Limitations of CETP's in Delivering True Zero Discharge
While the ZDHC Wastewater Guidelines set clear expectations for semi-treated wastewater quality at the facility level, the ultimate goal of the ZDHC Programme is to ensure zero discharge of hazardous chemicals into the environment. In practice, many suppliers discharge into centralized effluent treatment plants (CETPs) that receive effluents from multiple industries, often outside the textile/apparel sector and not aligned with ZDHC MRSL or ZDHC principles. Given that the final treated water from such CETPs is what eventually enters the environment, doesn't this compromise the ultimate goal of the ZDHC Programme? How does ZDHC address or plan to address this systemic gap, where the final discharge quality is beyond the direct control of compliant facilities?
Great question! We’ve discussed this over the past few years, including in a conversation I had with a couple of our community members after last week’s Wastewater Breakout Group on Expectations and Requirements. CETPs, especially those treating effluent from mixed industries, may limit our ability to keep hazardous chemicals out of the waterways, especially the conventional parameters. Some of the points related I’ve heard from the community over the years: 1)CETPs may be overloaded or not adequately designed to treat complex industrial wastewater, particularly when they serve diverse sectors. 2) Using suppliers where Indirect discharge is used may be unintentionally favored, even though it offers less control and visibility over final discharge quality. 3) Maybe future ZDHC rating systems should require indirect dischargers to show due diligence on their CETP’s capacity and performance to be rated above Foundational. 4) Brands could require this due diligence from their indirect suppliers. 5) Incentivizing CETP transparency—through data-sharing, benchmarking, or partnerships—could help drive improvement. 6) Collaboration with basin-level initiatives (e.g. WWF’s work) may offer a way to scale responsible discharge practices across regions. Does the community have ideas? Please share your thoughts!