TL;DR
A limiting layer is the soil horizon that restricts how deep a septic drainfield can treat effluent, whether seasonal high water table, bedrock, or a dense restrictive layer such as hardpan. State codes require a minimum vertical separation, often 18 to 48 inches, between the bottom of the trenches and that horizon so wastewater is filtered before it reaches groundwater.
What it means
A limiting layer is the soil horizon that restricts how deep a septic drainfield can treat effluent, whether seasonal high water table, bedrock, or a dense restrictive layer such as hardpan. State codes require a minimum vertical separation, often 18 to 48 inches, between the bottom of the trenches and that horizon so wastewater is filtered before it reaches groundwater. Its depth, documented during the soil evaluation, frequently decides whether a site gets a conventional system or a mound.
Where it sits in the glossary
Limiting layer 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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