Morphology, Geology and Water Quality Assessment of Former Tin Mining Catchment

Table 4

Interim National Water Quality Standards for Malaysia (INWQS) (2008).

Parameters		Classes
	Unit	I	IIA	IIB	III	IV	V
Ammonical nitrogen	mg/L	0.1	0.3	0.3	0.9	2.7	>2.7
BOD	mg/L	1	3	3	6	12	>12
COD	mg/L	10	25	25	50	100	>100
DO	mg/L	7	5–7	5–7	3–5	<3	<1
pH		6.5–6.8	6–9	6–9	5–9	5–9	—
Colour	TCU	15	150	150	—	—	—
Electric conductivity*	μmhos/cm	1000	1000	—	—	6000	—
Floatables		N	N	N	—	—	—
Odour		N	N	N	—	—	—
Salinity	%	0.5	1	—	—	2	—
Taste		N	N	N	—	—	—
Total dissolved solids	mg/L	500	1000	—	—	4000	—
Total suspended solids	mg/L	25	50	50	150	300	300
Temperature C	°C	—	Normal + 2°C	—	Normal + 2°C	—	—
Turbidity NTU	NTU	5	50	50	—	—	—
Faecal coliform**	Counts/100 mL	10	100	400	5000 (20000)a	5000 (20000)a	—
Total coliform	Counts/100 mL	100	5000	5000	50000	50000	>50000

Class I: Conservation of natural environment water supply—practically no treatment necessary. Fishery 1: very sensitive aquatic species.
Class IIA: Water Supply II—conventional treatment required. Fishery ll: sensitive aquatic species. CLASS IIB: recreational use with body contact.
Class III: Water Supply III—extensive treatment required. Fishery lll: common, of economic value, and tolerant species livestock drinking.
Class IV: Irrigation.
*: Related parameters, only one recommended for use.
**: Geometric mean.