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Get Informed | Viruses

What are Viruses?

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.

How Do Viruses Become a problem?

"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.

What are the Health Risks for Viruses?

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.

What are the Standards for Viruses?

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.

Get Tested | Viruses

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:

  • If your drinking water source is a surface water source that is down gradient from an urban area, wastewater treatment plant, or agricultural area with on-site manure/biosolids management.
  • If your drinking water source is groundwater source (spring or well) that is under the direct influence of surface water.
  • If your drinking water comes from a surface water source that has a history of operational issues or related "boil water advisories" and problems with discolored water with or without an odor.

Level 1 | Observational Self-Testing

Observations for Viruses

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.

  • You are getting your water from a spring, stream, roof cistern, or lake that is completely untreated or treated only using a standard particle filter.
  • You suspect a bacterial problem because of an odor, metallic sheen, or off-taste to the water and/or water quality tests have documented that the water contains total coliform bacteria and/or E. coli and/or the water has a high standard plate count.
  • When it rains or there is a snow melt, your drinking water gets cloudy or discolored or there has been a reported break in the water distribution system.
  • Individuals using your water have been ill. It may suggest you have a problem with a waterborne pathogen if one or more of your family members has been diagnosed with a specific disease or showing symptoms associated with waterborne disease.
  • You are located in an area that has a malfunctioning septic system, agricultural areas using manure and biosolids, or your water becomes dirty or discolored when it rains or when there is a significant snow melt.
  • You are experiencing gastrointestinal issues.
Try Our Level 1 Drinking Water Self-Diagnostic Tool
Have water issues? Answer our self-diagnosis questionnaire from your observations to get an initial diagnosis. Then follow our recommended steps to remediate your issue.
Self-Diagnostic Tool

Level 2 | Do-It-Yourself Water Testing

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.

Notes on Level 2 Testing for Viruses

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.

Level 3 | Informational Water Testing

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.

Notes on Level 3 Testing for Viruses

Most informational water testing services provide a screen test for Total Coliform Bacteria and E. coli, and some select informational tests for other microbiological agents. This test normally indicates if the organism is present or absent. It may also be advisable to screen for other disease causing organisms and other surrogates like nitrate, salts, and general water quality.  Therefore, we would also recommend the National Testing Labs Standard Well Water Kit to help determine if there are any other contaminants that may impact the disinfection and treatment process.

Level 4 | Certified Water 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.

Notes on Level 4 Testing for Viruses

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.

Get Treatment | Viruses

For a regulated water source such as most City Water, treatment for viruses would be required for any water sources that are either classified as surface water or groundwater under the direct influence of surface water and would require 99.9% removal or inactivation of Giardia and 99.99% inactivation of viruses. For regulated groundwater sources that show the positive presence of "fecal" or E. coli contamination, the EPA would require 99.99% inactivation of viruses. If you use a private water source, it is unlikely the source has been evaluated to determine if the source is vulnerable to contamination or directly influenced by surface water.

If your private water source is total coliform and/or E. coli positive and has an intermittent or continuous problem with turbid or discolored water with or without an odor, especially after or during a rainfall event, or if the well is repeatedly inundated or flooded, your source may be vulnerable to contamination by a waterborne pathogen.

Short Term Treatment

The first step for a private well system or unregulated water source is to inspect the source. Can you identify any problems with the well or system construction, such as: a leaky or cracked casing or piping, damaged well cap, damage to a spring box, direct influence by surface runoff, inundation associated with flooding, standing water, or runoff of contaminated water? Assuming there is no other contamination related to a trace metal, it may be advisable to shock disinfect the source and distribution system, consider boiling the water prior to consumption, or if the system is on a boil water advisory, consider adding some mechanical filtration that meets the NSF 244 or NSF P231 standards.

