While water is a renewable resource, the way water is filtered can leave behind a sizeable carbon footprint. Many water filters are made of some form of plastic, but recycling them may be more difficult than just placing them in your recycling bin. In fact, many water filters are not recyclable at all. However, whether they can be recycled or not, some water filters can efficiently clean water while needing few replacements because of their long lifespans. This keeps the system out of landfills and in your home for longer and leaves behind less environmental impact. Below you can find out what makes a water filter sustainable, what types of water filters are the most eco-friendly, and which methods of water treatment are more harmful to the environment than others.
What makes a water filter sustainable?
An eco-friendly water filter wastes less water, uses fewer materials, and lasts longer than other filters. Regardless of what type of water filter you use, using one is much more sustainable than buying water in plastic bottles. Even the shortest-lasting water pitcher filters replace around 300 plastic water bottles. When it comes to saving plastic, some filtration systems have an environmental advantage over others. Ceramic filters, for example, can be cleaned and reused for longer than other filtration systems. As a result, less product is thrown away over the lifespan of the filter. Reverse osmosis filters, on the other hand, cannot filter 100% of the water that feeds into the system. Some water must be used to wash away contaminants that are filtered, so it goes down the drain rather than into a storage tank. High-efficiency reverse osmosis systems, on the other hand, allow more water to reach the final product and less to wash down the drain.
Learn more: Bottled water vs filtered tap water: which is better?
Most sustainable types of water filters
No type of water filter is 100 percent sustainable, but some are more sustainable than others. Some systems within one category are more sustainable, while another system of the same type may use far more plastic or waste more water.
Ceramic filters
Ceramic filters are an affordable and effective water filtration solution for homes that are used in countertop, under-sink, and gravity-fed applications. Ceramic filters contain pores as small as 0.5 microns that catch debris as water passes through. These pores effectively reduce most bacteria, sediment, and turbidity in water. Ceramic filters are one of the best filtration options for the environment because they can be repeatedly washed and reused. The filters that do not contain a carbon core can be cleaned and reused until water no longer flows through them, while those that do contain a carbon core must be replaced when the carbon is ineffective, typically every six months to one year. This advantage of ceramic filters not only benefits your wallet, but it also helps the environment by less material being wasted.
Learn more: What is a ceramic filter?
Sediment filters
Sediment filters are sustainable because of their ability to sustain a home's plumbing, appliances, and other water treatment systems. These filters remove dirt, sediment, and other particulate matter before they can build up and clog water flow. Sediment filters are rarely standalone systems. Instead, they are used in conjunction with other types of water treatment. Reverse osmosis, UV disinfection, water softeners, and other water methods rely on sediment filters to clean water before it is introduced to systems down the line. Like most types of filters, sediment filters should be changed every six months to one year.
Learn more: What is a sediment filter? | What is a spin-down filter?
Activated carbon filters
Activated carbon filters require replacement more often than other filtration systems, but they do not contain as much plastic. If wasting plastic is a primary concern of yours with water filters, activated carbon filters are an excellent option. Carbon filters must be replaced once every six months to one year, and they should never be kept in place for more than a year. If the pores of a carbon filter fill up, they can break away from the carbon and enter the water supply. Carbon filters use adsorption, a process where contaminants cling to the carbon inside a filter, to reduce harmful elements in water. Once the carbon adsorbs all the contaminants it can, the filter must be replaced to ensure water quality. Activated carbon filters are common in reverse osmosis systems, refrigerator filters, and whole-house applications.
Coconut shell carbon blocks are also a great eco-friendly choice because they are made with renewable resources. These filters are composed of coconut shells, so they are sustainable in their production. Coconuts can be harvested year-round, making them practical for use as a filter material. Not only are they more environmentally friendly than other options, but coconut shells have a higher hardness and resist abrasion better than any other type.
Learn more: Activated carbon filters 101
Efficient reverse osmosis systems
Reverse osmosis (RO) systems are one of the most popular home water filtration solutions on the market because of their effectiveness at reducing harmful contaminants in water. They treat water in at least three stages: a sediment and carbon pre-filter, a semipermeable membrane, and a polishing carbon postfilter. All filters except for the membrane should be replaced every 6 to 12 months, and the RO membrane should be replaced once every one to five years depending on a variety of factors. Compared to conventional water pitcher filters, RO filters contain significantly less plastic. As a result, RO filters are typically not recycled and can be safely disposed of in the garbage.
Learn more: What is a reverse osmosis system?l
Another environmental component of RO systems is wastewater. In an RO system, water is placed under pressure and passed through a semipermeable membrane. When contaminants get caught by the membrane, they need to be washed away to prevent the system from clogging. RO systems use incoming water to wash contaminants trapped by the membrane down the drain. The efficiency of an RO system varies greatly depending on water pressure, quality of the system, and whether the system is designed for residential, commercial, or industrial use. The most environmentally friendly RO systems utilize the most water while wasting the least amount of plastic.
Another way to make your RO system more environmentally friendly is to utilize a permeate pump with your system. A permeate pump keeps a reverse osmosis system efficient by preventing pressure in the water storage tank from slowing down the system’s membrane. This allows the system to utilize more water in the filtration process and causes less wastewater to flow down the drain.
Learn more: How a permeate pump works in a reverse osmosis system
What are the least sustainable water filters?
No matter what type of water filter you use, it will be more environmentally friendly than buying water in plastic bottles. Almost 500 billion plastic bottles are used worldwide in a year, leading to an abundance of waste that leaves a sizeable carbon footprint. While all water filters are better than bottled water from an environmental standpoint, not all are created equal.
Ion exchange systems
Ion exchange systems are great at removing water hardness or other dissolved ions, but they can be harmful to the environment. For example, salt-based ion exchange water softeners discharge salt water into the drain when their ion exchange resin is recharged. In houses with a septic system, this water enters nearby soil and can pollute rivers and lakes, where high levels of salt are detrimental to marine life. Salt water is also detrimental to waste water treatment plants because it is particularly difficult to remove from water during treatment. Because of this, some states and municipalities have banned the use of water softeners altogether.
Learn more: What is a water softener?
However, one environmental benefit of water softeners is their ability to make other systems function more efficiently. Reverse osmosis systems, for example, can become clogged due to hardness in the water supply. Adding a water softener to a reverse osmosis system helps waste less water by helping the RO system remove contaminants before going through the RO membrane. While water softeners can be harmful to the environment, they are necessary for applications where water hardness is a serious concern, such as those who get their water from a well. If you wish to prevent limescale buildup in your home but do not want or cannot install a water softener, consider a water conditioner as an alternative.
Learn more: Water conditioners vs water softeners
Water pitcher filters
Many types of water pitcher filters use much more plastic than other types of water treatment systems. These units are appealing to consumers because they do not require complicated installation or a large sum of money, but they do require changing much more often than other filtration systems. Water pitcher filters should be replaced around once for every 40 gallons of water filtered. Compared to an activated carbon filter, which needs to be replaced once every six months to one year, water pitcher filters waste significantly more material. Pitcher filters also contain more plastic than other filter types, making the waste they produce more harmful to the environment.
Learn more: Do water pitcher filters really work?
If you have any additional questions about water filtration systems and their effects, please do not hesitate to contact our experts.