The applications of Canadian water quality index for ground and surface water quality assessments of Chilanchil Abay watershed: The case of Bahir Dar city waste disposal site

Surface water and groundwater have been experiencing increasing risks of contamination in recent years because of the poor management of the immense amounts of waste created by different human activities. Inappropriate dump sites have served for many years as marginal disposal sites for a wide range of wastes, including solid waste, fresh sewage and hazardous waste, in developing nations such as Ethiopia. Physical, anthropogenic and organic procedures continuously interact to deteriorate the waste. One of the results of these practices is artificially contaminated leachate, which is potentially hazardous waste from disposal sites. If not managed appropriately, such a dumping site can contaminate groundwater (through leachates) and surface water (through contaminant transport by flooding and groundwater movement). Along these lines, this study focuses on the applications of water quality index in the ground and surface water quality caused by the waste disposal site of Bahir-Dar city within the Chilanchil Abay during the study period. Water testing was performed on 5 samples of surface water and 6 samples of groundwater in each month from 30th March (dry season) to twentieth August (wet season). More than 13 water quality parameters, for example, pH, TDS, Electrical conductivity, Turbidity, Temperature, DO, TH, BOD, COD, TC, NO3 , PO4 3 , Cr, Mn, and Pb contents, were examined in both ground and surface water. It was discovered that water quality status of the Chilanchil Abay watershed ranges from 15.87 to 36.6 for surface water and 42 to 46.2 for ground water suggesting poor and marginal status for drinking water purpose.


INTRODUCTION
Water is the most abundant resource on earth but only 3% is accessible for human activities while the remaining is present in ocean as a salt water (Love & Luchsinger 2014). It may be available in various forms and quantity but its use for various purposes is the subject of quality. Of all the environmental concerns that developing countries face, the lack of adequate and clean water remains the most serious problem (Markandya 2006). Once contaminated, groundwater may forever remain polluted without remedy or treatment. Diseases may spring up through water pollution, especially groundwater contamination, and rapidly spread beyond human expectation because of its flow (Afolayan et al. 2012). Wastes of different types, mostly solid wastes are the major input of dumpsites/landfills. With respect to the hydrological analysis of groundwater, it flows from areas of higher topography towards areas of lower topography, thereby bringing about the examination of the degradable material which form leachate and contaminate the groundwater of the study area. Properly managed, derelict voids can be reclaimed by a process of sanitary, landfilling, ultimately bringing the land back into productive use and providing much of the needed waste disposal sites (Kola-Olusanya 2012).
An integral part of any environmental monitoring program is the reporting of results to both managers and the general public. This poses a particular problem in the case of water quality monitoring because of the complexity associated with analyzing a large number of measured variables (Saffran 2001). The data sets contain rich information about the characteristics of the water resources. The classification, modeling and interpretation of data are the most important steps in the assessment of water quality. The CCME WQI (Canadian Council of Ministers of the Environment Water Quality Index) is used to evaluate success and failures in management strategies for improving water quality. In general, the index incorporate data from multiple water quality parameters into a mathematical equation that rates the health of water body with a single number. That number is placed on a relative scale to justify the water quality in categories ranging from poor to excellent. The water quality is characterized as excellent (95-100), good (80-94), fair (65-79), marginal (45-64) and poor (0-44) (REFF).
This number can be easily interpreted and understood by political decision makers, non-technical water managers and the general public as a whole. The CCME Water Quality Index provides a convenient means of summarizing complex water quality data and facilitating its communication to a general audience and, like any other tool requires knowledge about principles and basic concepts of water and related issues (Nikbakht 2004). It is a well-known method of expressing water quality that offers a stable and reproducible unit of measure which responds to changes in the principal characteristics of water (Brown et al. 1972). The specific variables, objectives, and time period used in the index are not specified and indeed, could vary from region to region, depending on local conditions and issues (Environment 2002). It is recommended that at a minimum, four variables sampled at least four times be used in the calculation of index values. However, a maximum number of variables or samples are not specified.
The selection of appropriate water quality variables for a particular region is necessary for the index to yield meaningful results. Clearly, choosing a small number of variables for which the objectives are not met will provide a different picture than if a large number of variables are considered, only some of which do not meet objectives. It is up to the professional judgment of the user to determine which and how many variables should be included in the CCME Water Quality Index to most adequately summarize water quality in a particular region. It is also expected that the variables and objectives chosen will provide relevant information about a particular site. The index can be used both for tracking changes at one site over time, and for comparisons among sites. Sites can be compared directly only if the same variables and objectives are used. However, if the variables and objectives that feed into the index vary across sites, comparing among sites can be complicated.
In these cases, it is best to compare sites only as to their ability to meet relevant objectives. The advantages of this approach are as follows; it is flexible with respect to the type and number of water quality variables to be tested, the period of application, and the type of water body (stream, river reach, lake, etc.) tested. These decisions are left to the user. Therefore, before the index is calculated, the water body, time period, variables, and appropriate objectives need to be defined. The body of water to which the index will apply can be defined by one station (e.g., a monitoring site on a particular river reach) or by a number of different stations (e.g., sites throughout a lake). Individual stations work well, but only if there are enough data available for them. The more stations that are combined, the more general the conclusions will be. The time period chosen will depend on the amount of data available and reporting requirements of the user. Secondly, this model is flexible, allowing one to choose the parameters to use and standardize them according to the objectives and area of study. It is a useful tool for describing the state of the water column, sediments and aquatic life and for ranking the suitability of water for use by humans, aquatic life, wildlife, etc.
In developing nations, open and inappropriate dumping destinations have served as final removal sites for a wide range of wastes over many years; these wastes include city solid waste, raw sewage and hazardous wastes (Nathanson 2015). Physical, synthetic and natural procedures interact, resulting in breakdown of the waste. One of the side effects of these practices is artificially contaminated leachate, which is possibly unsafe waste from waste removal destinations. If legitimate waste administration is not performed, such dumping sites can contaminate groundwater (as a result of leachates) and surface water (through contaminant transport by flooding, wind and groundwater from open dump sites). The Bahir-Dar city open landfill is one such open dump site and is situated in a location close to human settlements. The people who live close to the removal site (both downstream and upstream) utilize contaminated ground and surface water in their everyday activities. This poses a great deal of danger to those communities with respect to water quality. Along these lines, the focal point of this study was to survey and assess the water quality in that watershed, especially close to the waste disposal site, to assess its impact on ground and surface water quality.

