Can you fulfill Netilat Yadayim by dipping your hands in a sink?

Question

According to the Gemara in Hullin on 107a, if there's a vessel with a hole in it, and there's a "stream" (more than a drip but not necessarily the "sheffoferet hannod" required for a real mikveh) connecting the water in the vessel to a kosher mikveh (i.e. a lake), you can dip your hands in the vessel and fulfill Tevilat Yadayim. My question is: can this work with a sink? It can be a great option when you're stuck without a cup available! you can stop the sink, fill it with water, leave the tap running and then dip your hands in it. There are two points I need to clarify for this to work:

A) Assuming the water comes from a reservoir, is a reservoir a kosher mikveh?

B) Is there a constant connection of water from the reservoir to the (cold water) tap, or is it broken at some point along the way?

Also, are there any other potential problems with this solution?

Answer 1

Firstly, there is no reason to leave the tap running. The laws of dipping one's hand in a vessel do not seem to depend on the water's connection to its source.

In halacha they seem to discuss buckets of water. Then it depends:

The Shulchan Aruch - Orach Chaim in סימן ד - דיני נטילת ידים says it's OK to dip your hands in a vessel of water for Shma and prayers, but he's not sure if it works for morning Neggel-Vasser - even if you dip them into 3 separate vessels.

יב: אִם שִׁכְשֵׁךְ יָדָיו לְתוֹךְ כְּלִי שֶׁל מַיִם, עָלְתָה לוֹ נְטִילָה לִקְרִיאַת שְׁמַע וְלִתְפִלָּה, אֲבָל לֹא לְרוּחַ רָעָה שֶׁעֲלֵיהֶם. אִם שִׁכְשֵׁךְ יָדָיו בְּשָׁלֹשׁ מֵימוֹת (יב) מְחֻלָּפִים, יֵשׁ לְהִסְתַּפֵּק אִם עָלְתָה לוֹ לְהַעֲבִיר רוּחַ רָעָה שֶׁעֲלֵיהֶם.‏

Regarding washing before eating bread, it says ibid סימן קנט - באיזה כלי נוטלין הידים, וכיצד יבואו המים לידיו that if the vessel is connected to the ground (like a built in sink, I assume) then you cannot wash for bread by dipping your hands into it.

If it's not built-in (like a bucket) then it's a dispute and he says one can rely on the lenient opinion, however, one should wash again properly if the chance arises.

ח: אִם הִכְנִיס יָדָיו בְּתוֹךְ כְּלִי שֶׁל מַיִם וְשִׁכְשֵׁךְ יָדָיו בָּהֶם, אִם הַכְּלִי מְחֻבָּר לַקַּרְקַע, לֹא עָלְתָה לוֹ נְטִילָה; וְאִם אֵינוֹ מְחֻבָּר לַקַּרְקַע, יֵשׁ אוֹמְרִים שֶׁעָלְתָה לוֹ נְטִילָה, וְיֵשׁ אוֹמְרִים שֶׁלֹּא עָלְתָה לוֹ, וּבִשְׁעַת הַדַּחַק יָכוֹל לִסְמֹךְ עַל דִּבְרֵי הַמַּתִּירִים; וְאִם אַחַר כָּךְ נִזְדַּמֵּן לוֹ לִטֹּל בְּדֶרֶךְ נְטִילָה, נוֹטֵל בְּלֹא בְּרָכָה.‏

Answer 2

^{I'm not sure what the OP is trying to gain, as I already answered the Tevilat Yadayim aspect, in my other answer.}
To answer his specific queries:

A) Assuming the water comes from a reservoir, is a reservoir a kosher mikveh?

There are basically ways to make a mikveh:

Either a pool of rain-water that is not flowing, or pool of Natural-Stream water that is still flowing and connected to its source.

I don't see how a reservoir meets either; it's mainly river water collected through pipes - and for pipes see below.

But even if it's rain water, it arrived via pipes, and it's flowing (to your tap).

B) Is there a constant connection of water from the reservoir to the (cold water) tap, or is it broken at some point along the way?

It's probably connected, otherwise you wouldn't get good pressure. However, if there's anything like a water pressure booster in the system, it probably breaks the halachic connection.

Also, are there any other potential problems with this solution?

Yes. Here are some possibilities:

1. Pipes

Pipes are possibly vessels, and that would make your Mikveh-extension passul.

See Yoreh De'ah סימן רא - דיני המקוה ומימיו.

