Status Kualiti Air Tanah | Department of Environment

GROUNDWATER QUALITY STATUS

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). The groundwater quality status was determined based on the National Guidelines For Raw Drinking Water Quality from the Ministry of Health (Revised December 2000) (Table 4.2) as the benchmark.

Table 4.2 Malaysia : National Guidelines for Raw Drinking Water Quality (Revised December 2000)

Parameter

Symbol

Benchmark

Sulphate

Hardness

Nitrate

Coliform

Manganese

Chromium

Zinc

Arsenic

Selenium

Chloride

Phenolics

TDS

Iron

Copper

Lead

Cadmium

Mercury

SO₄

CaCO₃

NO₃

250 mg/l

500 mg/l

10 mg/l

Must not be detected in any 100 ml sample

0.1 mg/l

0.05 mg/l

3 mg/l

0.01 mg/l

250 mg/l

0.002 mg/l

1000 mg/l

0.3 mg/l

1.0 mg/l

0.01 mg/l

0.003 mg/l

0.001 mg/l

Source: Ministry of Health, Malaysia

Iron (Fe) levels exceeding the benchmark were recorded in all samples (Figure 4.1). 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%). Other parameters exceeding the acceptable values are shown in Figure 4.1.