View Full Version : Question about septic systems

04-15-2010, 07:33 PM
Help! In all my years doing landscaping I have never had to deal with a septic leach field except to know that you can't plant anything except grass over it.... I have a prospective client that, among other projects, wants to level the backyard, including leach field, into a nice backyard. Currently, the area is very "lumpy". The house was new construction a few years ago and was essentially plunked down in the middle of a hay field. Very little finish work was done. What can I do to this area without damaging the field? Can I run a tiller over the area, level and reseed/sod like I would with any other lot? I am assuming that the system is a designed system with underground pipes, but I don't know how deep they would typically be. I asked the homeowner, trying not to sound too ignorant, but they had no idea about the system, other than that was were the leach field was. Any thoughts, or resources I can look for to learn more about them??

04-15-2010, 07:50 PM
I have leveled a few down here in Texas. I have always added top soil or bank sand over them to level. I stay off the tanks and try to keep the tractor weight off the lateral lines the best I can. Ours are typically 3' deep 3' wide with 2' of gravel with 4" pvc leach lines in the middle of the gravel and 1' of dirt on top. There should be a permitted drawing of the lay out if you can't see the lateral lines. I know here in Texas they used to be permitted through the the county but are now permitted through the state.

White Gardens
04-18-2010, 09:48 AM
Ditto to the above post.

I did one with a mini that all I did was fill in the low spots with dirt and made sure not to disturb the soil that was already there.

04-22-2010, 10:18 PM
How much traffic can a typical leach field take? Can I use a kubota tractor to run loam or does everything have to be done with wheelbarrow and hand tools??

04-23-2010, 07:30 AM
Different states allow different designs for septic systems (I work in an engineer's office). Some have very specific requirements for depth or vegetative cover. The best thing would be to talk to the engineer who designed the system and ask him what you can do.

04-28-2010, 06:36 AM
I work for an engineer as well and designing septic systems is just one of many things we do. Typically with a standard tank/trench system the minimum cover is 24". If its a non conventional system (drip emitter, mound) these depths can be less. I would at bare minimum go to the local health department and pull the permit and drawing just to see where everything is, what type of system and what depth its installed. If its 24" two feet of fill is plenty to drive a small tractor on without risk of damage to drainage system. I suppose this would depend on soil types.

Some of the systems out there are chamber systems....you have probably seen the plastic chambers at Home Depot, some of the other systems are gravel systems. The gravel system is less likely to be damaged if a heavy object is driven over top of it. I am sure if you look up the Infiltrator chambers they have load specs, if not the manufacture can provide them.

04-28-2010, 06:38 AM
I think you will find most states environmental health requirements to be very similar but its always good to ask.

Oh and if your system is 24" or deeper you will be fine tilling up the first 6" or adding an inch or two of top soil if you chose that route, in fact I couldn't see any health department turning down a grassed leach field since grass helps deal with the waste and the fact that the top of the leach field is where the least amount of treatment occurs, most is side to side and below.