Before I opened my store for sustainable goods and supplies, I had no idea that replacing an old toilet was something most handy homeowners could do in an afternoon—and that it provides such a huge environmental benefit. The Environmental Protection Agency explains it well, “By replacing old, inefficient toilets with WaterSense labeled models, the average family can reduce water used for toilets by 20 to 60 percent—that's nearly 13,000 gallons of water savings for your home every year! They could also save more than $170 per year in water costs and $3,400 over the lifetime of the toilets.”

Two That Matter Most

To know how well you are meeting your need for sanitation without wasting water, these two indicators matter most:

  • How much water do your toilets use per flush?

  • How many times per day are you flushing your toilets?

Plumbing 301

Installing efficient toilets

Install water-efficient toilets.

Equipment and Materials

  • A toilet that meets or exceeds the WaterSense standard

  • A flange

  • A wax ring

Steps

  1. Remove a water-wasting toilet (if necessary).

  2. Install a water-efficient toilet.

Discussion

Simply swapping out a pre-1980 toilet with a new WaterSense toilet enables every person in your family to save hundreds of gallons of drinkable water every week without changing habits.

In households in the United States, water that has been carefully collected and treated to be safe to drink is mostly used to flush toilets. Nationally, 70% of residential water use is indoors, and 30% is outdoors (although this ratio varies according to local climate). Surveys show that each person in North America flushes a toilet about 5.5 times daily. If your family follows the typical water usage pattern, each week, each person in your home will use between 50 and 270 gallons of water to flush toilets, depending on how many gallons your toilet uses per flush.

Toilet technology and standards have evolved over the years in the United States:

  • Before 1980: seven or more gallons per flush (gpf)

  • 1980 to 1992: 3.5 gpf

  • 1992 federal standard: 1.6 gpf

  • CA Drought Compliant standard: 1.28 gpf

  • TX Drought Compliant standard: 1.28 gpf

  • WaterSense standard: 1.28 gpf

  • Ultra-High Efficiency toilets: 1.0 gpf

Installing or replacing a toilet is a simple plumbing project that most homeowners can do on their own. You can buy water-efficient toilets online, at a plumbing supply house or hardware store, or at a home improvement center. A toilet requires one cold-water supply line and a floor drain. A typical design has two main components: a tank that is filled with cold water, and a bowl that water from the tank flows through on the way to the drain when the toilet is flushed.

  1. Measure the size of the bathroom,  the location of the floor drain from the wall, and the distance from the floor or the wall for the water supply line to ensure the new toilet will fit into the space and be usable.

  2. Buy a new WaterSense toilet that is the right size for the space and the right height for your family.

  3. Follow these steps to remove the old toilet (if necessary).

    1. Thoroughly clean the old toilet. Turn off and disconnect the water supply to it, drain the tank, pop off the toilet bolt caps, unbolt the toilet from the toilet seal or wax ring, then lift up the old toilet off the floor and onto a dolly or cart to take outside.

    2. If your old toilet is porcelain (the most common material used), decide whether you want to reuse it as a planter (toilets can be used as interesting flower pots), try to recycle it (porcelain can be difficult to recycle), or use a sledgehammer to break it into small pieces. You can bury these pieces or send them to a landfill. 

    3. Remove and dispose of the old wax ring.

    4. Repair or replace the flange on which the new toilet will sit.

  4. Make sure the flange has the correct bolt spacing for your new toilet and sits a little higher than the finished floor; use a flange spacer if necessary.

  5. Install new bolts by sliding them into the slots on the flange.

  6. Install a new wax ring to create a seal between the toilet and the drain.

  7. Set the toilet bowl on the flange and wax ring, making sure the bolts go through the proper holes. Lower the bowl straight down for a good seal rather than rocking it back and forth.

