Soylent Green is the first thing I thought of too... did not have a problem with Water World.... not a bad movie in my opinion....
But then just last night I told some friends what I wish could be done with my body once I'm gone... dropped in a salt marsh for a couple of days and there would be nothing but bones left..... then I told them to go to the nearest local sea food place in a few months and get some shrimp and crabs and have a feast on me!
The place wifey and I are planting our remains does not require a vault of any kind. We are being cremated and put in a cardboard boxes to be buried there when it happens. Fertilizer for the lawn and any nearby trees. South Dakota burial laws are pretty loose. You can be buried by your relatives in their backyard if you want. You just have to let the county know where they put you.
I like the idea, in theory but I looked into it and it's $6K. We're doing the cardboard box, cremation route. We set up a bequest for a great-nephew who wants to go into Marine Biology (My field in college) to pay for his education. Why waste some of it on something fancy after I'm gone? Cremation and a Masonic funeral from my Brothers. My family is across the western US and why ask them to pay to see me scattered?
I am within 10 miles of an area doing that here in Vancouver Wa. Years ago in the location of Longview WA. there was an Indian site on the Columbia River called Coffin Rock where the Indians would deposit their dead and they would decompose. When the jetties at the mouth of the Columbia River were built they used Coffin Rock as a major source of rock to build them.
the problem evolved in large urban areas years ago when they finally figured out just planting a lot of folks in one area leads to a health problem.... if we go on the principle that how ever one is planted that place will not be disturbed again then this is for sure going to be an issue.... one day. Wife and I get toasted and spread .... back to dust so to speak and I guess in the end just recycled.... which from my view and understanding of the actual history of the planet is as it should be.... we are always walking on and even eating the dead of the past.