I just listened again and he said the presence of dbp can strongly impact the ph of water by altering the concentrations of magnesium and calcium... Whatever that means.
tbh I looked at the study he mentions regarding this and, unless it's in one of the citations of the study, I can't find any mention of this
Absolute BS. If chlorine reacts with something, it's with organic matter. Carbon. Both Mg and Ca do not react with chlorine
as used in tap water (max 5 mg per liter). Now there's some semantic problem here. Ca does react with pure Cl2 gas, and forms CaCl. But the disinfectant isn't Cl2, as that immediately reacts with water to form Hcl. Hcl is the same acid as is present in your stomach. The low concentration in tap water is not dangerous, nor toxic. In the gaseous form, pure Cl2 is very dangerous and very toxic, as was shown in WWI. And that's what keeps driving this BS.
So what, you're saying that filling my jugs up at the water dispenser with it's filtering is not a good idea and I should start drinking the cocktail from the tap?
I don't know. I don't know your tap water, nor the water from the machine. In some parts of the US, the tap water is bad. But in the majority of places it's good. Well, CNN ran an article that over half of tap water supplies in the US is polluted. I'd be amazed if that was true. It's more like 10%. The major problem is "man-made chemicals, like PFAs. But there also were cases like Ferguson, Flint and Baltimore.
Anyhow, here's a starting point:
https://www.ewg.org/tapwater/
Over here, we still have one town, Verviers that has bad tap water. It's a logistic problem. The piping is still lead and the first water in the morning contains lead. Not enough to kill you, but still unhealthy. The problem is that to sanitise the pipes, the entire water system needs to be switched off. That's very, very expensive, as you can supply drinking water in bags, or bottles, but that doesn't run the washing machine, or the dishwasher. Belgium has been paying a yearly fine to the EU because that's cheaper.
I'd still say that recent terrorists coming from Verviers is probably a coincidence and not due to insanity from lead poisoning, but it could contribute if these people had lived in that town long enough (and drank enough tap water.)
Isn't there some gov lab in the area where you live that provides free water analysis? We have that over here. It's mainly for well water, but they also analyse surface water and tap water. Besides, tap water is continually monitored. Also out of fear for terrorism. If there's anything in it that's even remotely suspicious, the feeding pumps shut down automatically. Water towers can keep the pressure feed for at least 24 hours, allowing the water company to switch to a clean feed.
AFAIK Bleach is a common (redneck) water supply disinfectant. It is basically dilute HCL (hydrocloric acid). I recall my mother dumping some clorox down into our lake house well when it got funky from a dead critter falling in or something like that. 
