ANALYSIS OF WATER QUALITY PARAMETERS IN WELL WATER IN THE VICINITY OF AN INDUSTRIAL ZONE AND ANALYSING SOURCES AND EFFECTS

Abstract

The Ratmalana - Moratuwa area located in the south of Colombo has developed as anindustrial residential suburb of Colombo in the 1950's. It has been revealed that theenvironmental problems in the area are very acute due to the activities of large number ofindustries. About 150 industries arc densely packed, within this area. Most of the industries.are non-agro based industries. They can be catcgoriscd into several groups such as paintindustries, galvanising industries, asbestos industries, dyeing and finishing,pharmaceutical industries and battery manufacturing industries. According to aninvestigation of discharges produced in the area :: was found that major part of the effluentwas released via surface drainage to Lunawa and Bolgoda Lake. The main issue associatedwith this industrial pollution is water contamination. Even though many studies have bccncarried out on surface water contamination, studies on ground water contamination havenot been done in detail. The intention of this study was to, analyse ground water samples atvarious sites of the industrial zone and to relate the results to thc present industrialactivities of the area. From these studies it was found that the chemical oxygen demand(COD), levels far exceed the acceptable portable water quality standards, indicating highchemical pollution. In addition it was found that Chemical pollutants arc present in theground water. Biological Oxygen Demand (BOD) has exceeded the tolerant limits forportable water level at several locations. The trace metals that exceed the levels arc Zn, Fe,Cd, Pb, and Ni which had not been noted in a previous study done by De Silva et al.( 1986).

Low pH values- in some of the samples indicate water contamination with acids. SOl\1esamples have been contaminated with acids and it was revealed by low pl l of sonicsamples, Most industries in the area dispose their effluents directly in to thc drainagesystem without any prior treatments. Ground water contamination is thought to be a directconsequence of these inefficient effluent systems. This study discusses the analytical resultsof water samples taken from various locations of the industrial area and described theindustrial activities ill the area that might have caused this ground water contamination,and discusses possible health effects due to use of polluted watcr as a source of portablewater in this well water.