Three streams are mixing at a junction. The flow rate and total dissolved solids (TDS, a
conservative pollutant) for each is presented in the table below. An industry is discharging 800
cfs downstream of the junction. If the TDS concentration in the stream cannot exceed 250 mg/L,
calculate the maximum concentration (in mg/L TDS) allowable in the industry effluent if steadystate conditions apply.
Stream Flow (cfs) TDS (mg/L)
1 500 60
2 700 50
3 1,000 75