Lesson 2: Protect Water Quality At Home

From stream to sink

Did you know that the average American family of four uses about 400 gallons of water per day in and around their home? This added up to about 27.4 billion gallons of water per day being drawn for households across the United States in 2010 to be used for drinking, washing clothes, watering the lawn, flushing toilets, cooking food, showering, and more. The majority of this water that flows through the pipes in our homes comes from the public supply (remember this term from lesson one?), about 63% of which is drawn from surface water sources, and the remaining 37% is pumped from underground sources such as aquifers. Not one of the homes on the public supply? If your family draws their own water, it's very likely from a well, which pumps up groundwater to meet your needs.

Our drinking water can come from two sources: surface water (lakes and rivers) and groundwater.

What goes up must come down, and water that is pumped into your home is very likely going to be drained away from it as well, whether that's to a backyard septic tank or a large-scale wastewater treatment facility. Either way, the water needs to be treated, or cleaned, after it's used by people and before it can be returned to the watershed. While lesson one covered many ways in which the ecosystems of the watershed work to maintain good water quality, these systems are delicate, and would be overwhelmed with the amount of pollution they would receive if steps were not first taken to treat the used water, also called wastewater. When communities' wastewater is sent through a wastewater treatment facility, it goes through several steps of filtration and purification, where the facility can remove large pieces of debris, kill disease-causing bacteria, reduce the levels of nutrients such as nitrogen and phosphorous in the water, and more, improving the quality of the water that is released back into the watershed. (If you want to learn more about how wastewater treatment facilities work, check out this virtual visit to a wastewater treatment plant from the US Geological Survey. If you're interested in how water is made safe to drink before it arrives to your home, take a look at this explainer from the same agency.)

In this manner, each one of us touches a significant portion of this lifeblood of the watershed, as billions of gallons of water move from rivers, reservoirs, and aquifers, into our homes, and then eventually back out to the watershed each day. As the mighty waters of the watershed take a pit stop in our sinks, bathtubs, hoses, and toilets, small actions we take at home with this water can have a big impact on water quality down the line.

Water use at home: follow the flow!

So where is all of this water going? You're probably not taking a 400 gallon bath every day, so how do households typically use this volume of water? Depending on where you live, that answer can vary quite a bit!

In general, about 70% of household water is used indoors, with the majority of that volume being used in the bathroom. The remaining 30% is generally used outdoors, for activities such as watering the lawn—across the country, these outdoor uses typically consume about 9 billion gallons of water per day. That proportion of outdoor water use can increase for homes in hot, arid climates, and then more generally for homes across the country during the summer months as temperatures rise, leading some homes to flip the traditional figure and end up using up to 70% of their water outside for landscaping purposes.


Activity: State water use statistics

For more personalized information based on the state where you live, go to NEEF’s Home Water Use in the United States, and click on the link for your state. Read the short article about your state’s water use, and then fill in the field below.

Bad habits: Common water quality mistakes

Lesson one covered some ways that water quality in a watershed can be impacted by contaminants that enter the water, such as sediment clouding the water, nutrient overload causing dead zones, or trash washing into the waterway during a storm. However, it's important to note that water quality isn't just affected by what's added to it—it can also be threatened by overuse of water resources.

Water tower in a small town

Of the 400 gallons of water flowing into the average household each day, not all of it is making it to its intended destination, leading to wasted water and contributing to inflated demand. When communities aren't conscious of the amount of water they use, it can lead to issues of groundwater and surface water depletion, reducing the amount of water to be had underground and in lakes and rivers. If you're one of those homes discussed earlier that uses a well—watch out! Groundwater depletion can make it harder for you to get water, especially if the groundwater is reduced to the point that your well no longer reaches it—like a straw that can't quite get to the water from the bottom of the glass. People on the public supply need to be wary as well—when the groundwater is drawn down to such an extent, it needs to travel that much farther to reach the surface when it is being pumped for community use, adding to the costs of retrieval. In some cases, if the overdrawing is severe enough, the water that is yielded from underground pumping may be contaminated with salt water, reducing its water quality and making it unsuited for many residential uses and freshwater wildlife habitat. Closer to the surface, overdrawing can decrease the volume of rivers, lakes, wetlands, and streams, causing the water quality to deteriorate for local wildlife populations as the water may become too shallow for certain aquatic populations to survive, and reducing the amount of stored water communities can rely on in times of drought or other emergencies. Finally, remember the combined sewer systems discussed in lesson one? The more water communities use, the more water these wastewater systems need to treat, reducing their capacity to handle stormwater influxes during heavy precipitation events. By moderating your water use, you can reduce your contribution to overflow events and the subsequent release of partially or untreated wastewater into your watershed.

