Most water purification systems don't but the Berkey water filter system does.
The Berkey removes both the MS-2 and Fr Coliphage virus. The Berkey is the only gravity water filter to remove viruses actually.
Why does this matter to you? It matters because they both have the potential to make you sick.
It's been known to get into the water system whether it's rivers, lakes or ponds.
Why Eliminating These Viruses Through a Berkey Water Filter System Is Important
Unsafe drinking water is a leading cause of preventable disease, particularly among young children in developing countries. Waterborne pathogens, including a variety of viral, bacterial, and protozoan agents, account for much of the estimated 4 billion cases and 1.8 million deaths from endemic diarrheal disease each year. American Journal of Tropical Medicine and HygieneThis study they performed wasn't about rivers, lakes and ponds though. It was conducted because there is concern at the household level.
All you have to do is search for this subject in your favorite search engine and you will find dozens of studies about the filtration of MS-2 and Fr Coliphage.
In a nutshell Bacteriophages are viruses which infect bacteria. Here are the technical definitions of these two viruses. MS-2 - A positive-sense single-stranded RNA virus that infects the bacterium E. coli.
It is 24-26 nm in size. Fr Coliphage - A coliphage is a type of bacteriophage that infects E. coli.
It is 25nm in size. You can compare the sizes of these two viruses here. A coffee bean is 12x8 mm, a grain of salt is 0.5 mm and if you keep zooming in you'll see how small the E. coli is.
How These Viruses Are Eliminated Through The Berkey Water Filter SystemThe Black Berkey purification elements have a massive amount of micro pores. They are so small that micro fine particulate such as bacteria, virus and even food coloring are prevented from passing through.
The contaminants get trapped and the water passes through just fine. You might be asking yourself if there might be clogging problems with the purification elements.
Over time some of the surface pores may clog up slowing down the flow rate but it can easily be fixed by brushing the outside of the element with a ScotchBrite pad or toothbrush.
You don't have to worry about these viruses not being properly removed but I would change them out after the recommended 6,000 gallons per set of two.
Here is the official testing results report which was done by Analytical Services, Inc in their microbiological challenge study.
I feel much safer drinking from a Berkey water filter system and knowing it eliminates these viruses makes it that much better.