What is a percolation (perc) test?
A percolation test measures how quickly water drains through soil. It tells you whether a site can support a conventional septic system.
Read moreGlossary
Learn the terms
Plain-English definitions for soil testing, septic design, land surveying, and environmental consulting work — with sources from EPA, NOWRA, NSPS, and state agencies.
What is septic system design?
Septic system design is the engineered plan for treating wastewater on-site when municipal sewer service is unavailable. It covers tanks, drainfields, and soil suitability.
Read moreEnvironmental consulting, explained
Environmental consultants help property owners, developers, and government agencies meet environmental regulations through testing, reporting, and permitting.
Read moreWhat is a land survey?
A land survey measures and maps a property — its boundaries, features, and elevations. Different survey types serve different legal and construction purposes.
Read moreWhat is a test pit (soil hole)?
A test pit, or soil hole, is an excavation that lets a soil scientist read the soil profile in place before a septic system is designed or approved.
Read moreWhat is soil mottling (mottled soil)?
Soil mottling is the blotchy gray, orange, and brown coloring that shows water sits in the soil part of the year. It is a key signal in septic site evaluation.
Read moreWhat is a seasonal high water table?
The seasonal high water table is the highest level groundwater reaches during the wet season. It is a deciding factor in whether a site can support a septic system.
Read moreWhat is a restrictive layer (clay layer)?
A restrictive layer is a dense band of soil or rock, such as heavy clay or bedrock, that water cannot move through easily. It often decides whether a septic system fits.
Read moreWhat is a soil evaluation?
A soil evaluation is a soil scientist’s assessment of a site’s soil profile to determine whether it can support a septic system. It is broader than a perc test.
Read moreWhat is a drainfield?
A drainfield, or leach field, is the buried network of pipes and gravel where a septic system releases wastewater into the soil for final treatment.
Read moreWhat are septic setbacks?
Septic setbacks are the minimum required distances between a septic system and features like wells, property lines, water bodies, and buildings.
Read moreWhat is an onsite wastewater permit?
An onsite wastewater permit, or septic permit, is the government approval required to install and operate a septic system after soil, design, and inspection requirements are met.
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