Water treatment

Legionnaires’ disease: why water management is key in prevention

Legionnaires’ disease is a potentially fatal infection similar to pneumonia that is caused by Legionella bacteria.

This type of bacteria is found in most natural water sources and can be airborne through water droplets. However, in man-made water systems the conditions are optimal for Legionella, therefore growing and spreading.

This is a cause for concern in any business containing a water system and rightly so. With its potentially fatal effects, Legionella should be tested regularly. Water management is the key to protecting your workforce and users of your buildings.

Is Legionella testing a legal requirement?

There are several pieces of legislation laid out to help building owners or their designated ‘responsible person’ to understand their obligations. These pieces of legislation include:

The Health and Safety at Work etc Act 1974
The Management of Health and Safety at Work Regulations 1999
The Control of Substances Hazardous to Health Regulations 2002
Approved Code of Practice: Legionnaires Disease (ACoP L8)

What is the most important guidance?

Whilst all of these pieces of legislation are relevant. The last one (Approved Code of Practice: Legionnaires Disease (ACoP L8)) is the most appropriate to follow when managing Legionella risks. Employers and business owners should make themselves familiar with the guidance it provides.

The ACoP L8 helps through managing water to comply with legal obligations including:

Assessing water system risks
Managing associated risk
Implementing and monitoring precautionary methods
Documenting said methods

What must I do as the responsible person?

As a business owner you can manage this process yourself (if sufficiently trained and qualified). Alternatively, you can nominate a ‘responsible person’. This person can be an employee or an external water hygiene specialist.

The key contact in preventing Legionnaires disease must complete a formal assessment (in line with BS 8580:2010) of the site which includes water storage and water transport systems. You can read more about this here. They must also create a Legionella risk management plan that documents how to reduce or remove any risks of Legionella in water systems.

How can good water management prevent Legionnaires’ disease?

As a bare minimum, there must be temperature checks put in place to minimise spread of this microbe. Legionella bacteria have optimal conditions between 20–45°C, therefore water should be below 20°C or above 60°C (to ensure it remains dormant).

Other water management controls to prevent Legionella growth or spread include:

Distributing hot water only as a temperature of 50°C or above
Routine checks of storage and distribution temperatures
Regularly flushed and descaled shower and bathing equipment
Biocide treatments for tricky areas such as cooling towers
Frequent water testing and analysis

How to minimise the risk of Legionnaires disease?

There are several methods of maintaining a low level of Legionella, therefore decreasing the risk of Legionnaires disease developing in the vulnerable. The main things include:

Removing any corrosion in water transport systems such as pipes
Recycling the water that has been in the system too long
Removing any unused pipes that debris could build up in
Checking for a build-up of biofilm as this creates better conditions for the bacteria
Regularly dosing the system with a biocide

From this we hope you can appreciate that there is no one-size-fits-all in protecting against Legionnaires disease. However, managing water effectively can increase the changes of ensuring your water system is safe.

Your building’s responsible person must follow the guidance in the appropriate legislation to ensure they are doing as much as they can to prevent Legionella bacteria and save lives.

Water hygiene: leisure centres and gyms

Water hygiene is one of the most important considerations when it comes to the smooth running of swimming pool facilities in leisure centres and gyms.

In addition to smooth running, there are also legal procedures that should be followed to ensure the facility is suitable for public use. This guidance is laid out by the Health and Safety Executive (HSE).

What are the legal restrictions of water hygiene?

Duty holders for these facilities must comply with the HSE’s ACoP L8 and hold HSG274 supporting documents. This ensures the responsible people have the knowledge and documentation to comply with legal domestic water system regulations. Following this, the Pool Water Treatment Advisory Group also lays out quality standards that spas and pools alike must follow. These guidelines are supported by the HSE’s HSG282.

Pool hygiene isn’t the only important area of water hygiene…

As well as maintaining standards of swimming pools, many other gym facilities involve water and therefore also demand its safe upkeep. Examples include spas, drinking fountains and hot tubs. The same level of pool hygiene should be applied to these facilities also. This is particularly crucial as these areas – if untreated – act as breeding ground for legionella bacteria.

How does poor water hygiene cause legionnaire’s disease?

A build up of legionella bacteria can develop into legionnaire’s disease in humans, which causes nasty symptoms. Therefore, it is crucial that any water tanks and pools are thoroughly cleaned and treated to prevent this disease.

