CSM Remediation & Mitigation Strategies 3

Question 1

Which type of permeable pavement system is most appropriate for areas with clay soils where infiltration into native soil is not feasible?

Accepted Answer

Permeable pavement over an impermeable liner with an underdrain

Answer

In clay soils, an impermeable liner prevents water from entering poorly draining native soil while an underdrain still allows water quality treatment within the stone reservoir.

Question 2

A municipality discovers that road salt applications are causing elevated chloride concentrations in receiving streams year-round. Which mitigation strategy most effectively reduces chloride loading?

Accepted Answer

Implementing anti-icing and pre-wetting programs with precise salt application rates

Answer

Anti-icing and pre-wetting techniques apply brine before storms, requiring far less salt than reactive de-icing while achieving the same road safety outcomes.

Question 3

Which condition triggers a 'Level 2' corrective action for a stormwater BMP under a typical state post-construction maintenance program?

Accepted Answer

Structural failure impairing BMP hydraulic function

Answer

A Level 2 corrective action is required when structural integrity or hydraulic function is compromised, posing an imminent risk to BMP performance or downstream areas.

Question 4

Which sediment remediation technique involves placing clean material over contaminated sediment to isolate pollutants and prevent resuspension?

Accepted Answer

In-situ capping

Answer

In-situ capping isolates contaminated sediment by placing clean sand, gravel, or reactive materials on top, preventing pollutant release without sediment removal.

Question 5

When sizing a vegetated filter strip for stormwater pretreatment, which parameter is most critical for determining the required width?

Accepted Answer

Hydraulic loading rate per unit width

Answer

Hydraulic loading rate (flow per unit width) determines whether sheet flow can be maintained across the filter strip, which is essential for effective pollutant removal.

(CSM) Certified Stormwater Manager Practice Test

(CSM) Certified Stormwater Manager Practice Test

CSM Remediation & Mitigation Strategies 3