Abstract:
Concern over nitrate pollution of groundwater in integrated water quality management has been
growing recently. The levels of nitrate in wells from septic tanks and urban agriculture with nitrogen fertilizers
application may increase the potential groundwater pollution by nitrate. The purpose of this study was to
determine the concentrations and spatial distribution of nitrate (NO 3 − ) in groundwater in Morogoro
Municipality. Groundwater samples were collected from 20 wells during wet season period in March-April
2010 in 6 wards namely Kihonda, Mji Mpya, Mafisa, Saba Saba, Boma and Kilakala. The spectrophotometer
was used to measure the NO 3 − concentration in water samples. The minimum and maximum nitrate levels were
1.4 and 32.5 mg/L respectively in the wards studied with an average of 7.76 mg/L. These results showed that
all of the groundwater samples have NO 3 − concentration below the Tanzania Bureau of Standards upper limit
value and World Health Organization guideline of 75 mg/l and 50 mg/l respectively. Also, the level of nitrate
concentration tend to decrease with depth for most of the places due to the anoxic condition that is available at
the higher depth which facilitates the utilization of nitrate by anaerobic microorganisms.
