What is a perc test and why do I need one?
Most people who buy land to build a house never expect the many small but crucial steps that must be completed before the house is ready to live in.
Most contractors don’t either unless they are a general contractor!
This post is a quick overview so you can make an informed choice when you dive in to the wonderful world of home building.
In order to build a new structure, you need to first test for a septic system to be installed so you can have water and sewer capabilities. Pretty basic, right? Well, you also need to take into account WHERE you will place your septic system in relation to your driveway, garage, backyard and house.
If you want to get this done as a DIY without a professional involved, just imagine how quickly your yard, foundation or driveway could turn into a soggy mess because the leach field was not done properly! If this happens, the fix will cost you far more than if you choose to get the leach field done properly from the get-go.
STEP ONE: UNDERSTANDING LEACH FIELDS
A leach field (also called a septic drain field or infiltration basin) is a below-ground wastewater disposal system used to filter the water that emerges after bacteria break down waste in a septic tank.
The shape and depth of the leach field varies based on your landscape, local geography and soil quality. For example, if your soil contains a high level of clay, this will prevent water from being absorbed and means you will need extra sand.
A perc test measures how quickly the soil on a property absorbs water so the dirt work contractor and engineer can determine where on a property is best suited to build a leach field.
STEP TWO: HOW DOES A PERC TEST WORK?
In a perc test, several holes (usually a minimum of three, but anywhere from five to eight) are dug in various places on the proposed leach field. In the photo above, you can see two pink flags (circled in red) where two holes were dug.
Each hole needs to be around 6-8 inches in diameter, and 3-6 feet deep.
Then, water is added, and each hole is timed in minutes per inch to see how long it takes for the water to be absorbed by the soil.
That rate timed in water drained per minute is called the percolation rate.
Lastly, the water table depth needs to be determined by digging a deep hole, sometimes to 12 feet deep. This also shows where and how deep the leach field should be.
At the end of the test, all holes are backfilled and the data is sent to the local government authorities to finalize approval for the leach field and septic system plans.
STEP THREE: MOVING FORWARD
The local government will then issue a permit for the owner and builder to create the septic system and prepare the property for building the structure they have in mind (barn, shop, home, or business).
This is why you cannot DIY a leach field and need a trained professional with solid experience to help guide the local government representative and speed up the process as much as possible.
By offering input during the perc test and establishing a positive, professional relationship, the excavation contractor you choose can help or hinder you as the permit process begins.
An inexperienced or overburdened government representative can make or break your building timeline right from the get-go, especially if a sloppy job is done and the test needs redone and the leach field reworked.
So, to conclude: make sure you are choosing a high-quality dirt contractor from the start to partner with you on building your dream home or other property! Not sure where to start? Read our infographic on how to choose a high quality contractor here: https://www.completeexcavationsolutions.com/blog/howtohireagoodcontractor
