As cities grew in size and density during the Industrial Revolution, they all had to build more, and better, sewers. The cholera epidemic wasn't motivation enough for London, but the "Great Stink" of 1858, when the Thames smelled so bad that Parliament considered relocating, got the city government's attention; it built new sewers in the 1850s and '60s to carry waste downstream from central London. Brooklyn introduced sewers in 1857, and Chicago not long after. Boston, still largely building sewers privately, had about 100 miles of sewers in 1869; by 1885 that had expanded to 226 miles, and new houses were expected to connect to the system both for pump and washbasin waste and for the human waste now going into flush toilets instead of privies.
Every city had its own problems and its own characteristics. Some of Boston's sewers had outfalls dammed by the tide 12 hours of every 24; others, built by unscrupulous contractors in land reclamation projects like the Back Bay, sagged and lost their downhill slope, causing settling, clogs, and backups. Sylvan Seattle had pipes made of wooden staves--and faced a tide problem so severe that at certain times of day toilets became foul geysers; eventually the city simply rebuilt itself higher than its sewer pipes. In Chicago, the outfalls of the sewers made such a mess of Lake Michigan that during large rainstorms the plume of tainted water flowed all the way out to the intake for the water system. In response, engineers built a series of canals and reversed the flow of the Chicago River, turning it from a drainage into Lake Michigan into a flow from Lake Michigan toward the Mississippi. They also moved the intake farther out into the lake.
All these "solutions" merely moved the problem. As one historian said in describing Boston's covering a brook filled with sewage and routing it to the Charles River rather than directly into Boston Harbor, this "somewhat lessened the nuisance caused by it, or at least transferred it to another locality." Older cities on the coasts built combined systems channeling both sewage and stormwater, whereas newer and smaller cities built separate systems--both storm drains and systems of much smaller pipes that handled only sewage--thus preventing sewage overflows in storms. Lennox, Massachusetts, built the first such system in 1875, and Memphis built one in 1880. Since then, that's what everybody has built.
Raleigh laid its first sewer pipes in 1890. Fayetteville Street, Raleigh's main road, wasn't paved until 1886, at exactly the same time the first water pipes were being laid; where water pipes go, sewer pipes soon follow. The privies of Raleigh's population of barely 10,000 almost certainly had not yet polluted the soil enough to foul its wells, and the new sewer pipes, running north to Crabtree Creek and south to Walnut Creek, would not have discharged more than the streams could absorb. (A stream running at about 6 cubic feet per second can absorb the waste of about 1,000 people, so to support 10,000 people the two creeks together would have had to flow at around 60 cfs. Currently, on a dry day in a dry month, they flow at about 75 cfs.) Now, with 2,300 miles of pipes all heading roughly southeast to Raleigh's wastewater treatment plant, the sewer collection system turns out to be the only infrastructure stream that follows that natural tree pattern that I'd expected to find everywhere. The leaves are houses, connected by 4-inch service lines to 6- or 8-inch mains that run mostly beneath streets, and then to 18-, 24-, or 30-inch collectors that start out along streets but head downhill to creek basins, leading to larger and larger pipes and finally to the plant. I sat down with a friendly GIS expert to check it out.
The GIS map easily showed me the path of my own wastewater: the 4-inch lateral in my yard--the same pipe that "flushable" wipe clogged--runs into an 8-inch main, which heads downhill along my street until it crosses the Pigeon House Branch, down by the pool I like to sit by. It runs along the Pigeon House until it joins a 24-inch PVC east of town (the path is following rivers by then, not roads), and thereafter joins larger and larger pipes--some made of PVC, some of reinforced concrete, some of ductile iron. Eventually this stream hits the dual 72-inch reinforced concrete pipes that head directly to the sewer plant, though those sometimes separate into three or four pipes, for ease of maintenance. It's simple and, especially after the spaghetti tangle of the water lines, rather satisfying. It's much like the stormwater system, if every ravine in every drainage basin remained piped and they all came together in one place before entering the Neuse.