TL;DR
In water well construction, the annular space is the ring-shaped gap between the drilled borehole wall and the outside of the well casing. Regulations require sealing its upper portion with bentonite or neat cement grout, commonly the top 18 to 50 feet depending on the state, so surface water and contaminants cannot run down the casing into the aquifer.
What it means
In water well construction, the annular space is the ring-shaped gap between the drilled borehole wall and the outside of the well casing. Regulations require sealing its upper portion with bentonite or neat cement grout, commonly the top 18 to 50 feet depending on the state, so surface water and contaminants cannot run down the casing into the aquifer. An unsealed one is the classic route for bacteria and nitrates to reach well water. Grouting happens once, at drilling, and is recorded on the well log filed with the state.
Where it sits in the glossary
Annular space is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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