Water quality
Water chemistry and water quality are examined. Water quality parameters discussed include oxygen content, pH, nitrates, heavy metals, trace elements, hardness, odour and colour. Water quality standards from Europe and the USA, and their relation to human and aquatic health are examined.
 DESIGN OF AN INDEX OF WATER QUALITY
This paper describes the formulation of an Index of Water Quality to evaluate the level of pollution in fresh water. A Four‐Round Delphi equation, using a panel of seven nationally recognized water scientists, was performed to ascertain the pollutants to be included in the index, the relationship between the quantity of these pollutants in the water and the resulting quality of the water, and the importance of each pollution variable to each water use as well as to overall pollution. A multiplicative index was used to bring the pollutants together into one system.
 Tubificids and water quality: A review
In conditions of low dissolved oxygen concentrations prevalent in water bodies receiving heavy sewage pollution, Limnodrilus hoffmeisteri and Tubifex tubifex predominate and other species are eliminated in a rough sequence, dependent on the level of pollution. The respiratory physiology of some species is adapted to operate at very low oxygen concentrations and they are able to survive for long periods in anaerobic conditions. The reproductive rate of L. hoffmeisteri is also unaltered by decrease in dissolved oxygen to very low concentrations.
Heavy ions, such as copper, are likely to eliminate tubificids, but the insecticide BHC may cause an increase in tubicifids while other aquatic invertebrates are eliminated. Warm condenser effluents are likely to increase the abundance of L. hoffmeisteri and, in some cases, provide suitable conditions for colonisation by the exotic tubificid, Branchiura sowerbyi. An evaluation is made of the possible use of tubificids as indicators of water quality.
 Water Quality Assessment of Epie Creek in Yenagoa Metropolis, Bayelsa State, Nigeria
This study evaluated the physicochemical and microbial quality of water samples from Epie creek, Niger Delta. Water samples were collected from five different locations (Akenfa, Agudama-Epie, Tombia, Opolo and Biogbolo) in two seasons viz: dry i.e. January and February and wet season i.e. May and June, 2016). The samples were analyzed following standard procedure. Results from the water quality ranged from 5.80- 7.01 (pH), 0.12 mg/l-2.58 mg/l (salinity), 265.00 -1096.75 µS/cm (conductivity), 31.29-105.04NTU (Turbidity), 133.00-548.50 mg/l (total dissolved solid), 3.74-10.562 mg/l(total suspended solid), 6.23-7.17 mg/l (dissolved oxygen), 65.17-94.95 mg/l (biological oxygen demand), 121.72-252.80 mg/l, (chemical oxygen demand), 6.504-14.30 mg/l (sulphate), 0.63-1.69 mg/l (nitrate), 2.18-4.28 mg/l (Bicarbonate), 15.25-61.75 mg/l (chloride), 19.20-62.00 mg/l (Alkalinity), 52.86-280.00 mg/l (Total hardness), 16.53-43.09 mg/l (calcium), 3.07-10.46 mgl (magnesium), 3.34-16.02 mg/l (sodium), 2.06-5.26 mg/l (potassium), 0.32-2.52 mg/l (iron), 0.016-0.188 mg/l (manganese), Analysis of variance showed that there was significance difference (P<0.05) in most of the location, months and interaction. The values showed that anthropogenic activities (mostly from marketing wastes in the creek is having an impact on the water quality).
 Prevalence of Waterborne Diseases and Microbial Assessment of Drinking Water Quality in Ado-Ekiti and Its Environs, Southwestern, Nigeria
Aims: This study aimed to determine the prevalence of waterborne disease and assess the microbial quality of drinking water sources in Ado-Ekiti and its environs.
Study Design: Cross-sectional, descriptive type of study.
Place and Duration of Study: Ado-Ekiti and its environs, Ekiti State, Nigeria, between January 2014 and August 2014.
Methodology: A well structured questionnaire was used to observe the prevalence of waterborne disease in Ado-Ekiti and its environs. Questionnaires were administered to 1000 residents in the different communities from where the samples were collected. Also, 500 drinking water samples from different water sources were collected and analyzed using standard pour plate method for total viable bacterial (TVBC) and E. coli count and standard multiple fermentation test for total viable coliform count (TVCC). All data obtained in the study were analyzed using Pearson Chi-square test and Pearson correlation between variables. The significance level was set 0.05.
Results: The results revealed that prevalence of waterborne disease was found to be 27.7%. The study also showed a significant association between the independent variables except residential status and waterborne diseases (P < 0.05). The microbiological assessment of the water samples revealed that 21%, 73.6% and 47.2% did not meet the WHO standard for TVBC, TCC and E. coli count respectively. Also, a strong positive correlation was observed between TVCC and E. coli count (r = 0.885) and TVBC and TVCC (r = 0.902).
Conclusion: The detection of total coliforms and E. coli in some of the water samples from different water sources in Ado-Ekiti in large colony forming unit implies that the contaminated drinking water may be responsible for the prevalence of waterborne disease in the city. Therefore, effort should be made by appropriate authorities to conduct quality assessment of water sources from time to time to ensure that safe drinking water of good quality is available to everyone.
 McCutcheon, S.C., Martin, J.L. and Barnwell Jr, T.O., 1992. Water quality. Handbook of hydrology., pp.11-73.
 Dinius, S.H., 1987. Design of an index of water quality 1. JAWRA Journal of the American Water Resources Association, 23(5), pp.833-843.
 Aston, R.J., 1973. Tubificids and water quality: a review. Environmental Pollution (1970), 5(1), pp.1-10.
 Ben-Eledo, V.N., Kigigha, L.T., Izah, S.C. and Eledo, B.O., 2017. Water quality assessment of Epie creek in Yenagoa metropolis, Bayelsa state, Nigeria. Archives of Current Research International, pp.1-24.
 Olowe, B.M., Oluyege, J.O. and Famurewa, O., 2016. Prevalence of waterborne diseases and microbial assessment of drinking water quality in ado-ekiti and its environs, Southwestern, Nigeria. Microbiology Research Journal International, pp.1-13.