Access to a regular supply of safe water is a basic human right but many people are denied. This study investigated the physical, chemical and microbiological properties of well water installed close to septic tank in some location in Lagos metropolis. Samples were collected from five (5) wells from each location (Ikorodu, Mushin, Shomolu, Itire and Ilasamaja) during the rainy season when ground water intrusion is high. The well water were analyzed for pH, temperature, Total Solid, Dissolved Solid, Suspended Solid, Alkalinity, Acidity, Total Hardness, Dissolved Oxygen, Biological Oxygen Demand, Chemical Oxygen Demand, Sulphate, Manganese, Cadmium, Zinc (Zn), Total coliform count and Total Bacteria count. pH, temperature, TS were determined immediately in the sample. Analysis of the heavy metals was done using Flame Atomic Absorption Spectrophotometer. Data obtained were subjected to descriptive statistics. All the physical, chemical and microbial properties investigated except pH, Total Solid, DO, BOD and the coliform and bacteria count in the sampled well water were within the specified limit of WHO and hence, not suitable for domestic purposes for which they are presently used for in some of the residential area in the study area. Contamination from intrusion from septic tanks and runoff from storm water could account for these differences in sampled water and WHO Limits. Where affordable, water must be treated before consumption and Public enlightenment on water quality should be encouraged to foretell the looming danger from water contamination/pollution.