Septic Field Lines

Don't know where to post this and it may sound a little weard.
Anyway, where I live, it is extremly dry at my newely purchased home. My septic system is not giving any problems and I know where the Tank is located. I have some large equipment like trucks and tractors that I would like to keep off the Field Lines if possible. I realize that they probably won't harm their operation but rather be safe.
This is the first home I have owned in 45 years that shows NO Signs of field line activity. My grass is, basically, dead all around my tank and where I think the lines are.
Shouldn't the grass be different over the lines or should I just not worry about them?
The home is about 18 years old and all the homes in my neighborhood are on septic systems.

Its definitely a good plan not to have heavy equipment on your field. If its a gravity system you could have a camera run down the lines from your d box and locate each line of the field. Then mark them with something perminent like some stakes in the ground.

If the house was unoccupied for awhile, there wouldn't be enough flow to grow the grass for awhile. Depending on how big the tank is, if it was cleaned before the previous occupant left, you could go awhile before you filled it up so it would start draining into the leach field.

Actually, the sign of a good system is no indication of where the field is. The effluent should stay well below the line of grass roots. Here, where we have no rain for 4 or 5 months, a big green patch at the septic lines tells me the system is bad.

Especially if you have a green spot at the tank, you have problems. Maybe its the first good system you have had. I have installed several systems of various complexity, and none reveal themselves by greenery.

I always bring up 4" risers at the beginning and end of leach line runs to mark the field, and install risers at the tank and D box.

Driving cars or backhoes over the leach area is not to be encouraged, but really the compaction extends about 4 to 6" in depth and is a non issue. You do not however want to drive a JD 710d backhoe with about 4,500# of pressure on each tire over the tank. You might have a U-tube moment.

Thanks for the replies---It sounds good that I may have a good working system. I have lived here about one year and the tank was cleaned some time before I moved in.
I was told by two different people that I had the signs of a good working system and I would like to keep it that way.
Now for a maintenance question----I have conflicting opinions about three things---
(1) Should a system be pumped occasionally?
(2) Does it really matter if a large amount of sink water, bath water or whirlpool water is put through a system that is working properly---with common sense applied--?
(3) Is a garbage disposal good or bad for a system?
My family avoides grease in system and we have always wiped the dishes clean before washing.

There will always be some stuff washed down the drain that will not decompose, or at least decomponse quickly. Stuff like lint from the washing machine, hair, and some stuff you might grind up with a disposal. So, yes, to maintain the health of the system, you should get it pumped out periodically. The one thing you don't want to do is to get enough crud in the tank so that it forces some of those solids into your leach field...that will clog it up and require replacement. How often, depends somewhat on the size of the tank and it's use.

Lets say you have a 1500 gallon tank. If your girls flush feminine items in the toilet and mom uses "flushable" butt wipes and a garbage disposal instead of composting, a family of 4 or 5 might need a pump every 3 to 5 years or more. With composting, no girls, or girls that are "green" and no junk in the inlet except what naturally aspires from your privates, you might get 10 or more years.

Most health departments give pump charts and advice based on use and family members. Main thing is NOT to use a disposer.