Question

Groundwater is supplied to a community from a well through a 50-cm diameter pipeline 1.2 km in length. The pumping rate is 500 m3 /hr, and the water temperature is 10o C. Because of the location, the supply has been designated as being vulnerable to fecal contamination and the state has specified a minimum disinfection level of 99.9% virus inactivation. Groundwater pH is 7.0.

(a) What free chlorine residual is required in the pipeline?

(b) If the temperature of the water increases to 15°C, how does this affect the required chlorine concentration?

Answer 1