CWD Risk Assessment & Management 4

Question 1

What is the MOST effective engineering control to reduce drilling crew exposure to crystalline silica dust?

Accepted Answer

Using wet drilling methods or local exhaust ventilation at the dust source

Answer

Wet suppression and local exhaust ventilation eliminate or capture silica dust at the source, providing the highest level of protection under the hierarchy of controls.

Question 2

When drilling in karst terrain, which unique risk must be specifically addressed in the risk assessment?

Accepted Answer

Sudden borehole collapse into subsurface voids or sinkholes

Answer

Karst limestone contains dissolution cavities and voids that can cause sudden total loss of circulation, borehole collapse, or drill string drop without warning.

Question 3

Which federal regulation requires drillers to notify the appropriate agency before drilling within a wellhead protection area?

Accepted Answer

Safe Drinking Water Act (SDWA)

Answer

The SDWA's Source Water Protection program requires notification and often additional controls when drilling within a designated wellhead protection area.

Question 4

What does a 'stop-work authority' policy mean in the context of drilling site safety?

Accepted Answer

Any worker can halt work when they observe an imminent hazard without fear of reprisal

Answer

Stop-work authority empowers every employee to halt operations immediately upon identifying a serious hazard, creating a culture where safety supersedes production pressure.

Question 5

How does grouting a well annulus reduce environmental risk?

Accepted Answer

It seals the space between the casing and borehole wall, preventing surface contaminants from migrating downward

Answer

Annular grouting creates an impermeable seal that prevents surface runoff, bacteria, and other contaminants from channeling along the outside of the casing into the aquifer.

(CWD) Certified Well Driller Practice Test

(CWD) Certified Well Driller Practice Test

CWD Risk Assessment & Management 4