Failure to clean up orphan Sites may endanger public health and the environment (including groundwater and municipal drinking water sources). Contamination will continue to spread, affecting water, soil, people, and adjacent properties. Costs will increase with time, because the more contamination spreads, the more expensive it becomes to clean up. Conversely, a viable Orphan and Enforcement program encourages careful handling of hazardous substances, and removes any competitive advantage for businesses engaged in sloppy waste-management practices. Finally, contaminated property is economically unproductive land. Contamination that remains will continue to devalue building, land, and water assets on the affected and neighboring properties.