Available online at: www.cbioresearch.com/journal.html ISSN No. 0973-8207 Anthropogenic impacts on the water quality of river Cauvery around Tiruchirappalli city, Tamilnadu V. Jeena and S. Kalavathy* P.G and Research Department of Environmental Sciences Bishop Heber College, Tiruchirappalli -17 *(E-mail: [email protected]) Abstract Periodical determination of water quality and assessment of the various threats to our fresh waters, especially rivers, is mandatory for conserving it. Hence the present work has been designed to determine certain important water quality parameters (pH, EC, TDS, turbidity, DO, COD, BOD, alkalinity, hardness, chloride and coliform status) and the threats to river Cauvery, from Upper anaicut to Grand anaicut (about 30km) during the months of June to December, 2009. From this study it is noted that the water is moderately polluted. Anthropogenic activities (industrial, commercial, occupational, social, public and individual) contribute to the water pollution, which needs stringent and immediate action. Keyword: Sewage, solid wastes, water quality parameters, riverine systems, economic loss and water borne diseases. Introduction 2000 and Kalavathy et al., 2011). The evaluation of the water quality periodically and frequently is Rivers have the distinction of changing mandatory to prevent further degradation and to barbarians into civilized-men. Man has always make the best use of the available resources. preferred to live nearer to the riverine systems due Hence the quality of water and anthropogenic to the enriched water resources, vast flats for impacts around Tiruchirappalli city was chosen for agricultural activities and easy mobility through this study. water ways (Thirugnanamoorthy, 2001). Only when the population has exploded beyond the limit, man Materials and Methods started spreading over to the other areas. While The study area in the river Cauvery, the riverine ecosystems have excellent prospects, extended between Upper anaicut and Grand these are equally prone to disasters like flooding, anaicut, about 15km on either side of Tiruchirappalli soil salinity, soil erosion and land subsidence city. Samples were taken in the alternative months (Ramasamy, 2001). Today, this ecosystem suffers (June-Dec 2009) from the following four sampling from the twin assaults of water depletion and spots:- degradation leading to drought and diseases respectively. Hence the studies on the reverine 1. Upper anaicut (Mukkombu): Flood control water systems have always remained an area of greater reservoir cum picnic spot significance. 2. Kambarasampettai: Water pumping stations and Cauvery is one of the perennial rivers upstream of Trichy city supporting the economy of Tamilnadu. The holistic 3. Bypass bridge: Down stream of Trichy city and development of Tiruchirappalli city can be attributed sewage confluence points to the supporting water resource of river Cauvery. 4. Grand anaicut (Kallanai): Flood control water On the other hand the city discharges its wastes reservoir cum picnic spot impairing the water quality. Many human activities Through grab sampling method, water such as industries, agriculture, transport and samples were collected in clean plastic containers sewage from residential areas along with cultural from all stations between 6a.m. and 8a.m. For the and religious practices pollute the river (Jayaram, analysis of coliform bacteria, sterilized plastic 39 Journal of Basic and Applied Biology, Vol. 7, No.1, 2013, pp. 39-45 ©2012, by the Centre for Biological Research, Puthalam, 629 602, TN, India V. Jeena and S. Kalavathy containers were used and stored in ice packs BOD and COD of all the samples in all during the transit. Vulnerable parameters such as the months were found to be beyond the prescribed pH, DO were determined in the field and all other guidelines. parameters (physico-chemical and bacteriological) in the laboratory as prescribed by APHA (1998). Water for drinking purposes should be Also results were compared with drinking water devoid of coliforms (Harilal and Sasikala, 2004). In quality standards (BIS, 1991 and CPCB, 2008). the present study, total coliform and fecal coliform All the anthropogenic activities were recorded counts of water samples were found to be very through enquiry from the available local resources high (table 1- 4). Total coliform count is commonly and personal observations. used as an indicator of water safety, showing the presence of other pathogenic organisms. Major Results and Discussion coliform bacteria causing gastroenteritis include In the present study pH values (7.9 – 8.5) Shigella, E. coli, and Salmonella, which causes fall within the prescribed limits (table 1-4). Krishna dysentery, urinary tract infections, diarrhea and et al., (2004) report