Beware of toxic sewage sludge


Re “Current sewage lagoon poisoning Koojessee Inlet” by Jane George, Nunatsiaq News, Sept. 17, 1999.

“Leftover cakes of sludge are then placed under a tarp, where they are broken down and sanitized by a process of self-generated heating, or composting. The Town plans to use the resulting product as a fertilizer around town to create green areas. Rich in a variety of nutrients, human waste has been used for thousands of years in such countries as China as the main fertilizer in agriculture.”

True, human waste has been used as fertilizer for thousands of years, but sewage sludge is a contentious issue. More than human waste is dumped down the drain. The questions are not only esthetic.

Sludge can contain toxic chemicals, poisonous heavy metals like lead, and even radioactive compounds, in addition to fertilizer components like nitrates and phosphates that can be harmful if they pollute water.

Here is what the U.S Environmental Protection Agency says about toxic chemicals in sewage sludge

“The efficiency of the treatment of toxic chemicals in waste sent to sewage treatment plants varies, depending on the chemical and the sewage plant.

“This means that the amount of a toxic chemical that ultimately enters the environment may be an underestimate, because of these differences in treatment efficiencies.

“For example, some high-volume pollutants, such as methanol, are readily degraded by most sewage treatment plants. Other chemicals, such as methyl ethyl ketone (MEK), may be partially treated and partially released.

“Other high-volume chemicals, such as ammonia, are not readily treated by most sewage treatment plants and will pass through the plant into the aquatic environment.

“In addition, metals sent to sewage treatment plants may be removed with solid wastes and sent to landfills, or they may pass through the plant and be discharged into surface waters; they are not, however, destroyed.”

Nunavut obviously has problems with landfilling anything, including sludge, but I suggest exercising caution in populated areas before creating “green areas” that turn out to be brownfields.

Transferring pollution from the inlet to the shore will not benefit anyone.

Ralph Kirshner

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