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; 50% is seepage; 6% evaporates; and 9% 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, 70.6; seepage, 73.8; remaining due to evaporation, 24.7; in the water volume, 46.8.

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

(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?

Yes. The average chlorine compound concentration (mg/l) is too high.

Yes. The average chlorine compound concentration (mg/l) is lower than the target.

No. The average chlorine compound concentration (mg/l) is lower than the target.

No. The average chlorine compound concentration (mg/l) is too high.

Answer 1

Consider X: Concentration of chlorine compound.

	Weight	X	X*W
Outflow	0.35	70.6	24.71
Seepage	0.5	73.8	36.9
Evaporation	0.06	24.7	1.482
Remains in the water	0.09	46.8	4.212
Total	1		67.304

Weighted average of chlorine compound concentration for given ecological system.

b) Since Value of Weighted average chlorine compound concentration is 67.304 and EPA set the average chlorine compound concentration target no more than 58 mg/l .

i.e. Average chlorine compound concentration should be less than 58 mg/l.

For the given ecological system average value is much greater than 58.

Hence Wetland system does not meet target standard for chlorine compound concentration.

Correct Answer: No the average compound chlorine concentration is too high.