People have moved into houses built on the "Love Canal" toxic dump in Niagara unaware of its history as probably the worst toxic waste catastrophe in the US:

https://en.wikipedia.org/wiki/Love_Canal

https://www.nytimes.com/2023/06/12/nyregion/love-canal-toxic... (archive: https://archive.ph/UFJ96)

Seattle turned a creosote saturated lakefront area into a city park. And then had to shut it down within a year, scrape all the topsoil off to a deeper depth and replace it.

There are actual creosote superfund sites in Puget Sound, from railroad tie manufacture. For some reason the gasworks weren’t one, even though they are a point source of the stuff.

Gas Works Park is the Seattle city park referenced above:

https://en.wikipedia.org/wiki/Gas_Works_Park

https://www.seattletimes.com/life/50-years-since-gas-works-p...

The cleanup effort is still ongoing:

https://ecology.wa.gov/blog/june-2023/cleaning-up-cleanup-of...

> Seattle turned a creosote saturated lakefront area into a city park. And then had to shut it down within a year, scrape all the topsoil off to a deeper depth and replace it.

You're missing the part where it has been reopened for decades.

Just, uh, don't dig or wade in the water.

I assume by “reopened” you mean closed and reopened repeatedly? Yeah I moved a while ago and didn’t hear the comedy of errors continues. Looks like they’re thinking of dredging an area of lake union twice the size of the park?

The park's been open for 40 years.

It's entirely possible I'm wrong about this, and I missed an environmental closure, could you find a news article for it?

Yes, there's definitely a comedy of errors when it comes to remediating the site. I believe that there's a 2027 dredging plan.

As I understand it, the consensus is that the environmental danger largely lies in the buried waste poisoning the waterways, and the watertable, not picnic-goers. Am I wrong? Is the consensus wrong?

In the southern Midwest and in a few of the arid states, there are areas where flash flooding is a problem. In a heavy rainstorm, the shape of the watershed is such that most of the water shows up at a river or stream bed as a concentrated pulse. That can be particularly dangerous in a seasonal stream bed, because you are more likely to have people in a dry stream bed than a wet one. Of course you also have the problem of people crossing a dry bed and not being able to cross back until the rains stop.

There are some famous videos of people getting caught by flash floods in the Middle East as well. The return of the rains seems to have become a spectator sport and people get too close.