Question $3(10$ points$)$

LIsten

Determine the spacing between pipes in a leachate collection system by using granular drainage material and the following properties. Assume that most conservative design all storm water from $24-$hr$,25-$year storms enter the leachate collection system. Design storm $(24-$hr$,25-$year$)=8\mathrm{.}5$ inch $=0\mathrm{.}00028c\frac{m}{s}$; Hydraulic conductivity of the granular material $={10}^{-2}c\frac{m}{s}$; Drainage slope $=2\mathrm{.}5\%$; Maximum leachate depth on liner $=25\mathrm{.}4-cm(10-$inch$).$

$29$ m

$35$ m

$15$ m

$21$ m