Conservation at Home

By Jared Hodes

Toilets, faucets, shower, and clothes washers are the 4 largest sectors of indoor water use, which means that any improvements in efficiency in these categories will have a significant impact on total water use
Residential Indoor Water Use Distribution. Toilets, faucets, shower, and clothes washers are the 4 largest sectors of indoor water use, which means that any improvements in efficiency in these categories will have a significant impact on total water use

There are numerous efforts that individuals can make inside their respective residences such as replacing older appliances and faucet heads that waste more water than newer and higher efficiency appliances and faucet heads. Average bathroom and kitchen faucets run at 2.2 gallons of water per minute, but residents can receive a kitchen faucet aerator that runs at 1.5 gallons of water per minute and bathroom faucet aerators that run at 1.5, 1.0, or 0.5 gallons of water per minute. In the case using the 1.5 gallons per minute replacements, the owner will save about 1,000 gallons per year for both the bathroom and kitchen faucet. Showerheads that runs at 1.5 or 2.0 gallons of water per minute can be obtained for free by homeowners as opposed to showerheads that use 2.5 gallons of water per minute. Saving 1 gallon of water per minute in a showerhead can lead to a savings of over 11,000 gallons per year. Residents in Los Angeles can upgrade their kitchen and bathroom faucet heads for free through LADWP.

Shower (Maximum Water Saving Scenario)

(2.5 gallons/minute – 1.5 gallons/minute) x (8 minutes/shower) x (4 people) x (365 days)

=11,680 gallons/year saved for a 4 person family

Shower (Minimum Water Saving Scenario)

(2.0 gallons/minute – 1.5 gallons/minute) x (8 minutes/shower) x (4 people) x (365 days)

=5,840 gallons/year saved for a 4 person family

High efficiency toilets (HETs) are another way that individuals can reduce the amount of water they use at home. High efficiency toilets have a maximum of 1.28 gallons of water per flush, 20% lower than ultra low flow toilets (ULFTs) at 1.6 gallons of water per flush, and is a vast improvement from older toilets that can exceed 7 gallons of water per flush. Using these figures and the assumption that the average person flushes 5 times a day, a family of 4 would save 2,336 gallons per year by switching from an ultra low flow toilet to a high efficiency toilet. Using a value of 7 gallons of water per flush for older toilets, a family of 4 would save 41,756 gallons of water per year by switching from an older toilet to a high efficiency toilet. There is also a $100 rebate for those purchasing a high efficiency toilet who previously owned an older toilet that used 3.5 gallons of water per flush or greater.

Old Toilet to High Efficiency Toilet (Maximum Water Saving Scenario)

(7 gallons/flush – 1.28 gallons/flush) x (5 flushes/person/day) x (4 people/family) x (365 days/year)

=41,756 gallons/year saved for a 4 person family

Ultra Low Flow Toilet to High Efficiency Toilet (Minimum Water Saving Scenario)

(1.6 gallons/flush – 1.28 gallons/flush) x (5 flushes/person/day) x (4 people/family) x (365 days/year)

=2,336 gallons/year saved for a 4 person family

Washing machines are another area for significant improvement on an individual basis. Most washing machines use 40-45 gallons of water per wash, whereas High Efficiency Washers (HEWs) use 15-30 gallons of water per wash. The average American family does about 400 loads of laundry per year, which means that a family can save up to 12,000 gallons of water per year by switching from an older washer (45 gallons per wash) to a high efficiency washer (15 gallons per wash). For residents upgrading to a new high efficiency washer from an older less efficient one, there are up to $150 in rebates available.

Old Washer to High Efficiency Washer (Maximum Water Saving Scenario)

(45 gallons/wash – 15 gallons/wash) x (400 washes/year)

=12,000 gallons/year saved

Old Washer to High Efficiency Washer (Minimum Water Saving Scenario)

(40 gallons/wash – 30 gallons/wash) x (400 washes/year)

=4,000 gallons/year saved

Dish washer efficiencies have also been upgraded in recent years with new EnergyStar dishwashers using less than 5.5 gallons of water per wash, as compared to older dishwashers that use 10-15 gallons of water per wash. The average household runs the dishwasher 150 times per year, which can save up to 1,425 gallons of water per year.

