Question: We are in the process of designing a new synagogue, and the question of automatic flushers and faucets for the bathrooms has been raised. For conservation reasons, we’d like to use the automatic devices. One of the biggest is that they ensure that kids don’t leave the water running in the sinks! However, all the ones we’ve come across use an integrated battery-powered motion sensor, which would be forbidden on Shabbat and Yom Tov. Does anyone know of a company that manufacturers a ‘shabbastic’ automatic flusher / faucet? Or are we stuck with traditional fixtures?
Jeffrey Doshna
 
Answer:
The most overlooked aspect of building design is often water conservation technologies and strategies. This aspect, however, is rapidly gaining increased attention in a world where existing water resources are shrinking, per capita water consumption is increasingly annually, and new water supply options are either unavailable are too costly. Installing meters in buildings should be considered part of an overall water conservation accountability strategy. For example, a drip from the faucet or an invisible leak in the toilet can add up to 15 gallons of water a day, 105 gallons a week and up to 5,475 gallons of water wasted a year.
 
When designing a building plan, remember that the bathroom is generally the prime location for water waste. Over the past few years many water saving alternatives for faucets, toilets, and urinals have come onto the market. Some require special units and others can be installed or adapted to existing units.
 
Federal legislation passed in 1992 requires all U.S. plumbing, regardless of manufactured location, to meet or improve upon the water efficiency standard of 2.5 gallons per minute. Currently, lower volume faucets using only 1.5 gallons per minute are also available. Other available shut-off technologies include:

1. Metered valve faucets deliver a pre-set amount of water and then shut-off automatically (current US standards are 0.25 gallons of water per cycle)

2. Spring loaded self-closing faucets shut off automatically a few seconds after being activated.

3. Ultrasonic and infrared sensor faucets automatically activate when hands are detected and shuts off when the hands are removed.
 
Toilet and urinal flushing can account for almost 1/3 of a building’s water use. Fortunately, similar water saving devices exist for both. The standard toilet uses between 3.5 to 7 gallons of water and can be replaced with a low volume model using only 1.6 gallons .[1] Urinals can use up to 5 gallons per flush and can be replaced with models using only 1 gallon of water. Other options include:

1. Fitting urinals with an automatic flush valve programmed to flush after more than one use.

2. Ultrasonic and infrared sensors detect human presence and flush after they leave.

3. Waterless urinals are gaining acceptance as a viable alternative and depending on the model, they are designed for low or high volume. They are designed with a urine-repellant surface, do not use a sensor, require almost no water but a replaceable cartridge and an out pipe that require periodic replacement.
 
Of the above mentioned water saving options for sinks and urinals, the only ones that pose a difficulty on Shabbat and Yom Tov are those that use the ultrasonic and infrared beams to detect a person’s presence. Rabbi Halperin, head of the Institute for Halacha and Science in Jerusalem, Israel wrote a responsa to this difficulty. He outlines halachically permissible ways to use sensor operated facilities, but states that it is desirous not to use these technologies unless required.
 
In his responsa, Rabbi Halperin explains that, in order to use this technology, faucet sensors could be attached to two timers: one turns on the water at specific intervals and the other to regulate the electric pulses that keep the water from turning on. When a person puts his hands in the sink, it interferes with the electric pulses that close the water and allows the water to flow. When the hands are removed, the pulses are restored and the water stops. If the timers are set-up to delay the pulses from starting immediately after the person leaves, but resume shortly thereafter, this activation becomes a gramah.
 
Similarly, Rabbi Halperin says that timers could be installed in sensor activated toilets and urinals. The timer should activate on a cycle, at the end of which the facility flushes. The presence of constant electrical pulses interferes with the cycle and prevents flushing. When a person approaches, it interferes with the pulses and allows the cycle to complete, so that it flushes. The cycle should be programmed to the estimated amount of time it would take a person to finish. It is possible that the cycle may end before the person finishes, as it is a programmed cycle. Used in this manner, there is no halachic prohibition as the person is not actually carrying out any action, rather his presence blocks the electric pulses that cause the action.
 
While Rabbi Halperin states that sensor activated facilities such as faucets, toilets, and urinals may be used on Shabbat and Yom Tov in the manner described above, he does not believe that this option is halachically desirable. Therefore, while these options present a water savings solution, they would not be appropriate for a synagogue, as it may be problematic to install them if they will predominantly be used on Shabbat and Yom Tov.Therefore, it is preferable to use one of the other options, such as valve shut off faucets, which present a more viable water saving option and no halachic issues.
 
Alternatively, if your synagogue has catering or other facilities that are not used on Shabbos, we encourage the installation of more water efficient technology there, as long as it can be locked for Shabbos.
 

Notes:

[1]    http://www.cabq.gov/waterconservation/indoor.html
 
Originally posted in “On Eagles’ Wings” August 3rd 2005