Hazard Analysis of Domestic Ground Water Sources in Abubakar Tafawa Balewa University (ATBU, Yelwa Campus), Bauchi Nigeria

Ground water supply for domestic use accounts for a large proportion of domestic water use in the Abubakar Tafawa Balewa University (ATBU) (Yelwa Campus). This implies that the sanitary quality of groundwater for domestic use in the institution is of paramount importance for the well being of the end users. The water quality of domestic groundwater sources in ATBU campus was analyzed by determining their physical, chemical and biological characteristics and ‘Hazard Analysis’ of the ground water sources for domestic use was determined based on the Water Safety Plan concept. Results obtained were compared to international water quality standards to identify the potential risks to various parameters and identify priority interventions to eliminate/ reduce contamination levels in the sources of water. Laboratory results showed that samples from a water source had Total Dissolved Solids (TDS) and Conductivity levels higher than values stated in the Drinking Water Standards. All other samples met the World Health Organization (WHO) and Nigerian Industrial Standards (NIS) guidelines for drinking water in terms of the physiochemical requirements. Total bacterial count obtained from two of the water sources was linked to the method of abstract of water. Results from the Hazard Analysis showed that five water sources monitored met all the requirements for drinking water quality, corrective measured were proffered for three sources on Well/ Borehole head tightness.


Introduction
Pure water does not generally occur in nature. This is because all natural water whether surface, precipitation or ground all contain dissolved solids and gases as well as suspended matter. The quality and quantity of these constituents depends on geologic and environmental factors, which continuously change as a result of the reaction of water with contact media and human activities. These activities especially human can adversely affect the groundwater resources. Ground water is polluted by runoff from fertilized fields, livestock areas, abandoned mines, salted roads and industrial areas. Other sources of groundwater pollution include leachate from refuse dumps, gasoline leakage into ground water from underground storage tanks, waste water disposal systems. The effect of these pollutants in water can give rise to life threatening diseases especially diseases associated with unimproved domestic water supply, these diseases are water borne, water washed, water related insect vector etc.
Water-related diseases remain one of the major health concerns in the world, which are largely derived from poor water quality and sanitation, these account for about 3 million deaths and contributes to about 62 million 'Disability Adjusted Life Years' annually [1]. This health burden is primarily borne by the populations in developing countries and by children. Currently, it is estimated that 663 million people worldwide still use unimproved drinking water sources, including unprotected wells, springs and surface water. The majority of the people using unimproved drinking water sources live in sub-Saharan Africa, [2]. The use of unimproved drinking water sources is a major challenge coupled with uncontrolled siting of latrines. Sanitation facilities which are appropriate to meet the needs and demands of communities at affordable cost both at construction and operation and maintenance for end users are viable options to the control of contamination of domestic water sources. [3]. Factors such as the presence of uncapped wells and poor sanitary completion of the wells are as important as subsurface leaching of microbial contamination [4]. Around the world, especially in developing countries, there are billions of people who lack any hygienic and acceptable methods of excreta disposal [5].

Problem Statement
Ground water supply for domestic use accounts for a large proportion of domestic water use in the Abubakar Tafawa Balewa University (ATBU) (Yelwa Campus). The various Hazard Analysis of Domestic Ground Water Sources in Abubakar Tafawa Balewa University (ATBU, Yelwa Campus), Bauchi Nigeria On-site sanitation (excreta disposal) systems in the school constitute a major concern with regards to the quality of groundwater used for domestic purposes in the campus. Leachate has been identified as one of the source of ground water pollution, [6], leachate is the liquid formed when water passes through the waste in landfill sites and are regarded as highly polluted waste waters. They can contain large amount of organic matter as well as ammonium and nitrogeneous compounds, heavy metals, chlorinated organic and inorganic salts [7]. These compounds percolate deep through soil and subsoil causing extensive pollution of streams, creeks and water wells, if they are not properly collected, treated and safely disposed. Direct ingress of leachate affects the quality of groundwater [8]. The possibility of chemical substances and micro-biological organisms contaminating groundwater sources which poses health hazard to the community has prompted this research to assess the situation on the University campus.

Objective of the Study
The water quality of domestic groundwater sources in ATBU campus was analyzed by determining their physical, chemical and biological characteristics. Results obtained were compared to international water quality standards to identify the potential risks to various parameters and identify priority interventions to eliminate/ reduce contamination levels in the sources of water.