לו: צִנּוֹר שֶׁאֵין לוֹ ד' שָׂפוֹת אֵינוֹ חָשׁוּב כְּלִי וְרָאוּי לְהָבִיא עַל יָדוֹ מַיִם לְמִקְוֶה; וְאִם חָקַק בּוֹ גּוּמָא אַחַת קְטַנָּה קֹדֶם שֶׁקְּבָעוֹ, אִם הוּא שֶׁל עֵץ אֲפִלּוּ אֵין הַגּוּמָא מַחֲזֶקֶת, אֶלָּא כָּל שֶׁהוּא נַעֲשֶׂה כֻּלָּהּ עַל יָדָהּ כְּלִי וְכָל הַמַּיִם שֶׁעוֹבְרִין עָלָיו חֲשׁוּבִין שְׁאוּבִים; וְאִם הוּא שֶׁל חֶרֶס, אֵין הַחֲקִיקָה פּוֹסַלְתּוֹ אֶלָּא אִם כֵּן הִיא מַחֲזֶקֶת רְבִיעִית, וְאִם נָפְלוּ צְרוֹרוֹת אוֹ עָפָר בַּגּוּמָא, אֵינוֹ חָשׁוּב סְתִימָה לְבַטְּלוֹ מִתּוֹרַת קַבָּלָה, אֶלָּא אִם כֵּן יִהְיוּ מְהֻדָּקִים לְתוֹכָהּ. סִלּוֹן שֶׁהוּא צַר מִכָּאן וּמִכָּאן וְרָחָב בָּאֶמְצַע, אֵינוֹ חָשׁוּב קַבָּלָה לִפְסֹל בּוֹ הַמִּקְוֶה.‏

• The pipe cannot be closed on all 4 sides - a classic pipe has 2 openings.
• A U-shaped bend in the plumbing may create a 4 walled pipe and invalidate your connection.
• If the pipe has a curvature in it to collect water, it invalidates your connection.
  • The water meter usually has such a curvature.
  • Many (all?) water filters would have such a curvature
  • A water pressure booster would be even worse - and could cause a complete disconnect.
• A pipe that goes wider and then narrow again is OK.

2. Your sink is not a keli

Your sink - with the drainage hole in the bottom - is probably not a Keli - even with the plug in place.

See, for example, Yoreh De'ah ibid, that once there's a hole in the bottom of a vessel, it's not a vessel, even if it causes a leniency.:

מ: כְּלִי שֶׁנִּקַּב בְּשׁוּלָיו, אֲפִלּוּ כָּל שֶׁהוּא, אֵינוֹ חָשׁוּב כְּלִי לִפְסֹל הַמִּקְוֶה.

See the rest of the long section מ that if it's got a hole - even if it's plugged up (unless it's a permanent plug) - that it's not a vessel.

וְאִם עֵרַב סִיד וּצְרוֹרוֹת וְסָתַם בָּהֶם הַנֶּקֶב, לָא חֲשִיב סְתִימָה לְהַחֲזִירוֹ לְתוֹרַת כְּלִי. אוֹ אִם הוֹשִׁיבוֹ עַל גַּבֵּי הָאָרֶץ, וַאֲפִלּוּ עַל גַּבֵּי סִיד וְגִפְסִיס, לָא חֲשִיב סְתִימָה

3. Water falling vertically

Your connection to the Mikveh (reservoir) is with running water - and we have the rule that קטפרס אינו חיבור - water falling vertically isn't considered connected.

Look in Orach Chaim סימן קנט - באיזה כלי נוטלין הידים, וכיצד יבואו המים לידיו at the end of ז that it's a dispute as to whether we consider a vertical drip of water a connection for washing hands.

דְּנִצּוֹק זֶה מְחַבֵּר הַכְּלִי לַיְּאוֹר וַחֲשִׁיבֵי מַיִם שֶׁבַּצִּנּוֹר מְחֻבָּרִים לְמֵימֵי הַיְאוֹר, אַף עַל גַּב דְּנִצּוֹק כָּזֶה לֹא חָשִׁיב חִבּוּר לְעִנְיַן טְבִילָה. וְיֵשׁ חוֹלְקִין בָּזֶה וְאוֹמְרִים דְּגַם לִנְטִילַת יָדַיִם לֹא חָשִׁיב חִבּוּר

According to the second opinion, your sink is not connected to the reservoir.