$1\mathrm{.}5$ Design a rectangular Sedimentation tank for $18$ megaliters per day with a detention time of $3$ hours and velocity flow of $0\mathrm{.}6\frac{m}{m}in$ assuming tank depth of $2\mathrm{.}5m.$

a$.$ What will be the length of the tanks? $(8)$

b$.$ What will be the width, total depth, and the total volume of the tank? $(8)$

$1\mathrm{.}6$ Suppose a renewable energy project requires an initial investment of $R1$ million and is expected to generate $R200,000$ in revenue for every single year over its $7-$year lifespan. Calculate the project's net present value $($NPV$)$ using a discount rate of $5\%.(10)$

$1\mathrm{.}7$ A city is considering implementing a recycling program that would cost $$100,000$ per year to operate. The program is expected to reduce landfill usage by $500$ tons annually, resulting in avoided disposal costs of $$50$ per ton. Calculate the net annual benefit of the recycling program.

$1\mathrm{.}8$ After a thorough analysis of the current water scarcity, water pollution and water shortage in South Africa, VUT management has hired as a consultant you to develop a full plan to implement and install three main sustainable water management practices at Campus considering both conservation and treatment strategies which include rainwater harvesting, greywater recycling, and promoting water$-$efficient appliances. However, you used the money from VUT to buy flashy expensive cars, installed two JoJo tanks and gave one of the VUT Managers money to delay or silence VUT from following up on the project. you explained that you will install or implement other strategies in $2028.$

a$.$ Are you being ethical? $(1)$

b$.$ What are the four primary ethical considerations when investigating the impacts of a project on society and the environment? $(4)$

c$.$ Explain in detail who must be held accountable for the project failures and why. $(5)$

d$.$ Explain in detail the consequences of the project failures to the VUT community. $(5)$

e$.$ Explain in detail how VUT should deal with the Manager. $(4)$

f$.$ Creating a comprehensive ethical framework for sustainable water resource management. $(8)$