one in the Peace and Environment News (PEN). Viewpoints expressed should not be taken to represent the opinions of the Peace and Environment Resource Centre, the PEN, or our supporters.
