1. Written examination group „A”
Name:….……………………………… Semester:……………… NEPTUN code: ……………………. ……..
Course code: ………Practical lesson teacher: ……………………………………………..Date:…………………………..
1. Dimension the sanitary sewer branch 1-0-0 at the calculation point 1, location can be seen on the figure above.
The number of inhabitants is 1300 people, the slope is 4 ‰ between the point 1 and point 2, the roughness is
k=0,4 mm. The maximum design filling level is Q/QTOT = 0,8.
The design number of the people is 1200 people at calculation point 2.
The design number of the people is 1300 people at calculation point 3.
The following values are valid on the design area: q=120 l/person,d, β=1,4, the sewage ratio α=0,95, z=1/16,
the coefficient of the waste water =1.31*10-6 m2/s
Determine the following parameters at the point 1: Qh peak sewage loading (10 scores), the diameter of
the sewage pipe (10 scores) vTOT (10 scores), QTOT (10 scores)
 2.51
k 
vTOT  2 lg 

2 gId (the units: k – mm, d – m)
 d 2 gId 3710d 


2. Suppose the same location for the storm-water system. The catchment area is 2,5 ha, the runoff coefficient is
0,5 at designing point 2. The catchment area is 3,5 ha, the runoff coefficient is 0,25 at designing point 3. The
runoff coefficient is 0,4 and the catchment area of the storm water conduit 1-0-0 is 3,2 ha between the point 1
and point 2. Determine the average runoff coefficient at the designing point 1. (10 scores) The design
concentration time is at the points T(2) = 12 min and T(3) = 19 min. The runoff time is t2=4 min between the point
1 and point 2. Calculate the peak load of the storm-water at the point 1 if the formula is: ip=133 t-0,69 (10
scores)
3. The actual consumptions are 3 l/s at each node in the main-loop below. The fire water is Qout=600 l/min at the
point (7). The assumed initial flow of the branch 1-2 is 6 l/s. Calculate the total volume of the water flowing
into the system at point 1 (10 score). Calculate the initial flows for each branch based on the
assumption given for the branch 1-2. The network location can be seen on the picture below (10 score)
Result: 0 - 40: unsatisfactory, 41 –53: satisfactory, 54 – 64: fair, 65 – 74: good, 75 – 80: excellent