Wastewater Impact Through Regional Collaboration

Looking Back, Looking Forward

As we prepare for the upcoming version update of the ZDHC Guidelines, it is important to pause and reflect on the journey so far. Over the past years, our collective efforts have shown that water stewardship cannot be achieved in isolation. This shared responsibility has taught us a key lesson: regional collaboration is not just beneficial, it is essential.

Why Regional Collaboration Matters

Wastewater impacts are inherently regional. What happens upstream directly affects downstream communities and industries. When stakeholders work in silos, progress remains fragmented. However, when we foster collaboration across entire regions, we begin to see real systemic change:

• Shared Understanding: Bringing together diverse actors provides a fuller picture of wastewater risks and opportunities. Scientific data becomes more actionable when coupled with local knowledge and lived experiences.
  
  
• Collective Action: Individual investments in water treatment or efficiency multiply their impact when aligned with regional goals. Shared projects—such as wastewater treatment infrastructure or catchment restoration—are only possible through collective effort.
  ‍

‍"Regional collaboration is key to achieving sustainable chemical management and improving wastewater quality. We have observed that when suppliers progressively adopt chemicals in line with ZDHC MRSL conformance and improve their MRSL conformance, the occurrence of hazardous substances in their wastewater significantly decreases. This demonstrates that wastewater management is not the responsibility of a single facility — it requires upstream and downstream collaboration to achieve true systemic improvement."

– Lydia Lin, Chief Implementation Officer

‍

Case Examples and Insights

Through ZDHC’s Roadmap to Zero Programme, we have already seen how regional pilots can catalyse progress. For example:

South Asia – Supplier Clusters Driving Wastewater Progress
In India and Bangladesh, clusters of suppliers adopting the ZDHC Wastewater Guidelines reported consistent reductions in hazardous chemical parameters. Regional collaboration between suppliers, brands, and laboratories aligned monitoring approaches, improved comparability of results, and accelerated progress basin-wide.

China – Regional Engagement Platforms
Regional supplier roundtables and training programmes in China reduced non-conformities significantly. By engaging in a shared platform, suppliers learned from one another, building capacity faster and achieving higher compliance rates than they could individually.

Southeast Asia – Shared Infrastructure Investment
In Vietnam, suppliers and brands co-invested in wastewater treatment infrastructure at regional level. This collective approach allowed upgrades that no single facility could have financed alone, proving that cost-sharing models unlock transformative water quality improvements.

Looking Ahead: From Compliance to Collective Impact

As we move into the next version of the ZDHC Wastewater and Sludge Guidelines, we bring a stronger alliance with the ZDHC MRSL V3.1, which introduces stricter reporting limits and new test methods. Together, these frameworks reinforce the principle that wastewater quality cannot be separated from input chemistry — effective progress requires both ends of the pipeline working in harmony.

We are also expanding the Supplier’s Roadmap to Zero Output focus area to include Effluent Treatment Plant (ETP) Assessment. This will provide clear guidance on design, operational excellence, and team competence, ensuring that treatment systems are not only in place, but effective and resilient. By elevating performance standards across ETPs, we move closer to ensuring that regional waterways are protected, not merely monitored.
‍

"The ZDHC Wastewater and Sludge Guidelines are a great example of how a single guideline can significantly reduce duplication for suppliers who previously had to meet different testing and monitoring requirements from various brands and their supply chains.

The latest version, ZDHC Wastewater and Sludge Guidelines V2, includes new MRSL substances, stricter reporting limits, and updated test methods for wastewater and sludge aligned with ZDHC MRSL V3.1. To further enhance credibility, the ZDHC ETP Assessment will complement wastewater testing results and strengthen the reliability of ClearStream Reports."

– Tejas Edvankar, Water Technical Manager

The evidence is clear. The Impact Report 2024 shows that regional supplier clusters in South Asia and Southeast Asia achieved faster improvements in wastewater quality when they aligned around common monitoring practices and shared infrastructure. In China, supplier roundtables proved that knowledge-sharing platforms reduce non-conformities more effectively than factory-by-factory efforts. Similarly, Quantis’ study quantified that adopting ZDHC’s MRSL and Wastewater Guidelines can reduce freshwater toxicity impacts by up to 96%.

Our vision is clear: a future where regional collaboration amplifies the impact of individual action. This requires us to think differently—aligning factory-level improvements with basin-level outcomes, linking business performance with community wellbeing, and closing the data gaps that remain. By doing so, we can accelerate real-world improvements in water quality and ecosystem health — protecting water as a shared lifeline for people, nature, and industry alike.

‍