How can I get rid of recurring brown lines?
Every summer, when things begin to dry out, we get three brown stripes in our lawn. I'm guessing that these are the leach lines to the septic system. Is there anything we can do to prevent this from happening?
— George, Xenia, Ohio
Roger Cook replies: You're probably right about what's causing the stripes, but just to make sure, get a copy of the septic plan and see if the lines correspond to it. The plans might be with the deed for your house, or at your board of health or building department. If the stripes line up with the pipes, the field probably has too much stone or sand too close to the surface, which would cause the ground to dry out too quickly. There should be about 3 to 6 inches of stone or sand above the drain field pipes, with 6 to 12 inches of topsoil above that. Poke around gently with a shovel to see how deep the soil goes.
If your digging turns up stones or sand, you'll have to dig some of it out and replace it with loam. First, mark the locations of the areas that dry out. Then in the fall, when the grass is no longer dormant, rent a sod cutter and remove the affected lawn. It's always better to save the existing grass and reuse it because different sod or seed might take years to blend in. Lay the sod aside on burlap and keep it wet. Then dig out 6 inches of sand or stone and replace it with 5 inches of good-quality loam. Be careful with your shovel; you don't want to damage any pipes. Compact the loam slightly so that it won't settle, then put the sod back. Take your time to do a careful job and in a few months you won't know where the repairs were.
Now, if the septic field doesn't correspond to the brown areas, ask a local utility for the name of your local "one-call" center, which will come out and mark the location of all buried water, gas, or telephone lines. Once you know where it's safe to dig, dig down and see what's causing the area to dry out. You'll probably find sand, stone, or just compacted soil, but I've uncovered asphalt walkways buried under the grass.