CES CES Remediation Technologies & Site Cleanup

Question 1

What is 'pump-and-treat' remediation and what is its primary limitation?

Accepted Answer

Extracting contaminated groundwater for surface treatment; limited by slow contaminant desorption and NAPL source persistence

Answer

Injecting treatment oxidants and pumping out reaction products; limited by high chemical reagent costs

Answer

Pumping clean water into an aquifer to dilute contamination; limited by available fresh water supply

Answer

Excavating and thermally treating saturated soil; limited by deep excavation equipment costs

Question 2

What is 'in-situ chemical oxidation' (ISCO) used for in site remediation?

Accepted Answer

Injecting chemical oxidants into the subsurface to destroy organic contaminants in place

Answer

Excavating and chemically treating contaminated soil at the surface

Answer

Adding reducing agents to convert metals to less soluble oxidation states

Answer

Using biological organisms to aerobically break down petroleum compounds

Question 3

Which remediation technology uses microorganisms to break down organic contaminants in soil and groundwater?

Accepted Answer

Bioremediation

Answer

Thermal desorption

Answer

Solidification/stabilization

Answer

Air sparging

Question 4

What is 'soil vapor extraction' (SVE) and what contaminants is it most effective for?

Accepted Answer

A vacuum-based system that removes volatile organic compounds from unsaturated zone soil

Answer

A steam injection method that mobilizes semi-volatile contaminants for recovery

Answer

An electrokinetic technique that drives contaminants toward collection wells via electrical current

Answer

A chemical process that permanently binds volatile contaminants to soil particles

Question 5

What is 'monitored natural attenuation' (MNA) as a remediation strategy?

Accepted Answer

Relying on natural processes like biodegradation and dilution to reduce contamination to acceptable levels while monitoring confirms progress

Answer

Excavating contaminated soil incrementally and monitoring backfill quality after placement

Answer

Allowing a dissolved plume to discharge to surface water while collecting discharge monitoring data

Answer

Conducting periodic soil sampling without implementing any active remediation measures

Question 6

What is a 'permeable reactive barrier' (PRB) and how does it treat contaminated groundwater?

Accepted Answer

A subsurface wall of reactive material that passively treats contaminated groundwater as it naturally flows through

Answer

A surface barrier system that prevents precipitation from infiltrating into contaminated soil

Answer

A pump system that creates a hydraulic gradient barrier preventing plume migration downgradient

Answer

A reactive geomembrane liner installed beneath a landfill to capture and treat leachate