A virus is a microorganism that requires a living cell of a host to grow and reproduce. A virus is smaller than bacteria and after it enters a host, it uses the host's systems to reproduce and survive and a virus can adversely impact multiple biological systems, including the gastrointestinal, respiratory, and reproductive system. The following is a list of common viruses and their associated human/animal hosts and transmission routes.
"The most important waterborne viruses are members of six families, including RNA virus families such as Picornaviridae, Caliciviridae, Hepeviridae, Reoviridae, Astroviridae and the Adenoviridae within the family of DNA viruses. Viruses in these families cause asymptomatic infections and also outbreaks or sporadic cases with a wide range of symptoms from mild to severe gastroenteritis to meningitis, respiratory disease, conjunctivitis, myocarditis, paralysis, or hepatitis". (Source) Waterborne diseases related to viruses are associated with drinking water consumption, food consumption, and recreational use of contaminated waters and even healthy individuals will and can excrete viruses. Based on information from the Center for Disease Control, there are "at least 2,000 persons that contract a virus through a waterborne route". (Source) Even though viruses account for only 10% of waterborne disease in the United States, viruses are directly associated with three of the four organisms that are primary causes of waterborne disease, i.e., Cryptosporidium, Cytotoxins (algal based), Giardia intestinalis, and Diarrheagenic (causes diarrhea) Escherichia coli.
Waterborne illnesses have been associated with diarrhea, dizziness, nausea, dehydration, fever, abdominal cramps, headaches, and death. Recreational waterborne diseases may also impact the respiratory system and the skin.
The EPA regulates viruses indirectly through the "surface water treatment rule". The MCL is a technical standard and not a specific concentration and the MCLG is zero. The technical standard is a treatment standard that requires that 99.99% of the viruses are inactivated or killed. The surface water treatment rule applies to all regulated water systems that are classified as either surface water or groundwater under the direct influence of surface water (GWUDI). The surface water treatment rules can be found at this EPA website.
Note: The EPA does not regulate control Legionella (bacteria) because the "EPA believes that if Giardia and viruses are inactivated, Legionella would be controlled" and not pose a risk.
Viruses range in size from 20 to 400 nanometers; whereas, bacteria ranges in size from 200 to 2000+ nanometers. We can not see bacteria with the naked eyes, therefore, we can not detect bacteria or viruses with our eyes. The only way to determine if the even smaller viruses are present or more likely present is to test for the virus or a surrogate, like a bacteria or other organism. It may be advisable to test for viruses or one or more surrogates based on the following conditions:
Level 1 Testing is done with simple observations that an individual can make with their own senses such as sight, smell, and taste. These observations can be readily apparent or can be observed as they change over time. In addition, accessible related information about the home can also be used to narrow down the cause of your water issues.
As we previously mentioned, we can not see individual bacteria or viruses, but we may be able to document the effects of a colony of bacteria that may suggest a problem with viruses.
Level 2 Testing is Do-It-Yourself testing that can be done in your own home using a Testing Kit. After you’ve done Level 1 Testing, Level 2 Testing can confirm if your observations are correct. If your test results reveal the presence of a contaminant that is cause for concern, you can either proceed to determine the best treatment (see below) or continue to Level 3 Testing.
There are no low-cost Do-It-Yourself at home screening tests for viruses in your drinking water, but you can check your water for general bacterial contamination. If the water is positive for bacteria, it is more likely your water could contain a waterborne pathogen which could include viruses. This test normally indicates if the organism, i.e., a bacterium, is present or absent and does not provide a formal count.
<div class="product-note in-L6-bromate">Note: If the concentration is < 0.01 mg/L (POU Device System Component)</div>
Level 3 Testing is done through an accredited Water Testing Laboratory. With Level 3 Testing, you can order a testing kit that is used to prepare your sample and submit it to the lab. By utilizing a lab, you have the assurance that a certified water expert had analyzed your water sample. If your test results reveal the presence of a contaminant that is cause for concern, you can either proceed to determine the best treatment options (see below) or continue to Level 4 Testing - Certified Testing.
A Level 4 Certified Test Test uses chain-of-custody with a water professional coming to your home to prepare the water sample and then works with an accredited laboratory in order to certify your test results. This type of testing not only gives you the highest level of assurance in the accuracy of your test results, but can also be used as a document in legal cases. For Baseline Testing, we recommend that you use Certified Testing.
If you identified a bacterial problem and have identified a waterborne pathogen, we suggest certified testing to document the actual number of colony-forming units. Typically, this is done using a local certified laboratory, because the holding time and sampling requirements have a very short holding time. In addition, it may be advisable to conduct additional certified testing for other surrogates of contamination from a sewage source, such as: total dissolved solids, pH, nitrate, nitrite, detergents, and quats (quaternary ammonium), plus some informational screening testing.
The most common type of certified testing related to microbiological contamination is during a real estate transaction. When you do this testing, we strongly recommend testing for total coliform, E. coli, standard plate count, and other indicators that may be associated with the actual water source such as potential human, agricultural, or animal contamination. If you need assistance with certified testing or advice, please contact our team.