September 2007

Improving Water Quality in Moldova through an Environmental Infrastructure Project and Constructed Wetlands

The Nistru River starts in the Ukrainian Carpathian Mountains, flows through Moldova, and reaches Ukraine again near the Black Sea. This important transboundary water resource is under environmental pressure from municipal and industrial point sources in the city of Soroca and elsewhere and from agricultural nonpoint sources. In turn, Nistru’s pollution affects Moldova and the greater Black Sea, once a rich fishing ground and popular vacation site, but now a damaged ecosystem.

A GEF project is seeking to improve water quality in the Nistru River by helping the Moldovan government treat the wastewater from the city of Soroca and by building wetlands.

The project focuses on rehabilitation of wastewater collection systems in Soroca and construction of a wastewater treatment facility using constructed wetlands. It also provides technical assistance and support for building the Constructed Wetland Treatment Plant. This component will include important analysis of the opportunities for the replication of the technique in other regions of Moldova.

Constructed Wetlands

Constructed wetlands are man-made and can be placed where there are no wetlands. The main rationale behind the constructed wetlands is that they mimic nature by mechanically filtering, chemically transforming, and biologically consuming potential pollutants in the wastewater stream.

Removal rates differ in constructed wetlands according to the specific nutrients that may be targeted, but one can expect reduction rates around 50 percent for nitrogen and phosphorous and up to 90 percent for Biological Oxygen Demand (a measure of the organic material in the water). Generally, the costs of constructing a wetland are between 20-30 percent (in EU) and 50-90 percent (in United States) lower than conventional wastewater treatment systems. Moreover, only low-level operation and maintenance skills are needed.

GEF ‘s Constructed Wetlands Portfolio

The GEF has funded 10 projects that contain constructed wetlands as one of the outputs. Constructed wetlands projects are spread over Asia, Africa, and Central and Eastern Europe, with the main fraction being situated in Central and Eastern Europe. The focus on Central and Eastern Europe has been a natural effect of GEF’s work undertaken under the Danube/Black Sea Strategic Partnership—Nutrient Reduction Investment Fund.

The GEF supports constructed wetlands and other low technology approaches because they provide a range of economical, sustainable, and innovative solutions towards reducing nutrient run-offs into fresh and marine waters.