The National Park Service has increased monitoring at Arizona Hot Springs in the Lake Mead National Recreation Area due to elevated levels of fecal coliform bacteria, E. coli, and enterococci bacteria, indicating the presence of human waste. The bacteria buildup is attributed to sandbags restricting the flow of water, which deepens the water for swimming but creates a stagnant environment that fosters bacterial growth. While the trails leading to the hot springs are typically closed during hot summer months, restrictions may be implemented if bacteria levels continue to rise.