Descriptions of the study area
The Eriamecharia municipal waste disposal site is 5 km from Bahir Dar city, Ethiopia near the expressway to Addis Ababa and the Tis Abay waterfall. It is a part of the region in the Sebatamit provincial network. According to the Central Statistics Agency of Ethiopia (CSA 2007 G. C) approximately 6,401 people, 3,053 females and 3,348 males, live around the dump site. Its geographical location is as follows: latitude, 11.54; longitude, 37.38; height /length/, 1,803 meters at 3 degrees; and elevation above sea level, 1,801 metres. The length and width of this irregularly shaped removal site are 384 m and 174 m, respectively. It was not equipped with liners or a leachate sorting system until ten years ago. This site was not efficiently planned before being utilized for waste removal/dumping. In addition, no environmental impact assessment was performed before this location was established as a waste disposal site. Trucks and other vehicles from various parts of the city gather the waste, carry it to this site and dump it in a disorganized manner. The waste is dumped as-is without isolation. The base amount of solid waste that is generated from the city and dumped at the site is private waste 12,610 kg/day, business waste 4,202 kg/day, service provider waste 98 kg/day, municipal waste 1,044 kg/day, and overall 22,774 kg/day (Source: Solid Waste Portrayal and Evaluation from the Bahir Dar city report, 2007). Currently, the average amount of waste dumped at the site is to be estimated 31,321 kg/day.

