I have been using/switching between two brands of pitcher-type compact tap water filtering systems for about 2 decades. I started with the popular Canadian brand system, and then switched to a premium two-stage US brand system when it became available. (FYI, as of a little more than a year ago, the Canadian system can be found at a high end supermarket at the Financial Center in HK at about 3X the cost in New York City, while the US brand was not available.) Each filter is rated to be effective for about 40 gallons (152 litters) or 2 months. In my experience in the US & subsequently in HK, the filters were still doing the job well beyond the rated capacity/time. In the US, I drink the filtered water poured straight from the pitcher, but while in HK, I boil the filtered water before consumption.

Upon relocating to Kunming last year, I've continued to use the two-stage US filtering system as I did in HK. But in Kunming, I have found a new filter will yield about a quart (.95 litter) of filtered water in less than a minute (normal speed) for the first few days, then the filtering speed begins to slow down incrementally to about a quart (.95 litter) over a 12-hour period after a couple weeks. The filtering speed continues to drop with time thereafter. I have always suspected that something in the Kunming tap water is clogging the "two-stage" filter. Today, I discovered a noticeable amount of brownish sediment in the 2 tightly capped 1-liter bottles of unfiltered tap water I set aside weekly to water house plants. The sediment resembles the color from the ongoing subway (metro) project s well as the building demolition & construction dust commonly found in still puddles outdoors after a rainfall.

On my most recent trip back to NYC, I brought back to Kunming another Canadian pitcher system which seems to filter with only a very slight reduction in speed after 2 or 3 weeks (Likely because it does not claim to be multi-stage, therefore probably a "simpler" filtering system with less layering for clogging) but it also means I am probably drinking what is not being filtered out. Besides the mud sediment, how healthy or drinkable is Kunming tap water even if after boiling? How clean is the 5-gallon size "bottled" water commercially available in Kunming? Anyone has the same experience and/or thoughts to share on this subject?

I wouldn't do water filtering in Kunming for drinking water. Not because I do not trust (good) filters to function, but because of the costs.
I'd say that water here has a lot of sediment in it. You do not need to put it aside in bottles, in our house(es) it was enough not to run the tap for 12hrs and then take a look at what color the water has for the first seconds (I guess to prevent clogging your filter, you would need to build a slow moving water basin to let the sediment settle to the ground). I also noticed that Kunming's water some days has quite high amounts of chlorine, sometimes when I shower it reminds me of the water in a public pool (shudder...) and I won't drink that. I do not know about the bacteria content, but I would guess that, with the level of chlorine, it should be quite low, so I use it to brush my teeth and do not feel uncomfortable.

As far as drinking water goes, I think it's safer, cheaper and more convenient to switch to bottled water. The 5-gallon bottle runs around 10yuan, some more expensive, some cheaper (you also have to pay a deposit for the first bottle, and sometimes on company will not take the bottles from another with them). The "taste" (combination of minerals in the water) differs from brand to brand, so I would try some first and then pre-order them to get them even cheaper (some brands also offer smaller bottles so it's even easier to try). It's even delivered not only to your doorstep, but into your water dispenser. I also think that most of it is quite real drinking/table water. Almost everybody uses it and it never made me sick or had a strange taste. The only thing you need to do is to clean your water dispenser regularly to prevent bacteria from spreading (like with a filter), but other than that it's really hassle free.

Kunming water for sure has sediment in it. I used to use unfiltered water in a coffee maker knowing that the heating would kill bacteria. After a year the water reservoir on the coffee maker had a reddish/brown stain. I got the same discoloration in the shower, both on tiles and on the shower curtains.

@aiyaryarr
If you're curious as to what's in your filtered water - just boil a gallon or so dry and look at the residue in the pot. Use either stainless or a glass pot for this home experiment. Water (H2O) boils off cleanly. ANY chemical residues that remain are the impurities - white I think is chlorine, yellow would probably be sulphur, green is copper or chromium, etc etc.

Filters work on most bacteria and non-soluble metals/minerals.

Things which won't show up are the noble gases, which would be rare in water anyway, and the Nitrogen (N) family of gases - which are relatively harmless - the air we breathe is predominantly Nitrogen (~80%) mixed with Oxygen (~20%) and heavy doses of carbon oxides (mono and di ~ 1-2%) if you live around construction sites, adjacent major roads, or anywhere in Beijing - etc.

