Green grass streaks over septic tank field

It's probably the toilet that is the problem and nothing later in the line. I highly recommend the American Standard Champion4 Toilet. I installed this when I remodeled one of my bathrooms and two years later it has yet to clog (compared to the other two toilets in my house that clog on a regular basis). The advertisements show it being able to flush golf balls and although my kids have not tried that (at least not yet) I bet it really could handle it. You can find it at both Lowes and Home Depot.

It is entirely possible that if the toilet was running hard enough that that is the source of the problem. Assuming the weather conditions are fairly dry and surrounding ground is not saturated, I'd give it a day or two to subside and let the leach field catch up. If the problem doesn't clear quickly with the toilet fixed, I'd call for a pump and have them check the backflow of the leach field to determine if there is blockage downstream from the tank. Good luck.