Sample collection, preservation and laboratory analyses
Water samples were gathered from the selected test areas close to the dump site, which is locally called Abohoy manekia and Tikkurit. The samples were taken to the research centre for the investigation. The eleven testing sites were selected based on their availability and vicinity to contamination sources, for example, an accessible site, and lodging. A Worldwide Positioning System device (GPS etrex VISTA HCX) was utilized to identify the actual locations of the study sites, and the sites were geo referenced to guarantee consistency in the testing sites during the subsequent test periods. The test sites were deliberately chosen to incorporate the upstream and downstream networks, as shown in Figure 1. Sampling began during the dry season starting in March and proceeded through the wet season in August from all eleven study sites downstream and Water Supply Vol 00 No 0, 3 Uncorrected Proof upstream of the dump site. The classifications of the wet and drying season in this paper was based on the Ethiopian calendar (September up to May was considered as dry season and June up to August was also considered as wet season). Groundwater samples were taken from depths of 5-12 metres (both upstream and downstream) using borer drills to obtain a 3 L maximum sample with a straightforward core approach that allowed the study of water at different borehole depths for groundwater samples (Hamad 2018). To evaluate the water quality, the water samples were kept in 1 L polyethylene plastic containers cleaned with a cleanser that did not contain metals, flushed with deionized water, treated with Analytical grade nitric acid nitric acid (HNO 3 ) for 24 hours, and finally washed with ultra-pure water. All water samples were stored in a cooler and brought to the lab at approximately the same time. All samples were kept at a consistent temperature of 4°C to prevent the samples from deteriorating because of the impacts of light and temperature until the analysis was performed at the research centre (Clesceri et al. 1998). NaOH used for BOD analysis, Ferroin was used as indicator, standardized 0.1M FAS was used as titrant and K 2 Cr 2 O 7 used as digestion solution during COD analysis.The heavy metal (Cr, Pb, and Mn), phosphate (PO 4 3À ) and nitrate (NO 3 À ) contents were determined using a Palintest spectrophotometer (WAGTECH 8000).
Multi parameter water quality checker (model: YSI pro 30) was used to measure water quality for different parameters like temperature, TDS. Palintest spectrophotometer (model: WAGTECH 8000) was used to measure the concentrations of Phosphates ( The type of water source and the depth of the sample sites was affect the quality of the water samples since the imigrations of leachates and availablity of disolved oxygen is a functions of the path of the depth. From Table 2 above the river based surface water samples are perennial source and this is also the reason why the sample sites were selected to be target point. Water sampling was done at different points along the path of the flow. Canadian council of ministers of the environment water quality index (CCMEWQI) water quality index procedure The index ranges from 0 to 100 and depending on the value; the water quality is characterized as excellent (95-100), very good (89-94), good (80-88), fair (65-79), marginal (45-64) and poor (0-44) (Khan et al. 2004). In general, scoring 80% and above met expectation for water quality and are of 'lowest concern' whiles sample points with scores below 40% did not meet expectation and are of 'highest concern' (Khan et al. 2004). These numbers are divided into 5 descriptive categories to simplify presentation. This index doesn't give any weighted numbers but treats the values of parameters in mathematical way to ensure that all parameters contribute adequately in the final number of the index. The CCME WQI model consists of three measures of variance from selected water quality objectives (Scope; Frequency; Amplitude) (Khan et al. 2004). The 'Scope (F 1 )' the number of variables not meeting water quality objectives. The 'Frequency (F 2 )' the number of times these objectives are not met ('failed tests'). The 'Amplitude (F 3 )' represents the amount by which failed tests do not meet their objectives. These three factors combine to produce a value between 0 and 100 that represents the overall water quality. The formulation of the WQI as described in the Canadian Water Quality Index 2001 technical Report is as follows. (F 1 ), (F 2 ) and (F 3 ) are unit less they simply express numbers achieved standard values (objectives), failings and the values which will deviate from the objective.
The measure for scope F 1 is calculated as follow.
The measure for frequency F 2 is calculated as follows: The measure for amplitude, F 3 is calculated as follows.

Uncorrected Proof
Excursion is the number of times by which an individual concentration is greater than (or less than, when the objective is a minimum) the objective. When the test value does not exceed the objective: For cases in which the test value exceeds the objective The collective amount by which individual tests are out of compliance is calculated by summing the excursions of individual tests from their objectives and dividing by the total number of tests (both those meeting objectives and those not meeting objectives). This variable, referred to as the normalized sum of excursions (nse) is calculated as: F 3 is then calculated by an asymptotic function that scales the normalized sum of the excursions from objectives (nse) to yield a range between 0 and 100.
The water quality index (CCME WQI) is then calculated as: The divisor 1.732 normalizes the resultant values to a range between 0 and 100, where 0 represents the 'worst' water quality and 100 represents the 'best' water quality.

