Dirt

Dirt could symbolize immorality in the poem. It is not entirely clear if the speaker's critique of the station and workers' physical condition extends to morality, but it is possible. In the first stanza, the speaker characterizes the dirtiness as "a disturbing, over-all / black translucency" (4-5). The word "disturbing" in particular gestures toward immorality.

Domesticity

Domesticity symbolizes care in the poem. The speaker notices details such as an embroidered doily, a plant, and organized oil cans on the porch behind the pumps. These serve as evidence that "Somebody loves us all" (41).