scholarly journals Assessment of the Impact of Rainfall Variability on Drinking Water Production at Treatment Plants in Nzoia River Basin, Kenya

Author(s):  
Ernest Othieno Odwori

Increased wet season rainfall is associated with improved water supply at point water sources and improved river flows and water reservoir levels. For piped water supply schemes with surface water intakes, this is supposed to enhance operations since there is adequate raw water unlike in the dry season where operations are interrupted due to insufficient flows. However, this is not the case in Nzoia River Basin as established by this study. As rainfall increases, drinking water production in treatment plants at Moi’s Bridge, Lumakanda and Busia water supplies decrease and vice versa. Nzoia River Basin is one of the regions that is highly vulnerable to climate variability in Kenya, hence understanding rainfall variability and trends is important for better water resources management and especially drinking water supply. This study aimed at assessing rainfall variability and trends for 3 rainfall stations in Nzoia River Basin; Leissa Farm Kitale, Webuye Agricultural Office and Bunyala Irrigation Scheme and its impact on drinking water production at Moi’s Bridge, Lumakanda and Busia water supplies treatment plants. The rainfall data used in this study covers 31 years period from 1970 to 2001 and was obtained from the Kenya Meteorological Department (KMD), Nairobi, Kenya. Monthly water supply production data for Moi’s Bridge, Lumakanda and Busia water supplies covering 15 years period from 2000 to 2014 was obtained from the County governments of Uasin Gishu, Kakamega and Busia. Rainfall variability and trend was analysed using the parametric test of Linear regression analysis and the non-parametric Mann Kendall statistical test. Monthly rainfall and monthly drinking water production was analysed using Pearson moment correlation to establish the relationship between monthly rainfall and monthly drinking water supply production at Mois Bridge, Lumakanda and Busia Water supplies treatment plants. The results of variability and trend in annual rainfall shows Webuye Agricultural Office recording declining rainfall at -0.8994 mm/31 years (-0.029 mm/ year); whereas Leissa Farm Kitale shows increasing rainfall at 1.0325 mm/31 years (0.033 mm/ year) and Bunyala Irrigation Scheme’s rainfall is increasing at 0.5245 mm/31 years (0.017 mm/ year). Drinking water supply production at Moi’s Bridge, Lumakanda and Busia water supplies has been increasing with time between 2000 and 2014. The results of Pearson moment correlation coefficient shows a strong negative relationship between monthly rainfall and monthly drinking water supply production at 0.05 significance level for Moi’s Bridge, Lumakanda and Busia water supplies. This shows that as rainfall increases, drinking water supply production in treatment plants at Moi’s Bridge, Lumakanda and Busia water supplies decreases. During the rainy season, the cost of water treatment goes up as a result of increased turbidity. Increased rainfall in Nzoia River Basin presents water treatment challenges to the existing water supply treatment plants resulting into reduced production.Water supply managers should improve the capacity of the existing water supply treatment plants to cope with the increased rainfall variability under the changing climatic conditions.

2008 ◽  
Vol 8 (3) ◽  
pp. 319-324 ◽  
Author(s):  
P. Eckert ◽  
R. Lamberts ◽  
C. Wagner

Riverbank filtration (RBF) is a well proven natural treatment, which in many countries is part of a multi-barrier concept in drinking water supply. The induced infiltration of river water into the aquifer produces a significant improvement in river water quality. Riverbank filtration wells are characterized by a high capacity. Based on data from recent years, an integrated approach to assessing the impact of climate change on safe drinking water production by RBF is demonstrated in the Lower Rhine Valley, Germany. Influencing factors on quantitative as well as qualitative aspects were identified. During low river water periods, the capacity of the RBF-wells decreases. In addition the lower discharge within the river is accompanied by a increased concentration of several chemical compounds. Together with higher water temperatures which influence the hydrogeochemical processes during RBF, the changing raw water composition has to be considered for the subsequent technical treatment step. However, our investigations reveal that despite the impact of climate change on RBF, the multi-protective barrier concept, including both natural and technical purification, has proven a reliable method for drinking water production. The sanitation of the Rhine over the last decades was an important step to make RBF more resilient to climate change.


