Indianola Spit; Where does the S*** go?

Miller Bay from Port Madison with the Indianola Spit in between.

I've always wondered how Kitsap County ever allowed the spit to be developed. Check it out; large homes side by side and back to back along a narrow spit; no sewer and if you drive along the spit you'll see there are no mounds or other advanced septic systems. Hmmm, just wonder where all that s*** goes.

We rebuilt our deck a few years ago; smaller footprint; replacing an old deck with a new safer one and we had to designate an alternate drainfield to bring things up to new standards (eventually got onto sewer instead). Looking at the lots on the spit I can't figure out where one drainfield would go, much less one plus an alternate drainfield. It's not like they have stopped construction either; smaller homes have been taken down and empty lots have been filled with larger homes.

Click on the picture and look at it a bit larger; where are those drainfields? - keeping in mind there should be setbacks from property lines and from the water.

Just wondering.