Buy barrels specifically for water storage - they are rated for long term storage and are food safe. Sorry I don't have the brand I got at hand but it wasn't too difficult to find them - they drop shipped it to my house for cheaper than I would have expected. It was similar to this: https://www.amazon.com/Augason-Farms-Storage-Barrel-55-Gallon/dp/B06Y2H5GVX/ref=sr_1_7?crid=243SQ31QKZWON&keywords=water%2Bstorage%2Bbarrel&qid=1657692713&sprefix=water%2Bstorage%2Bbarrel%2Caps%2C170&sr=8-7&ufe=app_do%3Aamzn1.fos.18630bbb-fcbb-42f8-9767-857e17e03685&th=1