6. in the winter, a stream flows at 10 m3/s and receives discharge from a pipe that contains road runoff. the pipe has a flow of 5 m3/s. the stream's chloride concentration just upstream of the pipe's discharge is 12 mg/l, and the runoff pipe's discharge has a chloride concentration of 40 mg/l. chloride is a conservative substance.
(a) does wintertime salt usage on the road elevate the downstream chloride concentration above 20 mg/l?
(b) what is the maximum daily mass of chloride (metric tons/day) that can be discharged through the road runoff pipe without exceeding the water quality standard?