A septic system will only work if the soil is permeable to water, as determined by a ‘perc’ test. If the perc test fails, you may need to use a more expensive alternative system – or – the land may be unbuildable.
Perc Test procedure. A typical perc test consists of three or more holes dug about 30 to 40 feet apart in the proposed septic drain field area. The holes are typically 6 to 12 inches in diameter and generally 2 feet deep. This is the typical depth of the trenches in a septic leach field. Two inches of clean sand or gravel are placed in the bottom of the hole. Since the perc test is meant to simulate the actual conditions in a working septic system, the soil is then “pre-soaked” for several hours.
Next, each hole is filled with water to a depth of 6 inches above the gravel and how much the water drops in 30 minutes is measured. The times are recorded and can used to calculate the percolation rate. That is the time it takes for the water to fall one inch. This is usually expressed in minutes per inch of drop.
A rate of 60 minutes per inch, meaning the water dropped one inch in 60 minutes, is often the cutoff point for a standard gravity-flow septic system, although the number varies from 30 to 120 minutes depending on the state regulations. Test results are usually good for two years.
Call SES today at 1-866-249-5630 and leave your Clifton Va Perc Testing worries to us.