Table 1: Summary of the physical and chemical parameters of the Lower Cross River study stations (January–August, 2011). Values are mean ± SE. The minimum and maximum values are noted in parentheses.

ParametersStation 1Station 2Station 3Statistical significanceMaximum permitted levels

Air temperature (°C)

Water temperature (°C) Ambient

Transparency (m)

Water level (m)

TDS (mg/L) 500NHC

TSS (mg/L)0.0128 ± 0.005

TS (mg/L)

Flow velocity (m/s)

Electrical conductivity ( S/cm) 1000

pH 6.5–8.5NHC

Alkalinity (mg/L CaCO3)

Dissolved oxygen (mg/L)

BOD5 (mg/L)

COD (mg/L)

Nitrate (mg/L) 5050

Sulphate (mg/L) 100NHC

Phosphate (mg/L)

Similar letters indicate means that are not significantly different from each other.
NHC means not of health concern at levels found in drinking water.
: not significant; : significant.