In Denmark tap water is like spring water. Deep ground water supplied in a well designed distribution system without disinfectants.

Generally the tap water has a better microbiological quality than over priced bottled water. Standards for pesticides are stricter than for food. 

Thus, there is absolutely no technical or health need for bottled water unless one like carbonized water.

I think it depends where you live. In Brazil, advanced water treatment is not used for public supplying so, despite some cases of adulteration (bottles filled with tap water) I suppose that bottled are more secure. We have many water bodies eutrophicated with cyanobacterias and cases with metal pollution, POPs and others that are not removed by conventional treatment. For security, I usually buy bottle water (gallons) and filter it in a activated carbon filter since the carbon filter retains many pollutants that are not removed by our conventional water treatment.

In Denmark tap water is like spring water. Deep ground water supplied in a well designed distribution system without disinfectants.

Generally the tap water has a better microbiological quality than over priced bottled water. Standards for pesticides are stricter than for food. 

Thus, there is absolutely no technical or health need for bottled water unless one like carbonized water.

That is right Dr. Mahrosa,

Anyone reusing plastic bottles should wash them

thoroughly after each use with a mild detergent, and

carefully inspect them for cracks or thinning before

using them again. The better and safer alternative

is to pitch the plastic bottle in the recycle bin and not

reuse it at all. Allowing the bottle to be commercially

recycled protects the consumer, and promotes a better

environment for all.

Bottled water should not be contaminated if at all the processes were followed. but if the manufacturers want quick money, especially in Africa, then it might not be pure.

Dear Ndwiga, then it is a vital issue considering more than one-third of Africa's population lacks access to safe drinking water.

Dr  Yalcin Tepe, yes it is. but we have people who are supposed to check whether bottled  water is contaminated or not, but some of them are not doing their work.

In terms of fecal contamination, our systematic review identified that bottled and sachet water (or more generally, packaged water) are typically high quality sources. The articles are available for download.

Article Fecal Contamination of Drinking-Water in Low- and Middle-Inc...

Article Global assessment of exposure to faecal contamination throug...

The general feeling is that bottled water is safe than tap water. But this is not the case always. I have analysed the bottled water quality extensively and I have found that nearly 30% of them are of unacceptable quality, especially in terms of bacteriological quality. Since the bottled water industry is quite lucrative, people source water from poor quality wells and like that . Also the treatment procedures they adopt in bottled water industry such as uv treatment, ozone and activated charcol filters need regular checks to ensure efficiency as over period of time they tend to be ineffective. Tap water (municipal water) for that matter is chlorinated (sometimes at higher level than required) and bacteriological quality tend to be safe. The major issue with muncipal/ tap water supplies is the biofilms developed in distribution pipes which will reduce the level of available chlorine in tapwater. This might lead to the survival of potential pathogens in tap water occasionally.

If water is sufficiently pure before it enters the distribution system it can be distributed without chlorine. No problems with disinfection by-products and biofilm is not dangerous by itself.

You might be right Henrik, but it is really hard to find that much pure water source not requiring any treatment even chlorine before distribute to city. At least it is not possible here in Turkey. Coagulants might also be a danger for public health if they release into water during water treatment proccess

I totally agree with Hendrik. If the water is really pure and does not have any organic load it could be even distributed without chlorine and possibility of formation of biofilms is remote. However, in our country, breakages and leakages in distribution pipeline are very frequent and this allow entry of extraneous material sucked into the pipeline when there is no pumping (pumping and supply of tap water are intermittent very often).

Though biofilms as such may not be dangerous they can neutralize/ reduce the available chlorine level. In our recent studies (results unpublished) we have found pathogenic bacteria surviving in the biofilms

what is the effect of ultrasonic frequency on the degradation of Methylene Blue dye?

There is properly an effect, but for sure it very unrelated to the contamination of Tap and Bottled water. 

Bottled water is my preference .

Bottled water may be less contaminated if the proper treatment processes have been carried out for the parameters (if any) above the limits of WHO.

Colleagues - please find attached an article published this week which explores this very question -- how safe is bottled and packaged water? As our study finds, "packaged water was significantly less likely to contain detectable fecal indicator bacteria compared to tap water sources (pooled OR = 0.41, 95% CI 0.21–0.79, p

I agree with Dr. Mustafa Turkmen. I prefer bottled water.

Fatima

• In Denmark there are frequent publications in our national technical journals of comparisons of tap water and bottled water microbial quality. Obviously neither frequently contain fecal bacteria (would be illegal to supply), but the number of culturable bacteria (HPC) in bottled water is always higher than in tap water. The reason is that tap water is typically consumed in a few days while bottled water usually take days to months to get to the consumer (distribution storage + on shelf in the shop).
• In addition tap water has less organic chemicals such as pesticides and industrial chemicals.
• On top of that it is less expensive to supply tap water in piped systems - both for the user and considering the societal value.

Thus I never drink bottled water unless I am traveling in a country with underdeveloped water supply systems.

I think the paper mentioned by Dr. Cronk arrive at a different conclusion because it is based on scientific publications. If a water supply system doesn't have problems there is no story to base the publication on so well functioning piped water systems are not often described in scientific literature.

I'm from Germany where you can drink tap water and during my current studies in Brazil I'm aware of the quality differences, here chlorine is necessary. It has been claimed that water quality restrictions in Grrmany are beyond of those in bottled water. Nevertheless I'm not too sure about that when compared to some pricey swiss-french alps mountainwater and the like. I don't care about bacteria so much, as these sure can be removed completely by treatment. What I'm talking about are hormones, endocrine disruptors, and non biodegradable fuel additives. There are a lot of gasoline tanks in the ground. If I suppose there is a lesser chance of these anthropogenic Impacts happening to Glacier water, it must be healthier. Bacteria causes some infections, addtives can be genotoxic or cause severe brain damage that can not be reversed. Since I found reports that Californian ground water wells are heavily contaminated with the fuel additive MCMT, this does happen.