RESULTS AND DISCUSSIONS
Water quality index (CCMEWQI) for assessing changes in ground and surface water quality of Chilanchil Abay watershed

Calculation of Canadian Council of Ministers of the Environment Water Quality Index (CCMEWQI) in the surface water quality of Chilanchil Abay Watershed
Selections of parameters for testing of water is solely depends upon for what purpose we going to use that water and what extent we need its quality and purity. Water does content different types of floating, dissolved and suspended things. Some physical test (turbidity, TDS, conductivity and temperature) should be performed for testing of its physical appearance while chemical test should be perform for its BOD,COD, pH, TH, DO, nitrate, phosphate, manganese, lead and chromium and other characters to understand its deviation from the accepted limits. Based on this concept the tested parameters listed blow were selected upon the existing activities in the study area. For example testing of phosphate and COD was due to the existence shampoos and other chemical detergents on the dump site (derived from the city), nitrates due to fertilizers around the sample site (derived from the agricultural field), BOD and DO due to organic wastes, heavy metals due to dead batteries, discarded materials of garages, paints and Leachates of the dump site and temperature, turbidity and TDS due to the physical phenomena of the sample site. As one can see from all Tables below there are 14 tested parameters, sample collected months and objectives. According to the existing circumstances of the study area the researcher believes strongly those 14 parameters can show the conditions of a single water sample sites. When samples are collected from the given sample place nature of the surrounding, river flow, weather condition, general water condition and sampling frequency will affect the water quality of the sampling sites. Then during this work keeping all those phenomena was mandatory and that was why three months of dry season (March, April and May) and three months of wet season (June, July and August) were selected orderly to observe it's continual effect without gap of the month from the beginning up to ending of sample taking since the study period was staying for six months. During sampling time someone can take the sample weekly wise or monthly wise according to the changes that can occur and others. So this study consider monthly wise (30th end date of the month) after weekly wise preliminary observation. But the last month was at 20th August, this was due to high amount of rain was raining from the mid of July up to the mid of August during the study period so the researcher assure there is no significant change between 20th August and 30th August. The values of the objective blow Table indicates the standard values of drinkable water that all samples must be in range to be used for the planed target.
Calculation of CCME Water Quality Index for sampling site two (SS 2 ) The result obtained from the application of CCME WQI has categorized the Chilanchil Abay watershed quality at sampling site two as very poor for 30th March, 2011 to 20th August, and 2011.
The failed variables/tests/ to be higher or lower was due to the locations of the sample sites and seasonal changes.
In this study, the CCME Water Quality Index was applied and tested for the Chilanchil Abay Watershed using the method described by CCME 2001 guidelines (equation 1, 2, 6 and 7) and the results obtained from the application of this index with respect to nutrients, heavy metals and Physico-chemical characteristics of surface water were presented in Table 8 below. Uncorrected Proof Analysis in Chilanchil Abay watershed Table 8 above and Figure 2 below shows the variation of WQI with CCME standard level to evaluate the status of existing water quality in the study area. The calculated results obtained from all sample points of surface water (Table 8) were showing poor status for 30th March, 2011 to 20th August, 2011 considering CCME Water quality index (Table 1) or considering all observation in each sampling site, WQI for Chilanchil Abay watershed is poor which indicates that water quality of this sampling sites is always endangered or deteriorated; conditions usually deviate from natural or desirable levels. Figure 2 shows considering all sample points, sample point two has shown worst quality in context of CCME-WQI. The reasons may include direct discharge of effluent from waste disposal sit which lies within few meters from the sampling site. However, value for WQI obtained from CCME-WQI calculation indicates that the water must be treated to remove the physical and chemical impurities since there is a significant effect from the open field waste disposal site. Generally, the CCME Water Quality Index has shown that, the use of the Chilanchil Abay Watershed for various domestic activities such as drinking, cooking, recreation and livestock are not recommended. This is because the status of the watershed has departed from desirable or permissible levels in most of its nutrients, heavy metals and Physico-chemical parameters (Figures 2 and 3). It is evident from the results that water quality in the Chilanchil Abay Watershed is degraded considerably due to human activities such as anarchy way of waste dumping (absence of engineered /sanitary way of land fill), open field defecation, contamination of water by household sewage etc.