In this manner, not being careful with how much water you use at home can impact water quality for wildlife and human populations across your watershed. It's not just what you put into water bodies that can impact their quality—it's also what you take out!

Ready to make a difference with your 400 gallons? The first step is to break any bad habits that you may not even realize you have when it comes to water quality. Below is a list of some common water quality mistakes that you may be making in and around your home.


  • Ignoring leaks: According to EPA WaterSense, the average household's leaks can account for more than 10,000 gallons of wasted water every year. That's enough to wash 270 loads of laundry! If you see a leak, address it as soon as possible.
  • Using outdated fixtures: While it may be chic to go retro with some parts of your home's design, using old fixtures in your kitchen or bathroom isn't pretty. For instance, old, inefficient toilets can use as much as six gallons of water per flush, making them the main source of water used in the home, and putting an unnecessary strain on your wallet. More efficient models only use about 20% as much water per flush, saving you both water and money!
  • Improper waste disposal: While wastewater treatment facilities can remove many kinds of contaminants, they can't handle everything. Dumping pharmaceuticals down the toilet or the sink is a bad practice, as not all wastewater facilities are designed to remove these chemical compounds from the water. You should take care when disposing of any hazardous material, even if you're not planning to put it down the drain—batteries, old cleaners, paints, and other potentially hazardous materials should not go into the normal trash, as potentially dangerous chemical contaminants could make their way into the local ecosystem.
  • Nutrient pollution: Nutrient pollution can come from inside residences, particularly from using detergents that contain phosphates to wash clothes or dishes.
Nutrient Flow
  • Wasting energy: It takes water to produce the power needed to use the lights, run the television, or generate the air conditioning. By not being conservative with energy use, communities can inadvertently put a strain on water resources.
  • Wasteful behavior: Sometimes the problem isn't a particular fixture or piece of piping—it's the way those items are being used. By not using water thoughtfully, many may be using too much, perhaps by not properly filling the dishwasher before running it, or running a load of laundry only half full.



  • Ignoring leaks: Just as with indoor water systems, outdoor water fixtures can leak as well. Irrigation systems that have a leak with a diameter of 1/32nd of an inch—about the thickness of a dime—can waste about 6,300 gallons a month.
  • Watering at the wrong time: Watering during the hot daylight hours can mean that much of your water is being evaporated into the atmosphere instead of being absorbed by your plants, wasting water and money. When you combine this with inefficient systems and misdirected sprinkler heads, some experts believe that as much as 50% of water used outdoors is being wasted.
  • Putting leaves on the curb: Your yard waste is composed of organic matter, which can serve as nutrients when broken down for other organisms. By leaving leaves on the curb, these bits of organic matter can be washed into storm drains and contribute to nutrient pollution in the watershed.
  • Allowing erosion: If you're doing yard work or construction at home, and you've exposed bare soil in the process, you may be contributing to sediment loading in your area's watersheds.
  • Spraying off sidewalks or decks: Do you really need that hose? If you're spraying with a hose what you could be sweeping with a broom, you may not be using water very efficiently.
  • Over fertilizing: If you're using more fertilizer than is recommended on the package directions, or applying the product right before it rains, you may be contributing to nutrient loading in nearby waterways.
Water tower in a small town
  • Washing your car at home: Many detergents contains phosphates, and by washing your car in the driveway, you may be rinsing these nutrients and other contaminants from your vehicle and into local storm drains. Take your car to a commercial car wash instead.

Activity: Shower better

Test your WaterSense with the EPA WaterSense program’s online interactive quiz. See if you know where the water wasters are, and what kinds of actions you can take to help conserve water.


Go back to NEEF’s Home Water Use in the United States, and click on your state again. How much water would be saved if everyone in your state reduced their shower duration by one minute each time they showered? Are you planning to reduce your shower time?

Start protecting water quality at home!

Don't get discouraged—there are many ways to substitute good behaviors for these bad habits, and help to improve water quality for your area! Here are a list of some free ways to combat the bad habits outlined above:


  • Ignoring leaks: Start celebrating Fix a Leak Week! Check out this page from EPA's WaterSense program for a guide on how to detect and chase down leaks in your home. You can do it!
  • Improper waste disposal: Call your local trash service, and ask about their hazardous waste collection program, and whether they have any pharmaceutical take-back programs. If there doesn't seem to be a pharmaceutical take-back program near you, you can try this instead. If you've got something that you think could be recycled, but your local recycling service doesn't take it (such as some kinds of batteries), look for a recycling location near you at earth 911.
  • Nutrient pollution: Go easy on the soap! Always read the instructions on cleaning products, and do not exceed usage recommendations.
  • Wasting energy: Put an end to energy vampires by deciding to Resolve to Save with this interactive calendar. Don't worry that part of the year is already over—start from where you are!
  • Wasteful behavior: Make a conscious effort in your home to make sure that the dishwasher is properly loaded, the water is turned off while you're brushing your teeth, and you're making the most of each laundry load. These changes will save you both water and money on your bill—check out the infographic below for more ideas.
Where does the water go?


