The US Environmental Protection Agency (EPA) encourages state and local air monitoring groups to conduct short-term multi-site pollutant monitoring studies using a non-reference method, small portable samplers.

The concept is to "Saturate" an area with easily deployed, inexpensive filter samplers, to assess air quality in areas with high concentrations of pollutants or at reclamation sites.

The additional data acquired using saturation samplers helps air pollution control agencies to evaluate their monitoring networks consistent with requirements in 40CFR Part 58.

Saturation monitoring may also be conducted to characterize the spatial distribution of pollutant concentration or to evaluate the contributions of sources in support of receptor modeling.