If you are interested in purchasing a lot or parcel of land to build a home, chances are you have heard of a perc test. In this post, we will answer questions like how is a perk test done, why it is needed, and who can perform it on your land.
What is a Perc Test?
A soil percolation test (perc test) measures water absorption. The official name of the test is the percolation test. Percolation is the process of liquid slowly moving through a material or substance with tiny holes in it. A percolation soil test determines the rate at which water is absorbed by the soil, determining the drainage capability of the ground. Perc testing is done for stormwater or septic infiltration. It calculates how much water can pass through soil pores after it reaches complete saturation. This calculation determines the size the system has to be to receive incoming flows from a household or during a rain event. The drain field or basin is designed and built to store that amount of water in the stone voids and holds the water until surrounding soils perc the water through the environment in 24 hours and then is ready to receive more incoming flows.
When is a Perc Test Needed?
A septic system must be installed if a property does not have access to municipal sewer services. Perc tests are the critical first step for any septic system installation. In order to obtain proper permitting for septic systems, most county health departments require perc test results from an approved tester.
How is a Percolation Test Performed?
The first step in the perc testing process is digging holes. Typically several holes are needed, spaced 50 feet or more, and prepared by scraping and clearing debris. Hole depths range from 18 to 36 inches. After the holes are prepared, the tester will saturate the hole with water, filling it and keeping it full for 4 hours. Testing begins approximately 18 hours after the initial holes are prepared and saturated.
The official test involves filling the hole with water to a specific level and timing how long it takes to fall to another specified level. Multiple testing on each hole is often required for permitting. Results are recorded and interpreted with a higher percolation rate allowing for larger septic systems.
Who can Perform a Perc Test?
Anyone who understands how a perc test is done can perform one using DIY methods. However, county health or environmental departments require professionally certified results before issuing required permits when installing septic systems.
Percolation Test Results
Test results are reported as inches per minute. This calculation indicates how many minutes water in the test hole takes to drop by one inch. Rates acceptable for conventional septic systems vary from county to county. Also, good percolation rates depend on lot size and other geological and physical characteristics of the soil and surrounding land.
Failing a Percolation Test
Failing a percolation test will interfere with building plans. It is common for rural land parcels to fail perc tests preventing the ability to build a home on the land. There are times landowners can fix water absorption issues. However, it will cost more and require hiring and working with a civil engineer, geotechnical engineer, or another qualified professional to resolve the drainage issue. Completing a professional perc test on any land you want to purchase is advisable. Testing before purchase will help you make an informed decision about the land and how you will proceed.
Pricing for Perc Tests
Labor hours, soil conditions, and ease of access to the property or area being tested affect pricing for perc tests. In addition, several other factors, such as the soil type and testing depth, may affect pricing.
Delaware Valley Septic Sewer Storm
If you are in the Springfield, PA area, and need a perc test, contact Delaware Valley Septic, Sewer & Storm today. We offer many professional septic services, including inspections, installations, and perc testing.