Manholes in wastewater collection systems should be placed
a. no more than 30 meters apart
b. at each pipe intersection and change of pipe slope or size
c. at intervals no closer that 200 meters
d. with inverts no more than 2 meters below grade
e. all of the above
Question 2
A type of filter commonly Used for municipal water treatment is the
a. trickling filter
b. diatomaceous-earth filter
c. closed pressure filter
d. open mixed-media filter
e. membrane filter