• How Household Water Usage Contributes to CO2 Emissions

    Close-up of a person washing their hands in a bathroom sink, a toothbrush resting in a drinking glass against the backsplash.


    There are several greenhouse gas contributors, but carbon dioxide (CO2) levels are at a record high, so CO2 emissions get a lot of attention in the media. In 2019, Canada’s annual CO2 emissions amounted to 276.65 million tons. Although this is less than other CO2 emissions in the world, by comparison, reducing our carbon footprint is important for the environment, wildlife, the economy, and your health. While it remains difficult to completely eliminate CO2 emissions, there are certain things you can do within your household to reduce its carbon footprint. The article below is meant to provide readers with an understanding of how household water usage contributes to CO2 emissions and what you can do about it. 


    Boilers are common household systems that most homes have. A boiler is a source for heating the water used in your home and sometimes for heating your entire home. Six primary types of boilers are used today. These include:

    • Steam boiler: this type of boiler uses pressurized steam to deliver hot water through radiators;
    • Hot water boiler: this type of boiler uses water and a series of pumps to distribute hot water throughout your home;
    • Natural gas boiler: this type of boiler uses natural gas, a temperature gauge, and a thermocouple to regulate heat coils in the boiler. The coils heat the water in your boiler as needed;
    • Electric boiler: this type of boiler stores electricity during off-peak hours to radiate heat throughout your home;
    • Oil boiler: this type of boiler uses oil from a separate oil tank to heat your water and distribute heat throughout your home;
    • Condensing boiler: this type of boiler has two types of heat exchanges to heat your home. The first exchange functions similarly to how a natural gas boiler works. The second exchange uses the energy potential from the exhaust your boiler puts out to preheat any water returning to the boiler.

    Certain boilers are more energy-efficient than others — such as electric boilers — but if your water boiler isn’t working properly, it can potentially create excess emissions.

    Regular boiler maintenance — or replacing your boiler when necessary — can help reduce the amount of energy used, and this can help lower the CO2 emissions related to home and water heating. Homeowners can also take advantage of boiler system water softeners to reduce the negative effects of hard water and improve the efficiency of your utility system. 

    Personal Hygiene

    Many individuals are unaware of how personal hygiene efforts such as bathing, showering, and washing your hands contribute to CO2 emissions, but personal care is one of the “most carbon-intensive uses of time”. There are small things that you can do to your hygiene routine to mitigate this.

    Showers and Baths

    According to The Eco Guide, heating one single gallon of water produces 0.18 lbs of CO2. The average shower uses 2.1 gallons of water each minute. If you were to take a 15-minute hot shower, you would be producing around 5.67 lbs of CO2 (2.1 gallons x 15 minutes x 0.18 lbs). If you shower daily, this comes out to over 2,000 lbs of CO2 produced annually. If there are multiple occupants in the household, this number can increase tremendously. Bathing is also a huge contributor to CO2 emissions. Bathtubs can range anywhere from 30 to 50+ gallons. If you were to fill a 50-gallon tub up to the brim, you would be creating 9 lbs of CO2 emissions. 

    By simply reducing your time spent in the shower, you can reduce the amount of CO2 you produce. You should also avoid running the water for excessive amounts of time before getting in. Additionally, homeowners should aim to reduce — or eliminate — bathing.

    Hand Washing and Brushing Your Teeth

    When you run water while washing your hands or brushing your teeth, you are creating CO2 emissions. Studies show that washing your hands in hot water wastes energy, and it has no benefits over cleaning your hands with cold water. 

    You can reduce water usage in these two scenarios by:

    • Turning off the water when you are actively brushing your teeth or washing your hands;
    • Using cold water when washing your hands or brushing your teeth;
    • Using hand sanitizer as a handwashing alternative when possible.


    Household appliances also contribute to CO2 emissions. The amount created may vary depending on the age of the appliance, the appliance brand, and the amount of use. For the sake of a focus on water usage, we can look at two primary contributors:

    1. Dishwashers;
    2. Washing machines.


    According to a Kapital Electric article on household appliances and carbon pollution, a dishwasher between 700 and 3000 watts will produce anywhere between 455 and 1950 grains of CO2 emissions per hour. Hand washing your dishes versus using a dishwasher is a common topic of discussion, but it should be noted that most new dishwashers are more efficient than washing items by hand. Use the following tips for how to wash your dishes more sustainably:

    • Only wash full dishwasher loads;
    • Upgrade outdated dishwashers (generally every five to six years);
    • If you need to wash an item by hand, avoid running the water while scrubbing;
    • Reduce temperature settings;
    • Turn off heat-dry settings;
    • Avoid pre-rinsing your dishes. 

    Washing Machines

    According to the same Kapital Electric article, a washing machine between 500 and 3000 watts will produce anywhere between 325 and 1950 grains of CO2 emissions per hour. You can use the following tips for ways to do your laundry more sustainably:

    • Avoid small loads of laundry;
    • Wash on cold settings;
    • Upgrade outdated washing machines (generally every five to six years);
    • Switch laundry loads over to the dryer or clothesline immediately to avoid rewashing;
    • Re-wear clothing if possible. 

    Hard Water

    The hardness of water refers to the amount of calcium and magnesium that is dissolved in it. If you have noticed a slimy feeling after washing your hands, or bathing/showering, or if your water is murky, there is a good chance you have encountered hard water. Calcium and magnesium in your water can create a breeding ground for limescale build-up. When limescale builds up in your household pipes, your water efficiency is reduced. When your water efficiency is reduced, your CO2 emissions are generally increased. Water hardness levels can vary based on many factors, especially location

    The best way to reduce the effects of hard water is to utilize water softeners. A water softener is an appliance made up of two tanks:

    1. A mineral tank that contains softening resin;
    2. A brine tank that contains a water-rock salt mixture.

    Water softeners work by pushing your water through the mineral tank. As the water passes by, calcium and magnesium stick to the resin in the tank, and this makes the water soft. Once the mineral tank is full of minerals, it goes through a regeneration cycle using the brine tank. You want to be sure to get the right size water softener, so be sure to touch base with a professional.