n environmental engineer must recommend one of two methods for monitoring high

colony counts of E$.$ coli and other bacteria in watershed area $$hot spots.$$ Estimates are

tabulated, and the MARR is $10\%$ per year. Use the ROR analysis to select the better

method

Method A Method B

Initial cost, $ $-100,000-300,000$

Annual operation cost $($$ per

year$)$

$-30,000$ in year $1,$ cost

increase by $5,000$ each year

till end of lifetime

$-20,000$

Life, years $816$

Incremental ROR$=12\mathrm{.}87\%,$ choose method B