Learn more about what affects water quality, the science of water filtration, and frequently asked questions.
What affects water quality
The very thing that disinfects our drinking water can negatively affect taste. Municipalities use chlorine and chloramines in order to kill or inactivate bacteria, viruses and potentially harmful organisms in drinking water. That means our coffee, tea and soft drinks might not meet our expectations for smell and taste.
Our water can also have high levels of mineral content, hardness and sediment. If you run a foodservice business, that can mean scale build-up which may result in shorter service life for your equipment. Learn how these common elements can impact your business.
Some water companies have switched to chloramine to treat water in recent years to meet disinfection byproduct requirements. Chloramines, however, are more difficult to reduce through filtration than chlorine – and many water filters are not effective at reducing them. Chloramine can affect taste of beverages and can damage machinery by degrading rubber parts – such as O-rings – which may cause leaks and require repairs.
3M foodservice water filtration products with the abbreviation “CL” indicate the product is tested for chloramine reduction.
One of the most visible and costly effects of hard water – which has high levels of dissolved calcium and magnesium salts – is scaling. This can have a negative effect on machinery, ranging from damaged heating elements reducing their heat transfer efficiency to blocked valves and pipelines. Hard water has a potentially harmful effect on machinery by forming scale over time – which may cause machines breakdowns and additional service. Scale formation may increase running and maintenance costs. It also affects water taste and can reduce flow rates. Additionally, drinks made with hard water can appear cloudy. There are several ways to treat scale, but some – such as acid cleaners – can also damage sensitive metal machine components.
Scale reduction is particularly important in ice and espresso applications. 3M foodservice water filtration products with the abbreviation “S” indicate the product reduces scale for ice and coffee applications. The 3M™ ScaleGard™ Pro and ScaleGard™ blend products reduce scale for espresso applications. Please visit our ice and espresso pages for more information.
Sediment or insoluble particles in the water supply may have a negative effect on appearance of your beverage or ice and can affect the operation of machinery. The particles can range from inorganic materials – such as clay, sand or rust, some of which may be clearly visible– to living matter such as bacteria or cyst which are invisible to the naked eye.
Sediment can affect various types of machinery: in ice machines, for instance, it can trap air and lead to cloudy ice, while also clogging tubes and solenoid valves. All 3M foodservice water filtration products reduce sediment at different micron levels and select products reduce bacteria.
Although municipal water authorities are generally successful in reducing pathogens from water by treating the water with chlorine or chloramines, some unregulated substances can slip through. These include pharmaceuticals found in prescription medicines, over-the-counter drugs and hormones that may have gotten through the water treatment process.
Volatile organic compounds (VOCs) which range from natural substances to pesticides, herbicides and industrial substances are another concern¹. Some compounds known as “total trihalomethanes,” or TTHMs form in reaction to naturally occurring organic substances with chlorine – a common disinfectant.
¹ World Health Organization Information sheet: Pharmaceuticals in drinking-water
Water filtration technologies
Contaminants that may be present in local water require different filtration methods to reduce them. Solid particles, for instance, require a mechanical filter, while organic compounds and chlorine are best reduced with activated carbon. There are four main water filtration technology types, which use various methods to reduce contaminants in water:
Activated carbon filters are used to reduce chlorine in water – as well as some organic compounds. The main effect of activated carbon is to improve the water’s taste. It can and should be used in all areas regardless of water hardness or contaminants to reduce chlorine taste and odor, which is a major need for foodservice applications.
Activated carbon is engineered to have small pores that increase its internal surface area for adsorbing contaminants that may be in the water. Activated carbon may be in the form of a packed bed of large particles or may be in the form of a porous carbon-block made from much smaller particles to improve its filtration-efficiency. Contaminants such as chlorine or organic molecules present in the water passing through the filter get trapped in the pores of the carbon-particles when flowing around it.
Chloramine can be harder to reduce than chlorine, so 3M uses a special carbon block that has been designed to trap it specifically. The carbon block’s surface has also been modified to maximize the rate of chloramine capture. Activated carbon filters can vary in micron rating from 5 microns down to 0.5 microns, meaning various pore sizes are available depending on which contaminants are present in local water. Please see your product label or product detail page in our online catalog for which products reduce chloramines that may be used to disinfect your water.
Reasons to replace your carbon filter: Activated carbon filters can become blocked by particles in the water over time preventing water from passing through. The amount of water used and the concentration of sediment impact how quickly the carbon filter will clog. (Think of a sieve with sand and rice constantly flowing through it. Over time, the rice will likely block the holes and sand will no longer be able to pass through.)
Additionally, replacing your filter is needed due to exhaustion of the filtration media. The estimated "life" of 3M activated carbon commercial foodservice filters often range from 6-12 months. See the product label and operating manual for rated capacity for each 3M commercial foodservice water filtration system. Local water conditions and actual use of the filter influence change-out intervals. If you notice a drop in flow rate or an unpleasant taste in the beverages you’re processing, it’s most likely time to replace your filter.
Polyphosphates are additives that are dosed into water at a controlled rate to inhibit scale. The dosing can be performed manually or automatically at levels of around two parts per million (ppm). Water filters that contain polyphosphates usually hold them within the cartridge and slowly dose the water as it passes through.
The scale-inhibition technique works by coating the magnesium and calcium ions to prevent them from sticking to water-contact surfaces of equipment. This helps prevent them from accumulating on heating coils and blocking water lines. Dosing does not physically remove the calcium and magnesium from the water, but instead simply inhibits their ability to form scale.
Polyphosphate treatment works best for soft to moderately hard water for applications such as ice or coffee but becomes less effective in very hard water areas and for applications such as espresso or steam where other technologies such as ion-exchange or reverse osmosis will be required.
Reason to replace your polyphosphates filter: Over time, as polyphosphates get added and mixed into the water they diminish. (Think of it like eating a piece of hard candy – it gets smaller and smaller until it’s fully dissolved). When exhausted, there’s no more protection against scale.
Ion exchange resin is used to reduce scale minerals from the water and is a highly effective treatment for moderate to very hard water. It works by reducing calcium and magnesium ions which cause water hardness and scaling. It does this by passing the water through a polymeric resin that is impregnated with ions that strongly attract the calcium and magnesium ions. As the name “ion-exchange resin” suggests, calcium and magnesium ions, which have high scaling potential, are exchanged with other ions that do not have as high of a scaling potential.
Reason to replace your ion exchange filter: Like polyphosphates, they can be exhausted. In time, the resin will become saturated with calcium and magnesium ions, so the filter cartridge must be replaced because the ion exchange capacity has been reached.
Reverse osmosis (RO) is a relatively unique technology and with the right design, it can be used in any level of water hardness. It is most cost effective when used in hard water areas to reduce scale.
Reverse osmosis can allow for filtration down to 0.0005 microns. It is commonly used to protect and filter multiple pieces of equipment at one time, as opposed to the one filter per equipment item as is standard with other water filter technologies. RO membranes are self-cleaning, so units last for a considerable time, generally 2-3 years. In cases where high hardness leads to rapid exhaustion and frequent replacement of ion-exchange resin filters, reverse osmosis may be more cost efficient over time.