Question

Where does all the water go? According to the Environmental Protection Agency (EPA), in a typical wetland environment, 35% of the water is outflow; 47% is seepage; 6% evaporates; and 12% remains as water volume in the ecosystem (Reference: United States Environmental Protection Agency Case Studies Report 832-R-93-005). Chloride compounds as residuals from residential areas are a problem for wetlands. Suppose that in a particular wetland environment the following concentrations (mg/l) of chloride compounds were found: outflow, 68.9; seepage, 74.6; remaining due to evaporation, 29.8; in the water volume, 55.3.

(a) Compute the weighted average of chlorine compound concentration (mg/l) for this ecological system. (Round your answer to one decimal place.)

(b) Suppose the EPA has established an average chlorine compound concentration target of no more than 58 mg/l. Does this wetlands system meet the target standard for chlorine compound concentration?

Answer 1

Answer:

a)

Given,

To determine the weighted average of chlorine compound concentration for the ecological system

Water outflow, wo = 0.35

Water seepage, ws = 0.47

Water evaporates, we = 0.06

Water stays as water volume in the ecosystem = wv = 0.12

Chloride mixes as residuals in outpouring water = xo = 68.9

Chloride mixes as residuals in seepage water xs = 74.6

Chloride mixes as residuals in outstanding water because of evaporation xe = 29.8

Chloride mixes as residuals in the water volume xv = 55.3

Now consider,

μw = (xo*wo + xs*ws + xe*we + xv*wv ) / (wo + ws + we + wv)

substitute the given values

= (68.9*0.35 + 74.6*0.47 + 29.8*0.06 + 55.3*0.12) / (0.35 + 0.47 + 0.06 + 0.12)

= 67.601 / 1

μw = 67.6 mg/l

b)

Since here we can say that the weighted average compound concentration target is greater than 58 mg/l .Thus we can conclude that the wetlands system does not meet the target standard for chlorine compound concentration.