Flushing potable water

May 1, 2012
The single largest use of potable water in our homes is the toilet and it makes perfect sense to focus on water conservation first where we waste it the most.

No one drinks from the toilet — at least no one I’ve ever met! The only times I recall witnessing slurping from a toilet-bowl has been by man’s best friend — a dog. The single largest use of potable water in our homes is the toilet and it makes perfect sense to focus on water conservation first where we waste it the most.

If an average family of four replaced their 3.5-gpf. toilet(s) with 1.28-gpf. toilet(s), they would conserve, on average 21,134 gallons of potable quality-drinking water. Most folks are afraid of high-efficiency toilets due to memories of, or having heard about, the nightmarish first-generation of 1.6-gpf. toilets: a very expensive and painful nightmare that caused plumbers everywhere to yearn for 3.5-gpf. toilets. Manufacturers eventually corrected the defects and 1.6-gpf. toilets turned out to be reliable with excellent flushing performance.

Like any other plumber who suffered through the 1.6-gpf. nightmare, I was reluctant to embrace high-efficiency 1.28-gpf. toilets. Our home’s 4-in. cast iron sewer line, with a house-trap, runs a bit more than 300’ before it joins into the sanitary sewer main in the street. If the house-trap or drain line carry (DLC) was going to be an issue, it seemed like a perfect experiment. I replaced our 3.5-gpf. toilets with high-efficiency 1.28-gpf. models, using Gerber, Toto and Vortens. Then I waited for the DLC issue to rear its ugly head and a need to clean the sewer line. After several years’ time, I’m still waiting.

Reading about the DLC issue, the theory put forth is that commercial properties will have more frequent clogs due to a lack of other water uses, like showering and clothes washing. An opportunity arose to install WaterSense UHET toilets, .5-gpf. urinals and .5-GPM lavatory faucets at York County’s Nixon Park, www.yorkcountyparks.org/parkpages/Nixon.htm, where more than 10,000 visitors and school children visit each year.

The Park Service was installing a mural of York County’s extensive watershed to illustrate where our drinking water comes from and right smack in the mural’s lower right corner (easily viewed by children), a re-settable water-meter was to be installed so that school groups could see how much water they used during visits. It’s more than 75 feet from the public restrooms to the septic system: another grand experiment for DLC! Two years have passed without a single clog.

Over the past decade, use of our sewer-line video inspection equipment has also revealed, I think, why DLC is not the drain-clogging issue I feared in the past. Human waste decomposes quite rapidly in warm moist sewer lines and waste-products left behind are easily transported by subsequent flushes and secondary uses. While solid wastes and toilet paper aren’t carried all the way to the street, not even with 3.5-gpf. toilets, the decomposing and softened products are pushed and/or carried along with each subsequent flow. The only clogging issues we have seen occur when there is a belly or defect in the sewer line.    

With my fears of HET& UHET gone, it was time to concentrate on how to sell these more expensive products. In the past, we have used ECV to promote the sale of high efficiency HVAC appliances and now we can use Water Conservation Value (WCV) to sell HETand UHET toilets. Let’s use that family of four and the 21,134 gallons of conservation. If that family lived here, the WCV would look like this:

  • WCV = 21,134 x $0.013 = $274.74 (reduction in water billing)
  • Sewage = 21,134 x $0.008 = $169.07 (reduction in sewer billing)

Their first year WCV = $443.71. If a 1.28-HETcost $100 more than a 1.6-gpf. model, the ROI would be 100 ÷ 443.71 = 22.5%. If the HETlasts for 20 years and the costs for water and sewage treatment rise 3.5% per year, the accumulated WCV = $12,547.98.

Let’s imagine the same family of four gets water conservation fever and decides to swap out all faucets and fixtures to ones compliant with WaterSense. They’re using an electric water heater and electricity costs $0.12 per kWh. According to WaterSense,   www.epa.gov/watersense, they would reduce their potable water usage by 42,000 gallons (includes a 10,000-gallon leak-rate per average home). Their new conservation:

  • WCV = 42,000 x $0.013 = $546.00
  • Sewage = 42,000 x $0.008 = $336.00
  • Water heating = $875.64 - $381.49 = $494.15

First year WCV = $1,376.15. If we project a 3.5% annual increase, a look 20-years into the future reveals the WCV = $38,917.08.

As you can see, water is rapidly becoming the new “oil” and plumbers will be leading the charge forward where WCV is concerned.

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