"Wonderful, wonderful. No side effects, no consequences... Everything is fine, no rash," the minister said on the France Inter radio station in response to a question about her well-being.
Oudea-Castera added that the results of water quality controls are "100% encouraging".
The minister's swim took place in the center of Paris on July 13, near the venue of the Olympic competitions.
Since 1923, the Seine river has been closed for swimming due to the high content of pathogenic bacteria. The Paris authorities have said that the cost of water purification measures amounted to about 1.4 billion euros ($1.5 billion), and that water samples taken in the river in June showed that it is possible to swim in the Seine.