Water and waste in corporate ESG reporting: beyond carbon

Most corporate climate programs started with energy and carbon. Reporting frameworks have moved on. Water use and waste are now first-class disclosure topics, with their own standards, questionnaires and assurance expectations. For teams that already struggle to assemble clean energy data, water and waste add two more data streams that are often even less organized.

The pressure is coming from several directions at once: investor questionnaires, European standards, and Canadian regulation on landfill emissions. The organizations that handle this well treat water and waste the same way they treat energy, as metered, billed, auditable data rather than an annual estimate.

Water and waste are now standard disclosure topics

On the voluntary side, CDP runs the largest environmental disclosure system in the world. In 2024 a record of more than 23,000 companies disclosed through CDP, which now combines climate, water and forests in one questionnaire. Water leadership is hard to reach: only 133 companies earned an A for water security in 2024.

On the standards side, GRI 303 (Water and Effluents) and GRI 306 (Waste) are the most widely used global references, and the EU's ESRS add E3 for water and marine resources and E5 for resource use and the circular economy. ESRS E3 pays particular attention to water withdrawal in water-stressed areas, while E5 asks for resource inflows and outflows and how waste is treated.

Why water data is harder than it looks

Water reporting sounds simple: report what you withdrew and discharged. In practice, water bills are often the least automated of any utility. They arrive from municipal and regional providers on irregular cycles, mix water, sewer and stormwater charges together, and rarely break consumption into a clean series. Many organizations only discover the gaps when a questionnaire asks for withdrawal by source and by site.

Scale makes it matter. In Canada, industrial water use reached 33.1 billion cubic meters in 2019, the large majority of national water use, and commercial and institutional buildings withdraw a significant share on top of that. Water-stressed regions turn that volume into a genuine business risk that investors now expect to see quantified.

There is an operational upside to getting this right. A clean, continuous water series does more than answer a questionnaire; it surfaces leaks and anomalies that a once-a-year estimate would never reveal. The same dataset that supports disclosure can flag a spike that points to a failed valve or an unbilled meter, which turns a reporting cost into an operational saving. Teams that only touch water data at reporting time miss those signals entirely.

Waste and its emissions are under new scrutiny

Waste has a climate dimension that regulators are now acting on. In Canada, landfills accounted for 17 percent of national methane emissions and 2.7 percent of total greenhouse gas emissions in 2023, and more than 60 percent of landfilled waste is biodegradable material that generates that methane. New federal Landfill Methane Regulations create a national approach to measuring and cutting those emissions.

For a corporate reporter, waste disclosure under GRI 306 and ESRS E5 means tracking waste generated, diverted and disposed, by type and by route. That data usually lives in hauler invoices and facility records, in the same fragmented state as water. The reporting question is the same as for energy: can you produce a complete, documented number per site that survives review?

Diversion is where the reporting and the operations meet. Answering GRI 306 or ESRS E5 credibly means knowing not just how much waste left a site but where it went: recycling, composting, energy recovery or landfill. That routing lives in hauler contracts and pickup records that most facility teams never digitize. Without it, a company can report a total tonnage but not a diversion rate, which is the number investors and regulators increasingly want to see, and the one that shows whether waste management is actually improving.

Investors are asking, and so are lenders

The demand for water and waste data is not only regulatory. In 2024, more than 700 financial institutions with over 142 trillion dollars in assets requested environmental data from companies through CDP, and that request now spans water alongside climate. A company that can answer the climate questions but not the water ones scores worse and signals weaker management of a resource that is becoming scarce in many regions. For real estate and industrial operators, water risk is increasingly priced into how investors and lenders assess an asset.

The units and boundary problems

Water and waste share a data problem that carbon reporters know well: units and boundaries. Water may be billed in cubic meters, hundreds of cubic feet, gallons or kiloliters depending on the provider, and a single portfolio can span all of them. Waste is measured by weight or by volume, by hauler pickups or by container size, and the conversion between them is rarely clean. Before any figure can be summed across a portfolio, it has to be converted to a common unit and assigned to the right site and reporting boundary. That normalization is invisible when it works and a source of large errors when it does not.

Boundaries matter as much as units. A landlord and a tenant can both, in good faith, count the same water use, or neither can, depending on who reads the meter and how the lease allocates it. The same double-counting risk that complicates Scope 2 electricity applies to shared water and waste services in multi-tenant buildings. Clear rules about which party reports what, applied consistently across the portfolio, are the only way to avoid it.

Set targets you can actually track

Disclosure is moving from reporting a number to reporting progress against a target. For water that often means a reduction in withdrawal or in consumption in water-stressed areas; for waste it means a diversion rate away from landfill. Neither target is meaningful without a reliable baseline and a consistent monthly series to track against. Organizations that set a target before they have clean data end up restating their baseline later, which erodes trust with the investors the target was meant to reassure. Clean data comes first, then the target.

Treat water and waste like energy data

The organizations that report water and waste credibly do not run a separate annual project for each. They fold water meters and waste hauler invoices into the same data pipeline as electricity and gas, so every commodity lands in one place with a consistent structure and a link back to the source document. That turns a scramble into a query.

• Collect water and waste invoices continuously, not at reporting time.
• Separate water, sewer and stormwater charges so consumption is isolated.
• Track waste by type and disposal route to answer GRI 306 and ESRS E5.
• Tie each figure to its source document for assurance.
• Flag sites in water-stressed regions for the disclosures that ask specifically about them.

How MartinAI fits

MartinAI collects and cleans utility data across any commodity, not only electricity and gas. Water and sewer bills, and other metered utilities, run through the same extraction that structures energy data, so consumption is separated from charges and kept with its source document. That gives water and waste reporting the same auditable foundation as carbon, in one dataset that can feed CDP, GRI-aligned and ESRS disclosures. MartinAI supplies the data; it does not certify your report.