6.30.2012

does it make WaterSense?



I was at a shindig earlier this week when a slightly buzzed law professor turned to me and said: “Tell us in 25 words or less what you do.” (Seemed a little rude, but maybe he reads this blog and knows how verbose I can get...)

My answer: “Water.”

Indeed, my day job revolves around water, primarily on the supply side. This makes me a big hit at shindigs because it’s really hard to find a Texan not interested in water (I haven’t found her yet...). Given my honest interest in water and water conservation (my license plate refers to water, fer cry eye!), it shouldn't be a surprise that I've focused a wee bit on how our new house will use (or not use) water.

Broadly, residential water use can be divided between indoor and outdoor use. However, water use also appears in less obvious ways, such as embedded in power and the products we use, including food. 

In Texas (in general) on an annual basis about two thirds of water is used indoors and one third is used outdoors. Outdoor use primarily expresses itself during the summer such that summer use is typically twice winter use. Many water utilities decide how much to charge you for wastewater based on your winter water usage, so don’t let the in-laws linger over the holidays! Annual water use tends to go up during dry spells and down during wet spells due to outdoor water use. Typical indoor water use is about 40 to 50 gallons per person per day. 

Outdoor water use is mostly directed to irrigation, and this is mostly for lawns. Texans love their Saint Augustine, regardless of the climate. But the Augustine can be a thirsty turf, especially in the drier parts of the state or when the inevitable drought comes. 


In modern homes, indoor use is pretty evenly split between the toilet, clothes washer, shower, faucet, and leaks. Bath and dishwasher use are about a tenth of any of the previous uses. In older homes with less efficient fixtures, the toilet and clothes washer are the water hogs. Governmental efficiency standards for fixtures and appliances have stealthily resulted in considerable water savings. Studies show that houses built today use about 30 percent less water than houses built in the 1990s. If a home today is built using WaterSense fixtures and Energy Star appliances (for the clothes washer and  dishwasher), those savings increase to about 43 percent.




WaterSense is a U.S. Environmental Protection Agency program focused on water efficiency including the rating of water fixtures. A fixture with a WaterSense label uses at least 20 percent less water than the average fixture in its class. 


So what are we doing to save water in our house?


Outdoors, we are going to xeriscape the majority of the yard and only have about 200 square  feet of drought-resistant turf. We plan to have at least 5,000 gallons of rainwater harvesting with possibly up to 10,000 gallons. We'll use this water for the turf, the garden, and the hot tub. Our goal is to not use any city water outdoors. If you think about it, it seems a little goofy to spray drinking water on grass...


Indoors, we'll have dual-flush toilets in all of the bathrooms and (hopefully) WaterSense rated fixtures (see WaterSense assessment of our choices below). I think dual-flush toilets are the coolest, and they can save a lot of water. The EPA estimates that you will flush a toilet about 140,000 times during your life (the bride will probably tally out at 420,000...), so imagine the water savings!


The dishwasher du jour is very water efficient (federal requirements have gotten massive in this category...), and we will choose a water efficient clothes washer. Swank shower design these days call for vulgar multi-headed shower extravaganzas in luxury homes (Architect 1.0 kept insisting on multiple shower heads: I was, like, "Dude. I work in water conservation! I won't be able to have any of my watery friends over!"). Instead we have the one shower head (Party!!!).


Other elements of water conservation are hidden behind the walls and in the design of the house. We'll have small-diameter PEX tubing to carry water to the faucets. A small diameter means less water in storage in the line which means less running the fixture waiting for hot water. The design of the house around a core means the lines don't have to run very far, which means less water in storage in the line which means blah blah blah (see above).


Water is also embedded in a lot of things we use, including electricity. It (generally) takes water to create electricity (steam for steam turbines; water for cooling), and it generally takes electricity to pump, treat, and distribute water. This is something the cool kids call "The Energy-Water Nexus". For example, almost 20 percent of California's electrical consumption is dedicated to moving, treating, and providing water (source)! In Texas, we only use about 1 percent of our electricity for water [our water doesn't come from distant mountains or Arizona...]. Nonetheless, about 140 gallons per person per day of water is consumed for the generation of electricity (source; note that "consumed" means water "lost" to evaporation; ten times as much water is "used", but much of that water is used again or returned to the river or lake). Renewables such as solar, wind, and hydroelectric don't consume much if any water (solar requires some water to clean the cells; hydroelectric uses lots of water but consumes little).


Water is also embedded in our food, clothes, and electronics as well as the products used to build a house. Some attempt to calculate your "Water Footprint" based on your lifestyle (for example, here and here [warning: visiting these sites may cause immense guilt over eating hamburgers and drinking beer]). I have a few beefs (so to speak...) over these calculations (if it's "natural" water use such as rainfall that grows grass that feeds cows, should that be part of your water footprint? Methinks not...), but they're good to get you thinking about the use of water you never see.


So, how about an efficiency check on our fixtures? EPA lists its WaterSense certified products here.


Faucet for the powder room: Danze (D316244T) WaterSense certified!


Pooper for the powder: Duravit (Vero) WaterSense certified! Interestingly, the wall tank's certification is only valid if the basin is also WaterSense certified.

in wall tank (Geberit):



Faucet for the kitchen: Kohler Karbon. Unclear if WaterSense certified. EPA doesn't appear to rate kitchen faucets for WaterSense certification, which doesn't make sense, especially since they rate bathroom faucets.  Kohler offers a low-flow spray head adapter kit that restricts flow down to 1.5 gallons per minute. In fact, all kitchen faucets can have their flow restricted with lo-flow restrictors/aerators.


Potfiller for the kitchen: Danze (Parma) EPA doesn't rate potfillers, and it doesn't make sense to: the goal is to fill the pot, so it doesn't matter how quickly the water comes out. In fact, the faster the better!



Faucet for the laundry: IKEA (Tarnan) This is a kitchen faucet, so no ratings at EPA. Regardless, IKEA products are not WaterSense rated (it doesn't mean that they're not efficient; it could mean they've not submitted their products for rating). We're probably going to do something different than this anyway, and not being WaterSense rated seals the deal.
Faucets for master and guest bathrooms: Fresca (Orba) Fresca faucets do not appear to be rated under WaterSense. Aerators?


Tub spout for the master bath: Kohler (Laminar ceiling-mount) EPA doesn't appear to rate tub fillers, which makes sense. Just like a pot filler, the goal is to fill quickly!



Shower for the master and guest baths: Kohler (Loure, K-T14670-4) WaterSense certified!

Pooper for the master and guest baths: Kohler (Persuade Curv dual flush two-piece toilet) WaterSense certified! The bowl and the tank have to both be certified.



So there you have it. It's looks like we're making water sense!

2 comments:

  1. Hello again! I see that your Kohler shower for the master and guest baths are WaterSense certified, but I'm curious why you didn't also select a thermostatic valve (instead of a pressure balanced one)? Wouldn't that have helped cut down on water use even more? Thanks!

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    1. I may be wrong, but I think they are one and the same. A thermostatic valve keeps the temperature of the water (relatively) the same during a shower. This is achieved with a pressure balanced valve by adjusting the pressure of the incoming hot and cold water to keep the temperature the same. This is more of a quality-of-life thing (don;t have to duck out of the way when someone flushes the toilet) and a safety thing (prevents getting scalded) than a water-conserving thing (although time spent ducking cold or hot water does, indeed, waste water!).

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