Project: Sanitary Sewer Design $($HED$470$S$)$

You are a newly appointed emerging consulting engineering company appointed to design water,

sanitary and stormwater infrastructure. So far, the portion of work completed includes

population projections for various demand zones $($summarised in Table $1)$ and water reticulation

layout shown Figure $1.$ The sewer network will follow the same layout.

Table $1$: Design data for the project area

Consider the average household size to be A $(5),$ B $(4),$ C $(3),$ D $(7)$ and E $(5)$ and $3$ for

military barracks.

The current water source can meet projected demand.

The design period for all infrastructure is $20$ years.

The population growth rate is about $0\mathrm{.}3\%$ in areas $($B and D$)$ and $0\mathrm{.}5\%$ in other areas.

The current individual water consumption is $80\frac{L}{c}\frac{?}{d}($areas A$,$ D and E$)$ and $200\frac{L}{c}\frac{?}{d}$

in others.

The fire risk is low in all areas.

The design should focus on the following:

Water

You are required to determine the water demand for each zone and the total water demand for

the town. Also determine the amount of water abstracted from the source if water losses account

for $10\%.5\%$

Sanitary sewer

A sanitary sewer is to be designed considering dry weather flow as $85\%$ of water demand.

Consider $21\%$ allowance for infiltration and ingress.

$2\mathrm{.}1$ Total volume of sewage generated and $(5\%)$

$2\mathrm{.}2$ Design the main sanitary sewer pipeline for the current layout of the area by selecting

the most appropriate location for the wastewater treatment plant. The treatment

plant should be about $300$ m away from the end of the selected zone. The ground

levels for the junctions at A$1,$ B$1,$ C$1$ and D$1$ will be provided by the surveying team in

due course as they cannot prevent work from proceeding. $(40\%)$

$2\mathrm{.}3$ Provide a drawing of the network with all relevant information $(10\%)$

$2\mathrm{.}4$ Develop a profile of the main sewer $($datum$,$ manhole number, NGL$,$ invert level,

distance and pipe diameter$)(10\%)$