One of the 2 northernmost nodes in the Richmond subnetwork, the node on Collins Elementary sits just north of 80, a busy Bay Area freeway, and approximately 2 miles south of the San Pablo Bay. Comparison of this node with other nodes located along 80 provide information about emissions generated by traffic on this freeway at different locations along the route. In addition, this node is one of the most distant from the Chevron Richmond Refinery in the Richmond subnetwork. Comparisons of the Collins Elementary node to more southwestern nodes in the subnetwork provide information about emissions generated by the Chevron refinery.