Focuses on all environmental impacts on water resources (e.g. waste water, water pollution, aqua bio-diversity, water efficiency).

A variety of firm activities put water quality, water availability, or aquatic ecosystems at risk.  Some examples include agricultural water usage, deep-water drilling, fishing, and production - especially in developing countries.  Responsible water usage involves using water-efficient technologies such as irrigation systems and respecting the right to water of local communities.  Where relevant, firms should have policies in place to minimize the risk of harming aquatic ecosystems and aquatic biodiversity (for example, through oil spills).

Wastewater management is another set of practices that affect the water supply and aquatic ecosystems. In particular, hazardous industrial waste that contains chemicals, heavy metals, radiation, or dangerous pathogens must be carefully contained or treated in order to avoid contaminating drinking water or natural habitats. Hydrofracturing or “fracking” is a particularly water-intensive process that also generates large amounts of toxic wastewater.  In addition to minimizing and containing the wastewater it generates, firms are responsible for reducing the risk of water contamination and remediating groundwater or other bodies of water that it has contaminated.