The Physico-Chemical Quality of Streams and Channels Draining into River Rwizi, South Western Uganda

There is an increased human population along the catchment area of river Rwizi who are engaged in various activities with potential to contaminate river Rwizi especially along the streams. Studies have been done to examine the physico-chemical quality of the mainstream river Rwizi in Mbarara Municipality. However, the comprehensive source of contamination may be beyond the municipality and yet the streams have not been investigated to substantiate their contribution on quality degradation of the river and this formed the basis of the study. This study determined the physico-chemical parameters of streams draining into river Rwizi. Raw water was purposively selected from streams in the upstream, midstream and downstream sections of the river. Water samples were analyzed for 15 physico-chemical parameters including dissolved oxygen (DO), colour, turbidity, total suspended solid (TSS), total iron (Fe), phosphates (PO3-4), alkalinity, magnesium (Mg), calcium carbonate (CaCO3), temperature, pH, ammonium (NH+4), electrical conductivity (EC), chloride (Cl) and nitrates (NO3). The water samples were analyzed following the standard methods of American Public Health Association and standard operating manual (1985). The obtained values were also compared with the international Environmental Protection Agency (EPA, 2001) guidelines for water quality and the National Environment Management Authority (NEMA, 1999) standards for waste water. The results showed that most of the streams in the downstream generally recorded the highest levels (p i.e. bus park stream (temperature, 27.6°C; colour, 431.17 TCU; TSS, 99.33 mg/l; alkalinity, 468.33 mg/l; Mg, 121.89 mg/l; CaCO3, 588.67 mg/l; Cl, 333.33 mg/l), Kikutu stream (turbidity, 123.58 NTU; EC, 698 μs/cm; DO, 55.73 mg/l; PO3-4, 12.85 mg/l), Kakyeka upper (pH, 10.52; NH+4, 46.67 mg/l), Rwentondo (Fe, 3.44 mg/l) and Kakyeka GBK (NO3, 10.83 mg/l). Most of the parameters downstream were higher than the EPA guideline (temperature, 25°C; colour, 20 - 150 TCUs; TSS, 50 mg/l; alkalinity, 400 mg/l; Cl, 250 mg/l; DO, 5 mg/l; PO3-4, 0.5 - 0.7 mg/l; pH, 5.5 - 9.0; NH+4, 0.2 - 4 mg/l; Fe, 0.2 - 2.0 mg/l) and NEMA standards (colour, 300 TCUs; Mg, 100mg/l; DO, 5mg/l; PO3-4, 10 mg/l; pH, 6.0 - 8.0). On the other hand, the streams in the upstream registered the lowest values of the parameters i.e. Kibimba (temperature, 17.28°C; EC, 31 μs/cm; PO3-4, 0.24 mg/l), Kasharara (colour, 15.17 TCU; TSS, 2.5 mg/l; pH, 6.23; alkalinity, 19.67 mg/l; DO, 9.99 mg/l; Mg, 4.41 mg/l; CaCO3, 23.17 mg/l) and Karungu (turbidity, 7.02 mg/l; Fe, 0.12 mg/l). Calcium carbonate hardness of the waters ranged from soft to excessively hard across the stream. The variations of the parameters detected in the streams in the downstream could reach adverse conditions if no intensive measures are taken to regulate the different anthropogenic activities within the catchment of river Rwizi.

[1]  Chromium in Drinking-water Draft Background document for development of WHO Guidelines for Drinking-water Quality , 2019 .

[2]  John Bosco Nkurunungi,et al.  Suitability of Drinking Water Sources from Nyaruzinga Wetland for Domestic Use in Bushenyi Municipality, Uganda , 2017 .

[3]  M. Andama,et al.  Physico-Chemical Quality of Selected Drinking Water Sources in Mbarara Municipality, Uganda , 2017 .

[4]  Xiaobin Xu,et al.  Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain , 2017 .

[5]  Joanna B. Whittier,et al.  Annual Changes in Seasonal River Water Temperatures in the Eastern and Western United States , 2017 .

[6]  J. Wasswa,et al.  Assessment of Seasonal Variation in Water Quality in River Rwizi Using Multivariate Statistical Techniques, Mbarara Municipality, Uganda , 2017 .

[7]  G. Hutton,et al.  The Knowledge Base for Achieving the Sustainable Development Goal Targets on Water Supply, Sanitation and Hygiene , 2016, International journal of environmental research and public health.

[8]  Suzanne Linnane,et al.  Water is Life, Progress to secure safe water provision in rural Uganda Rugby , 2015 .

[9]  K. Bacha,et al.  Physico-chemical and bacteriological quality of drinking water of different sources, Jimma zone, Southwest Ethiopia , 2015, BMC Research Notes.

