2. The Member States concerned shall cooperate with each other, including by establishing joint teams of experts and with technical support from the Commission, to identify the sources of air pollution, contributions of those sources to exceedances in another Member State and the measures to be taken individually and in coordination with other Member States to address those sources, and draw up coordinated activities, such as the coordination of air quality plans pursuant to Article 19, in which each Member State shall address pollution sources located in its territory, in order to remove such exceedances.
Member States shall respond to each other in a timely manner, and inform the Commission, no later than 3 months after being notified by another Member State in accordance with the first subparagraph.