Question

4. A city currently in 2020) has a population of 150,000. The population is expected to increase to 210,000 by 2035. The city has a water treatment unit of capacity was 25 mgd. If the expected water use rate from 2020 to 2035 is 130 gpcd, will expanded treatment facilities be needed by 2035? If so, in about which year would they need it? In case the city would like to delay the need for a new facility until 2035, what reduction in water use rate would be needed? (15 points)

Answer 1

Soluticos Population Population in year (y=9 2020 = P, = 150,000 von year (y2=Do 2035 = P2 = 210,000 - Capacity of water treatment unit = 25 mgd (mega gallon Pen day) - Water per capita per day) got use rate = 130 (gallon = 130 gpcd I → Water requirement for 2035 Population = 130 x 210000 gallon per day = 27300000 gallon per day = 27.3 x 106 gallon Perday - 27.3 mgd.) since we have only treatment facility of 25 mad and requirement of 27.3 mgd. Therefore we have a need to expand the facility. 3) Now Population for which this 25 mad facility is sufficient = Capacity of treatment unit Water use rate & Population = per day 25x100 gallon gped 130

Population = 192307.692 cp let population so is tee linearly increasing. y = 2020 ,Pi = 150000 yz = 2035 P2 - 210000 making a equation of line (4-4)= (Y2-Y,) (P-P.) (P2P) Now we 1. put all values and p = 192307,692 So we will get value of year y = (2035-2020) (192 307,692–150000) (y-2020) = 210000-150000] =) (y-2020) = 15 x 42307.69 60000 y = 2030.57 year so on the year 2030 they would need expanded facility. Now water use rate for 25 mgd facility by Population of year 2035 water to use rate creduced) = 25x100 sunt het 25x10 Population 210000 gpcd, - 11g goed y reduced water rase a rate.