Assessment & Monitoring Methods Flashcards
7 cards from real CSM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Assessment & Monitoring Methods flashcards as text
What is the primary function of a storm sewer system map during an illicit discharge detection and elimination (IDDE) program?
Answer: Identifying all outfall locations and pipe connections for systematic screening
A complete storm sewer system map is essential for IDDE programs to systematically locate outfalls, trace drainage connections, and identify potential illicit discharge sources.
A portable multiparameter sonde is deployed in a receiving stream for continuous monitoring. Which combination of parameters would it typically measure simultaneously?
Answer: Temperature, pH, dissolved oxygen, and specific conductance
Multiparameter sondes typically include sensors for temperature, pH, dissolved oxygen, and specific conductance (and sometimes turbidity), all measurable electronically in real time.
What does a specific conductance reading that is significantly higher than background levels indicate during dry-weather screening?
Answer: Possible presence of dissolved salts or wastewater in the flow
Elevated specific conductance indicates dissolved ions, which can signal sewage, industrial discharge, or other non-stormwater contributions during dry-weather periods.
In a stormwater assessment, what is a 'lag time' and why is it important?
Answer: The time between the centroid of rainfall and the peak of the resulting runoff hydrograph
Lag time is the time difference between the centroid of rainfall input and peak streamflow, and it reflects how quickly a watershed responds to precipitation — shorter lag times indicate more urbanized conditions.
Which analytical method is approved under 40 CFR Part 136 for measuring total suspended solids (TSS) in stormwater samples?
Answer: EPA Method 160.2 (gravimetric filtration and drying)
EPA Method 160.2 is the approved gravimetric method for TSS, involving filtration through a glass fiber filter and weighing the residue after drying at 103–105°C.
A stormwater manager wants to assess whether a restored riparian buffer is reducing nitrogen loading to a stream. What monitoring design would best answer this question?
Answer: Upstream-downstream paired monitoring with pre- and post-restoration data collection
An upstream-downstream paired design with pre- and post-restoration data collection allows the manager to isolate the buffer's effect on nitrogen by accounting for background conditions and temporal variability.
When using an ultrasonic level sensor to measure water depth at a stormwater outfall, what environmental condition most commonly causes measurement errors?
Answer: Floating debris or foam on the water surface
Ultrasonic sensors emit sound pulses and measure their return time; floating debris, foam, or rough water surfaces can deflect or scatter the signal, causing inaccurate depth readings.