Water Conservation: Low Flow Toilets

I am still basking in the glow of our astounding water challenge success. I am also humbled by the awareness that some of my neighbors and friends have been conserving their water better than we have for a long time. The big conclusion for me is that it is possible to use substantially less water through unremarkable changes: washing clothes less (and only washing full loads), showering a little less and taking navy showers, and not flushing the toilet every time.

There is more to this story, however. On November 7^th of last year (2014), my favorite neighborhood plumbers Heise’s Plumbing  came by and installed 2 low-flow shower heads and 2 low-flow toilets. Thanks to the SFPUC website, I can see how our water usage changed with these new fixtures.  

Check out the reduction in our household water usage from November to December last year! Our December bill spanned November 15 – December 12. During that period, we used an average of 80 gallons of water per day compared to 174 gallons the previous month. That is about a 55% decrease in water usage from one month to the next.

You can see from the chart above, that the real impact is not that extreme, but in the 3 months prior to the toilet installation, we used in the ballpark of 150 gallons of water per day for our family of 4. Previously I noted that our family was using approximately 33 gallons of water per day per person up until the Water Challenge began in March, which took into account lower water usage since the HE toilets installation.

I just looked at our averages through last November when the low flow toilets and showerheads went in. I discovered that, from November 2013 through November 2014, our average water use was a little higher – 37 gallons per person or 158 gallons for our household each day.

Since November when the new toilets and shower heads were installed, we used closer to 100 gallons of water per day. We reduced our household water use by 30% with absolutely no behavior change other than having new toilets and showerheads installed. We reduced our water consumption from approximately 35 gallons per person per day to 25 gallons per person per day, or a ~7% reduction in water usage per person x 4. Toilets matter!

The Dirty about the Toilets:

I installed the Toto Eco Drake – model #ST743E tank andmodel #C744E bowl. I purchased these on the recommendation of Heise’s because they said, “They work well.” I agree. They get the flushing done. This toilet gets good reviews by other users too.

The toilets are single flush as opposed to the dual pee/poo settings that flush as little as .9 gallons of water. My toilets have the WaterSense sticker on them, indicating that they don’t use more than 1.28 gallons per flush, which is the standard to be considered a High-Efficiency (HE)toilet. (Mine use 1.28 gallons per flush.)

From what I understand, a standard toilet uses 3.5 – 7 gallons of water per flush. Who knew? I think some of my neighbors did, but I guess I wasn’t really paying attention, and no one I know has been talking about gallons per flush. Let’s talk toilet! I am sorry I didn’t replace my toilets sooner. I believe the low-flow shower heads are using less water too, although I would guess the bulk of our new water conservation is due to the HE toilets.

Start-up Costs:

I paid $370 per toilet. In looking around a little online today, I see I could have bought the toilets myself for around $250 and then just paid Heise’s to install them for me. I could even have installed the toilets myself, which I believe is fairly easy to do. But, I am lazy, and I love finished projects. With labor included, the total cost of this project was $1,250. The City of San Francisco gave me a $125 rebate for each toilet ($300 total rebate) to bring that back down to $950.

In looking through my new, favorite website some more – the San Francisco Public Utilities website – I just discovered it is even possible for some San Francisco residents to have a new HE toilet installed at no cost. You can find rebate information on this site too.

As I was looking around to find the best new toilets, I came across the Maximum Performance MaP website that tests toilets. It is a good resource for selecting a new HE toilet.

 More Questions:

For anyone else out there obsessing over their toilets: How has the installation of a dual-flush HE toilet impacted your water use? Are you seeing even more extreme reductions in water use than I am?