Thursday, November 19, 2009

Low down on low flush - for World Toilet Day

just in time for World Toilet Day...
The Low-down on Low flush

Some of them have a dirty reputation. And while they’re the law in the U.S., stories about homeowners trickling over the border to Canada to buy elicit older and bigger brothers abound. The low-flow toilet, since its introduction in the early 1990s, has produced quite a flush of debate.

Believe it or not, there are regularly updated reports and studies on toilets that ‘exceed customer performance expectations.’ I don’t expect much from my toilet. In fact, it might well be the poster child for neglected appliances. But when some recent household plumbing highlighted the possibility of new bathroom fixtures I got eyes and face, so to speak, into the lowdown on toilets.

For example, did you know that testing the efficacy of the low flow is now done with a soybean mixture encased in latex (condom) in 50 gram specimens? Similar in density and moisture content to human waste, this may kill the soybean industry as a palatable alternative protein. But I digress.

So, what does a green need to know about going low? Well, let’s take a brief look at the histoire of the pissoir: In the home, the toilet uses the most water, accounting for about 30 per cent of indoor water use. Older model (pre-1980) toilets flush with 20 litres of water (that’s about what the average person living in Africa uses per day). Considering that over the course of a lifetime, one flushes the toilet nearly 140,000 times, using one of these hummers is akin to wasting a waterfall.

In the ‘90s, the 13 litre toilet came on the market. Then in 1996 the Ontario provincial building code required 6 litre toilets (often called ultra-low-flush) for all new homes. This all time low legislation has not been met in any other province or territory although some municipalities, like Vancouver, have decided to see how low they can go including offering rebates on low-flow toilets a program which, St. John’s does not have. (But with the increasing costs associated with the new sewage treatment system, such a program would benefit everyone by helping to reduce the amount of water being processed).

In the U.S., federal law states that toilets may not exceed 1.6 gallons per flush (gpf)—that’s about 6 litres-- and many of their High-Efficiency Toilets (HETs) go beyond that standard and use less than 1.3 gpf. This is a nice twist to prevalent thinking that everything is larger in the U.S. Seems they can still flush it with less. And in case you’re wondering, the U.S. Environmental Protection Agency has adopted 350 grams as a minimum performance threshold (the average male dump is 250 grams) for High-Efficiency Toilets (HETs).

Meanwhile, down under, Caroma, the dominant supplier of sanitary fixtures to the Australian and New Zealand market, tested for plumbing problems using its dual-flush (half flush for liquid waste; full flush for solid) toilet system. The manufacturer concluded that to achieve water conservation objectives the entire plumbing system should be of the highest standard. In other words, and as others have found out, low flow toilets may experience problems when installed in locations with degraded or damaged drain line systems (e.g., root intrusion, sagging or broken lines, buildup of solids, etc.).

Still, let’s say your plumbing is dandy. The thing to remember is that not all toilets are made equal. Many first generation low flow models didn’t flush properly. But over the years, flushing systems have been redesigned and improvements in glazes, for example, help ensure that the bowl is as aerodynamic as possible. A good place to look at information on low flush toilet ratings is This TV/plumber personality has produced a consumer report on toilets taking into account such concerns as gram ratings, ease and cost of repairs, sound when flushing, and how well the bowl is rinsed.

One more cautionary note. Toilets can be gravity flushed (the most common) or pressure-assisted. While the latter requires still less water it can be noisy and may be problematic in homes with older plumbing.

Fine. I’m ready to go shopping (as long as I don’t have to bounce on the bedspring, so to speak). And choices in St. John’s have improved over the past couple of years though I still can’t find my favourite—the ‘Toto’ listed on Love’s website—in St. John’s. Still, retailers like Kent and Home Hardware carry a selection of 6 litre models providing both single and dual-flush options, the former starting at $90.

Meanwhile, if you’re not quite ready to buy a new toilet, you might consider retrofitting your old one to make it less of a water hog. Several types of devices can be installed in an existing toilet tank to reduce the amount of water used in flushing that work by: water displacement (plastic bag or bottle); water retention (toilet dams); or alternative flushing (early closure or dual-flush). Local plumbing supply or hardware stores can help find out which type will work best for your toilet. But don't put rocks or bricks in your toilet tank: Over time they’ll break down and can cause damage.

And if you’re really cheap but determined to save that pure drinking water that’s flushing your bowl, consider adopting this adage: "
If it's yellow, let it mellow, if it's brown, flush it down."

(© Alison Dyer 2009 )


Michael said...

Priceless! I may have injured my insides laughing, so might never need the information. Then again, I may need it worse than ever...

Alison Dyer said...

Hey Michael... have you figured out if your average in your, ahem, toilet demands :)
Squidink will continue to monitor and write on watershed environmental issues in coming months. Thanks for following & commenting. best to ya fellow paddler, A

greenplumber Bill said...

Alison: I did not even realize until rather late, this thing about international toilet day.My contribution to maximizing the message is that here at GreenPlumbers we have successfully transformed our vernacular to "high efficiency" rather than low flow. There is just too much negative carryover from the poor choices of the 90's, that today there are really even plumbers who think "dual flush" means you have to flush twice to be rid of the business! Thanks for the posting, Greenplumber Bill

Alison Dyer said...

Hey Bill,
We here are squidink aspire to high efficiency (and low flow), so I thank you for your posting.

Douglas Wilcox said...

Good grief Alison, Thomas Crapper will be turning in his grave at such a carefully penned critique of his high flow cisterns!

Alison Dyer said...

Hey Douglas,
Thank you - my 12-yr-old son may well be interested in an internet search and report on Mr. Crapper!

Thanks all - there has been quite a stream of discussion on toilets. And I'm sure we've only just rippled the surface.

Anonymous said...

Toilets account for approx. 30% of water used indoors. By installing a Dual Flush toilet you can save between 40% and 70% of drinking water being flushed down the toilet, depending how old the toilet is you are going to replace.
If you are serious about saving water, want a toilet that really works and is affordable, I highly recommend installing a Dual Flush toilet. Caroma toilets offer a patented dual flush technology consisting of a 0.8 Gal flush for liquid waste and a 1.6 Gal flush for solids. On an average of 5 uses a day (4 liquid/ 1 solid) a Caroma Dual Flush toilet uses an average of 0.96 gallons per flush. The new Sydney Smart uses only 1.28 and 0.8 gpf, that is an average of 0.89 gallons per flush. This is the lowest water consumption of any toilet available in the US. Caroma, an Australian company set the standard by giving the world its first successful two button dual flush system in the nineteen eighties and has since perfected the technology. Also, with a full 3.5″ trapway, these toilets virtually never clog. All of Caroma’s toilets are on the list of WaterSense labeled HET’s (High Efficiency toilets) and also qualify for several toilet rebate programs available in the US. Please visit my blog
to learn more or go to to learn where you can find Caroma toilets locally. Visit to see how we flush potatoes with 0.8 gallons of water, meant for liquids only

Anonymous said...

Hi Alison, visit too see how low a flush can really go. I am looking for a toilet, approved or not that can flush with less than 2l, can you help. Thanks Quintin