Ground water

The groundwater quality status was determined based on the National Guidelines for Raw Drinking Water Quality from the Ministry of Health (Revised December 2000) as the benchmark.

By 2006, 88 monitoring wells had been established at 48 sites in Peninsular Malaysia, 19 wells in Sarawak and 15 wells in Sabah. The sites were selected and categorized according to the surrounding land uses which were agricultural, urban/suburban, rural, industrial, solid waste landfills, golf courses, radioactive landfill, animal burial areas, municipal water supply and examining areas (gold mine).

In 2006, 340 water samples were taken from these monitoring wells compared to 250 in the previous year (2005). The samples were analysed for volatile organic compounds (VOCs), pesticides, heavy metals, anions, bacteria (coliform), phenolic compounds, radioactivity (Gross Alpha and Beta), total hardness, total dissolved solids (TDS), pH, temperature, conductivity and dissolved oxygen (DO).

Iron (Fe) levels exceeding the benchmark were recorded in all samples. Between 30 percent and 100 percent of the samples taken from all sites showed high levels of iron. The sampling results also showed that between 15 percent and 100 percent of samples taken from all areas recorded manganese (Mn) levels exceeding the benchmark. Between 5 percent and 13 percent of samples in rural areas (5%), landfills (5%), municipal water supply (5%), golf courses (7%), agricultural areas (9%) and industrial areas (13%) were found to exceed the nitrate benchmark except in urban/suburban, ex-mining areas and radioactive landfills. Arsenic levels exceeding the benchmark were recorded at radioactive sites (100%), ex-mining areas (67%), solid waste landfill (44%), municipal water supply (36%) and agricultural areas (20%).