Table 9.1 indicated that pit latrines are considered an improved technology for treating wastewater. Determine the depth required for a pit latrine 1 m x 1 m in area that serves a household of 6 people and has a design life of 10 years. Assume the pit is dug above the water table and the occupants use bulky or nonbiodegradable materials for anal cleansing (for example, corncobs, stones, newspaper); therefore, the solids accumulation rate is assumed to be 0.09 m/person/year. Allow a 0.5 m space between the ground surface and the top of the solids at the end of the design life, which is the point when the pit is filled