Chulin 2:9-10

Chulin 2:9

One may not slaughter into the sea, a river or utensils but one may slaughter into a puddle of water; when on a ship, one may slaughter onto the backs of utensils (from where the blood will flow into the sea). One may never slaughter into a hole but one may make a hole in his house for the blood to flow into. One may not do this in the street because that copies the practice of heretics (thereby strengthening their position).

Chulin 2:10

If one slaughters an unconsecrated animal (i.e., for food) in the name of a burnt offering, a peace offering, a conditional guilt offering, the Passover offering or a thanksgiving offering, the slaughter is invalid, though Rabbi Shimon declares it valid. If two people hold a knife and slaughter the animal together, one in the name of one of these offerings and the other for legitimate reasons, the slaughter is invalid. If a person slaughters an unconsecrated animal in the name of a sin offering, a definite guilt offering, a firstborn animal, animal tithe, or as a substitute for a lost sacrificial animal, the slaughter is valid. The general principle is that whatever can be brought as a freewill offering is prohibited if an unconsecrated animal is slaughtered in that name but whatever cannot be brought as a freewill offering is permitted if an unconsecrated animal is slaughtered in that name.