A surface flow wetland needs to reduce the average BOD of a wastewater from

$60$ mg$/$L to $15$ mg$/$L$.$ Daily flow of the wastewater is $3786$ m$3/$d$.$

$1)$ Estimate the size of the SF wetland without considering the requirement of

supplementary structural components.

$2)$ What is the size of the wetland, if supplementary structural components

are taken into consideration?

$3)$ How would you estimate the surface area requirement if there is a

considerable variation between the average flow rate and periodical peak

wastewater flow rates?

Exercise $(10$ min$)$