had to replace the septic tank and the area is a mess what can I plant that handles medium traffic,grows fast and smells good.
Did not want to put grass back in unless I could not find something more beneficial.

I'm not sure Alyssum (Lobularia) would stand up to foot traffic, but it grows fast and flops over, so it would cover ground quickly. It reseeds pretty eagerly in my yard. They are more like flowers than ground cover.

Often it looks like a snowdrift, say 5-10 inches deep if there is nothing to climb up on.

The variety that grew out of a seed mix for me either bloomed continuously or repeatedly all summer and into the fall (we have mild summers and mild falls).

Sweet Alyssum (Lobularia maritima)

My favorites for that kind of situation are creeping thyme and Roman Chamomile. Neither minds foot traffic much. There is a nursery called Steppables which specializes in foot-traffic tolerant groundcovers for all sorts of climates and conditions. Their website is a fount of excellent ideas for this! You might be too wet for wooly thyme, for instance; you might not have enough sun for chamomile, etc. They only sell by the flat, and I can never afford to buy that much plant material at once, but perhaps you can. If not, you can at least discover which groundcovers you'd like to experiment with.

There is also low-growing white clover, which I saw seeds for recently -- was probably either Territorial Seeds or Johnny's Seeds. They were advertising this clover as a ground cover in particular. Seeding instead of setting out plants would mean you'd need to out-compete bird seedeaters though.

Perennial Peanut. Some states are using it instead of grass. It can be mowed if you wish. Small yellows that are attractive to bees and butterflies.

Never heard of perennial Peanut, I have learned something new.

I just planted Frog fruit as a ground cover. No scent, but it attracts butterflys/moths. Is drought resistant and doesn't mind too much water.

if you are going to walk on it, i think grass.