Legionella is a natural bacterium that is organically found in natural water systems such as lakes as well as man-made water systems such as reservoirs. It typically breeds in conditions between 20*C and 45*C. Because of this is has previously been recommended that water systems are kept at 60*C, however, more recent research has demonstrated that some waterbourne bacteria such as Legionella can actually survive at this temperature also…

Therefore, now the HSE advises to keep water stores below 20*C at lower temperatures. However, this must include a water-system that is well maintained and has copper silver ionisation. The reason for the newly recommended lower temperature is that the colder conditions decrease the activity of the bacteria. The copper silver ionisation is also recommended to control the bacteria on a more chemical level.

Which other water systems need consideration?

As well as previously mentioned water coolers and spas, the water hygiene in showers in commercial areas should also be considered. Due to the number of people using showers pre and post workout or swim, this makes them another key area for legionella to spread.

Gyms and leisure centres should install water treatment methods that are reliable and hygienically proven. Then these systems should be thoroughly maintained to ensure a good level of hygiene in line with legislation.

We hope this gives you a good understanding of water hygiene and why it is necessary as well as the key risk areas in which Legionella can spread.

Wastewater treatment: what is the process?

How is wastewater treated?

To combat the ever-increasing costs of supplying and disposing of water, most commercial businesses are trying to treat and re-use wastewater.

By doing this, they are limiting these costs as well as managing strict regulations when it comes to discharging water. Additionally, if the water is cleaned to an acceptable level in the eyes of the industry, then this waste can actually provide your business with value.

How to treat wastewater

In the process of treating wastewater there are 3 main stages in the process: primary, secondary and tertiary. Here we will go into a bit more detail on the processes of each stage.

Primary wastewater treatment

This largely involves removing sediment from the water. Water is held in tanks that allow solid particles to settle, then they can be collected. Additionally, any oil or fat will float at the top, this is then scraped off. The remaining water is then moved onto the secondary stage.

In the meantime, the leftover sediment, and oils (also known as sludge) is removed to a different location and treated for alternate purposes. We will explain more about this later.

The two main methods used in the primary stage are Dissolved Air Floatation (DAF) and Volute Dewatering Press (VDP). DAP is used in the first part of the process to remove sediments and oils, then VDP is used in the latter half of the primary treatment in sludge removal. Both of these processes are used to remove and dispose of any contaminants that would impact industrial wastewater treatment systems in a negative way.

Secondary wastewater treatment.

Following the wastewater’s initial treatment, it is chemical treated. In this phase the goal is to break down the harmful particles into harmless ones. The chemicals typically used in this process are coagulants and flocculants and they aim to remove further solids by breaking them down.

Coagulants destabilise any remaining suspended particles, then the flocculants bind them to allow filtration out of the water.

This phase is vital, as much as 90% of suspended sediments are removed during this process. Since the strength of the wastewater has been significantly reduced, disposal costs at this stage are also lowered.

Tertiary wastewater treatment

Following the introduction of a chemical treatment to the wastewater, a tertiary phase is required for it to meet industry standards for discharge. This involves using a UV disinfectant and a chemical disinfectant.

The UV treatment aims to destroy any microorganisms in the water that could be harmful to us or other animals. Also, this treatment does not affect the taste, appearance or pH of the water making it safe for reuse. Following it’s UV treatment, the chemical treatment typically involves chlorine. The sole purpose of this treatment layer is disinfection.

After these treatments, the water is safe to be discharged into the environment or to be re-used.

What happens to the sludge?

At this stage your water is clean and safe for re-use, however you will still be left with the sludge from primary treatment. So, what happens to this…

Believe it or not, this material can be put to good use. Sludge can be transformed into energy in many ways. It typically is used for heat and power and can also be further cleaned to generate bio-methane and be returned into the power grid.

We hope this gives you a good overview of how to treat wastewater allowing it to be disposed of safely or re-used by your business.

Water filters: what, why and how?

Before it is fit for purpose, water filters are used to remove impurities, such as odour, bacteria, sediment and hardness.

By filtering water, its quality is drastically improved and can be used, whether that is drinking water, cooking or manufacturing. At a basic level, contaminants must be removed from water so it is as safe and as clean as possible.

Water filtration techniques

These filtration techniques are used singularly or in combination to improve the water’s quality. Here are the different types of water filters:

Absorption filter
Sequestration filter
Ion exchange filter
Reverse osmosis filter
Mechanical filter

Why are water filters important?

Water accounts for a huge 71% of the earth’s surface and is woven into a number of practices across the world, such as agriculture, medicine, heating, science, transport, food manufacturing and drinking.

Drinking water goes through thorough processes to ensure it is safe for humans, however, this means sometimes chemicals and odours linger in drinking water as these important factors keep it free from bacteria.

Depending on where you live in the country, the ‘hardness’ of water can vary. This means that it may taste nicer in some areas than others. Also hard water is responsible for limescale build up in places like kettles and boilers. To manage this it may be worth investing in a water filter.