that the pH value of river Bhadra vomiting (Kilmaren, 2011). to be 7.45. The Uyyakondan channel of Identified Anthropogenic Activities and their Tiruchirappalli city exhibited mild alkalinity (7.3 – Impacts 8.3) in a similar study (Kalavathy et al.,2011 and Jeena et al., 2012). A. Industrial, commercial and occupational exploitations EC values ranges between 670 - 982µS/ cm in the alternative months of June – Dec. In 1. Manufacturing industries earlier observation almost in the same area, the Closer to the sampling stations, there are EC range had been between 712 – 1025 µS/cm no major industries directly situated on the banks during summer (Sharma, 2009). of the river. Yet paper, dyeing, sugar, cement, diary, TDS ranges between 429 - 628mg/l. The tannery and distillery industries situated on the TDS value (513mg/L), at the By-pass bridge various directions, may influence the water quality exceeded the limit (500mg/L). indirectly through different water channels. Regarding impacts on the water quality, all the The average turbidity values of all the above mentioned industries have been grouped sampling stations exceeded the limit (5.0NTU). under red category by MoEF (1999). One of the distilleries located close to the sampling station Total hardness of all the samples in all at Bypass Bridge, discharge its treated effluents the months was within the limit (300mg/L). Lalitha in the Uyyakondan channel, a tributary of river et al., (2003) in an earlier study recorded the Cauvery. The impact is felt more during the rainy hardness range to be 200 – 750mg/L in the Cauvery season. water. Considerable changes are found in the The Alkalinity of all the sampling stations pH(Fig.1), EC(Fig.2), TDS(Fig.3), Turbidity(Fig.4), exceeded the limits (200mg/L). Jeyaram (2000) total hardness(Fig.5), DO(Fig.8), COD(Fig.9), and supported our observations through an earlier study BOD(Fig.10). The public report that at times the in the same river. Similar observations are also river water appeared colored and at these times reported by Rajurkar et al., (2003) in the water dermal and digestive disorders occurred. When this quality status of river Umkhrah at Shilong. water was irrigated the agriculture productivity was Observed values of chlorides were within the limit affected. (250mg/L). 2. Cottage industries In the present study, the DO levels of all the samples were well above prescribed limit Thatching and coir making activities are (6.0mg/l) excluding the bypass bridge during distributed randomly on the river banks especially December (table 1 - 4). between Mukkombu and Kambarasampettai. 40 V. Jeena and S. Kalavathy When the raw materials such as coconut leaves heavy metals from the benthic region, lowering of and fibres are soaked within or on the banks, the water table, change in the water course, reduction water soluble compounds viz. flavonoids, lignin, of self-purification capacity, disruption of the cellulose, phenols, sugar, tannins, amino acids, distribution and metabolism of aquatic organisms etc., (James et al., 2009 and Isreal et al., 2011) and impaired food chain of the riverine ecosystems diffuse in to the river. are the possible impacts of sand dredging. 3. Agriculture Because of the frequency and heavy weight of the trucks, roads are damaged and fatal The northern bank of the river is cultivated accidents occur. The local daily news papers often intensively with the wetland crops such as paddy, report this. banana, sugarcane, greens, vegetables, black gram and green gram. Various manures, synthetic B. Social and Public Abuses fertilizers, pesticides and growth regulators from 1. Water pumping stations the crop fields reach the river as runoff more during the rainy season, than due to irrigation. DDT(pp), All the villages, towns and cities situated chlordane and endosulfan have been estimated to on the banks of the river Cauvery are supplied with be in considerable quantities in the delta areas of the water, which is pumped out from the bore wells the river Cauvery (Kalavathy, 2009). The pH, DO, within the river. The ‘Ramanathapuram Combined EC, nitrogen and phosphorous of the water are Drinking water Scheme’ supplies water to the considerably affected. Algal blooms also Ramanathapuram district. Other beneficiaries are aggravates the situation (Jayaram, 2000). residents of Trichy, Srirangam, Thiruverumbur, Pudukottai, Karaikudi, etc., The water table lowers 4. Fishing down due to constant pumping out of water in Inland fishing is one of the chief various points of the river at the same time. occupations of the river bank dwellers. Upper anicut 2. Sewage discharges (Mukkombu) and Grand anicut (Kallanai) are commercial fishing stations and in other stations Point and non-point sources of sewage also fishing