| Popis: |
The impact of uncontrolled municipal solid waste disposal of 3800 tons per day on surface and groundwater downstream of the Jawaharnagar dumping site was studied. The un-engineered solid waste dumping yard site spreading over about 300 hectares (ha) is located on topographic high (hillock) and falls in Madyala stream and Dammaiguda watersheds of Musi sub-basin. Granites of the Archaean age underlie the area. Both surface and groundwater samples, collected covering hydrological cycles of 2011and 2012, were analyzed for major chemical constituents. Fifteen samples belonging to both seasons of 2012 were tested for BOD, COD, and TOC. The mean values of some tested chemical constituents of surface water samples (15) were - EC 13066 m S/cm, TH 753, Na+ 813, K+ 530, HCO3- 978, Cl- 1304, and NO3- 262 (all in mg/l), which prove that tanks and stream near the dump yard were pools of leachate. The average values of contaminated groundwater samples among the four sampled sessions (17) indicate EC was above 5000 m S/cm, TH 1624, Cl- 1502, and SO42- 284(all in mg/l), which were found much above the threshold values. Very high TOC (mean SW 241; GW 154 mg/l), BOD (5410; 117), and COD (6427; 176) content in both surface (SW) and groundwater (GW) samples indicate the presence of organic pollutants sourced from domestic waste dumps. Wide temporal and spatial variability in the concentration of many ion species could be due to rainfall deviation, point source changes, and heterogeneous fracture patterns. Low resistivity values (5 to 25 ohm.m) at a distance of 4 km from the dumping site and high infiltration rate (29 cm/hr) at the Madyala stream indicate hydrological features controlled the mass flux. The chloride-sulphate alkaline-earth water facies, K+:Mg2+ and BOD/COD ratios demonstrate apart from anthropogenic input water-rock interaction and evapotranspiration governed the evolution of water chemistry. The study supports the hypothesis that solid waste dumps, which attained the methanogenic phase, were a point source of pollution that generates leachate and dissipates contaminants to the aquatic environment through preferred pathways influenced by factors like soils, topography, aquifer hydraulics, and contaminant kinetics. |
