Nf. Gray, THE USE OF AN OBJECTIVE INDEX FOR THE ASSESSMENT OF THE CONTAMINATIONOF SURFACE-WATER AND GROUNDWATER BY ACID-MINE DRAINAGE, Journal of the Chartered Institution of Water and Environmental Management, 10(5), 1996, pp. 332-340
Temporal and spatial comparisons of acid mine-drainage contaminated wa
ters are difficult because of the complex physico-chemical nature of t
he pollutant, and an objective index has been developed and evaluated
for the assessment of such waters. The acid mine-drainage index is cal
culated using a modified arithmetic weighted index utilizing seven par
ameters which are most indicative of acid mine-drainage contamination,
i.e. pH value, sulphate, iron, zinc, aluminium, copper and cadmium. W
eighting is used to express the relative indicator value of each param
eter. pH and sulphate are considered to be of greatest indicator value
as they are unaffected by sorption processes, while sulphate is also
unaffected by natural neutralization processes. The acid mine-drainage
index, as proposed, is designed to detect and quantify contamination
from acid mine drainage, and to help categorize samples, quantify impa
ct and to monitor the recovery of receiving waters.