shortly after we moved in to our current house, i noticed this anomaly, down the street from our house, across the cedar river, near the intersection of SE 253rd and SE summit-landsburg road… 
it turns out, that is exactly what it is. from the late 1800s up until 1959, when the landsburg seam was exhausted, this was a coal mine. after the coal was all dug out, the mine collapsed into what they called a “subsistence trench”, which, in 1960, was the “ideal” place to dump a wide range of organic and inorganic industrial waste, including paint waste, polychlorinated biphenyls (PCBs), cyanide, metals, and oily sludge. naturally, in the early 1980s, this all had to be cleaned up when the state decided to create the “cedar river watershed” — the main source of tap water for seattle — less than half a mile up the road, and the cleanup and monitoring continues to the present day. the astounding part is that the “cleanup” consisted, largely, of removing the accessible barrels of toxic waste (approximately 100 barrels of an estimated 4,500 barrels were actually removed), and filling in and capping of the northern trench with concrete, which occurred from June 3, 2019 to November 9, 2020… the really astounding part is that we moved into our house on April 12, 2020, which was before they finished capping the trench! 😖
EEEEWWWW!! THERE’S A TOXIC WASTE DUMP RIGHT DOWN THE STREET FROM OUR NEW HOUSE!!! and less than a half-mile DOWN STREAM from the source of seattle’s water supply!! 🤨🤯
so, naturally, i HAD TO go and see what all the fuss was about! and today, i finally got around to doing it. my friend ian and i hiked up to the northern part of the trench, and walked down the western edge of the trench to the portal, and back.
Danville: A King County Coal Mining Town
Landsburg Mine Site, Phases I and II | Ravensdale, WA
human beings really suck! especially when it comes to figuring out what to do with our garbage. 😒