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your water footprint

Residential Water Uses and Impacts

Dish Washing
Laundry
Cleaning
Lawn Care
Winter Salt Use
Car Washing
Unused Medications
Pools and Hot Tubs

Dish Washing

Although today’s dishwashers are more efficient and use less water than in the past, we still have to mindful about how we use them.

While dishwashers are designed to be more resource efficient, decisions around their use make a big difference too. Studies indicate that water and energy consumption from household dishwashing is to a large extent controlled by the consumer through such decisions as machine versus hand washing, the extent of pre-rinsing dishes, the selection of dishwasher cycles, and how fully and efficiently the dishwasher is loaded. Many residents are not using available dishwashing technologies effectively and are wasting a lot of water in the process.

Cycle Choice – Most dishwashers today provide a number of cycle choices that, if selected to match the soil on the dishes, can benefit the quality of cleaning and use less water and energy. The pre-rinse or rinse-only cycle, with or without detergent, improves cleaning with minimal water use. This cycle also prevents dried-on foods in the event of a delayed wash. Choosing a heavy or "pot/pan" cycle may give more cleaning effectiveness and will use less water than pre-rinsing in the sink before loading the dishwasher.

Pre-rinsing – Pre-rinsing dishes in the sink under running water before loading the dishwasher is a common consumer practice; however, this can use up to 95L of water for 5 minutes of pre-rinsing. If dishes are pre-rinsed using a dishwasher pre-rinse cycle, approximately 3.8L of water is used. Only 25% of the participants in a field study said they used the water-efficient pre-rinse or rinse-only cycle on their dishwashers. (See Journal of Extension article below) Appliance manufacturers recommend only scraping (and not rinsing) dishes before placing them into the dishwasher.

Water temperature can affect dishwasher results. During the energy crisis of the 1970s and 1980s, consumers turned their water heaters down and many saw unsatisfactory results; the habit of pre-rinsing began. Most dishwashers today have booster heaters to raise water temperature and increase cleaning efficiency. Many consumers are not aware of this option.

Dishwashing Detergents – Phosphate tends to be a main detergent ingredient. It serves as a "builder" to improve the detergent’s cleaning efficiency, especially in areas with “hard” water that contain calcium and magnesium ions (builders prevent these ions from interfering with the cleaning process). While phosphate is an excellent builder, it has harmful effects when it gets into rivers, lakes, streams, and other fresh waters. High phosphate levels feed water algae, making it grow quickly. This can make drinking water more expensive to filter and can spoil its taste and smell. Excess algal growth can have devastating impacts on the health and age of a lake or river. Recently, some governments have begun to look at regulating phosphates in automatic dishwashing detergents, which can contain anywhere from 4-8% phosphorus.

What you can do:

  • Buy an energy star dishwasher that uses water efficiently.
  • Learn about your dishwasher and use the pre-rinse and other cycles to save water and energy.
  • Scrape rather than pre-rinse your dishes before putting them in the dishwasher.
  • Use a low-phosphate dish detergent.

Sources and additional information:

Laundry

Front-loading washers used dramatically less water than top-loading washers.

Top-loading washers, which use an agitator that pulls clothes down and lets them float up, can consume up to 152 Litres of water each cycle. Some front-loading washers, meanwhile, can consume only a third of that amount per wash as they simply spin and let gravity move the clothes around.

Energy star washers typically use up to 50% less water than standard washing machines. The typical American household does nearly 400 loads of laundry per year. That's why an energy efficient washing machine can be an important appliance when considering water efficiency.

What you can do:

  • When you're buying a new washing machine, look for an energy-star front-loading washer.
  • Purchase non-toxic, biodegradeable cleaning products.

Sources and additional information:

Cleaning

Cleaning products contain chemicals that can pollute water supplies when they are rinsed and disposed of into the drain, as well as when volatile components evaporate.

Chemicals from cleaning products can be hazardous to human health and the environment. Some chemicals can irate skin and eyes. Other chemicals, if subjected to improper sewage treatment practices, can become toxic in aquatic environments. For example, alkylphenol ethoxylates, a common surfactant ingredient in cleaners, has been shown to act as an endocrine disrupter, causing adverse reproductive effects. Cleaners containing phosphorus or nitrogen can cause nutrient-loading in water bodies, triggering eutrophication and other effects.

What you can do:

  • Purchase non-toxic, biodegradeable cleaning products. Use other cleaners sparingly.

Sources and additional information:

Lawn and Garden Care

Lawn Watering
Homeowners can waste thousands of litres of water a year through watering outdoor plants and yards. Simply changing some watering procedures can lead to big water savings.

One of the primary water wasters is over watering the lawn. It is only necessary to water a lawn until the ground is wet approximately 15 to 20 cm down. This is deep enough for lawn and plant roots to access the water that is being supplied. When a pool of water, on top of the soil or around plants, becomes apparent, water is being wasted.

Up to 50% of water applied to a lawn or garden can be lost to evaporation during peak temperatures and a significant amount can be lost to wind. To prevent this, watering should be done in the early morning or late evening.

Water is also often wasted when it is not really needed (i.e. after a rainstorm) and leaving sprinklers operating too long. When deciding which plants or grasses to plant, it is important to keep in mind that certain varieties require less water than others.

