European Journal of Biomedical and Pharmaceutical Sciences

DETERMINATION OF HARVESTED STORAGE TANK RAINWATER QUALITY IN OWERRI, SOUTHEAST NIGERIA.

*Ubuoh E. A. and C. Nwakanma

ABSTRACT

Despite the practice of domestic rainwater harvesting (DRWH)for domestic purposes, little or no effort has been made toward monitoring the quality of stored rainwater in storage tanks in Owerri, Imo to ascertain their impacts on domestic harvested rainwater quality (DHRWQ). During the study, samples of harvested rainwater were collected from surface GP tank from FECOLART and underground concrete tank from private dwelling in Ubomiri for physiochemical and bacteriological compositions using standard methods. The results of the analyses were compared with water quality guidelines of World Health Organization (WHO) to evaluate their suitability for potable and domestic purposes. From the results, some of physical parameters like colour in surface tank without cover recorded 750 Pt/co, odour and taste were objectionable, appearance was greenish and turbidity was 177 NTU all above the World Health Organization (WHO) stipulated standards for drinking water, with underground tank with cover showed lower than the WHO standard. Results of the chemical compositions recorded that rainwater stored in both tanks were slightly acidic with the mean of pH6.0, surface tank recorded iron with the value of 2.45mg/l-1, and manganese values in both tanks exceeded the 0.10mg/l-1 according to WHO, stipulated for drinking water. For bacteriological analyses, except the underground tank the recorded zero total coliform (TC), surface and underground tanks recorded highest values of bacterial that exceeded the WHO standards stipulated for potable water. The results further explained that surface tank without cover was more polluted than underground tank with cover in terms of physiochemical and microbiological compositions. From the results, it is observed that stored rainwater may not be suitable for direct drinking, without treatment, but could be used for other domestic purposes, which therefore need rainwater treatment, including operational and maintenances (O&M) strategies.

Keywords: Physical Analysis, Analysis chemical Analysis, Bacteriological Quality, Harvested Rainwater, Storage tanks.