Note: "The filters covered by this standard are intended for use only on public water supplies that have been treated or that are determined to be microbiologically safe. These filters are only intended for protection against intermittent microbiological contamination of otherwise safe drinking water. For example, prior to the issuance of a boil water advisory, you can be assured that your filtration system is protecting you from intermittent microbiological contamination. The standard also includes material safety and structural integrity, similar to other NSF/ANSI drinking water treatment unit standards. Manufacturers can claim bacteria, viruses and cysts reduction for their filtration system." (Source)

NSF 244 : Supplemental Microbiological Water Treatment Systems are evaluated using the NSF P231 Microbiological Water Purifier Protocol. The NSF P231 standard requires the product to provide for a 6 log reduction (99.9999 %) of bacteria, 4 log reduction (99.99%) of viruses, and a 3.3 log reduction in cysts.

NSF/ANSI 244 establishes minimum requirements for mechanical water filters designed to reduce bacteria, viruses and cysts during the period between a microbial contamination and a boil-water advisory or intermittent bacterial contamination.

Contact a Know Your H2O Recommended Professional

Want professional advice? Request a consultation from the KnowYourH20 Team Contact Us.

Long Term Treatment

For a regulated community water supply system, the system will most likely require disinfection with some form of chlorine and in some cases a combination of disinfection and filtration. If the source is classified as surface water a combination of filtration and disinfection would be required, but if the source is not a GWUDI and only has a potential problem with E. coli, the disinfection system would need to provide for 4-log inactivation of bacteria/ viruses. Both of these systems would require a comprehensive assessment and in some cases pilot testing of a filtration system. The formal design would be prepared by a licensed engineer and most likely reviewed and permitted by the state health department or the federal Department of Environmental Protection.

If the system is a private or unregulated system, it may be possible to utilize an ultraviolet treatment system that meets the NSF 55 standard. A Class A system would be required if the source is positive for E. coli, and a Class B system would be utilized in cases where previously disinfected water or water with an elevated presence of only standard plate count and total coliform is being polished. Class A point-of-entry and point-of-use systems covered by NSF /ANSI 55 are designed to inactivate and/or remove microorganisms, including bacteria, viruses, Cryptosporidium oocysts and Giardia cysts, from contaminated water. These systems are not intended for the treatment of water that has obvious contamination or an intentional source such as raw sewage, nor are systems intended to convert wastewater to drinking water. These systems are intended to be installed on visually clear water.

Class A- UV sterilizers that meet NSF/ANSI Standard 55 Class A are required to provide a UV dose in excess of 40 mJ/cm2 over the entire life of the UV lamp. These units are required to monitor the UV output and water flow restriction to control the rate of flow through the unit.

Class B — These ultraviolet water treatment systems must have an “intensity & saturation” rating of at least 16,000 uw-sec/cm2 and possess designs that will allow them to provide supplemental bactericidal treatment of water already deemed ‘safe’. i.e., no elevated levels of E. coli or a standard plate count of less than 500 colonies per 1 ml. NSF Standard 55 "Class B" UV systems are designed to operate at a minimum dosage and are intended to "reduce normally occurring non-pathogenic or nuisance microorganisms only."The "Class B" or similar non-rated UV systems are not intended for the disinfection of microbiologically unsafe water. This unit should only be used on water that has already been disinfected and only additional or supplemental treatment is needed or water that meets the potable water supply standards.

In either case, it is advisable to conduct a comprehensive microbiological and water quality analysis and it would be advisable to work with a professional in developing the treatment system. In all cases, we strongly recommend a multiple-barrier approach to protecting your drinking water. This means protect the source, ensure the system is secure, conduct a comprehensive assessment, implement a system to pretreat the water to optimize treatment for the target contaminant, add a post-treatment final barrier, regularly monitor the system, and work with a professional. If you need help locating a professional or need assistance in evaluating a source, please contact our team.

If your water does not have a bacterial, waterborne pathogen, or other microbiological problem and you only want to install a final barrier that will provide some protection, we recommend considering Filter Water Thunder 4000M RO with UV Barrier.

Contact a Know Your H2O Recommended Professional

Want professional advice? Request a consultation from the KnowYourH20 Team Contact Us.

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