Using Water Wisely . . .
. . . even in an emergency!
- By Casey Hayes
- Oct 01, 2005
ONE doesn't normally think about water conservation during an emergency. A fire, for example, needs to be contained and extinguished as quickly as possible. And that usually means using copious amounts of water. However, efficient use of water--in certain circumstances--not only conserves the resource, but also aids in a better outcome, with less collateral damage.
One such circumstance is the use of an emergency drench shower or eyewash. Certain aspects of shower or eyewash design and operation allow for optimal use of the water that flows through the equipment, resulting in using less water overall, a better outcome for the accident victim, and easier cleanup after the crisis is over.
Emergency equipment designs that center on the comfort of the victim during drench shower and/or eyewash use will usually--and not coincidentally--limit and soften the strength of the output flows from shower heads and eyewash sprayers. Ideally, these designs also will deliver water that is immediately useable, in terms of temperature. Overall water savings are therefore driven by both gross water volume reductions and more efficient use of the water that is used.
Specific features that result in more efficient use of water in emergency equipment include:
* Flow controls. An often-neglected aspect of emergency equipment design, flow controls provide stability and upper pressure limits to output sprays from shower heads and eyewash sprayers. Output flows without limitations can be stronger and more aggressive--to the extent that they can make accident victims uncomfortable, often resulting in curtailing shower or eyewash use prior to the required, 15-minute drench or irrigation cycle.
The 15-minute use cycle is required by ANSI Z358.1, the American National Standard for Emergency Eyewash and Shower Equipment, to ensure removal of hazardous materials and to aid the start of the healing process. Flow controls limit the total amount of water used during a use cycle, which is also an important consideration in instances where shower or eyewash wastewater must be contained for proper decontamination and/or disposal.
* Diffused spray heads. Emergency equipment that offers diffused spray pattern shower or eyewash spray heads logically will use water more efficiently by spreading less water over a wider area. While ANSI Z358.1 requirements mandate prescribed minimum pattern widths, certain head designs can accommodate the requirements more efficiently than others. Those efficient head designs will also, once again, use less water to accomplish the same required result.
* Tempering and recirculation. ANSI Z358.1 requires that output water used during the entire 15-minute emergency shower or eyewash use cycle be within the range of no less than 60 degrees F on the low end to below 100 degrees F as an upper limit. This is to support the full, 15-minute use cycle without endangering the victim from the effects of either hypothermia or scalding.
Once again, this requirement also drives a more efficient use of the water that flows through emergency equipment because the flow is immediately useable, as opposed to having to "let it run" before it reaches a comfortable, non-dangerous temperature.
* Emergency equipment freeze protection. If emergency equipment is used in an environment that is subject to freezing, it can lead to disastrous consequences without proper protection. To avoid frozen, broken pipe situations, freeze-protected emergency equipment is often equipped with heat-traced tape and freeze-proof housings. Additionally, freeze plugs can be installed in installations that are not ordinarily subject to freezing to guard against snap-freeze situations. These cost-effective safeguards drip a small amount of water during infrequent freeze periods to avoid a catastrophic equipment failure and resulting water loss.
* Factory pre-assembly and pre-testing. Emergency equipment system installations can be rather complex. They are therefore subject to significant opportunities to leak, obviously wasting water and limiting their effectiveness. Emergency showers and eyewashes that are substantially assembled in the factory and then pressure tested prior to shipment are less likely to leak. Specifiers should seek products that require less on-site assembly and are thoroughly tested by the manufacturer. Likewise, the ANSI-required weekly and annual inspection and testing protocols will enhance the likelihood of both proper operation when needed and short-term correction of leaking situations that might have developed over time.
* Emergency equipment for remote locations. What do you do when the job site has no potable water to use in emergency equipment? The obvious answer is to bring it with you! A wide variety of portable products are available, ranging from self-contained, gravity-fed designs to air charged, tempered water systems. Emergency equipment used in remote locations can be concurrently effective and efficient. It's important to realize that ANSI Z358.1 does not relax its requirement for 15-minute use cycles for portable emergency products.
To minimize the risk of non-compliance, specifiers should target portable response products that meet the standard. It is possible to provide remote area workers with a portable eyewash, for example, that uses only nine gallons of water to provide a full 15-minute irrigation cycle. The key is to understand the specifics of the ANSI requirement, your unique situations, and the full range of products that are available for your consideration.
An Odd Topic? Hardly
At first thought, it might seem odd to consider the water efficiency of emergency showers and eyewashes. After all, they may be used infrequently. This information sheds new light on the topic. Likewise, it's interesting to consider the fact that the same design configurations and features that make certain products more victim-friendly, in the interest of assuring a full 15-minute use cycle, also make those products more water efficient.
To paraphrase an old expression, I guess you can have your water and effectively use it, too!
This article appeared in the October 2005 issue of Occupational Health & Safety.
This article originally appeared in the October 2005 issue of Occupational Health & Safety.