$7\mathrm{.}29$ An engineer is seativity no greater than $10^{-8}$ a sanitary landfill. This soil must have a hydraulic conductive been tested in a falling$-$head borrow $7\mathrm{.}19.$ This specimen was $120mm$ in diamet permeameter similar to the one in inside diameter of $8\mathrm{.}0mm.$ Initially, the water in the $32mm$ tall. The standpipe had an water in the water bath surrounding the specimen. Then, $8$ hours $503mm$ above the water was $322mm$ above the water in the water bath. Compute $k$ minutes later the soil meets the specification.