Now let’s follow the water flowing through the meter into the typical household. Low-flow toilets, faucets, and showerheads continue to be associated with residential water conservation among many builders and homeowners. Surprisingly enough, we find that while inefficient fixtures do cause us to use more water than we need to, most of the water consumed inside the house is being wasted down the drain at various sinks and showers after you turn the faucet on and stand there waiting for the hot water to arrive. It is most important that we make improvements to reduce that waste before we invest in more efficient fixtures for delivery.
- Wasted Down the Drain:
If you are building or remodeling, your best opportunity to address this is by incorporating a central core plumbing design with a centralized location of the hot water heater. Other alternatives include adding tankless gas water heaters located near each of your plumbing zones (a very expensive solution), or installing an on-demand recirculation system at the end of the plumbing runs, with controls placed at each wet location along that zone run.
- Appliances and Fixtures:
By following the water through the pipes, we can determine how much of it goes to each use, and we can recognize opportunities to improve each application. The pie chart below from a 1999 American Water Works Association Research Foundation (AWWARF) report, “Residential End Uses of Water Study,”5 shows that water used to wash clothes and flush toilets represents a significant portion of the indoor consumption. This indicates that over one-third of the water used inside our homes could come from non-potable sources. This is a great opportunity to use untreated rainwater for laundry activities and graywater for flushing toilets, eliminating those completely from the potable water treatment equation.
Once you have addressed efficient delivery of water and water reuse opportunities, it’s time to look at fixture efficiency. The most readily available options are high-efficiency toilets (HETS) or dual-flush models. As water resources are further stressed, composting toilets may become more accepted and used in order to reduce the size of this piece of the pie. There are various faucet models available with reduced flow rates, or you can install aerators to lessen flow without sacrificing the feel of the flow required for hand washing. The federal limits on faucets are currently 2.5 gallons per minute. Same for showerheads, which are now available in less than two gallons per minute flow rates. If you do not know how many gallons of water your fixtures flow, you can put a one-quart container below the faucet and turn it on to its maximum flow rate. Watch the second hand on your watch to determine how long it takes to fill up the container with water. The time it takes to fill the container is divided by 60 seconds. This will give you how many quarts you can fill with water in one minute. Your answer (including its fraction) divided by four gives you the flow in gallons per minute.
Most new dishwashers do not require pre-rinsing, and to really conserve water, you should only run them with full loads. In this case, if you only fill and run your dishwasher every few days, the dishes will probably come out cleaner if you do rinse off any food that might dry and cake on. The most efficient way of doing that is to fill the sink with as little water as you need to dip each dish in, swipe with a rag and transfer to the dishwasher. Look for new models that are ENERGY STAR rated for both energy and water efficiency. This is also true for clothes washers. Developing technologies will soon support other water-conserving appliances as well.
Changing How You Use Water
Your habits and way of living can also drastically cut down on indoor water use. Showering typically takes much less water than bathing in a tub, especially if the tub is a large soaking or jetted type If you have teenagers living in your household, they might be taking long showers without consciously realizing the water waste involved. Teaching the importance of water conservation is part of a comprehensive sustainable living curriculum and might be best approached by setting an example when children are young and you are actively engaged in their bathing. This includes training in the use of any mechanical controls that reduce water waste, as well as choosing the correct source of water for each activity. If you have installed a graywater system, education on what it should and should not be used for is critical for both water conservation and health safety.
Residential bath and shower controls are now available with flow control valves that allow you to manually pause the water flow during bathing. This is similar to fixtures that have been available for years in the recreational vehicle market. If you’ve ever been camping and stood below a 5-gallon water bag to take a shower, it’s a similar experience. After getting wet, you turn off the flow, wash your hands, and then turn it back on to rinse. It’s surprising how many people can bathe off a 5-gallon container, as compared to 30-50 gallons for the average home bath, or 20 gallons for the average 4-minute home shower.
Washing your car with a water hose with a control head will save you a similar amount of water, as the average person spends over 500 gallons of water each year! With a small bucket and hand-washing sponges and rags, you can wash a car with a gallon or two of water and just enough pressure from a spray attachment to rinse it off. The same is true for power washing your deck. Again, this is a good application for rainwater, no need to use potable water for washing the car or deck! In fact, there’s little reason at all to connect outdoor hose bibs (faucets) to a municipal water system, as long as users (including kids!) are well-educated that this is not a drinking water source.
Note that water-quality regulations may require that these sources be clearly labeled as not for drinking. In fact, we can reeducate ourselves to expect that all of our outdoor water needs will be met with non-treated rainwater, unless you have an outdoor kitchen or shower, which should be connected to your potable water source. One of the main causes of water waste is water leaks, which can be detected by adding food coloring to the tank and watching to see if any of it leaks into the bowl. Keep an eye on exterior hose bib faucets, as leaks not only wastewater but can damage the foundation of your home. Paying attention to your water usage, whether examining your bill from the water utility provider or by watching the level line on your rainwater tank, can alert you to possible leaks before they get expensive to deal with and require you to pay for water you did not get to use.
- The Future of Water Use:
Already, much of the world has ongoing water availability and safety concerns. We believe that, at some point in time, we too will be faced with choosing between outdoor landscape water use and our more basic water needs. We may need to prioritize water uses in order to assure water supplies are available for local food production, dedicating available groundwater and surface water to assuring that we have local sustainable food sources. But at some point, we are going to have to move beyond the low-hanging fruit to delve deeper into how to make more substantial improvements in water conservation.
This means looking at not only what we use water for, but also where it comes from and where it goes after we use it. To have ample water resources in the future, we are going to need to recognize a strategy that provides each of us only our fair share.
