How a drain field works and why it fails
A drain field is a network of perforated pipes buried in gravel-filled trenches. Effluent flows out of the septic tank, through a distribution box, and into these pipes, where it seeps into the surrounding soil. The soil itself does the final treatment: bacteria in the top few feet break down the remaining organic material before it reaches groundwater. When the system is working, the field is invisible. When it is not, the signs show up on the surface.
The most common cause of drain field failure is solids leaving the tank. A missing baffle, a tank that went too long without pumping, or a heavy load of grease can push material into the distribution lines that was never meant to reach them. The solids coat the inside of the pipes and fill the gravel bed, reducing the soil's ability to absorb water. The effluent backs up and surfaces as standing water, soft ground, or a persistent sewage smell in the yard.
Repair depends on the extent of the damage. In some cases the distribution lines can be jetted and the gravel bed restored. If the biomat (the layer of organic buildup at the soil interface) has sealed the field beyond recovery, part or all of the field needs to be excavated and rebuilt with fresh aggregate and new pipe. Mississippi's clay-heavy soils make the work harder than it would be in sandy ground, and the crew needs to know the local soil conditions well enough to set the trench depth and gravel specification correctly the first time.
Lacey's Digging Services has been doing drain field work in Flowood, Florence, and the surrounding Rankin County area for over 30 years. The team knows this soil and what it takes to get a field working again.
