Unless your intestines are well accustomed to Tanzania, donโt drink tap water that hasnโt been boiled, filtered or chemically disinfected (eg with iodine tablets) and be wary of ice and fruit juices diluted with unpurified water. Avoid drinking from streams, rivers and lakes unless youโve purified the water first. The same goes for drinking from pumps and wells; some bring pure water to the surface, but the presence of animals can contaminate supplies. Bottled water is widely available, except in very remote areas, where you should carry a filter or purification tablets.
According to the CDC tap water is generally not safe for consumption.
According to the Numbeo water drinkability and accessibility index, tap water has a score of 38.57 / 100 (100 being best).
Numbeo considers this score to be "Low"
1 adult could save about 635$ per year in Tanzania by drinking tap water instead of buying bottled water.
๐ณ Drinking tap water would also help with reducing your plastic footprint and improve environmental pollution.
Like in most countries, water quality and accessibility differs from location to location, therefore it's the best to check the information available on that place.