The Study Area
Abubakar Tafawa Balewa University (ATBU) (Yelwa Campus) is located in Yelwa town of Bauchi Local Government Area in Bauchi State of Nigeria with coordinates 9.845 o E and 10.329 o N. The area experiences five months of wet season between May and September with the remaining months of the year as dry season. The annual rainfall ranges between 900mm and 1000mm and a temperature range of 18℃ to 35℃. Although in extreme weather conditions, the temperature can be as low as 12℃ during the harmattan and as high as 40℃ in March/April periods when the weather is hot.

Geological and Hydro-geological Data of Study Area
The geological formation is composed of crystalline basement complex made up of coarse foliated granite of the older granite suite formation and of Palaeozoic age. Crystalline rocks such as granite and gneisses, when in the unweathered and unfractured state, exhibit very low porosity and are completely impermeable. However, due to prolonged geological activities of chemical weathering, the residues of these rock types are predominantly silty clays and quartz particles, the residue therefore has high porosity, composed of very small interstices. It has been found that even the finest grained clays have only a slight filtration effect on viruses [9], therefore, with such prolonged geological activities, basement complex became favourable to groundwater storage, and can be tapped through boreholes and hand dug wells, monitoring of the groundwater quality is still paramount to ensure the safety of the supply.

Limitation of Research
Limited funds led to the constraint on duration of research.

Materials and Methods
Domestic Water Samples were collected within the ATBU campus at different locations and these samples serve as representation of the school's groundwater supplies. The sample bottles used for sample collection were sterilized before use, and a visual inspection of the water samples' at source were made as information concerning the sanitary condition of this location is of paramount importance in the assessment of the ground water quality at each location. This research was conducted between June, 2013 and May 2014, water samples were collected in the months of February and March, 2014.
The following water quality parameters were analyzed in the laboratory based on Standard Methods for the Examination of Water and Wastewater [10]

Water Safety Plan
The Hazard Analysis of the Ground water source for Domestic use was determined based on the Water Safety Plan using 'Guidelines for Drinking-water Quality

Hazard Analysis
Hazards analysis is based on identifying potential risks in systems and preferring solutions to eliminate/ manage the risks accordingly. The following tables are used to monitor the various types and sources of hazards and how they can be identified (from catchment to consumer point of use) [11].

Results and Discussion of Results
Water samples were collected from various locations on the campus as presented in table 3:

Results
The laboratory results obtained from the analyzed water samples are presented in table 4. (The average result from multiple water sampling bottles for each water source is presented).  The results of the Hazard Analysis are given in Tables 5 to 8.

Discussion of Results
From the results presented in table 4, it is observed that Sample C (obtained from the hand pumped well, Block E of the boys' hostel) contain the highest Total Dissolved Solids (TDS), and of course the highest turbidity and conductivity levels which are 710mg/L, 1.97NTU and 1430 µS/cm respectively.
The Nigerian Industrial Standards for Drinking Water [12] specifies that the maximum permitted levels of TDS and Conductivity be 500mg/L and 1000 µS/cm respectively. In sample C, the highest obtained values of TDS and conductivity are 710mg/L and 1430 µS/cm respectively, which are slightly higher than the stated standard. The turbidity and pH levels range from 0.25NTU to 1.97NTU and 7.1 to 8.2 respectively with sample C ranking highest for turbidity and lowest pH of 7.1. Values of pH and turbidity obtained in these analyses fall within acceptable Balewa University (ATBU, Yelwa Campus), Bauchi Nigeria limits for WHO and NIS specifications.
All other samples met the WHO and NIS guidelines for drinking water in terms of the physiochemical requirements. Among all samples analysed, only samples A and D were found to be contaminated with total bacteria with values of 9 Cfu/mL and 36 Cfu/mL respectively. Sample A, located in front of girls' hostel is a borehole pumped into an underground concrete storage tank. The tank is virtually always opened and the water abstracted using a local fetcher. This explanation also justifies the result obtained for sample D (a hand dug well within the school's ICTC premise). Since sample C (hand pumped well behind block E of boys' hostel) has a concrete apron with vegetation around the apron.

Hazard Analysis
Four Domestic Water Source Hazards were identified for analysis: 1. Poor Water Quality 2. Septic Tank Location 3. Well/ Borehole head not Water Tight 4. Flooding around water source Poor Water Quality: Two (sources B and E) of the five water sources monitored met all the requirements for drinking water, corrective measured were proffered for three sources as seen in table 5. Table 6 presents the hazard analysis for septic tank location in relation to the water sources. All the water sources met the minimum requirement of a distance of at least 30m from a water source. Table 7 presents the analysis for unprotected well head. Sources A and D had corrective measures proffered. Table 8 showed the analysis for flooding. All the five water sources were not located in flood zones.