Backgrounder: Textile Mill Effluents

What are Textile Mill Effluents?

Textile mill effluents (TMEs) are wastewater discharges from Canadian textile mills that use wet processes, such as bleaching, dyeing, or printing. TMEs contain a wide range of chemicals, so the scientific assessment did not attempt to determine the contribution of individual components to overall toxicity and focused on the impacts of whole effluents.

TMEs are not generated by textile mills that only conduct dry processing, such as weaving and spinning or laundering, or that manufacture synthetic fibres through chemical processes.

Where are common sources of this substance?

In 1999, there were 145 wet processing textile mills operating in Canada, 84 of which are in Quebec. There are 50 "wet" mills in Ontario, with the remainder located in Nova Scotia, New Brunswick, Prince Edward Island and British Columbia.

Most wet processing mills in Canada (96%) discharge to municipal wastewater systems and 99% of municipal wastewater receives some form of primary, secondary, or tertiary wastewater treatment prior to release. Some mills discharge untreated effluents directly to lakes, rivers or other bodies of water.

Why have TMEs been found to be toxic to the environment?

The assessment found that textile mill effluents are entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity. These substances are not found to be bioaccumulative, or to transfer up the food chain.

TMEs are complex mixtures of chemicals, varying in composition over time and from mill to mill. Although untreated and primary-treated TMEs are known to be toxic to a wide variety of aquatic organisms, conventional wastewater treatments producing secondary or tertiary level treatment appear to be effective in reducing toxicity.

Untreated and primary-treated textile mill effluents have been shown to be toxic to a wide range of aquatic organisms including fish, aquatic invertebrates, bacteria, freshwater mussels, and algae.

Concentrations of untreated TME as low as 8.2% of effluent have been shown to be lethal to rainbow trout in 96 hour exposures.

Why were TMEs only assessed for environmental toxicity and not human health?

As recommended by the Ministers’ Expert Advisory Panel on the Second Priority Substances List, the focus of the assessment on textile mill effluents was effects on environmental organisms directly exposed in the aquatic environment. Human health effects were not part of the assessment because exposure to humans was judged to be minimal, and any action taken to reduce release on the basis of effects on more sensitive environmental organisms would be protective for humans.

What are the next steps for the federal government to reduce the effects of TMEs in the environment?

The assessment report recommends that evaluation of options under the Canadian Environmental Protection Act, 1999 (CEPA) to reduce exposure be considered a priority. Options to reduce environmental risk will be examined on a site-specific basis. In addition, pollution prevention opportunities and control technologies for the management of TMEs should be identified and evaluated, with particular attention to the use and release of Nonylphenol and its ethoxylates.

Since most textile mills in Canada have their wastewater treated at municipal wastewater treatment plants, the report recommends that discussions with the appropriate authorities (municipal and/or provincial) should be undertaken to address the risks.

Under CEPA, the federal government has two years to develop preventive or control measures for and a further 18 months to finalize them.

A range of options is available to reduce or minimize releases of substances that are found to be toxic. They include regulatory and voluntary initiatives, economic measures, environmental quality or release guidelines, codes of practice and pollution prevention plans.

For more information please contact: Danie Dubé Environment Canada (819) 953-0356

Robert Liteplo Health Canada (613) 957-1880