Hard water treatment disaster

A large bore contractor got called to fix a problem with a pump. Pulled it out and found a contractor had added a large amount of raw oxalic acid to the bore that was having calcium problems. This is what calcium oxalate looks like, an insoluble precipitate and very bad for the pump!

https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0013/164101/Farm-water-quality-and-treatment.pdf