Monday, February 27, 2017

How to do a water audit

We live in a desert so we should be especially careful with our water. Over the decades, our use of river and ground water has depleted river flows. So what can you do?

Arizona Water can do a water audit for their customers but their budget is tight for this service so get your name in early in the calendar year. What follows is a simple audit anyone can do.

(Photo courtesy Darcy Hitchcock)

1. Identify all the water-using fixtures and estimate their monthly use.

Below is a list of typical water-using fixtures and the standards for low flow or Energy Star. You'll have to estimate how many times your employees use the bathroom, how many loads of dishes, etc.

  Fixture               Number of units            Est gallons each/month     Total expected. monthly use

Bathroom Sinks 
(1.5 gpm)

Toilets 
(1.6 gpf)

Urinals 
(waterless)

Showers 
(2.0 gpm)

Washing machines 
(residential front-loaders 13 gal per load)

Dishwashers
(see your manual) 

Cooking/processing
(varies) 

Irrigation
(multiply emitters and flow rates)

2. Compare your estimates with actual water and sewer bills.

If you are using a lot more water than you think you should, investigate. You can also compare your usage with industry benchmarks. This manual has a lot of information about benchmarks, etc.

Where is your biggest water use and what can be done about it? Do you really need grass? Could it be replaced by native plants?

3. Do a walk-around, checking flow rates and leaks

Check for leaks. Do you see any dampness under sinks or calcium stains under faucets? Put food coloring in the toilet tank and see if it shows up in the bowl. Walk around outside when the irrigation is on.
Check flow rates. With a stopwatch and bucket you can see if sinks and showers are low-flow fixtures.
Check the meter. When no one is using water in the building, check the water meter two hours apart. If it's moving when it shouldn't you have a leak. You can also use this method to estimate irrigation usage.

4. Take action

Fix leaks: According to EPA's WaterSense website, a leaky faucet dripping once a second will waste 3000 gallons a year. Households are known to waste 10,000 gallons a year. According to the American Water Works Association,
"Every single day, nearly six billion gallons of expensive, treated water is simply lost. Why? Crumbling infrastructure. Leaky, aging pipes and outdated systems are wasting an estimated 14 to 18 percent of our nation’s daily water use." Source.

Behavior change: Of course, you can't tell employees not to use the bathroom! But you'd be surprised what a little education can do. Let employees know you care about water use and publish your bills. Sometimes just posting the water bill in the bathroom stalls will cause change. Ask them to report leaks.

Retrofit fixtures: Some changes are really inexpensive. Your local water utility or electric utility may have rebates for replacing inefficient fixtures. They may also have free aerators that can slow water flow in sinks and showers. Can you use moisture meters for irrigation?

Reuse water: Cottonwood is building a ring of "Purple Pipes" around the city and requires builders to use their reclaimed water in construction. Graywater from showers and rainwater collection systems can replace irrigation.

Minimize irrigation:   Plant only drought resistance, low water-use tress or pants in your landscaping. Surround the plants in your landscape with a bed of  mulch or other organic material or gravel, the bed will slow evaporation and discourage weed growth. Water  during the coolest part of  the day. If possible set your automatic sprinkler and bubbler system to operate during the night, reducing the loss of water due to evaporation.     
 

Resources:

WaterSense: https://www3.epa.gov/watersense/commercial/bmps.html
Water Efficiency and Self-Conducted Water Audits at Commercial & Institutional Facilities: https://www.sfwmd.gov/sites/default/files/documents/water_efficiency_improvement_self_assess_guide.pdf





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