Fertilizer Use
Applying excessive amounts of fertilizer or misapplying fertilizer can lead to fertilizer run-off from lawns and gardens. This run-off, which contains nutrients such as nitrates and phosphates, travels via storm drains directly to lakes and streams.

The nutrients enter the water ecosystem and affect aquatic growth through eutrophication (explosive algal and aquatic plant growth). This plant growth clogs waterways and prevents light from entering deeper water, which causes deeper aquatic species to experience weak growth and eventually die. Eutrophication also results in increased operating expenses for public water suppliers, taste and odour problems, and at times the loss of recreational use of water due to slime, weeds, and odours from the decaying algae. Although fertilizer chemicals are natural, most of those found in water are human-added. As little as one pound of phosphorus has the potential to produce up to 10,000 pounds of wet weeds and algae (City of Carmel Engineering Department).

Pesticides
The term “pesticide” can refer to a substance that has been developed to control or kill pest populations. This can include herbicides, fungicides and insecticides. Pesticide runoff moves into streams, rivers, and lakes and also enters groundwater systems by leaching through soil to the aquifers.

Pesticide concentrations in water can vary significantly depending on land use and pesticide use patterns. Runoff from a site also depends on a number of biogeographical factors such as soil type, moisture, compaction and the amount and type of vegetation. Runoff is much less likely to occur on a dry, sandy soil that is not compacted than on a wet, compacted clay soil. Tall, thick turf is less likely to allow runoff than a bare soil.

In 2009 the Province of Ontario enacted its cosmetic pesticides ban, which has limited the use of pesticides in the province. When the use of pesticides is necessary, homeowners should ensure that application instructions are followed, and that pesticides are not be applied before a rain or following heavy rains, as this increases the chance of pesticides runoff. Pesticide application to impervious surfaces such as concrete also encourages pesticide runoff.

What you can do:

  • Only water in the early morning or late evening to prevent evaporation and don't overwater.
  • Choose fertilizers with a low phosphorus number, as only newly-seeded lawns or phosphorus-deficient soils really require phosphorus.
  • Use fertilizers and insecticides sparingly; follow application instructions; and don't apply before a rain or following heavy rains, as this increases the chance of runoff.
  • Plant and foster trees and bushes along streams, rivers and storm drainage that act as natural barriers and prevent erosion.

Sources and Additional Information:

Winter Salt Use

For safety purposes, road salt, usually NaCl, is used to de-ice roads and walkways in the winter. There have been increasing incidences of roadside habitat degradation, wildlife kills, and water-quality issues linked to NaCl, however. Discussions are underway to decide whether de-icers should be considered toxic substances.

Road salts usually enter water supplies via direct or snowmelt runoff to surface waters, or when they seep through the soil to contaminate groundwater aquifers. Salts tend to remain in water supplies as there are no natural processes to remove them.

What you can do:

  • Minimize or avoid spreading and storing road salts and look for alternatives at the store.

Source and additional information:

Car Washing

According to the International Carwash Association, summer car washing is second to lawn watering for peak summer water use. A number of studies have shown that commercial car washing uses much less water than washing a car in a driveway. Additionally, washing a car at home can be more harmful to the environment since the contaminated water that comes from washing a car runs off into local streams, rivers, and lakes via the local storm sewer system.

In Canada, laws dictate that all commercial carwashes must drain their wastewater into sanitary sewer systems. This way, the waste water is treated before it is released into the outdoors again. This protects surface and groundwaters from contamination, since wastewater generated from the car wash doen’t have a chance to move through the environment and subsequently contaminate other water supplies. Additionally, many commercial car washes use computer controlled systems and specialized nozzles and pumps that use less water than standard varieties. Some newer car washes even recycle and re-use their wastewater.

What you can do:

  • Use a commercial car wash to wash your car.
  • If you do wash your car at home, don't let the suds drain into the storm sewer.

Sources and additional information:

Unused Medications

Many residents flush unused medications, such as from old, partially used prescriptions or ones that are past their expiration date, down the toilet or drain. However, sewage treatment facilities are unable to degrade or remove some of the compounds that they contain, including various endocrine disruptors. To help keep these substances out of our sourcewater, residents can prevent unused medications from entering wastewater in the first place.

What you can do:

  • Do not put unused medications down your drain or in the garbage. Bring all unused medications back to a pharmacy. Most pharmacies in Ontario have pharmaceutical take-back programs and dispose of unused medications properly.

Sources and for more information:

Pools and Hot Tubs

The amount of water used to fill and maintain a pool can be significantly reduced if the amounts of leakage and evaporation are reduced.

What pool owners can do:

  • Install and use a pool cover to significantly reduce the amount of water lost to evaporation and to keep your pool cleaner.
  • Regularly maintain the pool to prevent leakage.
  • Frequently clean the pool and deck area.
  • Monitor the pH level and chemical content in the pool.
  • Drain your pool into the sanitary sewer – not the storm sewer on the street.

Sources and for more information:

General

  • Don't flush anything potentially hazardous – including medications, solvents, cleaners, poisons, motor oils, fertilizers, paints, etc... – down the sink, toilet or storm sewer.
  • Purchase non-toxic, biodegradable cleaning products.
  • Learn about how to dispose of hazardous wastes properly, including bringing them to hazardous waste depots and disposal days.