According to the WHO, tap water is safe for consumption for 64% of the country.
There is a divide between rural and urban areas, tap water is safe to drink in 72% of urban areas, while it's only safe to drink in 51% of rural areas.
Water is drinkable in the cities, but avoid it in the countryside. In the Chaco it is positively salty.
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 59.09 / 100 (100 being best).
Numbeo considers this score to be "Moderate"
1 adult could save about 475$ per year in Paraguay 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.