The Clean Air Act Amendments (CAAA) of 1990 will have far-reaching effects on the monitoring of the deposition of atmospherically transported chemicals. The CAAA incorporate significant new regulatory requirements for emission reductions designed to reduce risks to public health and protect the natural environment. The paper presents the preliminary monitoring plan for a comprehensive network designed to provide adequate spatial coverage and reasonable temporal trend resolution for chemical deposition variables. While much of the network is regional or national in scope, it also includes a focus on increased monitoring in sensitive ecosystems areas such as high elevation sites and watersheds. The design process involved an evaluation of the uncertainty in the spatial prediction of unknown deposition levels at non-monitored sites and the ability of existing networks to detect and quantify temporal changes in precipitation sulfate.