Mound & Alternative Septic Systems in Chattanooga, TN
Chattanooga Drain Field Pros is a septic contractor building mound and alternative systems, replacing failed drain fields, repairing fields, installing complete new systems, replacing tanks and baffles, arranging soil testing and design, and handling commercial work. We serve hard sites across Chattanooga, Signal Mountain, Sale Creek, Birchwood, Ooltewah, and Hamilton County, Tennessee.
A mound is built from imported washed mound sand placed above the natural grade, with pressure distribution laterals running through it and an effluent pump, floats, and a control panel with an alarm feeding them in timed doses. The sand is the soil your site did not have. The laterals put every gallon across the whole bed instead of down one end. Set that against a gravity trench forced into ground with rock two feet under it, where the water has nowhere to be treated before it reaches something it should not.
Vertical Separation in Plain Words
There has to be a depth of clean unsaturated soil between the bottom of your trench and whatever lies beneath it, whether that is bedrock, a hardpan layer, or water sitting high in a wet season. That soil is where treatment happens. The number is set locally and your evaluation reports it. Enough of that depth and trenches work in the natural ground. Short of it, the sand gets hauled in instead.
At-Grade Systems
An at-grade is the lower profile relative of a mound. It places the distribution right on the prepared natural surface with cover over it, rather than lifting the whole bed into a sand berm. It suits sites that fall a little short on depth rather than badly short. Less imported material, less height in the lawn, same principle.
Pumps, Floats, Panels, and Alarms
Every dosed system carries mechanical parts, and mechanical parts are the honest cost of a hard site. A pump chamber holds the dose. Floats tell the pump when to run. The panel runs the timer and sounds the alarm when the level climbs anyway. None of that is exotic, and all of it needs a person to look at it occasionally. We hand you the panel and show you what the alarm means before we leave.
Why Even Loading Outlives Gravity
A gravity field feeds the near trench hardest. That end works overtime and seals first, while the far end sits dry and does nothing. Small orifice laterals fed by a pump load the whole bed in a batch, then let it rest and drain. Rest is what keeps soil accepting water. On the same ground, the evenly loaded system lasts longer.
What It Costs and What the Alternative Is
More than trenches. Imported sand, a pump chamber, controls, and a longer build all carry real money. The alternative to a correctly designed alternative system is not a cheaper system. It is a system the county will not permit, on ground that cannot treat what you send it. Call (423) 555-0125 and we will tell you which category your ground falls in once the soil is read.
Why does my site need a mound?
Because there is not enough clean unsaturated soil under the natural grade to treat your wastewater. Three things cause that here. Rock sitting close to the surface, which is common on ridge and slope ground. Water standing high in the profile through a wet season, which the mottling in a soil pit reveals. And clay so tight it will barely accept water at any depth. When the site does not have the soil, the soil gets brought to the site. That is all a mound is.
Is a mound better than a regular field?
It is not an upgrade and nobody chooses one for fun. A mound is the honest answer for ground that will not take a conventional trench field, and on the right site it works very well. The trade is real and worth saying out loud: it costs more, it needs a pump and controls that a gravity field does not, it takes up lawn, and it is visible. If your lot would pass for trenches, trenches are the cheaper and simpler system and we will tell you so.
What is an aerobic treatment unit and do I want one?
It adds air to the wastewater so bacteria treat it before it ever reaches the ground. Effluent leaving the unit is cleaner than tank effluent, and cleaner effluent can mean a smaller field, a shallower field, or a workable system on a site that could not carry a conventional one. The trade is that it runs on power, it has a blower that eventually needs work, and it needs service on a schedule rather than when you remember. Some sites make it the obvious answer. Most do not need it.
How much lawn does a mound take up?
More than people expect, and the footprint is set by the design rather than by preference. The sand bed itself takes the core of it, then the slopes fall away on all sides, and the whole thing needs a clear buffer with nothing driven or parked on it. Plan the rest of the yard around it rather than the other way round. We stake the outline before anything is built, so you can see the real shape on your grass before you commit to it.