Just £137k of £8.6m invested to refurbish minor wastewater works in NI from November 2011 to spring 2013 was spent in Londonderry.
The upgrades were at Bready, Creaghcor and Knockbrack.
Danny Kennedy said: “NI Water’s Base Maintenance Investment scheme was set up specifically to refurbish over 50 minor wastewater works that span the length and breadth of Northern Ireland. Phase one of the project is progressing on schedule, with the upgrades at these sites now complete.
“The latest technology that has been used has already increased efficiencies to the wastewater treatment plants, including cost reductions in running cost, and reduced energy use. All the improvements meet Northern Ireland Environment Agency Standards and will facilitate future local development.
“Each project represents a significant investment in modernising wastewater treatment in rural areas. They bring environmental benefits for local communities. I am confident of continued positive progress on this essential project.”
Sara Venning, interim Chief Executive of NI Water added: “The team has made great progress to date and I would like to take this opportunity to thank all the teams involved in getting us to this stage of the project.
“There has been a sustained improvement with compliance of discharges from wastewater treatment works over a number of years, which is a direct result of investment programmes such as this Base Maintenance project.
“We are looking forward to continuing to work with teams of specialist local contractors including Graham Construction and Lagan Construction. We also welcome the opportunity to work with other local companies in the supply chain and will continue to develop new technologies and processes that will benefit wastewater services for our customers.”