The tradition started in 1962, when city pollution-control workers used dyes
to trace illegal sewage discharges and realized that the green dye might provide a unique way to
celebrate the holiday (St. Patrick's Day!!!). That year, they released 100 pounds of green vegetable dye into the
river — enough to keep it green for a week!
Today, in order to minimize environmental damage, only forty pounds of dye are used.

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