Anchor: So they'll be gone by this winter--just as soon as the Christmas shopping season is over.
Entailed: When the Christmas shopping season ends, they'll no longer be around. 
Contradiction: So this winter they'll be gone, just before Christmas season ends.
Contradiction: They will come in greater numbers after the Christmas season.
Contradiction: They'll stay long after the Christmas shopping season ends. 
Contradiction: Operators of facilities can have whatever level of mercury they'd like.
Contradiction: pet is playing in winter