The pipe belonged to Tesla. The dark liquid was wastewater from the company’s nearly $1 billion lithium refinery, which began operations in December 2024 and was, at the time, the first commercial-scale spodumene-to-lithium-hydroxide refinery in North America. Tesla had marketed the plant for years as an “acid-free clean process,” promising sand and limestone as the main byproducts. The drainage district had not been told that 231,000 gallons of treated wastewater per day would be flowing through its infrastructure.