Solutions For Water and Wastewater Engineering Chapter 1 Problem 2

b. Calculate A| p factor to be used for all three alternatives. Alternatively, use a table in an engineering economics textbook

c. Annual cost for connection to WTP

A = $1,500,000 (A| p, 0.06, 20) + $300,000

A = $1,500,000 (0.0872) + $300,000

A = $130,800.00 + $300,000

A = $430,800

d. Cost for membrane A

New capital cost = $2,374,000 + $500,000

= $ 2,874,000

A = $2,874,000 (A| p, 0.06, 20) + $209,000

A = $2,874,000 (0.0872) + $209,000

A = $250,612.80 + $209,000

A = $459,612.80 or $460,000

e. Annual cost for membrane B

New capital cost = $2,162,000 + $500,000

= $ 2,662,000

A = $2,662,000 (A| p, 0.06, 20) + $258,000

A = $2,662,000 (0.0872) + $258,000

A = $232,126.40 + $258,000

A = $490,126.40 or $490,000

f. Recommend connection to WTP as least cost