  • Ignoring leaks: Again, EPA WaterSense's Fix a Leak Week program has resources to help you diagnose and address some of your dripping issues, including your hose or outdoor irrigation system.
  • Watering at the wrong time: Try to only water at dusk or in the early morning, when the sun isn't at its strongest. Planting your yard's foliage in groups based on how much water they need can also help you stay efficient when watering each zone.
  • Putting leaves on the curb: Instead of piling leaves on the curb, take advantage of their nutritional qualities by mulching them over the soil of your garden bed. That way, your plants are the ones getting a nutrient boost from this organic matter, and you've saved a little money on fertilizer.
Fall leaves
  • Allowing erosion: Try not to allow bare spots to remain in your yard, particularly if your yard is on a slope that water may wash off of. Cover the area with a tarp if it looks like it may rain, and think about some planting to fill the bare spot.
  • Spraying off sidewalks or decks: Sweep, don't spray! Sweeping saves water while still getting the job done.
  • Over fertilizing: Always read the product label, and try to apply the fertilizer over a hard surface where you can sweep up any spills if possible. Are you also managing a pile of yard waste? Consider mulching it to serve as homemade fertilizer, eliminating two birds with one stone.
Do your part to protect water quality

Activity: GRACE water footprint calculator

Go to the GRACE water footprint calculator, and take the quiz to find out how much water you typically use at home. In the field below, share what your calculated daily use comes to, and list three suggestions that GRACE provided you at the end to help reduce your water use.

Take the plunge: Water quality conservation strategies that take some investment

There are also a variety of ways to make changes at home to help protect water quality that may be more of an investment—a cost is associated with these strategies up front, but they pay off in the long run. This list includes suggestions that range from innovative technologies, to changes in your home landscape, to even trying out a new cleaning product.


  • Check out the EPA Safer Choice product list. This searchable database contains a list of cleaning and other products that have qualified to carry the Safer Choice label, indicating that every ingredient in the product has been reviewed by EPA scientists, and found to meet strict health and environmental criteria. These products perform well, and are certified to be safer for you, your family, your pets, workers, and the environment. As all water that goes down your drain ends up elsewhere in the watershed, this extra level of safety is a good thing! Take a look to see if your go-to products have earned the label.
  • Still thinking about how much of your water is going down the toilet—literally? Check out the EPA WaterSense program. Similar to the ENERGY STAR label, the WaterSense label is a sign that these water fixtures—toilets, showerheads, faucets, etc.—are third-party independently certified to be at least 20% more water efficient than average products in the category, while performing as well as or better than the less efficient models. For instance, by switching to WaterSense labeled showerheads, the average family could save 2,900 gallons of water per year. Learn more about WaterSense.


  • There are many ways to make beautiful changes to your landscape to reduce stormwater runoff during heavy rainstorms. If you have access to a yard, consider installing a rain garden at a low point in the terrain to absorb the rain and overland flow, while adding a pop of color to your home with native flowers in the process. If you're interested in saving some money from watering your garden while reducing stormwater runoff, maybe a rain barrel is the thing for you—collect rainwater that you can use to water plants and tend your yard without ever turning on a hose. For those of you with more concrete than grass at your home, consider switching to a permeable pavement—you can still park atop the surface, but now rainwater can soak into the ground below, reducing overland flow.

You can also bring the tech outdoors—EPA WaterSense labeled irrigation controllers, which use local weather and landscape conditions to determine whether a watering is necessary for your lawn. These watering schedules are better adapted to what your plants need based on local weather patterns, saving water and making a healthier yard in the meantime. Replacing a standard clock timer with one of these WaterSense labeled irrigation controllers can save an average home almost 8,800 gallons of water per year.

Urban savings

Activity: Get a sense for WaterSense

Get a sense for WaterSense by going to EPA’s WaterSense calculator to estimate your potential savings by switching to WaterSense certified water efficient products. Once you click the link, click on the third tab from the left, reading “Calculate Your Savings.” In the field below, tell us what products you looked at and what your estimated savings would amount to.

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