I read this story a while back, and as I recall, the woman had used water from the campground's piping.
I have long-standing sinus issues, and I occasionally irrigate my sinuses. I use only distilled water for this. I dry mix non-iodized salt and baking soda 3 parts salt to 1 part soda, and add 1 tsp of that mix to a cup of water in a clean jar, warm it a bit in the microwave, and have at it. I would never use ANY tap water for this.