CHMM Site Remediation 3

Question 1

A permeable reactive barrier (PRB) using zero-valent iron (ZVI) remediates chlorinated solvents primarily through which mechanism?

Accepted Answer

Reductive dechlorination via electron donation from iron

Answer

ZVI donates electrons to chlorinated compounds, causing reductive dechlorination that breaks chlorine-carbon bonds and produces less-toxic or non-toxic daughter products.

Question 2

In a remedial investigation, what is the primary purpose of installing groundwater monitoring wells in a transect downgradient of the source area?

Accepted Answer

To delineate the contaminant plume extent and direction

Answer

Downgradient transect wells define the lateral and vertical extent of the dissolved-phase plume, confirming contaminant migration pathways.

Question 3

Which RCRA corrective action document establishes the final cleanup standards and schedule for a facility subject to a corrective action order?

Accepted Answer

Corrective measures implementation (CMI) plan

Answer

The CMI plan details the selected corrective measures, implementation schedule, and performance standards that a RCRA facility must achieve.

Question 4

Thermal in situ remediation techniques such as electrical resistance heating (ERH) are most advantageous for which contaminant class?

Accepted Answer

Chlorinated solvents with low vapor pressure in low-permeability soils

Answer

ERH heats the subsurface to increase volatility of chlorinated solvents, enabling vapor extraction even from tight, low-permeability formations where other methods fail.

Question 5

Risk-based corrective action (RBCA) frameworks allow remediation to a site-specific risk level rather than a generic standard. What primary factor drives site-specific cleanup levels?

Accepted Answer

Exposure pathways, receptor populations, and contaminant toxicity

Answer

RBCA tier calculations incorporate contaminant toxicity, site-specific exposure pathways, and sensitive receptors to derive protective cleanup levels tailored to actual risk.

CHMM - Certified Hazardous Materials Manager Practice Test

CHMM - Certified Hazardous Materials Manager Practice Test

CHMM Site Remediation 3