What occurs when the water truck arrives that indicates Stanley's status in the group of boys is improving?

When the water truck arrives at Camp Green Lake, Stanley's status among the boys improves as he is chosen to fill the water containers instead of being sent to dig. This indicates that the other boys are beginning to see him as more valuable and capable, shifting his position from being an outsider to someone who is trusted and included in group activities. Additionally, his willingness to help and take on responsibilities further enhances his standing within the group.