Don't need much in the way of sewer pipes. I live in the US, in NY, 70 miles north of Wall Street, in a house with two bathtubs, four sinks, three toilets, one washing machine, and one dish washer, with nearly no use of "sewer pipes". Right, no city sewer. Instead there is some PVC pipe, cheap, super simple to work with, darned rugged, and, presto, bingo, a big concrete box in the ground just behind the main piece of big, white PVC pipe. That box is the septic tank. It's been working great, with essentially zero maintenance, for 20+ years.

So, all the water used in the house, from the toilets, sinks, etc. is collected via PVC pipe and fed into the septic tank. The water from the septic tank flows into a "drain field" in the back yard.

Works great.

With the septic tank, there
was only one problem only once: I had an infection on the edge of the nail on my left big toe and daily applied triple antibiotic cream (eventually cleared up the infection). Soon I had water, etc. bubbling up near the back of the back yard.

Why? The antibiotic cream was powerful stuff; some of it got on my socks; when I washed the socks in the washing machine, some of the cream got into the septic tank and basically killed off the crucial bacteria that was eating everything not just H2O (right, and creating CO2 and methane which bubbled out, rarely noticeable).

Solution? Sure, the grocery store sells a box of little, dry granules. So, flush about half of the box down any one of the toilets. Then the bacteria in the septic tank are alive and working again; the spot in the backyard dried up again, and no more problems!

Just need a septic tank, a little PVC pipe, and no sewer pipe or sewer treatment plant, etc.

For water, nope, I get nothing from the city. Instead I have a well. Well, the septic tank is in the back yard and the well, in the front yard -- not sure that makes much difference since the well is deep enough, likely 100+ feet, not to use "surface water".

So, how do I get "pure water"? Hmm. Running out of a faucet or standing in a glass, the water looks fine. Eventually discover that the water is saturated with calcium carbonate, that is, limestone, if you will, marble. Why? Down there, maybe 100 feet, where the water comes from, there are some old, dead sea shells, however many hundreds of millions of years old.

Otherwise I have a filter in the line: The filter is a tube about one foot long and 3 inches in diameter and made from some kind of foam or a lot of string wrapped tightly. My hardware store sells these for not very much, and they have several varieties that filter out everything down to some number of microns, different number for different varieties. One filter lasts for over a year.

No evidence of disease in or from the water.

Yes, the calcium carbonate ruined the dishwasher, so I wash dishes in the sink and dry them a traditional dish drain rack. I have the rack on a plastic base designed for that purpose, tilted, and set in an aluminum tray to catch the runoff water.

So, after some months I can notice that, while the dishes dry nicely and look just squeaky clean, from all the water that ran into the aluminum tray and evaporated, some mud was left behind. So, the water seems to have calcium carbonate plus some additional dissolved solids that, after enough water has evaporated, look like mud. Or for all I know, the "mud" is left over dish detergent? Naw, I suspect the mud is dissolved solids. Maybe if I used a finer filter I would get less mud, but I doubt it.

But the mud is doing me no harm. The usual remark from the local plumbers is that the water is safe to drink, won't hurt you.

On the calcium carbonate in the water, yes I could use a water softener. Actually, I have one. To use it, have to buy big bags, maybe 40 pounds each, of rock salt, that is NaCl. The softener takes the water and converts the calcium carbonate to calcium chloride which is more soluable (doesn't settle out on hot water pipes), doesn't create the scum with old style soap does with calcium carbonate, and feels soapy or slippery in the water. For the chloride in the calcium chloride, that comes from the salt, the NaCl. For the carbonate from the calcium carbonate, that goes out the drain as sodium carbonate. The water softener has a big barrel with ion exchange resins, little beads that, when flushed with water with a high concentration of NaCl, grab some of the Cl. Then when flushed with water with calcium carbonate grab the carbonate and replace it with the chloride, thus converting the incoming calcium carbonate to calcium chloride. But the big tank with the beads gave trouble; I paid to have the tank serviced, etc. And the automatic unit with that tank that flushed the beads with salt water, from the big barrel of salt from the big bags of salt, gave trouble. So, I pushed a big red button that had the water bypass the softener and unplugged the softener control unit from the wall A/C power. So much for the water softener.

Also, it does appear that calcium chloride from the softener can corrode the solder used in the copper pipes -- bummer.

