So full disclosure: writing a time travel agency where time travellers are forced to live in the past. So I was reading Jodi Taylor's Bells of Saint Mary's and she mentions 14 days worth of water purifier tablets. I realised the characters in my own novel would need the same, however at one point they get trapped in the Levant 2000 years ago for 1 year.
Are there any alternatives to the plot supplying them with 3285* water purifying tablets? Will boiling water be enough to remove cholera and dysentery? Time travel to the ancient Mediterranean would be like worse camping+poverty+feces-clean mountain streams. What other supplies would you pack?