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
When calculating an event mean concentration (EMC) for a storm event, what two measured quantities are required?
Answer: Total pollutant mass and total runoff volume
EMC is calculated by dividing the total pollutant mass (load) discharged during a storm event by the total runoff volume for that event.
A stormwater manager is evaluating a bioretention cell's performance. Which parameter best demonstrates volume reduction effectiveness?
Answer: Difference between influent and effluent total runoff volume
Volume reduction effectiveness is measured by comparing the total volume of stormwater entering the bioretention cell to the total volume discharging from its underdrain.
Which method is used to assess soil infiltration capacity in the field for green infrastructure siting?
Answer: Falling head permeameter test
A falling head permeameter (or double-ring infiltrometer) measures the rate at which water infiltrates into the soil, which is critical for sizing infiltration-based BMPs.
What does a flashiness index (R-B index) measure in a stream monitoring program?
Answer: The rapidity and magnitude of short-term changes in streamflow
The Richards-Baker (R-B) flashiness index quantifies the frequency and rapidity of streamflow changes, with high values indicating flashy urban stream behavior driven by impervious surface runoff.
A sampling technician notices that a collected stormwater sample has a greenish tint and strong odor of sewage. What should be done first?
Answer: Document the observation and report it as a potential illicit discharge
Unusual sample characteristics such as color, odor, or turbidity should be documented and reported as potential illicit discharge indicators for follow-up investigation.
In a hydrograph analysis, what does the 'recession limb' represent?
Answer: The declining portion of flow after peak discharge as storage drains
The recession limb of a hydrograph shows the decreasing streamflow after the peak as surface runoff ceases and channel storage gradually drains.
Which GIS-based method is commonly used to delineate watershed boundaries for stormwater assessment?
Answer: Digital elevation model (DEM) flow direction analysis
Watershed delineation using GIS relies on digital elevation model (DEM) analysis to determine flow direction and accumulation, identifying the drainage area contributing to a point of interest.