2018 ◽  
Vol 16 (2) ◽  
pp. 84
Author(s):  
G A Blagodatsky ◽  
A A Bass ◽  
M M Gorokhov ◽  
D S Ponomarev

Работа посвящена системному анализу данных показателей исходной воды при производстве питьевой воды в системе центрального водоснабжения крупного населенного пункта. На сегодняшний день на фоне увеличивающегося негативного антропогенного воздействия на окружающую среду наблюдается ухудшение состояния многих источников питьевого водоснабжения в широком спектре показателей, в частности, таких как органолептические свойства воды. Как следствие, возникает проблема и для питьевой воды. В работе приводится процесс подготовки данных о параметрах исходной воды, забираемой из водохранилища, которые ежемесячно (с 2002 по 2014 год) учитывались на предприятии при дезодорации воды. Приведенные параметры оказывают существенное влияние на органолептические свойства конечной воды. Подготовка данных для анализа проводится методом главных компонент К. Пирсона. Данные, полученные в пространстве R9, переводятся в пространство меньшей размерности R3. Понижение размерности позволяет снизить автокорреляцию между компонентами. Отбор компонент в пространство R3 проводится по правилу Парето. В пространстве R3 методом сферической кластеризации данных «Форель» с постоянным радиусом группировки проводится кластеризация. Приводится пошаговое визуальное представление алгоритма кластеризации в пространстве R3. В работе показано, что в данных показателях качества исходной воды имеются кластеры. Проводится корреляционно-регрессионный анализ данных, представленных в главных компонентах. Строятся регрессионные зависимости показателей органолептических свойств от главных компонент из пространства R3.


2016 ◽  
Vol 16 (4) ◽  
pp. 922-930 ◽  
Author(s):  
L. Richard ◽  
E. Mayr ◽  
M. Zunabovic ◽  
R. Allabashi ◽  
R. Perfler

The implementation and evaluation of biological nitrification as a possible treatment option for the small-scale drinking water supply of a rural Upper Austrian community was investigated. The drinking water supply of this community (average system input volume: 20 m3/d) is based on the use of deep anaerobic groundwater with a high ammonium content of geogenic origin (up to 5 mg/l) which must be treated to prevent the formation of nitrites in the drinking water supply system. This paper describes the implementation and operation of biological nitrification despite several constraints including space availability, location and financial and manpower resources. A pilot drinking water treatment plant, including biological nitrification implemented in sand filters, was designed and constructed for a maximum treatment capacity of 1.2 m3/h. Online monitoring of selected physicochemical parameters has provided continuous treatment performance data. Treatment performance of the plant was evaluated under standard operation as well as in the case of selected malfunction events.


2001 ◽  
Vol 43 (8) ◽  
pp. 9-18 ◽  
Author(s):  
T. Schofield

Dissolved Air Flotation (DAF) has become increasingly important in the field of potable water treatment, as a preferred option for treating upland and stored lowland waters. This paper outlines the development of dissolved air flotation (DAF) in potable water treatment, the benefits and disadvantages and the recent advances that has taken the process technology from an art to a science.


Author(s):  
Л.В. Боронина

Волга почти на всем протяжении от Твери до Астрахани является истощенным водоемом по качественному составу. По Нижневолжскому бассейну ресурс экологически чистой воды составляет не более 3% общих ресурсов поверхностных вод Астраханской области. В связи с этим в Астраханской области проблемы качества питьевой воды обусловлены загрязнением природной воды, неудовлетворительной очисткой ее на водопроводных станциях, вторичным загрязнением в разводящих сетях. Проведен анализ экологического состояния Нижней Волги, а также оценка его влияния на качество питьевого водоснабжения. Применяемые в Астраханской области технологии очистки воды для водоснабжения запроектированы и построены в 1960–70-е годы и не рассчитаны на грязевую нагрузку по качеству и количеству, значительно отличающуюся от современной ситуации. Проведен анализ работы водозаборных и водопроводных очистных сооружений, который показал, что они находятся в крайне неудовлетворительном техническом состоянии и морально устарели. Предложены пути решения вопросов по улучшению качества питьевого водоснабжения с учетом сложившейся кризисной экологической обстановки на Нижней Волге и мирового опыта. Almost along the entire length from Tver to Astrakhan, the Volga River has been a depleted water reservoir in terms of its qualitative composition. In the Lower Volga basin the resource of ecologically clean water is less than 3% of the total surface water resources of the Astrakhan Region. In this regard, drinking water quality problems in the Astrakhan Region have been caused by natural water pollution, poor water treatment at the waterworks, secondary pollution in the distribution networks. The ecological state of the Lower Volga has been analyzed, and its impact on the quality of drinking water supply has been estimated. The technologies of water purification used in the Astrakhan Region for water supply were designed and implemented in the 1960s–70s; they were not designed for the pollution load in terms of the quality and quantity significantly different from the current situation. An analysis of the operation of water intake and water treatment facilities was carried out that showed their extremely unsatisfactory technical condition and obsolescence. The ways of solving the problems of improving the quality of drinking water supply with account of the current critical ecological situation in the Lower Volga Region and world experience, are proposed.


