Following the launch of the Green Sink Initiative (GSI) CPD webinar in conjunction with CIOB, industry leaders are being urged to prepare for new regulatory and reporting expectations under the EU REACH Microplastics Restriction (Entry 78, Annex XVII) — and their emerging link to Scope 3 emissions from wastewater.

A new era for environmental accountability

The built environment is entering a period of heightened scrutiny over how it manages waste, water, and pollution. The EU’s REACH Microplastics Restriction, adopted in October 2023, represents the most comprehensive legislation yet to limit microplastic releases. It covers far more than consumer goods, extending to construction materials, coatings, adhesives, and sealants that release microplastics during use and clean-up.

From October 2025, manufacturers and contractors must begin to quantify and report microplastic emissions, adopt mitigation practices, and provide clear guidance on safe disposal. For construction sites, this includes washwater from paints, plasters, and cementitious products — all of which can carry microplastic and polymer residues into drains and sewers.

“Every bucket of washwater now represents a measurable and reportable emission source.”

From site practice to policy priority

Until recently, liquid waste discharges to sewer from construction sites was viewed as a logistical issue rather than an environmental one. However, research supported by the Green Sink Initiative and partner universities such as Western Sydney and Deakin has revealed that washwater is a highly concentrated microplastic source. These discharges contribute to the urban wastewater load, yet are largely missing from national pollution inventories.

As legislation expands, this oversight can no longer continue. The GSI’s new CPD module, produced in collaboration with CIOB, helps project teams understand how these emerging rules apply to everyday site activities — and how early compliance can also deliver measurable ESG value.

Connecting REACH and Scope 3 Emissions

The connection between the REACH restriction and Scope 3 carbon reporting may not be obvious at first glance, but it is rapidly becoming critical. Under the Greenhouse Gas Protocol, Scope 3 includes indirect emissions generated throughout a company’s value chain — such as waste processing and wastewater treatment.

As REACH now demands quantifiable reporting of microplastic emissions, organisations will have to trace the life cycle of pollutants produced during product use and cleaning. The energy and transport required to treat or dispose of this wastewater contribute directly to Scope 3 totals.

“You can’t manage your carbon footprint without managing your pollution footprint.”

This alignment means that pollution prevention and carbon reduction are no longer separate goals; they are part of the same accountability framework.

Zero liquid discharge: from compliance to competitive edge

Forward-thinking firms are already responding. Closed-loop wash systems eliminate on-site discharge by recycling washwater and capturing solids for verified disposal. These systems generate data that can support REACH compliance, Scope 3 carbon accounting, and corporate ESG disclosures.

By combining pollution control with digital tracking, construction companies can demonstrate measurable environmental leadership, an increasingly powerful differentiator in tenders, investor relations, and public procurement.

Preparing for the reporting shift

To adapt to this integrated regulatory landscape, construction professionals should begin developing literacy across four key areas:

1. Product awareness: Identify materials containing or releasing microplastics.
2. Liquid waste quantification: Record washwater volumes and disposal pathways.
3. Zero discharge adoption: Implement on-site recycling and containment systems.
4. Data integration: Feed verified water and waste metrics into ESG and carbon reports.

The CIOB - GSI partnership provides the educational foundation for this transformation. The new CPD training equips site managers, sustainability officers, and procurement teams with practical tools to meet both REACH obligations and Scope 3 readiness.

From awareness to action

The Green Sink Initiative emphasises that these developments are more than compliance exercises — they represent an opportunity to modernise how the industry measures and manages its impact. By re-defining washwater as a reportable emissions stream, construction can bridge the long-standing gap between pollution control and climate accountability.

As the sector prepares for new disclosure standards, those who act early will not only stay compliant but also lead the narrative on responsible, data-driven construction.