Two reservoirs are connected through a homogeneous and isotropic aquifer having hydraulic conductivity (K) of 25 m/day and effective porosity (\( \eta \)) of 0.3 as shown in the figure. Ground water is flowing in the aquifer at the steady state. 
If water in Reservoir 1 is contaminated then the time (in days, rounded off to one decimal place) taken by the contaminated water to reach Reservoir 2 will be \(\underline{\hspace{1cm}}\).