The majority of muck in your tap water is from a combination of copper sediments (from the copper piping) and just plain old kunming dirt.

As a rule of thumb - NEVER drink filtered or unfiltered tap water after heavy rains. When we first moved to the city after living in the countryside for decades, we used to mock our cousins as everyone (and this was over 30 years ago) drank bottled water.

Also - trace amounts of lead and mercury high enough to cause physical problems are difficult to detect in the brute force "boil off the water" experiment. You'll have to scoop up the sediment and send it to a REAL lab for analysis if you want to know the gory facts (or any university chem lab).

Thanks to all for the input.

Cost of the Canadian pitcher filter is US$6.00 in NYC or about Y39 yields 40 gallons vs. local bottled water which cost Y80 for 40 gallons. It has been tested and certified by NSF International (NSF/ANSI Standards 42 & 53) to reduce copper, mercury, cadmium, chlorine (taste & odor), & zinc (metallic taste) after filtering. Cost of the 2-stage US brand filter is US$8.00 in NYC (also yields 40 gallons) and claims to filters out additional contaminants, but it apparently works too well and begins to clog up after a few days in Kunming.

The Canadian pitcher system filtering speed so far, after nearly a month's use, has only slowed a little bit. My next test is to put aside a bottle of the filtered water for a couple of weeks and see if it, like the un-filtered tap water, shows any brownish sediment.

I remember reports of unscrupulous bottled water companies filling the 5-gallon jugs with tap water both in the USA & China. The commercially available bottled water I have seen (so far and to my naked eyes) in Kunming is clear, and my hope is the water is "clean".

The choice is not ideal, but the lesser of all evils.

The poor quality of the water in China is the reason why I am no longer able to live there. I have a chronic skin condition which allows the sediment in the water easily pass through the skin barrier, causing terrible dryness and an unbearable chronic itch.

I've lived in many areas of China, and pretty much all seem to suffer from poor water sanitation to some degree. I moved to Dali for a time as I hoped to seek refuge in a *clean* environment. It's not so much a problem with pollution as it is the lack of proper infrastructure. Without investing in a large, expensive well water treatment system there is little hope of me returning at present.

I apologise for trying to focus on my own personal problems, but I am just trying to illustrate that the problem you have noted with your water is not trivial, and you likely won't be able to find a solution without spending some serious bucks.

Aside from the shitty brown sediment causing problems with skin and hair, it also ruins my laundry, ceramic fixtures, food, and I just can't ever seem to get anything clean really.

If you are renting there's not much you can do about this problem. However, if you have your own place your best option is invest in a large backwashing filter. The filter medium will depend on what kind of crap you need to filter out. An activated carbon filter is good at removing chlorine and byproducts. However, if you have iron in your water (usually causes rust coloured stains) you will need something else. These types of filters can also be fouled easily if a huge mess of brown sludge suddenly comes down the pipeline, and then you need to consider installing a large retention tank.

@anonymous coward
If water's the issue but you love living in China - you may want to consider Tsingdao (qingdao) - yes the famous beer company. The source of their water is the local river so they are extremely vigilant about their water quality - but don't rely on my hearsay - take a short term trip (3-6 months?). Only problem is Shandong can be cold in the winters.

Shandong people have a different culture from south of China - but it's also famous for it's military leaders and strategists. They love to read, recite poetry, play the erhu - even our driver could recite classic poetry - but he was unusual - retired police.

This might sound bizarre, but I have already accepted the fact that my life expectancy here in China is lower.

If it isn't the water it is the drivers.
If it isn't the drivers it is the lack of paramedics.
If the hospital doesn't kill me then some virus could see me off.

If I ever have a heart attack, my survivability will be based on my bodies ability to cope, because by the time I get to hospital, the decision will already have been made. I don't expect to get a life saving ER intervention when I arrive at hospital either.

@tigertiger,

Aiya! You forgot to mention the unscrupulous manufacturers/producers and the subsequent ubiquitous tainted products & food that we use & eat everyday.

Steering more in the direction of the original topic...

With pollutions everywhere, resultant acid rain, and warnings of global warming consequences, I can't help but recall reading somewhere, in recent years, of the opinion that future wars may be fought over the access and/or control of FRESH WATER. It may sound like a far fetched theory at the moment, but I believe it's prudent not to discount that probability.