May 2012, Vol. 24, No.5
Test your knowledge of collection systems
True or False Questions:
- The acronym “I/I” refers to inflow and investigations.
- The difference between sanitary and combined sewer collection systems is that in addition to wastewater, a combined collection system is designed to receive and convey stormwater runoff.
- Atmospheric testing should occur at regular intervals during entry into a sanitary sewer manhole.
- Performing smoke testing on a sewer requires the following equipment: the smoke blower unit, source of smoke, and pipe plugs.
Multiple Choice Questions:
Which of the following pipe rehabilitation/replacement methods is not considered a trenchless technology?
A. Pipe bursting
B. Split lining
C. Open cut
D. Cured-in-place pipe
Elements of a grease management plan should include identification of accelerated cleaning cycles, enforcement capability, and what else?
A. An equipment inventory
B. Organizational charts
C. Public outreach and educational programs
D. Collection system preventive maintenance cycles
Reasons for a program of closed-circuit television (CCTV) inspection for preventive maintenance include identification of and rating of pipe defects, system condition assessment, and what else?
A. Prioritization of future capital improvement projects based, in part, on information gathered during CCTV inspections
B. Keeping crews busy when other equipment is broken
C. Making sure the sewer cleaning crews are getting the pipes clean
D. Cool rat pictures
What is the primary purpose of a written sewer release response plan (SRRP)?
A. To prove there is a plan
B. To define the difference between a sanity sewer overflow and a combined sewer overflow
C. To tell field crews what to do
D. To provide employees with consistent training and ensure that the public receives the highest level of customer service possible
What is the purpose of a lift station?
A. To pump wastewater to a treatment plant
B. To lift wastewater from a low elevation to a higher elevation where it can continue to flow by gravity
C. To provide a location where wastewater from septic systems is lifted out of trucks and released into a sewer collection system
D. To provide a place where trucks full of waste from cleaning sewers are tilted (lifted) up so their loads can be dumped
Why were capacity management operations and maintenance (CMOM) plans created?
A. To force utilities to raise sewer rates
B. To make the NPDES permit process more simple
C. To require specific asset management goals
D. To assist in the reduction of sanitary sewer overflows
What is the pump cycle “on” time of a 500-gal/min pump within a 10-ft diameter wet well? The pump cycles on at a depth of 13 ft and off at a depth of 1 ft, and has a constant inflow of 25 gal/min.
A. 14 minutes, 50 seconds
B. 14 minutes, 6 seconds
C. 4 minutes, 27 seconds
D. 22 minutes, 12 seconds
What is the flow rate in a 2.5-ft-wide channel with a flow 12 in. deep and a velocity of 2.3 ft/s?
A. 101 gal/s
B. 2 gal/min
C. 43 gal/s
D. 43 gal/min
Click here to show or hide the answer key
Volume of a cylinder = pr2h.
1 ft3 contains 7.48 gal.
Questions written by
senior public works supervisor for the City of Portland, Ore., and reviewed by the Operations forum editorial advisory board and the Association of Boards of Certification (Ankeny, Iowa) Wastewater Treatment Validation and Examination Committee.