Households Drinking Water Sources and Treatment Methods Options in a Regional Irrigation Scheme

Access to safe and clean drinking water is a major challenge to the people living around Ahero Irrigation Scheme (AIS). Water sources in the area are constantly and increasingly polluted by agrochemical like pesticides from rice farming. 2, 4-Dichlorophenoxyacetic acid (2,4-D) is an herbicide extensively used in AIS. The neurotoxic, immunosuppressive, cytotoxic and hepatoxic effects of (2,4-D) have been well documented. Residues of (2,4-D) have been documented in ponds, rivers, lakes and irrigation canals. Therefore this study surveyed agrochemicals used in AIS, the drinking water source for the residents and finally water treatment option for the obtained water in the year 2013. The study established that (52.8%) of the farmers used hand-weeding and 20.8% of them use (2,4-D) for the weeds control. Results indicated that the most preferred water source was lined improved well (47.2%) followed by irrigation canal (22.2%), the least preferred was rain water with (2.8%). The most used method of water treatment was chlorination (45.8%). Spearman’s coefficient of correlation (rs) revealed that there was positive correlation between the two variables (rs=0.145, n =72, p=0.224>0.05). As rs is positive, it implies that the type of treatment given to water depend on its source of the water. Despite the use of chlorinate with almost half of the residents, some of them (22.2%) do not treat their water at all, which may pose a risk of getting water related diseases. Furthermore, despite a proportional number of residents obtaining their water from irrigation canal, all of them do not have appropriate method/s for treating water contaminated with organic pollutants such as herbicides. There is a need to promote water appropriate drinking water treatment method/s in the study area to prevent water related diseases at the family level.


Introduction
Water is a major component of the environment and consequently, is the most vital natural reserve which is crucial for life [1,2]. Safe, reliable, affordable, and easily accessible water supply is essential for good health [3,4]. Yet, globally 2.2 billion people lack access to safe drinking water due to water pollution [5]. Adverse agricultural activities are cited as the leading cause of surface and ground water pollution [6,7]. Pollutants such as agrochemicals are some of the most toxic contaminant to human health, fauna and the environment [8][9][10]. Agrochemical refers to various chemical compounds that are used in agriculture. It encompasses insecticides, herbicides, and fungicides also raw animal manure, synthetic fertilizers, hormones among others [8,11,12].
2,4-Dichlorophenoxyacetic acid (2,4-D) is the most commonly used pesticide in Ahero Irrigation Scheme (AIS) and it is a selective herbicide with highest toxicity to broadleaf plant [13,14]. It is used for post-emergence control of annual and perennial broad-leaved weeds in cereal, maize sorghum, rice and grassland as well as for control of aquatic weeds [15]. In plants it functions by maintaining high levels of plant hormones auxine, resulting in overstimulation of plant growth and ultimately death. It also increases ethylene production and therefore acts as defoliating agent [16][17][18]. Residues of 2,4-D can enter ponds and streams by direct application or accidental drift; by inflow of herbicide previously deposited in dry stream-bed, pond bottom or irrigation canals; run-off from soil or leaching through the soil column [19,20]. Only a small fraction of applied pesticides affects the target organisms and the rest often remains in the soil, contaminates surface water and groundwater resources, or mixes with the air [21,22]. Its production and degradation leads to creation of many compounds that exert strong toxicity [23,24]. 2,4-D has been linked to several forms of cancer, primarily lymphoma and non-Hodgkins lymphoma as well as tumor of lungs, liver, kidney and brain in humans [14,[25][26][27].
Irrigation practices play a major role in the accumulation of pesticide residues encountered in water resources and extensive use of pesticides may pose serious concerns about health risks arising from the contact of farmers when mixing and applying pesticides or working in treated fields and from residues in food and in drinking water for the universal population have been on raise [28,29]. Therefore, this paper aim was to survey agrochemicals used in AIS, the drinking water source for the residents and finally water treatment option for the obtained water in the year 2013.

Study Area
The Ahero Irrigation Scheme (AIS) is situated in the Kano plains between Nandi Escarpment and Nyabondo Plateau in Kisumu County ( Figure 1). Construction of the scheme started in 1966 and operations started in 1969 [30]. The scheme is managed by the National Irrigation Board in partnership with the farmers who are charged Kshs.3100 per acre per year for scheme Operation and Maintenance (O&M). The area under cultivation is 2168 acres which is divided into 12 blocks with a total of 1650 farmers. Nearly all irrigated farmland is used for paddy cultivation [31,32]. The area has a relatively humidity of 65% due to its proximity to Lake Victoria. Local climate is characterized by three peaks of rains with an average annual rainfall of 1,000 -1,800 mm and yearly mean temperatures vary between 17°C and 32°C [33]. The main economic activities include farming and subsistence farming of cultivated maize, sorghum, cassava, millet, and vegetables. Most people keep animals including cattle, goats, sheep, and poultry. Other activities include fishing due to its proximity to Lake Victoria and the Nyando River [30,33]. Nyando River is the major water source to the people living around the scheme. During rice planting season some residence obtain their water for domestic use from the irrigation canals from the scheme. Rice farming is the main cash crop in the region and it covers approximately 2404 hectares. The residents' main source of water for domestic water are both surface water and groundwater through Nyando River, boreholes, few ponds and irrigation canals during rice planting season. In AIS, rice planting is done throughout the year but in rotation (spatial) due to scarcity of water from Nyando River.

