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2000-07-01 - Canada Gazette Part I, Vol. 134 No. 27

DEPARTMENT OF HEALTH

CANADIAN ENVIRONMENTAL PROTECTION ACT, 1999

Publication after Assessment of a Substance -- Textile Mill

Effluents -- Specified on the Priority Substances List

(Subsection 77(1) of the Canadian Environmental Protection

Act, 1999)

Whereas a summary of a draft report of the assessment of the substance textile mill effluents specified on the Priority Substances List is annexed hereby,

Notice therefore is hereby given that the Ministers of the Environment and of Health propose to recommend to Her Excellency the Governor in Council that Textile Mill Effluents be added to the List of Toxic Substances in Schedule 1 to the Canadian Environmental Protection Act, 1999.

Public comment period

As specified under subsection 77(5) of the Canadian Environmental Protection Act, 1999, any person may, within 60 days after publication of this notice, file with the Minister of the Environment written comments on the measure the Ministers propose to take and the scientific considerations on the basis of which the measure is proposed. All comments must cite the Canada Gazette, Part I, and the date of publication of this notice and be sent to the Director, Commercial Chemicals Evaluation Branch, Department of the Environment, Hull, Quebec K1A 0H3, (819) 953-4936 (Facsimile), or by electronic mail to the PSL Webmaster, PSL.LSIP@ec.gc.ca.

In accordance with section 313 of the Canadian Environmental Protection Act, 1999, any person who provides information in response to this notice may submit, with the information, a request that it be treated as confidential.

Annex

Summary of the Draft Report of the Assessment of the Substance Textile Mill Effluents Specified on the Priority Substances List

Textile mill effluents (TMEs) are wastewater discharges from Canadian textile mills that are involved in wet processes such as scouring, neutralizing, desizing, mercerizing, carbonizing, fulling, bleaching, dyeing, printing and other wet finishing activities. They are not generated at facilities that conduct only dry

processing (carding, spinning, weaving and knitting), laundering or manufacture of synthetic fibres through chemical processes. In the context of this report, TMEs do not include waste streams such as air emissions or solid waste.

As of 1999, there were 145 wet processing textile mills operating in Canada. Most wet processing mills were located in Quebec (58 percent), followed by Ontario (34 percent), Nova Scotia (3 percent), New Brunswick (2 percent), British Columbia (1 percent) and Prince Edward Island (1 percent). Most wet processing mills in Canada (96 percent) discharged to municipal wastewater collection systems, 99 percent of which had some form of wastewater treatment. The highest percentage of TMEs received secondary treatment (61 percent), followed by primary (28 percent), tertiary (9 percent) and none (1 percent). The dilution potential for TMEs varied principally according to the volume and flow of the receiving environment, and the total TMEs discharged ranged from 17 percent to 0.000 01 percent of the receiving environment.

TMEs contain a wide range of chemicals and are known to have a range of pH, temperature, colour and oxygen demand characteristics. The assessment did not attempt to determine the contribution of individual components of TMEs to toxicity or environmental effects, due to the complexity of such a task combined with time and resource limitations, and focused instead on the impacts of whole effluents.

In order to supplement the sparse database on the environmental effects of TMEs, a number of studies were undertaken in support of the assessment. The combined results of a battery of whole-effluent toxicity tests indicated a reduction in toxicity with increasing intensity of treatment of TMEs. The battery of tests used included rainbow trout (Oncorhynchus mykiss) acute lethal, Daphnia magna acute lethal, Microtox (Vibrio fischeri) acute sublethal, Microtox chronic sublethal, Ceriodaphnia dubia chronic (lethal and reproduction), and algal growth (Selenastrum capricornutum). All untreated TMEs had effects on all of the organisms tested. Primary-treated TMEs had slightly less toxicity than untreated effluents. Most of the secondary-treated effluents produced no effects on test organisms, with two exceptions, both of which discharged to municipal wastewater treatment systems. At one of those sites, where the treatment system was believed to be not operating optimally, aquatic toxicity was detected in all whole-effluent toxicity tests conducted. At the other site, significant inhibition of reproduction in C. dubia was detected; however, no aquatic toxicity was observed in the other three tests conducted. No tertiary-treated TMEs produced effects on test organisms.

There were limited data available on the aquatic toxicity of samples obtained from aquatic environments receiving TMEs. There were no data on the aquatic toxicity of environmental samples near untreated TME discharges, and only one site receiving primary-treated TMEs was studied. At that site, chronic toxicity (C. dubia survival and reproduction) was detected at 120 m below the outfall, and acute toxicity to the bacterium V. fischeri was detected 30 m from the outfall. No acute toxicity was measured in samples from environments receiving TMEs that were subject to secondary or tertiary treatment. At a single site receiving untreated TME, an in situ bioassay was conducted using caged clams (Anodonta implicata), and significant mortality occurred up to 120 m downstream of the outfall. Pore water from sediments taken from locations up to 80 m from an outfall discharging primary-treated TME inhibited fertilization in the white sea urchin (Lytechninus pictus). Toxicity was not detected by

using a variety of other sediment toxicity tests at sites receiving

secondary-treated TMEs.

Studies measuring impacts on benthic invertebrate communities in aquatic environments receiving TMEs were conducted at single locations for each of untreated, secondary-treated and

tertiary-treated effluents. Changes in community structure were detected 120 m below the outfall at the untreated site; however, no impacts were detected at the sites where secondary or tertiary treatment was provided by a municipal wastewater treatment system.

Estimated Toxic Exposure Values based on nonylphenol toxic equivalency quotients (EEV) for nonylphenol (NP) and nonylphenol ethoxylates (NPEs) in untreated TMEs exceeded the chronic toxicity threshold for invertebrates in 90 percent of samples and the chronic toxicity threshold for fish in 86 percent of samples. Eighty-three percent of untreated samples had NP and NPE EEVs falling within the range of acute toxicity to fish, invertebrates and algae. All five primary-treated TME samples had NP and NPE EEVs falling within the range of acute toxicity to fish and invertebrates and exceeding chronic toxicity benchmarks for those organisms.

Based on the available data, it is proposed 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. Thus, it is proposed that textile mill effluents be considered "toxic" as defined in section 64 of the Canadian Environmental Protection Act, 1999 (CEPA 1999) and that evaluation of options under CEPA 1999 to reduce exposure be considered a priority at this time. It is recommended that options to reduce environmental risk 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 NP and its ethoxylates. Given the fact that most textile mills in Canada have their wastewater treated at municipal wastewater treatment plants (MWWTPs), it is recommended that discussions with the appropriate authorities (municipal and/or provincial) should be undertaken to address the risks. This may require additional effects monitoring of textile mill effluents and municipal effluents.

J. A. BUCCINI

Director

Commercial Chemicals

Evaluation Branch

On behalf of the Minister of the Environment