The Tel-Aviv municipality managed to take the area around the radio-active water-stream of the Yarkon River and turn it into a fairly nice and active Park Hayarkon (Ganei Yehoshua). It has been there for many years, but I think it’s looking much better now.
Not nearly enough has been done to address the water pollution, it seems, but that doesn’t seem to bother the local visitors who just enjoy using the park.
The last time I visited the spot was many many years ago and I was surprised just how pleasant the area was and with how sports aware the local population became. You look at people and they seem genuinely happy and healthy.
More? Here are some relevant links :