Millions of gallons of raw sewage stemming from a sewer break in Westchester is threatening the upcoming Ironman U.S. Championship set to take place on Saturday.

NBC reports the sewage break, which occurred in Tarrytown on Thurday, prompted officials to approve a "controlled discharge" in order to begin repairs in the sewer line and chlorinate the sewage.

An Ironman spokeswoman said in a statement organizers were "diligently monitoring the situation" and they "will be sure of the water quality and that the venue is safe before we allow our athletes to swim on Saturday."

Officials are warning swimmers and kayakers to avoid direct contact with the sewage. Although the advisory may be lifted by tomorrow's 7AM start time, environmentalists are still working to perform tests to see if swimmers will be able to compete in the championship.

However, organizers say Friday and Saturday's forecast of heavy rains brings even more challenges to ensuring the competition can go forth as scheduled.

The Ironman US Championship involves a 140.6-mile race taking place in parts of New York City and New Jersey and combines a swim, bike ride, and a run.