Dishwasher (Maximum Water Saving Scenario)

(15 gallons/wash – 5.5 gallons/wash) x (150 washes/year)

=1,425 gallons/year saved

Dishwasher (Minimum Water Saving Scenario)

(10 gallons/wash – 5.5 gallons/wash) x (150 washes/year)

=675 gallons/year saved

The average single family residence uses 359 gallons of water per day in Los Angeles, which means that a household uses approximately 130,000 gallons of water per year. The cumulative water savings for these household appliances are compiled below.

(359 gallons/day) x (365 days/year)

=131,035 gallons/year

Total savings from basic indoor appliance upgrade

Maximum Water Saving Scenario

131,035 gallons/year

-1,000 gallons/year (bathroom faucet aerator)

-1,000 gallons/year (kitchen faucet aerator)

-11,680 gallons/year (showerhead)

-41,756 gallons/year (old toilet to High Efficiency Toilet)

-12,000 gallons/year (High Efficiency Washer)

-1,425 gallons/year (dish washer)

=62,174 gallons/year used

(68,861 gallons/year saved)

52.5% reduction in total water used.

Minimum Water Saving Scenario

131,035 gallons/year

-1,000 gallons/year (bathroom faucet aerator)

-1,000 gallons/year (kitchen faucet aerator)

-5,840 gallons/year (showerhead)

-2,336 gallons/year (Ultra Low Flow Toilet to High Efficiency Toilet)

-4,000 gallons/year (High Efficiency Washer)

-675 gallons/year (dish washer)

=116,184 gallons/year used

(14,851 gallons saved/year)

11.3% reduction in total water used.

The 11-52% reductions shown above are only due to upgrades of basic indoor appliances. There are further reductions to be obtained from things such as pool covers, which can save thousands to tens of thousands of gallons per year depending on the size of the pool and quality of the pool cover. Decreasing the flippant water use outside will help a family save a large percentage of water used due to the simple fact that single family residents use 54% of their water outdoors (most of which is devoted to watering lawns).

One effort that has been underway is the alternating of watering days throughout the week based on street address. Residents with even numbered addresses water their lawns on Tuesdays, Thursdays, and Sundays and the residents with odd numbered addresses water their lawns on Mondays, Wednesdays, and Fridays. Also in the ordinance is the prohibition of watering outside between the hours of 9:00 am and 4:00 pm, when incoming solar radiation is strongest, and would lead to the most evaporation and least efficient use of residents’ water. There are many education outreach programs, often available through LADWP, which will increase the awareness of such ordinances. There are LADWP team members that patrol communities looking for wasteful water practices, as well as LADWP customer service field representatives, that can punish violators. A first time offender is given a verbal warning and water conservation tips and multiple time offenders can have charges added to their utility bill ranging from $100 to $600. Right now it is not feasible for these task force teams to find and cite a reasonable number of violators due to the shear size of Los Angeles and the relatively small size of these task force teams. Until enforcement of such rules is made more effective and efficient, it will take a great deal longer and be more difficult to get people to adhere to new and more stringent water usage policies. If successfully implemented, the plan will save a large amount of water due to the simple fact that less than half of the water normally being used to water lawns is being saved (water 3 out of 7 days a week, as opposed to 7 out of 7 days).

The Water Efficiency Requirements Ordinance was passed in 2009 and has helped lead to the installation of millions of high efficiency plumbing fixtures because the ordinance requires that all renovations and new buildings install all high efficiency plumbing fixtures. In addition to that, all residences have to be fitted with ultra low flow toilets and water saving showerheads prior to resale.Over 1.3 million water efficient toilets installed and rebated, and over 3.5 million indoor water efficient devices installed and rebated by LADWP.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s