Environmental policy is now a shared competence. EU law may therefore be able to suppress member states' existing legislation and their right to legislate in this area.
See Art. 4 TFEU and Art. 191-193 TFEU.
EU law sets minimum rules for the protection of the environment. Most common environmental rules are decided by qualified majority voting in the Council and co-decision with the European Parliament.
There are still exceptions that require unanimity voting in the Council, such as the choice of energy source, town
and country planning, management of the amount of water resources and land use.
Waste management requires a qualified majority vote.
Member states have the right to establish higher levels of
protection for their country than the EU provides based on Article 193 TFEU.
Often national rules for the environment are seen as obstacles to the free
trade of goods.
Such rules may go against Internal Market rules or the general non-discrimination principles of the EU treaties, although under Article 114 TFEU the EU has to consider environmental aspects while regulating the internal market.
The national environmental laws can be outlawed by the Commission or by the EU Court.
Links
See also Environmental clause.
http://europa.eu/scadplus/leg/en/s15000.htm
http://ec.europa.eu/environment/index_en.htm
European Environment Information and Observation NETwork: http://www.eionet.eu.int