As part of the annual process, sites should consider cumulative impacts. Cumulative impacts are the combined (potential) impacts of multiple sites, activities, or companies in an area on a community, part of a community, or an individual, where the site has contributed to the impact. The context review should assess whether new companies or industry have moved, or are planning to move, into the area, and sites should assess whether this affects cumulative impacts.
Examples of cumulative impacts include, but are not limited to:
- Environment – emissions of each site or activity in relation to air, water, or noise may be within legal limits, but together they may cause significant health impacts.
- Natural resources – while one site or one company alone may not have a material impact on an area’s natural resources, several companies active in the same area may together have impacts that go beyond acceptable limits in terms of environmental impact, impact on land availability, or human health.
- In-migration – in-migration into a certain area may be due to the presence of several sites or companies in the same area.
- Traffic – while the number of site vehicles on a public road alone may not exceed the road’s capacity, in combination with vehicles from the community and other sites or companies, the site’s use of public roads may lead to traffic volumes that are opposed by local communities.
In , the potential adverse community health impact as a result of poor air quality should be assessed on the basis of overall pollution levels (which includes the site’s emissions), not simply on the site’s emissions alone.
Cumulative impacts also exist where a community, part of a community, or an individual is potentially exposed to multiple types of site impacts at the same time. For example, the households living near a site may be exposed to noise, vibration, air quality, and traffic impacts concurrently. In these cases, stakeholder engagement with affected households and impact prevention and mitigation should be prioritised.