According to the WHO, tap water is safe for consumption for 27% of the country.
There is a divide between rural and urban areas, tap water is safe to drink in 34% of urban areas, while it's only safe to drink in 26% of rural areas.
Donโt drink the water in Nepal. Ice should be avoided except in upmarket tourist-oriented restaurants. While trekking, purify your own water rather than buying purified water in polluting plastic bottles.
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 34.39 / 100 (100 being best).
Numbeo considers this score to be "Low"
1 adult could save about 219$ per year in Nepal 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.