Physico-Chemical Quality of Selected Drinking Water Sources in Mbarara Municipality, Uganda

The study assessed the physico-chemical quality of selected drinking water sources (springs, boreholes, shallow wells and rainfall) in Mbarara municipality with respect to World Health Organization (WHO) drinking water guidelines and other guidelines in light of the increased anthropogenic activities in the municipality. A total of 70 water samples were collected from purposively selected boreholes, springs, wells and rainwater in Nyamitanga, Kamukuzi and Kakoba divisions of Mbarara municipality with various human activities. The samples were analysed for physico-chemical parameters: Temperature, pH, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Total Dissolved Solids (TDS), Electrical Conductivity (EC) and Total hardness using American Public Health Association (APHA) standard methods. The mean temperature and pH ranged between 18.07 °C - 23.45 °C and 5.74 - 7.54, respectively. The mean DO values were found to be between 4.84 and 12.86 mg/l;whereas mean BOD was within the range of 1.83 - 7.71 mg/l. The mean TDS and EC of the water samples ranged, between 33.40 - 569.20 mg/l and 29.30 - 1139.90 μS/cm respectively. Furthermore, the lowest and highest mean total hardness were 70.00 and 264.00 mg/l, respectively. The recorded mean water temperatures for each of the water sources were above the WHO threshold temperature (15 °C) which makes drinking water palatable. Boreholes in Nyamitanga and Shuhaddea Secondary Schools, spring in Kiswahili, well in Kisenyi and rainwater in Mbarara University of Science and Technology (MUST) had mean pH below the WHO minimum guideline value (6.5) hence acidic. Borehole in Nyamitanga secondary school, spring in Kisenyi, shallow well in Nyamitanga and the rainwater in MUST had mean DO values below the WHO range (10 - 12 mg/l). Borehole in Shuhaddea Secondary School and the well in Kisenyi had average BOD values above the range of European Union guideline values (3 - 6 mg/l). TDS and EC of all the water sources were below the WHO maximum guideline limits of 1000 mg/l and 1500 μs/cm respectively. Total hardness was also below the WHO harmless limit of 1000 mg/l. However rainwater in MUST was moderately soft while the other drinking water sources exhibited moderate to full total hardness. The physicochemical parameters of some of the selected water sources in Mbarara municipality have been compromised mainly by the increased human activities especially croplands, latrines, landfills, transportation, animal and municipal wastes at the vicinity of the water sources. Mbarara municipal council should therefore ensure proper sanitation and water safety plans for these drinking water sources to avoid further contamination from the human activities.

Bacterial Analysis of Selected Drinking Water Sources in Mbarara Municipality, Uganda

Surveillance of water quality to ensure microbiological safety is a vital public health function to prevent water borne diseases. Bacterial total coliform and Escherichia coli (E. coli) examination provide indication of the hygienic condition of drinking water and are major tools in the assessment of the health risk borne by pathogen in water. Unfortunately, there is insufficient information on the total coliform and E. coli amounts in the common drinking water sources in Mbarara Municipality, Uganda despite the eminent anthropogenic sources of contamination. Hence the study established the sanitary risk and quantified the total coliform and E. coli load in selected drinking water sources in Mbarara Municipality, Uganda. A total of 70 water samples were collected from selected boreholes, springs, wells and rainwater in Nyamitanga, Kamukuzi and Kakoba divisions of Mbarara municipality. The water samples were analysed for total coliform and E. coli abundance using the American Public Health Association (APHA) standard method. The total coliform and Escherichia coli counts were compared with the World Health Organization (WHO) drinking water standard guidelines. The findings indicate that all the studied groundwater sources (boreholes, springs and wells) in Mbarara Municipality were not compliant to either both or one of the WHO total coliform ( ml) and E. coli (0 CFU/100 ml) criteria for drinking water hence they are unsuitable for drinking without treatment e.g. boiling etc. Only rainwater collected from Mbarara University of Science and Technology met the WHO total coliform and E. coli criteria for drinking water thus is suitable for drinking without any treatment. There is a strong linkage between bacterial (total coliforms and E. coli) water quality and water source sanitation, as well as the proximity of latrines, animal farms and landfills around the water sources. Mbarara municipal council should therefore ensure effective and regular operation and maintenance of the drinking water sources through the adoption and promotion of appropriate water safety plans.