For the calcium carbonate, it is a curious chemical since hot water dissolves less of it than cold water, the opposite of most solids. So, when the water is heated in the hot water coils of my furnace [here I'm talking about the coils for the domestic hot water and not the hot water for heating the house], the calcium carbonate settles out on the inside of the coils and after six months or so lowers the flow rate of the domestic hot water.

So, I went shopping and got a length of copper water pipe, the tools to work with copper water pipe, some shutoff valves, some faucet valves, some connection fittings, some lengths of garden hose with fittings and intended as supply and drain hoses for a washing machine, a drill pump with connections for garden hoses, some plastic cups, a plastic bucket, a gallon bottle of muriatic acid, and a big, several pound size, bag of baking soda.

So, I used the tools and the copper pipe to install the faucet and shutoff valves at appropriate places in the copper pipes leading to and from the domestic hot water coils of the furnace and attached garden hoses to the faucet valves. Then one of the garden hoses goes to one side of the drill pump, and a hose from the pump and another hose from the faucets go to the bucket.

So, using the valves, I run some water into the bucket, nearly fill the bucket. Using an old 1/4" electric drill, I turn on the drill pump and get water flowing from the bucket, into the coils, and back to the bucket. I put one of the little copper pipe fittings, a right angle elbow, in the bucket.

Then I pour about 4 ounces of the muriatic acid into one of the plastic cups, maybe the same cups apparently so popular at college frat parties or on Spring Break, and pour that acid into the bucket. Soon I get, sure CO2 bubbles in the bucket. Also, right, review high school chemistry, I get some calcium chloride in the bucket. Why? Secret: Muriatic acid is hydrochloric acid, that is, HCl, about 28%. In the residential construction industry, the acid is commonly used to remove, right, lime from concrete off bricks. It also nearly instantly removes lime from the inside of copper pipes.

When the rate of the bubbles slows down, I add another 4 ounces of muriatic acid to the water and observe that the rate of bubbles does not increase again. Guess: All the calcium carbonate is out of the copper pipes. Then I add maybe one teaspoon of the baking soda to the water and observe that I get bubbles: Guess: There is still plenty of hydrochloric acid in the water. So, conclusion: The domestic hot water pipes in the furnace are clean.

Then I turn off the drill pump, place the ends of the hoses that were in the bucket in a plastic tray intended for kitty litter, remove the little copper elbow from the bucket, carry the bucket to the back yard, and throw the water with the acid in a wide sweep onto the grass (I never see any effect on the grass).

I look at the little copper elbow for evidence that my use of the hydrochloric acid is corroding the copper pipe -- so far I have seen no such evidence. Actually, inside the furnace, the coil for domestic hot water is lined with Teflon so that calcium carbonate will be less likely to stick; no doubt the Teflon would also protect that pipe from the acid.

Back in the house with the bucket, I insert the hoses into the bucket again, use the valves to fill the bucket nearly full again, adjust the valves, turn on the drill pump, and get water flowing again from the bucket to the coils and back.

Then I add to the water in the bucket baking soda, about 1/2 cup at a time, until there are no more bubbles. Then I add another 1/2 cup of baking soda to the water to be more sure.

Then, doing the right things with the drill pump, valves, and hoses again, I dump the water in the bucket again, fill the bucket again, use the drill pump to circulate relatively fresh water, turn off the drill pump, set the valves back for ordinary use, and again dump out the water in the bucket.

At the kitchen sink, I let the hot water run for a while to be more sure I've removed all the hydrochloric acid or baking soda from the water, and declare the project done -- lots of hot water flow rate now for months!

Of course, I don't have a wife and six daughters in the house with each of them each day taking three baths, washing six changes of clothes, and washing their hair!

But, still, I have no city water, no city sewer, no sewer pipe, and no big problems.

Sure, when my startup is successful, I will look into getting, say, reverse osmosis to give me domestic hot/cold water that is much closer to pure, distilled water, that is, just good, old H2O and nothing else.

But for India, in a place rural enough to permit the women to walk to the woods at night and use the woods as a toilet, septic tanks and wells should be a really big step up and solution to the problem.

About India, I've long suspected that such really bad aspects of their living conditions have been so common, even standard, for so long that they have long since just accepted that living like that is okay with little or no desire or effort to do anything about it.