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ZDHC Unveils Updated Wastewater Guidelines

As the need for more sustainable production increases, environmentally focused organizations are tightening their requirements. Earlier this week, the Zero Discharge of Hazardous Chemicals (ZDHC), a group dedicated to chemical management, released updated guidelines for the textile, leather and footwear industry regarding industrial wastewater and sludge.

The ZDHC Wastewater Guidelines Version 2.0 includes combined textile and leather wastewater guidelines (which were previously separate), as well as a streamlined approach to sampling and testing for direct, indirect and zero liquid discharge, incorporation of the ZDHC Manufacturing Restricted Substance List (ZDHC MRSL) Version 2.0, guidance on appropriate sludge disposal pathways, and an update on sludge testing parameters.

Updates were determined by the ZDHC’s Wastewater Council, a group of independent wastewater experts from the textile industry, academia and the water treatment industry. The revision also includes the ZDHC Sludge Reference Document Version 1.0, which provides a methodology for facilities to determine the pathways used for sludge disposal, and ZDHC Wastewater and Sludge Laboratory Sampling and Analysis Plan Version 2.0, which provides a detailed framework for laboratories to test and determine the concentration of parameters in wastewater and sludge.

“Since the publication of the first ZDHC Wastewater Guidelines, the ZDHC Roadmap to Zero Program has evolved to become much more of a holistic chemical management program, and this update is an important pillar in that approach,” said Phil Patterson, ZDHC Wastewater Council chair. “It is closely aligned with the chemical input management process and the testing advice is much more streamlined to enable facilities and brands to demonstrate conformance and rectify issues more easily.”

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The ZDHC Wastewater Guidelines were first introduced in 2016 as a way to document a unified set of global wastewater quality expectations for the apparel, textile and footwear industries. The update strengthens the evolution of its Roadmap to Zero Program, which launched in 2011 with six signatory brands to transform the global fashion supply chain. The program now has more than 160 contributing partners, including brands like H&M, Gap, Inc. and G-Star Raw, mills such as Isko, Soorty, Elevate Textiles and Candiani, and more.

The guidelines come at a time when the industry is paying ever more attention to their environmental impact. In August, Water Witness International (WWI), a U.K.-based organization focused on sustainable water resource management, found extreme water pollution in certain African countries that support the global fashion supply chain. Waterways in top sourcing countries such as Ethiopia, Lesotho, Madagascar, Mauritius and Tanzania had a pH of 12—the same as household bleach—as well as high levels of carcinogenic chemicals. In other areas, water was visibly polluted with blue dye from denim production. The polluted runoff is a threat to the local communities’ health and crops that are irrigated with the water, and contact with the pollution also results in skin burns and disease.

According to Jimmy Summers, vice president, environment, health, safety and sustainability chief sustainability officer at Elevate Textiles, more work needs to be done in spreading awareness about the effects of this kind of pollution, and companies must clean up their processes.

“Metals and compounds found in sludge can be released and cause negative impacts on human health and the environment,” he said. “In too many cases around the world, sludge quality and the impact on the environment is poorly understood. It is crucial for sludge to be tested, properly characterized, handled and disposed of properly, and for this information to be transparent and available for brands and retailers to see.”