Physico-Chemical Quality of Lake Kyoga at Selected Landing Sites and Anthropogenic Activities

Lake Kyoga, one of the great African lakes in Uganda is facing an increasing pressure from human activities yet there is limited information on water quality of the lake. Therefore this study determined selected physico-chemical parameters of Lake Kyoga at some landing sites (Kayei, Acholi inn, Waitumba, Masindi port) and anthropogenic activities (boat dock, waste site, garden, fishing). The parameters included temperature, pH, water flow rate, dissolved oxygen (DO), nitrite (NO2-) and phosphate (PO4-P). The American Public Health Association (APHA) and Water Watch Australia protocols, standard meters, Merck’s rapid test kits and timing of a float were used to measure the parameters. The results showed that the mean temperature, pH, DO, and PO4-P significantly (p 2- levels were within the EPA drinking water guideline of 0.5 mg/l. The orthophosphates (PO4-P) were highest in the waste sites (0.35 mg/l), followed by gardens (0.24 mg/l) and least in the fishing areas (0.12 mg/l). However, phosphates in the form of P2O5 were higher than the EPA standard value (0.5 mg/l) at Kayei (0.55 mg/l) and Acholi inn (0.55 mg/l) landing sites as well as at waste sites (0.80 mg/l) and gardens (0.55 mg/l) pointing to high nutrient (phosphorus) input at these sites. The high concentrations of nitrites in Lake Kyoga at the investigated anthropogenic activities and landing sites plus phosphate amounts close to waste sites and gardens including Kayei and Acholi inn landing sites call for vigilance in protection of Lake Kyoga through optimized planning. Hence, National Environment Management Authority should ensure proper sewage management in Lake Kyoga catchment to avoid discharge of untreated sewage into the lake. The authority should also regulate waste dumping and cultivation around the lake so as to reduce nutrient (phosphorus) enrichment.

Proliferation of <i>Salvinia molesta</i>at Lake Kyoga Landing Sites as a Result of Anthropogenic Influences

Salvinia molesta (native of south-eastern Brazil) is a free floating aquatic fern that has spread to several countries around the globe including Uganda. Under optimum growing conditions, the plant is capable of spreading rapidly where it can have immense environmental, economic and human health impacts. Thick mats of the weed have been recorded in some parts of Lake Kyoga, Uganda where it hinders the abstraction of water, docking and boat take-off, bathing and swimming activities. Therefore this study aimed to determine the extent of S. molesta at selected landing sites in Lake Kyoga and the influence of anthropogenic activities on the weed coverage as well as the effect of physico-chemical parameters of the water on the development of the weed. Quadrats were used to ascertain the coverage of S. molesta while the physico-chemical parameters were determined by standard methods. The results showed significant positive correlation of S. molesta weed coverage with phosphates (PO4-P) and negative correlations with pH, dissolved oxygen (DO) and water flow rate. Though statistically insignificant waste sites recorded the highest overall S. molesta coverage (82.61 ± 21.12 m2) per 400 m2 quadrat followed by boat docks (82.24 ± 19.45 m2), gardens (50.93 ± 11.82 m2) and finally fishing areas (27.94 ± 5.93 m2) respectively. The overall weed coverage was highest around the shoreline locations of Acholi inn landing site (101.72 ± 22.89 m2 per 400 m2) followed by Masindi port (60.39 ± 15.64 m2), Waitumba (41.89 ± 10.55 m2) and the least in the offshore location at Kayei landing site (39.71 ± 10.17 m2). Salvinia molesta distribution in Lake Kyoga is linked to nutrient (PO4-P) supply, proximity to the shoreline and the associated anthropogenic activities. Hence waste sites, gardens and boat docks enhance S. molesta invasion in Lake Kyoga. Therefore, sources of nutrients (phosphates) into Lake Kyoga that favour the proliferation of S. molesta should be minimized through adequate waste treatment and prohibition of cultivation close to the lake. Salvinia molesta coverage along the routes of moving boats should also be contained so as to reduce the spread of the weed in the lake through boat movements. Furthermore, eradication efforts of S. molesta weed in Lake Kyoga should be heightened at the shoreline areas of the lake in the various landing sites within the lake basin.