At 457ppm you won't be seeing any adjustable wrenches or screwdrivers in your water but you may see a few nuts-and-bolts and maybe a screw or two.
Yes, I've seen 500ppm stated as the limit for human consumption but that is all it was...a "statement". The total dissolved solids give the water "taste". The taste maybe salty, metalic, organic, mineral, etc.,. Lots of people like "some" taste to their water rather than no taste. It's up to the person. As to the safety...it depends on what the dissolved solids are. How would you rate the taste of your water?
Side note: I was traveling through eastern Arkansas one day. I kept a 1/2 gallon jug of ice water in a cooler to sip on occasionally. The jug had ran dry and I pulled into a service station and filled the freshly iced-up jug up with water from an outdoor faucet. I turned that jar up and immediately my lips rolled outward much like a camel rolls its lips out when it's about to spit on you or bite you!
It was some of the bitterest, terrible, most awful-tasting water that ever touched my lips. I poured it out and walked into the station and asked the clerk what was wrong with there water!!!
His response was, "YOU DIDN'T DRINK THE WATER DID YOU!!!!!!??????"
I ended up filling my jar up from the 5-gallon water jug dispenser they had inside. I mean, dude, they need a sign up warning people!!!!! That water's TDS must of been 1,000,000+ppm!!!! I think you could've used it to etch metal!
So your water is within the realm of safe drinking...I would think it's more of a personal taste issue at that level. My tap water is around 325ppm and is good tasting water...we live over a large limestone aquifer that our water comes from. Through a Pur pitcher filter it drops down to around 285'ish and barely drops when ran through the refrigerator filter. But, those filters (I've found) *are* filtering out metals and other dangerous toxins. And our water tastes good. Of course, our tap water isn't good for carnivorous plants so I try to save all the rainwater that I can. I just bought a 32-gallon garbage can for bulk storage and I also store rainwater in gallon milk jugs and old distilled water jugs. We have a dehumidifier which produces a fair amount of water, maybe a gallon or gallon and a half in a days time that I haven't used but would use if my other sources ran out. My last option is buying distilled water...which I did to start with and would do again in a heartbeat if it came down to it.
I understand about the TDS meter and wanting to test all the water sources around me. I've checked a couple of different places tap water and they all have tested in the same range of TDS as my tap water tests...like I said, we sit over a large limestone aquifer. I test each new batch of rainwater that I collect, too. I've found that it can vary a bit but is mostly down around 1 or 2ppm with the highest I've ever seen being around 12ppm (which i think was odd). I've got a few other places I'm going to test, too. Filling a couple of 5-gallon buckets full of water from a service station's faucet in a nearby town or a park somewhere isn't above me I start getting low on good water for the plants. I've just got to find that "source".