It sounds perfectly okay, doesn’t it? Water is a good thing to drink and certainly water that is filtered should be good for us, right?
In fact, that isn’t necessarily the case, but let’s start at the beginning, with what filtered water actually is and why people choose it.
Why Use a Filter?
Sometimes, perhaps due to stories in the news or a local issue, people become wary about how clean and ‘pure’ the water that comes out of their taps at home really is. Sometimes, the taste of tap water can change, or you suddenly develop a dislike for the water that you’ve happily drinking for years.
First of all, it makes sense to find out what exactly you’re hoping to filter out of your water. Finding the answer to that question also helps with deciding what kind of filter you should be looking at; a filter that literally ‘sieves’ out impurities? A chemical version that ‘cleans up’ your water as it passes through the filter? Most filter systems work by using activated carbon, that attracts and holds on to impurities. Carbon removes some, but by no means all, of the contaminants in your water supply.
Filters and Bacteria Risk
You also need to think about whether you want a filter that is fixed on to your tap, or a simple jug filter that you fill and chill in the refrigerator. So far, so good. But what about the dangers?
Well, let’s look at a jug-type version that usually works by water passing through an activated carbon filter. With this type of product, any bacteria ‘captured’ by the filter will remain trapped there (the filter will not kill bacteria) and not removed until the filter is replaced. With the life of a jug filter being up to 6 months, the bacteria remains there for a long time.
If you choose to use a filter jug then it’s important to keep the jug constantly refrigerated to avoid the trapped bacteria from multiplying to levels where your health is likely to become affected.
If the jug is kept at room temperature, then the conditions mean that the unchecked microorganisms may well thrive.
Anti-bacterial silver nanoparticles in the filter can help to prevent this, but not all jug filters contain them.
Chlorine and Toxic Chemicals
The other important fact to remember is that pour-through jug filters are frequently designed and purchased with taste and smell in mind, rather than filtering out all of the undesirable elements that you’re perhaps trying to avoid.
Specifically, although many filters remove the majority of chlorine, by and large, they do not remove the chlorine by-products Trihalomethanes (THM), a group of four toxic chemicals that can be harmful to health.
The Environmental Protection Agency is unequivocal about the potential risk if more than the maximum contaminant level (MCL) is consumed.
“Some people who drink water containing total trihalomethanes in excess of the MCL over many years could experience liver, kidney, or central nervous system problems and increased risk of cancer.”
The Environmental Protection Agency
This report links ingestion of excessive levels of THMs with birth issues, low birth weight and miscarriage.
The Plumbed-in Option
The other option is an under-counter or counter-top filter that is plumbed to your water supply. That means that all of the water that comes out of the tap with the filter attached will have been passed through an activated carbon filter (and sometimes a second filter). The first thing to be aware of is that most filters are designed to be effective where the water supply is a municipally treated one, and not from a private well or a unknown source.
Although fitted water filters do a more thorough job that a jug when it comes to removing contaminants; as with most things, all plumbed-in water filtration products are not created equally.
Do Some Detective Work
The National Sanitation Foundation (NSF) helpfully has a search function that enables consumers to enter in the details of a particular filter to see if the product meets the minimum requirements to be certified under NSF standards.
To do so, a product must – among other things – be structurally sound and demonstrate that the system is able to reduce levels of lead in the water supply from 15 parts per billion (ppb) to 10 ppb or less.
Some products advertise themselves as ‘meeting NSF safety standards’ or ‘tested to NSF standards,’ which is, arguably, a somewhat misleading claim.
Being a certified product means that the NSF have vetted it and that the filter has been tested and met the NSF standards. It’s definitely worth using the searchable database to find out more about particular filter models before you buy.
Changing Filters – How Often?
Water filters need to be replaced with variable frequency. Some filters must be replaced within a few weeks; others last for months. How effective the filters will be as they near the end of their life is something else that will need research before parting with any money, as the different types and brands vary a great deal.
Some types of filter have a warning system that alerts you once the filter is beginning to become ineffectual, and others rely on you checking manually. Either way, for a filter system to continue to effectively remove impurities, the filter itself needs to be checked and replaced regularly, something that needs to be factored into the cost of buying a filter system.