Septic field landscaping ideas (meadow?)

Hi all. I’ve read that shallow rooted plants including some wildflowers can be planted over septic fields in place of lawn, but I’m hesitant to do it. Has anyone tried this with any luck? I’d really like to conceal our ugly septic lid that sticks out like a sore thumb and replace the lawn with plants that don’t need water in the summertime, as all the grass dies off that time of year anyway. Looking for ideas. Located in western Washington, zone 8b for reference.

When I built my home I placed the septic tank off the front corner of the house because that is where it had to be so i could save the trees in the back yard.  The top of the tank is a couple feet below ground level though, not sitting above the ground.  Right now I have a treated wood frame around the tank and a 4x8 sheet of painted plywood over top but I plan to eventually build a Snoopy Dog house with a cut out of Snoopy and Woodstock on top.  If you can't hide it, make something decorative to cover it.
Maybe a small windmill type house, or something like an old farm wagon full of flowers or decorations.

Are you talking septic tank or septic drainfield?
My septic tanks have very shallow grass growing over the tanks with the lids poking up. My drainfield is currently grass and stinging nettle and blackberries (unintentionally).

My plan for the septic tank area is to make fake rocks to cover the lids and seed wildflowers over the tanks. I think it will work just fine. There are lots of videos online how to make the rocks and it looks like fun.

In the septic drainfield I originally planned to seed it with a bunch of wildflowers but the stinging nettle grows so nicely there that now I'm just focusing on getting rid of the blackberries and I want to use the stinging nettle for fiber. The reason I gave up the wildflower plan for the drainfield is that I was worried that trying to kill the grass might mess up the drainfield. I don't think I should smother it because it needs to respirate and it would be risky to till it because I could damage the drainfield stuff under the grass.

Depending on which wildflowers you decide on, many wildflowers bloom in the spring when the grass is nice and green and like grass die off in the summer.

Perennial flowers might work if you make a perennial flower bed.

I have a butterfly garden with blue sage and mealy blue sage that works well without water.  I like to plant sweet alyssum as a ground cover though that will need water.

Though most plants that are drought resistant don't have shallow roots as the seep roots are what make the drought-resistant.

This thread is about a different situation than what you are suggesting though some of the flowers mentioned might work for you:

https://permies.com/t/142667/Wildflower-Meadow

This is another interesting thread:

https://permies.com/t/1760/grow-neat-stuff-lawn

Maybe some kind of wetland bushes? I would suggest Buttonbush, but then, you might end up with a wasp problem if you ever need access to that septic tank. I haven't had any attempt to grow, yet, so I don't really know how much of an issue the wasp species which are attracted to those bushes really are.