Primary Data Collection
Interviews were conducted and structured questionnaires were administered to stakeholders (Agro-chemist stockiest, National Irrigation Board and local people). All the entire agrochemical stockiest were interviewed while participants from the local community were selected using systematic sampling [34]. The research assistants were trained on how to administer the questionnaires correctly. It consists of selecting the first house along the road and/or path from the irrigation scheme as the first participant and after that every 10 th house was interviewed. Data collection was obtained from 72 households living within Ahero irrigation scheme.

Sample Size
Sample size was determined from the formula proposed by Yamane cited by Isreal (2009), which state that: Where: n= sample size; = target population size; = level of precision (sample error); Therefore, N=89 stakeholders and e=5%: The returned questionnaires were validated through focused group discussion in Ahero Irrigation Scheme. The obtained information was used to give the data on the types, amount of the pesticide used around the scheme and also to identify the water sources. The farmers' questionnaires were translated into local dialect for better understanding. The agrochemical stockiest and NIB questionnaires consisted of questions on the type of pesticide and the amount applied per acre.

Secondary data collection
Secondary information was obtained from National Irrigation Board, ministry of water and agriculture. All these institutions availed information from their reports on the soil type or texture, topography of the area, population, vegetation cover, and crops planted.

Data Analysis
Each set of questionnaires, the responses from the farmers, stockiest and NIB were coded and keyed in the statistical package of social scientist (SPSS) to analyze data. Spearman's rank order correlation (rs) was used to show whether and how strongly pairs of variables were related where rs value varies between -1 and 1 (-1≤ rs ≥1).

Socio-economic Characteristics of Households
The general information about socio-economic characteristics of household heads determined were as follows: gender, education level and the length lived in the scheme. The gender distribution of the household is given in Table  1. The level of education is presented in Table 2 and the length of period lived is presented in Table 3. Slightly more than two thirds (68.1%) of the interviewed household were female compared to close to a third (31.9%) who were male.
Among household heads interviewed, 75.0% attained primary school level, 16.7% secondary school level, 4.2% tertiary college 2.8% university and only 1.4% vocational/village polytechnic. Three quarter (75%) attained primary level maybe due to poverty and early marriages Table 2. Majority of the household 87.5% have lived around the scheme at the time of the project more than two years, 8.3% less than six months, 2.8% between one to two years, while 1.4% between six months to one year. The results indicate that majority of the household are permanent residents of Ahero Table 3.

Pesticides Application in Ahero Irrigation Scheme
This study established that (52.8%) of the farmers used hand-weeding and 20.8% of them use 2,4-D for the weeds control ( Figure 2). Slightly more than half (52.8 %) of the farmers use mechanical method of weeding and the remaining 47.2 % use various chemicals.

Types of weeds control
It was establish that 20.8% of the farmers applied 2, 4 D herbicide, 12.5% of the farmers used Sevian while 8.3% of the farmers used Di-amine. Murhamine and Dicopur were used by 5.6 % of the farmers. All there herbicides, were applied with the sticker, wetter or sprayer with 0.5 liters of water to enhance efficiency of herbicides to the rice. In MWEA Irrigation Scheme [35] reported about 95% of the respondents using herbicides for weed control. Out of these, about 54% used glyphosate while 31% applied 2,4-D. Rodenburg et al., (2019) noted that 34% of the rice farmers in Sub-Sahara Africa used herbicides for weeding and majority used hand weeding. Mattah et al. (2015) [36] recorded 35% of the respondents used round-up (glyphosate 41%), while 8.3% used gramoxone (paraquat) for controlling weeds in the catchment of Ashaiman irrigation scheme of Ghana. From this study, majority of the farmers used handweeding, however for those who used different types of herbicides its impact on household water cannot be underestimated. Health effects linked with pesticide use have been well documented by researchers [37][38][39].

Domestic Water Sources
The respondents were asked the source of water for their household and the results are given in Figure 3. The results showed that 47.2% of the people living around Ahero irrigation scheme draws their water for drinking and domestic needs from lined improved well, 22.2% from irrigation canal, 16.7% from Nyando River, 4.2% for open well dug in river bed/wetland and tap water respectively, 2.2% from pump bore and rain water reservoir respectively.

