July 2023-07-19
Salmonella is commonly found in the environment and lives in the gastrointestinal tract of many birds, reptiles, livestock and other animals including humans. A common source of salmonella in drinking water can be from using stream, pond or lake water to drink or irrigate. Causes can range from natural occurrence in the environment to overflowing sewage, septic systems not working properly, polluted storm runoff and agricultural runoff. What are the symptoms of salmonella in the water we use ?
Most people with Salmonella infection have diarrhea (can be bloody), fever, and stomach cramps. Symptoms usually begin six hours to six days after infection and last four to seven days. However, some people do not develop symptoms for several weeks after infection and others experience symptoms for several weeks.
If you suspect that your drinking water may be contaminated with salmonella, contact a private water testing laboratory to conclusively determine the presence of salmonella in your water. In the meantime, make sure that you don’t consume water directly without treating it first. You can boil it at a rolling boil for a full minute for immediate needs. You can also opt to use bottled water or water from another clean source until the contamination can be remediated.
Removing it from drinking water.
Boil your water for 1 minute (at elevations above 6,500 feet, boil for 3 minutes) or disinfect it using chemicals such as unscented household chlorine bleach or chlorine dioxide tablets. Do not get creative with the manufacturer’s directions.
Specially designed filters and other water treatment technologies might also be effective. Micro filtration, ultra filtration, nanofiltration, reverse osmosis, distillation and UV with previous filtration are all approved technologies. Follow the instructions carefully for every method.
You cannot boil your well or rainwater harvesting tank so other methods are needed to make your water source safe, if possible. This can work for a well or storage tank but do not do it to a stream, lake or pond. To treat your drinking water source, you must undertake a multistep process to kill the salmonella in the water and restore it to safe standards. Chlorine must be added to the well to kill off the pathogen. If the contamination is severe, you may need multiple rounds of treatment to completely remediate the problem. After each round of chlorine treatment, be sure to retest the water. If the tests come back positive, another round of treatment will be necessary. There is currently no filter that can remove salmonella from drinking water. There are some UV light treatments available that can kill the bacteria, however. Unfortunately salmonella is immune to hydrogen peroxide which is a disinfectant that is better for the environment but will not work in this situation.
Pseudomonas is an opportunistic waterborne pathogen that can be found in lakes, sea water, swimming pools and even in drinking water. We generally notice it because it forms a biofilm, to use the scientific term, slime to most of us and known to one person recently at the sluggish warm Sooke Potholes as “river snot”. It can be transmitted to humans and animals through drinking water, bathing, washing or eating food exposed to contaminated water and in some cases from contaminated bottled water and contaminated water in dental chair units. Some people have it on the warm damp areas of their bodies all the time. It can cause vomiting and severe diarrhea and resultant severe dehydration. It does not usually cause problems for people unless they are immunocompromised or it gets onto burns, open wounds, or people have cystic fibrosis.
A problem is that it is breeds quickly and is slimy and sticky and often is on faucet heads and shower heads. It can grow at temperatures up to 42 C. and can even colonize in distilled water with limited available nutrients. If your pet water bowls do not get cleaned regularly and get a film, it may well be pseudomonas. It is resistant to disinfectants such as chlorine and alcohols but 3% acetic acid, otherwise known as vinegar, works well to get rid of it.
The detection of pseudomonas in water sources is troublesome due to time-consuming methods requiring laboratory procedures and expensive labor costs. The water samples need to be collected manually from the source and transported to the lab quickly. The good news is that UV light that people have on their water systems usually kills the incoming pseudomonas. It does not affect the post UV light water. Removing the shower and faucet heads and soaking them in a glass container of vinegar will kill the pseudomonas until it comes back.
Legionella can be found in low concentrations in any public water system. Legionella causing Legionnaires’ disease is rare and is caused by inhaling water droplets which contain the bacteria. It only poses a health risk if the water is aerosolized or misted and inhaled like in a steamy shower or hot tub and sometimes from an air conditioner. It is not generally a health risk if the person drinks the water. It was identified as Legionnaires’ disease after so many American Legionnaires became ill at a conference in Philadelphia in 1976. The health authorities were baffled as it looked like an outbreak of pneumonia. It can also cause diarrhea, vomiting and confusion. Symptoms usually begin in 2 days to 2 weeks but it can take longer to appear.
Legionella grows well in stagnant water. Pipes you have in your house and no longer carry water should be removed and you should weekly flush out outlets that are not used regularly such as a guest room powder room. . Remove scale from shower heads at least once every three months. Vinegar works for this.
Legionella, pseudomonas and other waterborne bacteria can colonise any man-made water system, whether it issues hot or cold water. Filters can certainly help mitigate this, removing the bacteria before it reaches the point of use, whether that is a tap or showerhead. To kill Legionella bacteria, you need to make sure that the water is too hot for them to live. You don’t need to boil them, but you do need to get the water above 60°C. Water at that temperature wouldn’t be good for you to bathe in as you would get scalded. There was a movement a few years ago to ask people to lower the temperature on their hot water tanks from the preset level. The preset level is too hot for Legionella so do not loser the temperature or you will likely be creating an incubator. Find a safer way to lower your energy consumption.
As a person on a well and therefore thrifty with water, it really is against the grain to repeat the experts’ advice which follows. We are told that when we first move into a home we should run the kitchen, bath and hand basin taps continuously for at least five minutes as it will flush through any bacteria. If your shower has not been used for a week or more, run water from both hot and cold supplies through the shower hose and showerhead for two minutes.
That is a lot of water. Beyond the needs of a householder, control methods designed to disinfect an entire water distribution system include thermal (super heat and flush), hyperchlorination and copper-silver ionization. Control methods designed to disinfect only a specific portion of a water distribution system include ultraviolet light sterilization, ozonation and instantaneous steam heating. Selecting one or a combination of these two types of control methods would be best for eradicating Legionella colonies and preventing recolonization of the water distribution system. Or don’t take long steamy showers.
References:
Centre for Disease Control
https://www.cdc.gov/healthywater/drinking/homewatertreatment/household_water_treatment.html
Environmental Protection Agency
https://www.epa.gov/sites/default/files/2015-10/documents/legionella-factsheet.pdfETR Laboratories
https://etrlabs.com/all-you-should-know-about-salmonella-in-drinking-water/#:~:text=Water%20containing%20salmonella%20can%20come,flood%20or%20other%20natural%20disasters.
Frontiers in Public Health
https://www.frontiersin.org/articles/10.3389/fpubh.2018.00159/full
Legionella Control
https://legionellacontrol.com/legionella/can-you-get-legionnaires-disease-from-a-
shower/#:~:text=In%20the%20case%20of%20showers,killed%20before%20
Science Direct
https://www.sciencedirect.com/science/article/pii/S0263224122003864
OPSRRA 