[10]  J. Rumohr,et al.  A shared water risk assessment for a vulnerable river basin: River Rwizi in Uganda , 2015 .

[11]  J. Rumohr,et al.  Policy And Institutional Framework Considerations In The Implementation Of Catchment-based Water Resources Management In Uganda: Highlights From The River Rwizi Catchment , 2015 .

[12]  Nejat Rahmanian,et al.  Analysis of Physiochemical Parameters to Evaluate the Drinking Water Quality in the State of Perak, Malaysia , 2015 .

[13]  F. Fatone,et al.  A basic bottom-up approach for small systems of safe-water supply: A decentralized case study in Uganda , 2015 .

[14]  J. Poesen,et al.  Conserving soils: Soil and water conservation technologies in the upper Rwizi microcatchment of Southwestern Uganda , 2015 .

[15]  Junlei Tang,et al.  Effects of drinking water acidification by organic acidifier on growth performance, digestive enzyme activity and caecal bacteria in growing rabbits , 2014 .

[16]  S. Deepak,et al.  The Relationship between Physico-chemical Characteristics and Fish Production of Mod sagar Reservoir of Jhabua District, MP, India , 2014 .

[17]  C. Olowu,et al.  Physico Chemical Parameters and Phytoplankton Assemblages along Spatial and Temporal Gradients in Great Kwa River, Calabar, Nigeria , 2014 .

[18]  J. Mbabazi,et al.  Heavy Metal and Nutrient Loading of River Rwizi by Effluents from Mbarara Municipality, Western Uganda , 2014 .

[19]  S. MacIntyre,et al.  Assessment of physicochemical parameters in relation with fish ecology in Ishasha River and Lake Edward, Albertine Rift Valley, East Africa , 2014 .

[20]  O. Akintoye,et al.  Seasonal Variation in the Physico-chemical Characteristics of Surface Water in EtcheRiver, Niger Delta Area of Nigeria , 2014 .

[21]  Aarti Patel,et al.  SEASONAL VARIATIONS OF PHYSICO-CHEMICAL CHARACTERISTICS OF RIVER BETWA IN VIDISHA DISTRICT , 2014 .

[22]  Reetu Sharma,et al.  Diversity of Macrozoobenthos in Morand River- A Tributary of Ganjal River in Narmada Basin , 2013 .

[23]  A. Mahazar,et al.  Monitoring urban river water quality using macroinvertebrate and physico-chemical parameters: case study of Penchala River, Malaysia. , 2013 .

[24]  Michael,et al.  Rainwater Quality Assessment In The Tamale Municipality. , 2013 .

[25]  K. Schwartz,et al.  Commercialisation and centralisation in the Ugandan and Zambian water sector , 2012 .

[26]  M. Muthangya,et al.  Physico-chemical and bacteriological quality assessment of shallow wells in Kitui town, Kenya , 2012 .

[27]  K. Murugan,et al.  Identification of source of faecal pollution of Tirumanimuttar River, Tamilnadu, India using microbial source tracking , 2012, Environmental Monitoring and Assessment.

[28]  O. Joseph,et al.  Biological and physiochemical properties of shallow wells in Ikorodu town, Lagos Nigeria , 2011 .

[29]  B. Kiran,et al.  Fish diversity in relation to physico-chemical characteristics of Bhadra reservoir of Karnataka, India , 2011 .

[30]  U. D. Kulkarni,et al.  AN ASSESSMENT OF THE PHYSICO-CHEMICAL PROPERTIES TO STUDY THE POLLUTION POTENTIAL OF UJJANI RESERVOIR, SOLAPUR DISTRICT, INDIA , 2011 .

[31]  R. K. Somashekar,et al.  Physico-Chemical and Bacteriological Investigation on the River Cauvery of Kollegal Stretch in Karnataka , 2010 .

[32]  M. Mustapha,et al.  An assessment of the physico–chemical properties of Moro lake , 2008 .

[33]  O. Adeyemo,et al.  SEASONAL CHANGES IN PHYSICO-CHEMICAL PARAMETERS AND NUTRIENT LOAD OF RIVER SEDIMENTS IN IBADAN CITY, NIGERIA , 2008 .

[34]  D. Hongve,et al.  Spectrophotometric determination of water colour in hazen units , 1996 .

[35]  Y. Sayato,et al.  WHO guidelines for drinking-water quality. , 1989 .

[36]  G. Ozolins,et al.  WHO guidelines for drinking-water quality. , 1984, WHO chronicle.

[37]  W. P. Mason.  WATER ANALYSES. , 2022, Science.