The Deru 2 directive for urban wastewater treatment in France will drive heavy investments averaging about 2 billion euros annually from 2028 through 2045 to upgrade discharges, treat nitrogen and phosphorus, and remove micro-pollutants, with energy-neutral plants as a long-term goal.

Most of the benefits are tied to ecosystem services, healthier rivers and lakes, reduced eutrophication, and better aquatic life, with additional gains for public health and economic activity.

In addition, the upgrades are expected to boost tourism, support ongoing industrial activity with less treatment pressure, and protect shellfish farming by lowering pollution.

Policy clarity from the government is urgently needed to enable timely planning and implementation, so regions can start investing and transforming infrastructure once rules are defined.

A CSFE study estimates that annual benefits could surpass costs, averaging around 3.08 billion euros per year over the investment horizon.

Member states must transpose the directive by a deadline before late July 2027, underscoring the urgency for upfront planning and long-term capital commitments.