Calculation of Canadian council of ministers of the environment water quality index (CCMEWQI) in the groundwater
Calculation of CCME Water Quality Index for station one (SS 1 ) Excursion i ¼ 100 À 2061 1000 À 1 þ 100 À 1998 1000 À 1 þ 100 À 2052 1000 À 1 þ 100 À 9:33 5 À 1 þ 100 À 9:21 5 À 1þ 100 The result obtained from the application of CCME WQI has categorized the Chilanchil Abay water quality shed at sampling site one as marginal for 30th March, 2011 to 20th August, and 2011 Calculation of CCME Water Quality Index for station two (SS 2 )  The result obtained from the application of CCME WQI has categorized the Chilanchil Abay water quality shed at sampling site four as marginal for 30th March, 2011 to 20th August, and 2011.
Calculation of CCME Water Quality Index for station five (SS 5 ) Excursion i ¼ 100 À 2252 1000 À 1 þ 100 À 2298 1000 À 1 þ 100 À 2263 1000 À 1þ 100 À 0:058 0:05 À 1 þ 100 À 0:057 0:05 À 1 þ 100 À 0:06 0:05 À 1 þ 100 À 0:063 0:05 À 1þ 100 À 0:068 0:05 À 1 þ 100 À 9:16 7:5 À 1 þ 100 À 9:4 7:5 À 1 þ 100 À 9:11 7:5 À 1þ 100 À 7:53 7:5 þ 100 À 7:69 7:5 þ 100 À 7:58 7:5 À 1 þ 100 À 0: The result obtained from the application of CCME WQI has categorized the Chilanchil Abay water quality shed at sampling site six as poor for 30th March,2011 to 20th August, 2011. The overall results of CCMEWQI for all ground water samples of Chilanchil Abay watershed were summarized as follow having Table and Figure. Analysis in Chilanchil Abay watershed Table 15 above and Figure 3 below shows the variation of WQI with CCME standard level to evaluate the status of existing ground water quality in the study area. The calculated results obtained from all sampling sites of ground water were (Table 15) showing four sample points as marginal and two sample points as poor for 30th March,2011 to 20th August,2011. All the marginal status sample points are found in the upstream of waste disposal site. This      indicates that Water quality is frequently endangered or deteriorated; conditions often deviate from natural or desirable levels. This could be resulted due to decaying of plants and animals, agricultural fertilizers and open defection activities. While the remaining two poor status sample points were found in the downstream of waste disposal site. This indicates that water quality of these sampling sites is always endangered or deteriorated; conditions usually deviate from natural or desirable levels. Figure 3 shows considering all sample sites, sample site five and sample site six has shown worst quality in context of CCMEWQI. The reasons may include the migrations of leachate in downstream from the dump site towards those two sample points.

Comparisons of the effect of open dump site on surface and ground water quality of Chilanchil Abay watershed
The overall water quality assessment (ground and surface) of the Chilanchil Abay watershed was compared. The result is presented in Figure 4. As it can be seen in Figure 4, one can see that the average values of standardized surface water quality parameters were higher than that of standardized values of the ground water quality parameters. Subsequently, it can be conceivable to state that surface water quality was more influenced than ground water quality by the dumping site leachate. For the most sampling sites this has been seen with the parameters of phosphate, chromium, total dissolved solid and electrical conductivity. The reason for surface water to be affected more than that of ground water was due to surface water is more readily exposed to pollutants caused by anthropogenic activity. Every anthropogenic activity was started from the surface  Uncorrected Proof and then its first effect was applied on the surface phenomena. On the other hand, ground water is less susceptible to different pollution than surface water because the soil and rock through ground water flows screen out most of the pollutants. This is by no means saying that ground water is invulnerable to contamination since easily soluble chemicals are the primary candidates of ground water pollution. This is similar with the work of P. Trivedi (Trivedi et al. 2008) who found surface water was more affected than ground water by the introducing of external influences.

CONCLUSION
According to the Canadian council minister of Environment water quality index (CCMEWQI) the water quality of Chilanchil Abay watershed was categorized under poor and marginal. The temporal and spatial variations of ground and surface water quality of Chilanchil Abay watershed was assessed following WHO quality parameters (January 2004) and Canadian water quality index (Khan et al. 2004) The analysis of physicochemical properties, concentrations of heavy metals and nutrients recorded values show that TH, BOD, COD, Mn and Pb     Uncorrected Proof were within the acceptable limit (values of the objective in the above all Tables) for both ground and surface water during the study time while the remains were fluctuated with the seasons. From the findings of the study it assured that sample sites below the dump site were more affected than the sample points of upstream.
The aim of this study was to survey and assess the water quality in that watershed, especially close to the waste disposal site, to assess its impact on ground and surface water quality. Therefore according to the CCMEWQI all status of the samples sites was affected by the existence dump sites and other effects from surround (like fertilizers, open defections and other anthropogenic activities). Then data suggested that the dump site should be displaced from its current location or must be engineering way of landfill (currently it locates at the center of human settlements and agricultural fields).