Same. My area is built into limestone. My toilets get crusty after a couple days.
I’m about to install a polyphosphate water softener cartridge before the whole house filters, to combat this. My pipes and appliances are scaled no doubt; I get a ton of sediment in my faucets.
Polyphosphate supposedly not only softens water but also descales everything it runs through over time, and it lasts a long time. (I plan to just refill the cartridge when it runs low, so it’ll be fairly cheap long term compared to a salt softener, and it’s the size of a standard single stage filter). Fortunately all the pipes in my house are copper, except the ones leading in which are lead but won’t be impacted by the anti-scale (and just in case I use a reverse osmosis unit for all consumed water, the water here tastes like shit so..)
It depends where you descale from and where the lead pipes are, but absolutely yes. In my case the lead is only feeding to the house and I would have my polyphosphate filter running about 15 feet after that so the only way it would seep back is long periods of stagnation or if the city pipes depressurized. Everything inside my structure but not going through the foundation (why I haven’t replaced it) is copper.
That’s basically what happened in flint Michigan. They changed the water supply which changed the ph, which de-scaled the lead pipes.
I have the reverse osmosis unit installed though for any consumed water (drinking, cooking, pets, anquariums) and that definitely would filter out lead. It’s as safe as I can manage here.