Along the southern shore of the Pool, the land is swampy between the mouths of the Nsele and Ndjili rivers, a distance of 30 kilometres (19 mi), with the swamps covering 10,800 hectares (27,000 acres).
When turbidity levels rise above the 1,000 NTU limit, which has often been reported in the Ndjili and Lukaya rivers during the rainy season, water purification plants have to stop their operations.
[9] On a positive note, after a four-year 51 million euro project financed by the World Bank, in 2009 the Ndjili plant doubled its capacity to 330,000 cubic metres (12,000,000 cu ft) daily, providing nearly 65% of Kinshasa's water supply.
[10] In 1954 the Belgian colonial administration distributed land to women and the unemployed in the marshy region of the Ndijili River in an effort to create a garden peasantry to provide fruit and vegetables to the capital.
Problems included difficulty in obtaining seeds, fertilizers, farm tools and irrigation water, theft of vegetables during the night, poor roads, infectious diseases, lack of electricity and flooding.
[13] Human African trypanosomiasis, or sleeping sickness, is a disease that usually only occurs in rural locations, since it is spread by tsetse flies that need a combination of forest and water to thrive.
Counts of tsetse flies from insect traps along the Ndjili River indicate that market gardening has recreated the conditions needed for active disease transmission.