There are essentially five types of contaminants to be concerned about, particularly in drinking water.
The concern here is not merre particulate matter. It is the tiny things that pass through most filters that is the concern. Each of these elements requires a different technology to remove it from water. Often multiple systems must be installed upon each other, and there is a specific order each must follow. Simple filters are not capable of removing most of these elements. Some systems require chemicals, electricity, multiple media combinations, regeneration, and more. Totally clean water is becoming increasingly rare, and it is becoming not a luxury but a necessity to treat the water we consume.
Following are some definitions of these primary pollutants.
Particulates and dirt in the water never used to be a concern because they could easily be removed with a simple filter, until it was discovered that asbestos was used to line many of the older water lines in metropolitan areas. Suddenly smaller and smaller micron sizes were required.
Any type of biological hazard is a concern. This includes bacteria, virus, pathogens, and more. Nitrates are often the result of run-off from livestock fields.
Minerals include natural dissolved minerals from the rocks in the ground, but also heavy metals that are the bi-product of industry and manufactured waste. While it is good to take mineral supplements that are absorbable, crystallized minerals do not absorb in our bodies and can build up in us or are passed through us.
Staining on fixtures is a result of dissolved minerrals that have oxydized on the toilets, sinks, tubs, showers, clothes and dish washers.
Chemicals are in the air we breathe and are carried in the soil via ground water. Rain drops are formed around tiny particles, many of which are pollutants in the atmosphere. Acid rain is becoming a problem for the world: famous statues are being etched away, frog populations are dying off, and commnunity water aquifers are requiring pH stabilization. Jet fuel is in the blood of every living creature on earth. Cases of ADHD, autism, neural disorders, physical deformities, and more are on the rise. Toxic coalitions are battling big industry. Most home owners purchase cleaning products made with harmful ingredients and are oblivious of the fact that much of these chemicals ultimately end up in our water.
Who would ever think that we needed to worry about radiocativity? First people were concerned about radon off-gassing from concrete. Now we are conceerrned about fall-out from Chernoble, from Japan, and leaks from our failing nuclear waste storage sites. Radioactivity will remain in the water for generations to come.
Most likely you know somebody who is taking prescription drugs. You probably also know somebody who is taking illegal drugs. Many of these drugs are thrown in the landfill or flushed down the toilet. Either way, they do not go away. Instead, they permeate our water supplies. Already scientists have found deformed fish containing pharmacueticals in their blood, have done water tests on water that has been officially approved for municipal consumption with the results of not hundreds but thousands of toxins in the water; many of these toxins are pharmaceuticals.
For more information on water contaminants,
go to http://www.thewaterexchange.net