The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock's law, is
For having central angle `alpha`, the area of cross-section of sewers running partially full, is
Boussinesq's equation for ascertaining unit pressure at a depth H on sewers due to traffic loads, is
In a sludge digestion tank if the moisture content of sludge V_{1} litres is reduced from p_{1} % to p_{2} % the volume V_{2} is
Hazin's formula `V_S = 418 (G_S - G_W) d [(2T + 70)/(100)]` is used for the settlement velocity of the particles of diameter