ENVIRONMENTAL IMPACT ASSESSMENT OF AN ENGINEERED WASTE DUMPSITE AT UVWIAMUGE, DELTA STATE :IMPLICATIONS FOR PUBLIC HEALTH EDUCATION

Abstract

The Environmental Impact Assessment of an Engineered dumpsite and its implications for Public Health Education was investigated using dumpsite located at Uvwiamuge, a community in Ughelli North Local Government area of Delta State. The dumpsite is owned and operated by Shell Petroleum Development Company (SPDC-West), Warri, purposely for the disposal of domestic wastes. The operator of the dumpsite (SPDC, Warri) started its use 1st March, 1995. From the commencement of its operation in March 1995 to October, 1997, a total of 9,415 4 tonnes of wastes were disposed. The total site area is about 16,500m². The study area is a lowland that lies in the Niger-Delta area. The ground water table in this area is very high, ranging from 1.0-3.5m at the peak of rainy season rendering the area susceptible to pollution from dumping of waste. There are no presence of surface water close to the dumpsite except the stagnant water in the leachate lagoon that receives the discharge leachates from the saver pit. The study is to assess the impact of the dumpsite on the environment, viz groundwater, soils and other ecological systems in the vicinity. The study was exploratory and analytical in design. Samples of deep borehole (located within the dumpsite) intended for community use and monitoring boreholes (shallow boreholes), surface waters, soils at depths of 0-15cm and 15-30cm samples of the streams of waters and their leachates from the saver pit were collected using purposive sampling method. A total of different samples were analysed using analytical methods as described by the American Public Health Association (APHA, 1991) and Association of Analytical Chemist (AOAC, 1980). A Health survey was conducted by administering questionnaires to all the workers (32) at the dumpsite and a control group (32) living away from the dumpsite to assess their demographic characteristics, occupational characteristics and common health problems as experienced and perceived by them. Results indicated that the leachates from the solid wastes in the saver pit showed amber appearance. The samples were basic with mean pH of 7.03±0.180 as against the pH value of the background level of 8.40 that was carried out in March, 1995. The B0D₅, COD, oil and grease contents, turbidity, and iron (mean value )of the leachate were 138.2 ± 14.8 mg/l, 240.7 ± 14.8 mg/l, 3.28 ± 1.60mg/l, 15.±2.21 mg/l and 1.97 ± 2.524mg/l as compared to 10mg/l, 40mg/l, 10mg/1, 10mg/1,10mg/1 respectively of department of petroleum Resources recommended values. The soil samples showed pH values ranging from 4.0 - 5.63 mg/kg while the oil and grease content 35.5-65.38mg/kg. The iron content ranges from 13.26-17.80mg/kg as against the critical value of 5.0mg/kg. The analysis also showed presence of other heavy metals of varying ranges as follows: lead 0.38 - 0.623 mg/kg, copper 0.0665 - 0.210 mg/kg, chromium 0.043 - 0.253 mg/kg, nickel 0.64 -0.85mg/kg and zinc 0.345 - 0.40 mg/kg. The surface water in the leachate lagoon showed COD and BOD₅ values as 16.30 ± 0.836 and 6.89 ±2.515 respectively. The heavy metals assessed were within WHO, DPR and FEPA's limits except the values for iron which is 0.156 ± 0.023 as against WH0 limit of 0.1 mg/l. The results of the total coliform count (MPN/100) showed 43 ±29 as against "virtually absent" recommended by WHO for domestic use. The deep borehole water analysis showed that all the parameters determined except iron, TSS and oil and grease content were within WHO limits of potable water anaiysis. The iron mean value was 0.122 ± 0.128mg/l as against 0.1 mg/l and <0.3 mg/l of WHO and FEPA's limit respectively. The TSS value was 1.72 ± 0.832mg/l as against "virtually absence" recommended by WHO and FEPA. The oil and grease contents was 5.93± 1.502mg/l. The microbiological examination showed absence of total coliform, E. Coli, faecal streptococci and clostridium perfringens. The shallow boreholes water analysis showed pH mean value of 6.79 ± 0.506 as against 5.4 of the baseline value. The BOD₅, mean value was 5.28 ± 3.958 mg/l and oil and grease content 0.46± 0.918mg/l. The heavy metal analysis showed lead values as 0.021± 0.080mg/l and iron 0.387± 0.651mg/I. Although all the parameters exceed baseline values, only TDS and iron values exceeded the recommended limits by WHO, DPR and FEPA. Result of the questionnaire analysis revealed that the poor maintenance of the dumpsite has a negative impact on the health of the waste workers. The most common health complaints were headache (87.5%), aching joints (93.8%), back pains( 75.0), skin irritation/itching (68.8%), sinus congestion (71.9%) for the experimental group as against headache (71.9%), aching joints ( 15.6%), back pain (62.5%), skin irritation/itching (21.9%) and sinus congestion (31.2%) for the control group. The most significant problem associated with the management in operation of the dumpsite is the infestation of the dumpsite by vermin which are of public health importance. Based on the results of this study, the identified enyirenniemal problems and health risks associated with the operation of the engineered dumpsite will no small measure help in the formulation of better management methods for improved environmental quality and public health status.