Table 1.

Environmental quality standards for Peruvian river water³⁹.

Physicochemical and biological indicators	A1 Waters that can be made potable with disinfection	A2 Waters that can be treated with conventional treatment conventional treatment	A3 Waters that can be treated with advanced treatment
T (°C)	Δ3	Δ3	**
pH	6.5–8.5	5.5–9.0	5.5–9.0
DO (mg/L)	≥ 6	≥ 5	≥ 4
EC (µS/cm)	1500	1600	**
TDS (mg/L)	1000	1000	1500
TSS (mg/L)
Cadmium (µg/L)	3	5	10
Arsenic (µg/L)	10	10	150
Chrome (µg/L)	50	50	50
Lead (µg/L)	10	50	50
Escherichia coli (NMP/100 mL)	0	**	**
Pseudomonas aeruginosa (NMP/100 mL)	**	**	**
Enterococci (NMP/100 mL)	**	**	**

**Not applicable.