quality of water and food in 1855

I can think of a couple you missed without much trouble.

Lye
Saltpeter
Vinegar

As far as the muddy water goes, I believe that Mark Twain tells a story in Life on the Mississippi about a refined visitor to a Mississippi steamboat who complained about the muddy water served at table (which, IIRC, was obtained directly from the river). The captain heartily drank it down himself, and said that without the muddiness you were losing half the benefit. The suspended matter, after all, was food.
Others note that the pellets in the rabbit they ate were buckshot – that’s how the rabbit was killed, after all.

The quality of food wasn’t necessarily worse, and some people think we’ve lost something. It’s true that using untreated water from a high density area (or water from a well placed impridently close to the latrine) can spread disease, but that’s not an issue if you’re far enough from other folks. One of the things that struck me on a visit to Sturbridge Village (a mid-19th-century “living village”) was that people took their grain to the mill pretty frequently, rather than milling huge sacks at a time, because the flour thus produced would go bad otherwise. It contained the whole grain, and produced wheat of a quality different from our storable flour. But it lacked the convenience and storage ability of the flour we keep on supermarket shelves and in our cupboards.

Nope. It was birdshot.

Actually, the germ theory of disease was developed by Koch and Pasteur in the 1870’s. Pasteurization was demonstrated in 1864. Lister published on antiseptic surgery in 1867. By 1885 there were vaccines for smallpox, anthrax, rabies and cholera.

How widespread this knowledge was by 1885 is probably open for debate.

Things weren’t always so efficient. My grandfather worked in Montreal in the early years of the last century. There the city government rolled the roads in the winter, compacting the snow so that sleighs and sleds could be used. Come spring, five months or so of snow, ice, and horse manure would melt. Grandfather was a farmer, and not at all squeamish, but he often remarked about how badly the city stank in the spring.

Weren’t we discussing the 1850’s?

The thread title specifies 1855, but the movie the OP references was set in 1885.

According to Otto Bettman (“The Good Old Days-They Were Terrible”), spolied meat was sold in city markets up until the early 1900’s. If you cooked it long enough, the toxins would be destroyed-but it was still dodgy.
I also read that the Franklin Expedition (1842)-which was the first Arctic expedition to carry canned food, suffered high mortality because the canned food was infected with botulism.

Alternately, they suffered from lead poisoning from the solder used on the cans.

What the heck, maybe they suffered from both! Plus scurvy!

Pepper is a preservative too (chorizo and salamis have never been pasteurized); home preserves where the “preservative” was boiling the hermetically-closed jar were also available (jam, vegetables) - people didn’t know why what we now call “pasteurization” worked but they knew it did, they also cooked things which lasted a long time (for example hard nougat) or used pH as a preservative (pickles).

Not only that-but I also read that the cans were soldered by hand-using ARSENIC as a flux!! Those poor buggers didn’t have a chance-scurvey, lead posioning (with arsenic thrown in) plus botulism-and slowly going mad from being trapped in the ice pack for 3 years!

They certainly drank cider. But you’re saying they avoided water entirely?

I’d like to see evidence that water consumption in 1830s New England was rare.

I was going to mention this book, too. Rural or urban, the food, drink and air were quite likely to be far from ideal. Contrary to an earlier post, city streets were fetid with horse dung. The immediate area of a farmhouse was quite likely to be contaminated with waste as well, whether that of 2-legged or 4-legged creatures. We tend to have a highly romanticized image of “the old days,” and forget that there is a reason for our modern inventions.

Bill Bryson covers food quality in England in his book about his house. There were a bunch of muckraking books in the late 18th and early 19th centuries exposing how unscrupulous bakers adulterated bread by adding all sorts of crap to the flour. But recently someone tried to bake bread with these contaminants, and got bread that never rose, smelled horrible, or was clearly inedible. The conclusion was that the actual bread (which made up a substantial portion of peoples diets) was a lot better than the books implied.