Breast-milk pumping results in job loss?: ACLU takes action on behalf of Heather Burgbacher

Did a Jefferson County charter school decide not to renew the contract of veteran teacher Heather Burgbacher because she pumped breast milk at work?

That's the contention of the ACLU of Colorado, which has taken legal action on Burgbacher's behalf that could lead to a lawsuit against Jeffco on both state and federal grounds.