With respect to the situation of water in Jerusalem there is a point that you've clearly missed. The Jews were very big on ritual purity, hence mass 'bathings' in the city's drinking water simply wasn't on. Ergo, I really must disagree with your assessment about the Pool of Siloam. As for Hezekiah's Tunnel, the water there is about four inches deep, the entire thing wends its way underground, and isn't wide enough for two people side-by-side! Eric and I briefly discussed the Pentecost baptisms, and how they were performed, only a month or so ago. We noted that there were ample mikva'oth in Jerusalem to accommodate the pilgrims attending the Temple; however, these were segregated by gender and were large enough only to accommodate a single person at any given time. Consequently, they were impractical for Christian baptism (if one is thinking strictly along immersionist lines), because: (a) they didn't allow for public spectacle of the baptism itself, given that a public witness is necessary. (b) The baptiser wouldn't fit alongside the person being baptised in the mikveh, Jewish washings being a strictly individual affair. And, (c) the thousands of Jews there to celebrate the Passover would've been quite miffed that Peter and his crowd were hogging all the available mikveh! 

And what of simple practicalities? If we assume that the 12 apostles performed the baptisms, and that 3,000 people were baptised as Acts records, then each apostle baptised 250 people. Over a six hour period this equates to 41 baptisms per apostle, per hour. That's a sustained rate of one baptism every one and a half minutes for six solid hours! Who was answering the crowd's questions during this time? Who was responding to the vocal objections of the naysayers during this time? Who was praying for the crowd during this time? The Revivalist position just doesn't fit, so mandating that what took place must have been immersionist baptism seems quite the stretch to me ;)

When every c-o-n-t-e-x-t-u-a-l factor is considered (i.e. location, time available, water available, number of people baptising, number of people performing the baptisms, etc) the most probable course is that the 3,000 odd baptisms took place on the Temple Mount itself, and involved pouring rather than immersing.

To close, you might like to reflect on the fact that the early Christian Church linked Ezekiel 36:25 to the work of regeneration performed by God's Spirit; consequently, they viewed baptism as being the cleansing from impurity mentioned in that passage. In point of fact, this particular passage was appropriated by the early Church for the Pentecost event! And what did the prophet write about the renewing of Israel? "I will sprinkle clean water on you, and you will be clean; your filth will be washed away, and you will no longer worship idols." (NLT). What does that sound like to you, eh? ;)

Blessings,

Good morning, Ralph.

You will note that I specifically said, 'mass bathings' and not individual one-offs. There is a significant difference in what would apply to one person using the pool than 3,000 people en masse. Incidentally, the Talmud (Mishna s. Tohorot, t. Mikva'oth) speaks to the issue of individuals using public water sources for Jewish lustrations. What Jesus commanded of the blind man complies with accepted traditional practice; however, a Pentecost-like event certainly wouldn't  ;)

Blessings,