During the cholera epidemic, donor and United Nations agencies and international nongovernmental organizations (NGOs) drilled over 200 boreholes in areas around Harare to provide safe drinking water. While those boreholes provided a needed source of potable water four years ago, they have not been maintained and many are now contaminated. Although some residents believed that boreholes were a safe water source because they were drilled by international organizations, a January 2013 study by Harare Water found that one-third of boreholes tested were contaminated.