Mostly it was industrial plumbing supplies. This included pipework, valves, flow meters, gauges and pumps. I had to know the chemicals used in order to ensure that the supplied materials were compatible. Some of chemicals were indeed nasty. Chlorine will kill you in the most unpleasant way. But the dosage is small (.0002 %) and chlorine dissipates and breaks down quickly.
Drinking water can be acidic. Calcite, better known as limestone, can balance Ph. Acid water can damage copper tubing and hot water services.
Some reservoirs use flocculants to settle organic materials like leaves. I've used some in a fishpond to make it easier to clean. The fish were fine.
Water authorities monitor water quality continuously in Australia, at least in the major population centres. I trust tap water more than something sitting in a plastic bottle for who knows how long.
You mentioned bottled water.
I agree with you. In America there are no real oversights.
Most bottled water is city water run through a filter. The spring water is from unknown sources.
That said, I had serious hormonal decline that put me down. The Lord helped me diagnose myself. It was revealed to me that the tap water I was drinking were full of endocrine disruptors.
I understand the need to kill pathogens. The cheapest chemical for that is chlorine, so that's what gets used.
The master gland, the thyroid requires iodine. That's something we all know. Unfortunately, MDs refuse to look at the common other halides in the diet of most people. In America, bromine/bromide is used as a cheap grain preservative. It's in all flours, doughs, breads and pastries. Because it's a halide, the thyroid accepts it, blocking the miniscule amount of iodine in the typical American diet. Guess what other elements are halides?
Fluorine and chlorine
All three are given in high doses to us. All three cause endocrine dysfunction. All three are treated as toxins by the body, so they must me processed and poison enzyme pathways for metabolic health.
This is incredibly valuable information that MDs in my country plug their ears to.
My Great Physician revealed this to me, provided a source of dietary iodine and restored my life. I got off of municipal water, drink my own source after purifying it, avoid bromine containing products and supplement with iodine.
I'm taking time to share this, because it might also be a blessing to you, your family and others.