Legionella Removal in building technology

Preventing Legionnaire’s disease and Pontiac Fever is of vital significance. Legionella are dangerous when inhaled, which can lead to severe pneumonia (legionellosis) after about 2-14 days. Annually people become diseased and die of legionellosis.

FAQ about Legionella

What is legionella?

Legionella is a genus of pathogenic bacteria that causes Legionnaires’ disease (legionellosis)–as well as Pontiac fever–which affects 8,000 to 18,000 people a year in the United States. The name comes from an outbreak of pneumonia–due to the bacteria–after an American Legion convention in 1976.

Pontiac fever is a lesser form of legionellosis. Its symptoms usually last for two to five days and the person doesn’t get pneumonia. It is also caused by the legionella bacteria.

Where does legionella come from?

Legionella are naturally occurring and survive in a wide range of environmental conditions. They live in soil, lakes, creeks, and even aquifers. They survive by consuming the remains of dead bacteria that they come in contact with, which makes older water systems ideal for legionella growth as there is an ample supply of biomass (a.k.a. “bacteria food”).

The legionella bacteria spread around a water system by first attaching to microorganism communities contained in biofilms. A biofilm is a vast array of microorganisms that stick together by excreting a glue-like sludge made of sugars. These communities grow in size as other microorganisms attach to it, which supplies legionella with plenty of food to continue multiplying. Once the community reaches a sufficient size it can’t hold onto its original mounting point and sloughs off down the waterway, breaking up and spreading the legionella bacteria throughout the water supply.

How do you get Legionnaire’s disease, or Pontiac Fever, from legionella?

Legionella are dangerous when inhaled, which can lead to severe pneumonia (legionellosis) after about 2-14 days. The bacteria get into the lungs via tiny water droplets, like those created by showerheads, drinking fountains, or air conditioners. Hot tubs in particular are ideal for bacterial growth like legionella.

Most large-scale outbreaks of legionella involve water cooling towers that are part of older buildings, such as hotels, schools, and hospitals. These units were later shown to have been building up biofilms in their water lines for some time and were built without antibacterial measures put in place.

How many bacteria live in the pipes of a typical building?

Seccua has discovered that:

  • Per liter, around 100 million bacteria are floating around in the water-lines of most buildings.
  • Because of this, people are exposed to billions of bacteria from water, per day, from tap water.
  • Analyzing the concentration of legionella in water routinely produces an error ratio of 100 to 1,000 times less than the actual bacteria count.

To test for micro-organisms in drinking water Seccua performs the plate-count method. This method, which is over a century old, involves taking a water sample and smearing it on a petri dish filled with agar (a type of bacteria food). Using an incubator, the dish is warmed up, allowing any microorganisms to multiply on the plate. Afterward, the now-visible colonies are counted and the number of bacteria in the sample is calculated using a scientific algorithm.

Does chlorination help protect against legionella?

Unfortunately the biofilms that develop on the inside of water pipes don’t allow the chlorine or chloramine to penetrate deep enough to completely sanitize potable water from legionella, and if high concentrations of chemicals are used then the pipes either degrade or the water becomes unsafe for drinking. However at lower concentrations the chemicals aren’t strong enough to deeply penetrate the biofilm and kill the bacteria.

Will high-temperature disinfection and a higher circulation-temperature protect against legionella?

Heating water to high temperatures (above 158 °F) will kill most bacteria, including legionella, but it requires lot of heat and wastes a lot of energy. According to current safety guidelines, water used to disinfect pipes must be heated up to 158 °F (70°C) to kill legionella almost instantly. Scientific studies have proven, however, that legionella can survive temperatures below that point for more than 60 minutes. Seccua recommends feeding into a hot-water circulation loop at a minimum of 60°C or through a single pass at 70°C to effectively combat legionella in your water supply, if using this method.

However, high-heat disinfection has its drawbacks: the biggest of which is that heating water to disinfect it also means cooling some of the water back down to use it. This makes disinfecting water, using high-heat, a terribly inefficient process. Additionally, some water-heater appliances won’t work as well with such hot water. For example, geothermal heat pumps provide their best efficiency at temperatures of around 50°C, and modern gas water-heaters require returning water temperatures to be below 30°C.

That’s how Seccua Filtration stops legionella

Seccua Filtration: Long term protection against legionella

Seccua filtration utilizes a semipermeable membrane with 20 nanometer pores, which is smaller than all known waterborne diseases. Therefore legionella, E.Coli, Crypto, Hepatitis C, Enterovirus, and all other pathogens are unable to pass through the barrier and find their way into your water supply. It does this without the massive amount of energy required to apply high-heat disinfection or the high concentration of chlorine or chloramine which would degrade your building’s pipes or make the water undrinkable.

To provide the most comprehensive protection against legionella and other pathogens, Seccua recommends:

First, the continuous influx of microorganisms and nutrients from city waterways must be stopped. A Seccua filtration unit, such as the UrSpring home or the Virex Pro, is installed directly at the point of entry from the municipal water supply.

If the showerhead is the only point of concern for contracting legionellosis, a Räyn Shower Filter can be installed in the shower pipe, instead.

Next, installation of a UrSpring HotWater into the warm-water circulation loop provides removal of the existing biofilm and bacteria, which would otherwise keep circulating in the loop. Seccua filtration has been proven to achieve a dramatic decrease in microorganisms inside the water systems of existing buildings within only a few weeks of installation. After 4-6 weeks, legionella are no longer detectable in the water supply.

Seccua filtration is even better for new buildings, because it prevents legionella and micro-organisms–as well as tiny particles like hard-water flakes or rust sediments–from ever entering the water supply. This allows the pipes inside a building to stay cleaner in the long-term and will prevent biofilms from even forming.

Get our extensive case study about legionella removal

We have prepared an extensive case study about the application of our technology to remove Legionella from piping systems in existing commercial and residential buildings.

The building reflected in the case study is a building with more than 300 apartments, 19 floors, several floors of shops, offices and doctors practices. It was severely contaminated with Legionella, concentrations of up to 15,000 CFU/100 mL had been measured. Together with minor changes in the piping system, in September 2014 a Seccua Phoenix system was installed at Point-of-Entry of the cold-water system into the building, which significantly improved water quality. Read more …

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Which solution meets best your needs?

According to your peak load, you need different filtration systems with different performances. We help you to find the correct filtration for your maximum water consumption.

Get in touch with us Sizing Calculation

Phoenix GT & Virex Pro

Protecting the water of appartment blocks, hospitals and school buildings.

Phoenix GT Virex Pro

UrSpring Hotwater

Optional for immediate action: filtration for desinfection of a hotwater-circulation.

UrSpring HotWater

Räyn filter

Optional for immediate action: quick solution for high legionella concentration.

Räyn filter