Figure 3. Source of water at the community level
The results indicated that a significant number of household draw their water supply from irrigation canal (22.2%) and sixteen percent from River Nyando which has a high potential of contamination from agricultural runoff, with pesticides residues (Figure 4). [40] reported Lake Victoria, shallow wells, unprotected springs, boreholes and roof catchment systems as a source of water for Kisumu City residents. while evaluating appropriate water treatment for the Nyanza Province of Kenya reported lake, spring, borehole, rivers, ponds, tap and rain water as the sources of water for domestic use [41]. Kiosks and wells/boreholes serve as the primary source for 25.8% of the households living in Kisumu municipality, Kenya according to Wagah et al. [42]. Wambu et al. (2014) on the other hand reported that majority of the residents of Bondo-Rarieda Area used water from Lake Victoria (37.4%) and the other preferred dams, open pans , boreholes and streams [43].
Further when respondent were asked on the preference of the water source their results in (Figure 5) shows that 37.5 % of the people living around the scheme prefer water from lined improved well, slightly more than a third (36.1 %) from irrigation canal 18.1% from the river, 4.2 % from tap water, 2.8% pump borehole and 1.4% open well dug in riverbed/wetland. Slightly above a third of the household that preferred to draw their water from irrigation canal said it was less salty and closer to them. The problem is that the turbidity is much higher than the improved well. Its only problem was a higher turbidity. High turbidity issue was solved by use of a coagulant (Alum) as stratified by (16.7%) of interviewers. Common alum is hydrated potassium aluminum sulphate KAl(SO4)2.12H2O [44], which allows the suspended particles to settle down leaving the water clean and clear. Water from irrigation canal could be polluted by agrochemical which difficult to remove rendering it unsafe for consumption and use by residents.

Type of Water Treatment used by the Community
The study also focused on type of treatments the local community uses for their drinking water and presented in Figure 6. The study established that almost half (45.8 %) of the people are chlorinating their water, 22.2% do nothing to their water for drinking, 16.7% uses coagulant, 12.5% filters with a cloth and only 2.8 % boil their water before drinking. The household that uses alum (16.7%) for their drinking water treatment was perceived to obtain their water from either irrigation canal or river where the water turbidity is high. While those who do not use any water treatment was perceived to obtain their water from lined improved well, pump borehole or tap water due to low turbidity of the water. Belay et al. (2016) [45] in their study reported more than half 213(59.7 %) boil water, 74(20.7 %) settle and stand and 70(19.6 %) used chlorine in Burie Zuria Woreda Rural Households, Northwest Ethiopia. The types of treatment methods that the households reportedly used to treat water were boiling, bleach, filter, SODIS, let the water stand and settle, cloth straining, and other methods with the respective percentages of 10.81, 8.64, 0.79, 0.07, 1.25, 1.69, and 1.82% in Burundi, Lesotho, Namibia, Nigeria, Tanzania, Togo, and Uganda [46]. The revealed that majority of the people understand the importance of treating water, however the water can be contaminated with inorganic and organic pollutants such as herbicides and cannot be easily removed by conventional water treatment option making the resident vulnerable to diseases

Relationship between Water Source and the Type of Water Treatment
The source of water was perceived to influence the type of water treatment and Spearman's coefficient of correlation was used to establish any relationships and the results are given in Table 4. It shows that 13.9 % of the people who obtain water from lined improved well do not treat their water, 4.2% filter their water with cloth and 25% chlorinate their water. Spearman's coefficient of correlation (rs) revealed that there was positive correlation between the two variables (rs=0.145, n=72, p=0.224>0.05). As rs is positive, it implies that the type of treatment given to water depend from it source of the water.

Conclusion and Recommendations
The study established that (52.8%) of the farmers used hand-weeding and 20.8% of them use 2,4-D for the weeds control. The people living around Ahero irrigation scheme draw their water from lined improved well, Nyando River, irrigation canal, pump borehole and rain water reservoir. The most preferred water source to the villages is line improved well. Due to the saltiness of water drawn from the well and the long distance to the source, some people draw their water from irrigation canals. Close to half population of people around the scheme prefer to us chlorine as a method for water treatment. There is a positive correlation between water sources and the method of water treatment. The following recommendations were made; finding and using substitute chemical for pest and weed control which is easily degradable and have less environmental and human impacts should be encouraged. Also adaptation of improved Bio-Sand filters as a small scale purification process. For people who use the raw water from rivers and irrigation canal for drinking and cooking purpose. The improved Bio-Sand filter reduces the amount of organic contaminant such as pesticides, removes harmful micro-organisms that could be present in the water and reduce water turbidity making it clean and safe for consumption. Further studies to be done on the epidemiological studies on association between 2,4-D and its degradation products used as an agro chemical and it's health related issues and also the amount that could be found in the environment. These finding can be used by the ministry of health or public health to sensitize community on the safe measures of the use of agro-chemicals in order to alleviate the risks and carry out water quality analysis to validate the levels of 2,4-D in the irrigation schemes and finally further research to be done on the removal of other type of pesticide contaminants where other people practice different types of agriculture.

Data Availability Statement
The data presented in this study are available in article.

Funding
The author received no financial support for the research, authorship, and/or publication of this article.

Declaration of Competing Interest
The author declare that there is no conflict of interests regarding the publication of this manuscript. In addition, the ethical issues, including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, and redundancies have been completely observed by the author. [5] World Health Organization.