The Application of Statistical Process Control Techniques in Water Quality Monitoring in the Muda River Basin, Malaysia

This study focuses on measuring and evaluating river water quality using Statistical Process Control (SPC) techniques at the Muda river basin, Malaysia, based on the Interim National Water Quality Standard (INWQS). The individual control chart is proposed as a tool to monitor water quality data so that abnormal changes beyond the control limit can be detected in a timely manner, using the process capability indices, for evaluating river system performance, in terms of the risk of non-compliance situations. Two selected water quality parameters are taken into consideration - Dissolved Oxygen (DO) and pH. The study fills an important gap in the ISO 14000 and Total Quality Environmental Management (TQEM) literatures, which have focused more on environmental management systems and qualitative aspects, rather than on quantitative tools. It also explores how the process capability indices have the potential to be useful as a risk management tool for practitioners and how they help regulators execute and prioritize their enforcement efforts. Together, this should help in setting up useful guidelines for evaluating actual environmental performance against firms’ environmental objectives, targets and regulatory requirements, as well as in encouraging further development and application of SPC techniques in the field of environmental quality management and data analysis