Parameters

Dimension

Weight

Function

Dissolved oxygen

% saturation

0.109

0.82 DO + 10.56

BOD₅

mg/L, at 20˚C

0.097

108 (BOD)^−0.3494

Coliform

NMP-Coli/100 ml

0.090

136 (COLI)^−0.1311

E. coli

Faecal-Coli/100 ml

0.116

106 (E-COLI)^−0.1286

Alkalinity

ppm CaCO₃

0.063

110 (ALK)^−0.1342

Hardness

ppm CaCO₃

0.065

552 (HA)^−0.4488

Chloride

Mg/L, fresh water

0.074

391 (CL)⁻³⁴⁸⁰

Sp. Conductance

µmhos/cm 25˚C

0.079

506 (SPC)^−0.3315

pH

pH < 6.9

pH-units (6.9 - 7.1)

pH > 7.1

0.077

10^{0.6803 + 0.1856 (pH)}

1

10^{3.65 − 0.2216 (pH)}

Nitrate

As NO₃, mg/L

0.090

125 (N)^−0.2718

Temperature

˚C

0.077

$\text{1}{0}^{\text{2}.00\text{4}-0.0{\text{382}}_{\left({\text{T}}_{\text{a}}-{\text{T}}_{\text{s}}\right)}}$

Colour

Colour units-Pt std

0.063

127 (C)^0.2394