Let’s discuss each type of water filter in a little more detail

The five types of water filter are listed above.

Absorption filters

These filters often contain carbon and are very effective at removing any contaminants. Since carbon has a textured internal surface, it is a great component to trap chemical impurities such as chlorine. Most domestic water filters use absorption filters to remove unwanted tastes and odours.

Sequestration filters

This filtration method involved chemically isolating a substance. Usually polyphosphate is used to prevent scaling on metals. This is a preventative method as opposed to softening the water itself. This is not suitable for all types of water, where water is very hard other methods such as ion exchange is usually more suitable.

Ion exchange filters

This process softens hard water by replacing magnesium and calcium ions in the water with sodium and hydrogen ions. This in turn removes the harder minerals which reduces limesales. This is typically carried out through small beads which are added to the water. This method is not commonly used on drinking water as it raises the salt levels due to the addition of sodium.

Reverse osmosis filters

RO for short, involves removing inorganic solids (like magnesium) by adding pressure so water passes through a semipermeable membrane in which the contaminants are left behind. This is a highly efficient way to purify water that is usually used in combination with mechanical filters.

Mechanical filters

This process physically removes sediment and dirt from water as it flows through a filter made of mesh. This allows larger debris to be removed. This filter can be compared to water flowing through a sponge. The water on the other side would flow through a lot cleaner as most debris would not be able to pass.

Which water filter system is right for my business?

Typically more than one filtration system is used to purify any sample of water. For example, drinking water will go through at least mechanical and absorption filters. By understanding the five different types of filters it should be easier to identify which are needed for certain types of samples.

Water filters are often categorised by domestic (usually attached to a sink) or commercial (for use in a restaurant kitchen for example). The most popular types of filters include: coffee machine filters; inline water filters; fridge filters; drop in filters and commercial water filters.

We hope this gives you a good overview of how water filters work and what they are used for. This helps build a bigger picture of how they could be used in your business.

The environmental effects of water management

Waterways throughout the UK have traditionally acted as a dumping ground for waste until the UK government introduced legislation to prevent this.

Continuing this behaviour would have resulted in harm to several animals living in these waterways. Any polluted animals that go on to be consumed by humans would then also affect humans!

Where does water contamination come from?

Most water contamination comes from industrial processes (such as metal and solvents) as well as human activities (such as sinks and toilets). Despite the introductory legislation, industrial processes still count for up to as much as 25% of water incidents in the UK. Because of this, many companies are trying new techniques to understand the best ways to treat water and its contamination.

There are many reasons that have motivated this:

To comply with regulations
Re-using water saves money
Becoming environmental advocates
Reducing discharge costs of untreated water

What are the benefits of wastewater treatment on the environment?

It goes without saying the less pollution in water, the safer it is for humans and animals. However, what impact does this have on the environment? A healthy ecosystem depends on a lot more than healthy humans and animals. It also needs a balance of bacteria and fungi which all interact with each other, be that directly or indirectly.

If toxins were left untreated in our ecosystem then they would ‘spread’ and eventually become harmful to all forms of life. By treating our waterways we enable a level of balance to be restored. This treatment also minimises pathogens spread which in turn helps us humans stay healthier.

The importance of net-zero water buildings

Another environmental consequence that should be considered is treating water itself. There are environmental consequences in the treatment of water, that’s why facilities are aiming for net-zero water buildings. This means the volume of water returned to the water source is the same as the volume of water used. In the long-term this prevents deterioration in natural water resources in terms of quality and quantity. Other water sources can be used to minimise the use of freshwater.

How can water be reused to prevent environmental consequences.

This process requires 4 stages: primary; secondary; tertiary and sludge treatment. Here we go into a little more detail in what each stage needs.

Primary treatment: this separates SS (suspended solids) from the water. More than 70% of these materials are removed through specific processes such as flocculation. Chemical reagents are sometimes introduced at this stage also.
Secondary treatment: biological treatments are introduced at this stage to remove pollutants such as carbon or nitrogen.
Tertiary treatment: at this stage all dissolved SSs will be removed and the water will be purified and disinfected so it can be reused.
Sludge treatment: any pollutants and materials which were removed in any of these 3 stages are turned into sludge and often sold on for processes that fuel heat and gas for example.

Converting a building into a place where water is not only tested but is efficiently treated so it also benefits the environment is not an easy task. The right machinery, chemicals and systems are all crucial! If you are looking to treat the water in your business or premises it is often simpler and more efficient to partner with a specialist water treatment company like AquaStat. In the long run this will save your business, time, money and environmental suffrage.