One of THE most confusing terms I heard when I first moved to Lake Norman and re-established my real estate business was the term “perc” . I would hear agents ask such questions as: Did the land perc? How many bedrooms did it perc for? When I visited a new housing subdivision in Mooresville the agent on duty told me they were delaying construction because only 20 lots ˜perced.
So what in the world does perc mean? Technically, it is short for the term: Percolation. And, very simply, a perk test measures the ability of the soil to absorb water.
“The percolation tests are designed to simulate conditions in a septic system. The percolation test consists of a hole 6-12 inches in diameter dug in the area of the proposed septic system. The depth of this hole varies depending on the soils encountered but it is generally not greater than 24 inches. The hole is initially filled with water (presoak) in an attempt to saturate the soil, allowed to drain away and than refilled with approximately 12 inches of water. The rate at which the water drops in the hole is measured at intervals over a period of time ranging from 30-60 minutes. The uniform slowest rate of drop of the water level over a measured time interval is converted to minutes per inch and used as a basis of design in determining the septic system size”.
Any unimproved lot will require a perk test to determine if it can qualify for a septic tank and if so, how big a house will the septic system handle. The size of the house is actually the number of bedrooms so, if a lot perks for three bedrooms, the maximum number of bedrooms that a house on that lot can have is three.
When buying raw land that is not in the town limits and thus does not have sewers, it is critical to know whether it will perk as this will determine not just how large a home you can build but IF you can build a home at all. Sometimes in subdivisions you will find oddly shaped lots which many times are bigger than the average. This is probably due to the septic system requirements.
Each county around Lake Norman has their own requirements for septic systems. The process usually goes like this:
- You/your builder string off where the home and driveway will be placed on the lot itself
- Apply for a septic permit from the county health department
- Draw an initial site sketch
- The county will come out to the site and perform a perk test
- If the soil does not perk, then you will not get a permit
- If it does perk, you will be given the limitations by number of bedrooms
Another important step in any plans for expansion of an existing home is to pull the septic permit to find out how many bedrooms it allows. You would not be allowed to add a fifth bedroom to a home that perked for four!
To learn more about this process go to the website: Percolation Test or contact your county health department.