Because it is not necessary
Because walmart got tired of the public being jackwagons to the employees trying to enforce it. It ended in fist fights between staff and customers. They staff got aggressive about enforcing it and the public got aggressive back. It was a mess. https://www.google.com/amp/s/www.cnet.com/google-amp/news/walmart-cvs-wont-enforce-mask-rules-to-avoid-conflict-with-customers/
Face mask are not Mandatory in Westmoreland County they are suggested everyone should wear face masks when entering Walmart.
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