Author(s):  
Ernest Othieno Odwori

Nzoia River Basin is one of the regions in Kenya that is highly vulnerable to climate change. An understanding of community knowledge and perception on climate change and drinking water supply will provide strategic directions for national and county government policy, adaptation strategies and development of community-based guidelines on climate change. This study assessed community knowledge and perception on climate change and drinking water supply in Nzoia River Basin. A cross-sectional survey design was used. Three counties were randomly selected from the basin for study with Busia representing the lower catchment, Kakamega middle catchment and Trans Nzoia upper catchment. The study was carried out from May, 2017 to September, 2017. Multistage random sampling technique was used to select the 403 households administered with questionnaires. An observation checklist was used by the interviewers to collect household- and community-related information. The study results revealed that the community largely comes from low socio-economic background: only 24 % had post secondary education or higher, the majority were small scale farmers, housewives, casual workers and househelps (58 %), and only 25 % earned a monthly income above Ksh. 20,000 (equivalent to US $200). The majority of the participants 81 % had some knowledge about climate change but 19 % did not. On level of knowledge about climate change, 70% know a little/something about climate change, 21% know nothing about climate change and 9% know a lot about climate change. Majority of respondents, 76% receive climate change news from mass media (radio, newspaper and magazines, television); and 81 % point out that climate change will have public health risks in the community. The knowledge level about climate change in the basin was average. National and county governments should work with the sector stakeholders in the basin to improve community knowledge and perception regarding climate change, drinking water supply and health needs with proper content. The results of this study will go a long way in bridging the gap between policy formulation and building adaptive capacity to climate change in the basin.


Author(s):  
A. P. Levchuk ◽  
V. I. Maksin

In terms of water consumption from decentralized water supply systems there are a number of problematic aspects that negatively affect water quality, especially drinking water supply, namely: lack of modern control methods and integrated water treatment systems, qualified service personnel, long logistics of components and reagents, long distances to the final water consumer, inability to respond timely to the need of control laboratory equipment calibration and the failure of units and others. Unpredictable natural or man-made factors further complicate these problematic aspects. All this and the constant changes in the requirements to water quality and technological processes, leads to the search of new, modern approaches to solving such problems and issues of uncentralized drinking water supply. Therefore, this paper analyzes the current experience of developing small autonomous water purification systems for drinking water supply, which do not require constant presence of the operator and laboratory quality control of water and can work automatically in difficult conditions. Also a rationale for technological and structural design as well as the description of adaptive water purification systems using an adaptive approach to the structure as a whole, individual units, assemblies and to the power supply of electrolytic processes, giving it adaptive properties for the use in modern drinking water treatment is provided in the paper. The adaptive function of neutralizing the manifestation of dangerous biological agents and the efficiency of the system is designed for man-made and natural emergencies and water disinfection from bacteria and viruses. The pH was chosen as the main control parameter of water quality. The system uses an effective process of synthesis by electrolytic methods of coagulant, disinfectant and destructive effects on hazardous biological agents - pulsed current with changing parameters and shape. In case a working solution changes the pH, the parameters of the pulsed load current are changed by the adaptive power supply to the most efficient one. The proposed approach and model of the system are effective and preventive and is offered as an option to improve existing water treatment systems for drinking water supply.


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