How to Save Water With a Toilet
Owners of older homes often don't realize that their fixtures, irrigation, and energy systems might be costing them a whole lot more than is necessary. For example, older toilets—those installed before 1992—use anywhere from 3.5 to 7 or 8 gallons of water each time they flush. The new ones, with updated technology, use only 1.28 gallons. That's a huge difference. Not only is that extra water essentially wasted, but you're also paying more on your water bills than you need to. Here's the skinny about toilets.
Old Toilets vs. High Efficiency Toilets
When water suppliers ran studies about water use in the home, they discovered that toilets alone were using almost as much water as what you'd use to irrigate a medium size landscape! They decided to help their customers save water by providing new, more efficient toilets, like the ones manufacturers were making that used 1.6 gallons per flush (gpf)—called ULFT's or Ultra-Low Flush Toilets.
As happens with all new inventions, some things about them worked and others didn't. Most of what didn't was related to how the flush was handled by the existing piping system that carried it away. The flush needed more push. In response to customer feedback, manufacturers redesigned them to use only 1.28 gpf, but with a higher velocity flush. These worked a lot better than the original ULFTs.
Then manufacturers saved even more water by creating dual flush HETs that had a light flush and a heavy flush. The light flush uses only 0.8 gpf and is used for flushing liquids. The heavy flush is for solids. Water suppliers, after testing the new ones for efficiency, started providing this kind of toilet to customers for free.
Toilet Distribution Event
Have you ever seen a toilet distribution event? Several years ago I worked for Waterwise Consulting Inc., a small consultancy that carried out conservation programs for California water suppliers. One of their most successful projects was setting up distributions of new High Efficiency Toilets (HET) free to the public.
For these events we would negotiate a contract to buy 500-1,000 new toilets, schedule an event, then contact a water supplier's customers and invite them to come pick up a freebie. They had to agree to bring their old toilets back, as soon as they'd installed the new ones, and we would recycle it for them. The water supplier would pay us based on the number of toilets distributed.
Then I supervised another contract with a big water wholesaler where we went into hotels to see how they used water, and helped them figure out ways to save. I discovered that toilets use more water than any other function inside a house or hotel.
Water suppliers advertise these types of services on their website, so you might want to look at yours to see what kinds of water saving services they offer. Meanwhile, let's look at toilets to see how they work and why you save with the newer ones.
What are the different types of toilets?
In the United States there are two main types of HETs - the tank type and the flush-valve type (see photos above). The tank type is what is installed in most homes. It uses gravity to move water from the tank down to the bowl and out with each flush. It generally has a less effective flush than the flush-valve type.
Flush-valve toilets are used primarily in commercial buildings, like hotels and gyms, where the supply pipe diameter is larger. Flush valve toilets do not have a tank to store water. Instead the water comes directly from the main pipes every time someone flushes. This guarantees built-in pressure. Flush-valve toilets are more effective and normally cost more than the tank types.
Is a new toilet worth the money? How much can it help me save?
Consider this: With a single user at home, if you flush a 3.5 gpf toilet five times a day you are using almost 18 gallons of water. If you flush a 1.28 gpf toilet five times a day, you use just over 6 gallons. That's a big difference - almost 2/3 less water with the newer one!
Per month that would mean 540 gallons compared to 180 gallons per person. If you include flushes for cleaning the toilet, you use more. If you have more than one person in your household or business, you use much more. See the following chart:
# of Flushes per Day
Old 3.5 gpf Toilet
Newer 1.28 gpf Toilet
5 (single person staying at home)
12 (3 people with one working)
15 (3 people all at home, or 5 people with 2 working outside)
Now imagine your house or company, plus each person in your part of town using that much water, and you can see where using a lower flush toilet can contribute a lot toward reducing the amount of water needed from municipal water systems.
Here is a calculator to use, if you are curious to know how much water your toilet and other bathroom fixtures are actually using: Water Consumption Calculator
Will the savings be worth it, or will it cost too much to install?
An easy way to decide if a conservation purchase is worth making is to see how long it would take to repay its cost with the money you save. If you get your toilet for free, then of course its worth it, especially if you can install it yourself.
If not, you would estimate how much you use it (number of gallons) per year, figure the number of gallons you would use with a more efficient toilet, and subtract to get the gallons saved (like we did above). Then multiply the gallons saved by the cost of water and sewer to show how much money you could save on your water bill.
Once you have your potential savings, calculate how much it will cost to buy and install the new toilet. Divide that figure by how much you could save. This will show you how long it will take savings to pay back the installation. Once you've paid back your costs, that is when you really start saving.
The formula: Purchase cost + installation cost / dollar savings = Simple payback time.
If I should decide to get one, where would I go for it?
First check with your local water supplier (look on the bill for their phone number). Some suppliers still give out water-efficient toilets for free.
Then check the ads on this page or search online to find your options. You can either purchase one online, or make note of what you liked and go around to local department or plumbing stores to find it. Your best bet, if you have one in your area, is a Home Depot or Lowes.
What will I do with the old toilet?
This can be tricky! You will need to look for a recycling company (one that collects, if you are replacing a high number of toilets). If you got your toilet at a distribution event, they often arrange for recycling of old toilets. If not, call your water provider to see if they know of a recycler. Your city or trash pickup company might also be able to help you.
Another option is to keep the old toilet, clean out its innards, and turn it into a dual-level planter for flowers or ferns. You can paint the enamel outside for additional decoration. See this site for how to adapt your old toilet to a Potty-O-Planter: Potty-O Planter
What is the latest in low flow toilets?
The most modern type of toilet you can buy today is actually a no-flow toilet. This kind of toilet does not use water at all or if it does, just a tiny bit to clean the bowl with.
In recognition that the bad smells we all associate with toilet use actually come from mixing urine with the hard wastes, this kind of toilet separates them from the get-go. Solids go down one way and, mixed with a dry soil enhancer, actually become compost. Urine goes down another way, is mixed with graywater, and used as a liquid fertilizer for the landscape.
Depending on the country, this kind of toilet is called a waterless toilet, a dry toilet, or a compost toilet. There are many different varieties on the market.
Treat your current toilet well.
In the meantime, until you do replace your current toilet with a more efficient one, be sure to treat it well. Keep it clean. Don't use harsh chemicals or brushes that could erode the surface. Don't put anything in it that doesn't easily break down in water. And while you're becoming more efficient, think of other ways you can conserve water too.
Above all, if your toilet runs, stop it right away. Running toilets can waste a lot of water.