It would seem that collecting human waste in a pit would pose a health risk. After all, water comes from the ground. In places far from a city, such as my village, people can get water from communal taps built on street corners, but some families will also have boreholes drilled on their property for when the taps are dry, which they often are. Could it be dangerous to have a pit latrine too close to a borehole? Provided that it’s properly maintained, no. A person with healthy kidneys is not going to pass more than a few liters of urine per day, so the flow of fluid into the pit should not be torrential. What doesn’t evaporate may leech into the ground, but contaminants won’t permeate far enough through the soil to reach the water table. Some pits will be lined with bricks or other casing for structural integrity, and it’s not the end of the world if the lining develops cracks. For the most part, a user of a pit latrine will not know or care what, exactly, is under him.