The European Investment Bank (EIB) is lending €100 million (£75.7m) for a wastewater project in Belgium.
It is the second part of a €200 million (£151m) loan agreed in December 2014.
Wastewater operator Aquafin will use the funds to solve bottlenecks in the existing sewage infrastructure, separating stray and rain water from the sewage network.
It will also upgrade existing treatment plants and build new facilities.
EIB Vice President Pim van Ballekom said: “Since 1990, Aquafin has managed to raise the percentage of water being treated from 30% to over 80% and the investment we’re doing today is a tangible implication of the European and Belgian priorities for man and nature.”