  8. Screw washers and nuts on the bolts, then cover them with caps.

  9. Follow the instructions to attach the tank to the bowl (if there is a separate tank).

  10. Connect the water supply, fill the tank, flush, and repeat a few times, checking for leaks, especially around the base on the floor. If all the floor bolts are tight, but you see water seeping out, the wax ring is not sealed properly. You’ll need to remove the toilet, install a new wax ring, reinstall the toilet, and check again. No water should leak anywhere from the toilet.

  11. Both the International Plumbing Code and the Uniform Plumbing Code require making the joint between the toilet and floor watertight. The easiest way to do that is to caulk around the base of the toilet. This will prevent liquid on your bathroom floor from seeping under your toilet.

  12. Install the seat and let your family know the new toilet is ready!

The most common material for toilets is porcelain, which is heavy and hard to recycle. Metal toilets are also available; unlike porcelain, metal is easily recycled everywhere in the world.

Definitions

  • CA Drought Compliant Standard: a set of water efficiency standards enacted in California in response to the drought that the state experienced between 2011 and 2017

  • Dual-Flush Toilet: a toilet with two flush settings, usually a half-volume flush and a full-volume flush

  • Gallons per flush (gpf): how many gallons of water a toilet uses per flush

  • High-Efficiency Toilets (HET): 1.28 gpf

  • Maximum Performance Testing (MaP): a test to identify how well toilet models flush, using a realistic test media

  • Porcelain: a smooth, hard, easy-to-clean ceramic material made from kaolin clay, feldspar, silica, and other materials

  • TX Drought Compliant Standard: a set of water efficiency standards enacted in Texas in response to the drought that the state experienced between 2010 and 2015

  • Ultra-High Efficiency Toilets (UHET): 1.0 or 1.1 gpf

  • WaterSense: an EPA national voluntary partnership program that offers a simple way for consumers to identify water-efficient products

Troubleshooting

  1. You worry that a WaterSense toilet will require two flushes instead of just one.

    1. Federal standards require toilets to meet performance standards, and manufacturers report that their high-efficiency toilets provide the same performance as older wasteful designs.

    2. Use the Maximum Performance Testing (MaP) search tool online to find models with high MaP flush scores.

    3. Even if you flush it five times more often, a WaterSense toilet will still save water compared to a pre-1980 toilet that uses 7 gallons per flush.

  2. You worry that the environmental cost of buying a new toilet outweighs any benefit from saving water.

    1. You can buy a WaterSense toilet for $150, start saving $110 per year on water bills, and after 18 months, donate the money you save every month to an environmental organization.

    2. Collecting water, disinfecting it, delivering it, and treating wastewater all have environmental impacts. Over a few years, those impacts outweigh the environmental costs of making a new toilet.

    3. Buying a metal toilet reduces its total lifecycle cost because its metal can be easily recycled and made into another product at the end of the toilet's life. Metal recycling can continue forever.

  3. No new toilets seem to fit the drain pipe for your old toilet.

    1. Call a plumber. In the worst case, you’ll need to replace your drain pipe.

  4. You are on a well and septic system, so you don’t pay a water or sewer bill.

    1. Your well uses energy to draw water from an underground aquifer.

    2. Your septic system has a finite capacity to treat wastewater.

    3. Reducing how fast water flows from your well, through your toilets, and into your septic system will save you money and protect your aquifer. 

Strategies and Goals

  • Water

    • Increase water efficiency

      • Use less water with every flush

Milestones

  • Reduce the amount of water your household consumes

    • Measure: Water consumption

    • Method: Water bill (or pump electricity if you are on a well)

    • Time Period: Year

Limitations

  • Not everyone has indoor plumbing.

  • Not everyone can afford $150 to buy a new toilet.

  • Not everyone has the time or inclination to replace a toilet themselves.

  • Plumbers can be hard to find.

Opportunities

  • Plumbing 101: Finding and fixing leaks

    • Check for leaks: besides flushing toilets, undetected leaks are one of the leading uses of water in American homes

References

Keywords

plumbing, water, efficiency, toilets