Well Construction
Well Construction
Well Construction is the core technical domain of the Colorado well driller exam. It tests whether you can take a permitted well from site selection through casing, grouting, development, completion, reporting, and-when necessary-abandonment without creating a pathway for contamination or a cross-connection between aquifers.
Permit, siting, and responsibility
A well may not be constructed until the State Engineer/DWR has issued a well permit. The licensed driller is responsible for construction according to the permit and the Water Well Construction Rules, even when equipment or crews are shared. Before drilling, check permit conditions, proposed use, setbacks from contamination sources and property lines, and any special aquifer or subdivision requirements. The most restrictive applicable setback controls.
Casing, grout, and sanitary protection
The well must have sound casing that extends above grade, is capped, and is sealed to the formation. The annular space is grouted to prevent surface water and shallow groundwater from moving down the borehole. Grout must be placed positively-typically by tremie from the bottom upward-not dumped from the top, because bridging leaves voids. The sanitary seal, pitless adapter, and backflow protection must keep the wellhead watertight. Development and disinfection follow the rule and permit conditions.
Completion, reporting, and abandonment
After completion, the driller files the well construction report with DWR within the required period and gives the owner the well information. A well that is unusable or abandoned must be sealed according to rule by a licensed person; simply covering the casing is not abandonment.
Worked example
A permit requires continuous grout from the bottom of the casing to land surface. The crew sets casing and pours bentonite chips from the top; the chips bridge at 30 feet, leaving the lower annulus open. Reasoning: the visible top seal does not prove a continuous seal. The driller must clear the annulus and place grout by tremie, then document the corrected seal. If the annulus cannot be sealed, the well cannot be approved as completed.
Traps that cost marks
- Treating the permit as a formality; permit conditions can be stricter than the general rule.
- Confusing “casing depth” with “grout depth.”
- Relying on a surface seal while the annulus is bridged.
- Missing the construction-report deadline or filing incomplete water-level and yield data.
- Leaving an unused well unsealed because the casing is capped.