Tosefta sobre Terumot 8:3

[With respect to] a spring, as long as it flows, the prohibition of exposed liquids does not apply, said Rabbi Yishmael son of Rabbi Yochanan ben Berokah. It so happened that Rabbi Yochanan ben Berokah went down to visit Rabbi Yochanan ben Nuri in Beit She'arim, and he came across a pool that did not have three logs [of water in it], and he kneeled down and drank from it. (See Y. Ter. VIII.3.29).) [However, exposed] wine, whether in vessels and whether in the earth, is forbidden.

A[n unsealed] flask that is placed in a litter or a chest [and then forgotten], behold, it is forbidden (see Y. Ter. VIII.3.21). [If] he checked them (i.e., the litter or the chest) and then placed it there, behold, it is permitted. [With respect to] a flask in its case, behold, it is forbidden. [If] he checked and then placed it there, behold, it is permitted. If he put it in a pit, even if it is one hundred amot deep, behold, it is forbidden. [If] he put it on top of a tower, even if it is one hundred amot high, behold, it is forbidden. [If he places it in] his drawing room (טרקלין), even if it is lime-plastered and decorated (i.e., like a palace, where one would not expect to find a snake), behold, it is forbidden. [If] they were covered but not corked, or if the cork is split (per MS Erfurt, adding "חוצץ"), behold, it is permitted. How big must the hole be [to render the flask susceptible to poison]? Big enough to stick a child's little finger inside. [With respect to] puncture marks in cooked foods or cabbage stalks, and anything that is moist, it is forbidden (see Ter. 8:6). Rabbi Shimon ben Manasya says, he can throw out [the portion containing] the puncture marks and eat the rest. Mushrooms are forbidden due to the danger to life. A puncture mark in a fig that was made into a dried fig, [or] on a date that was made into a dried [date], both of them are permitted. [If] he saw a bird that made a hole [with its beak] in a fig, [or] a mouse that bit a hole in a watermelon, they are both forbidden, for I say, lest there were puncture marks [beforehand]. [If] a watermelon had puncture marks and ten people ate from it -- the remainder, behold, [remains] forbidden. And likewise with a barrel [of wine] that was exposed and ten people drank from it -- the remainder, behold, [remains] forbidden.