Sump pumps are self-activating electrical pumps that protect homes from moisture intrusion. They are usually installed below the basement or crawlspace floors to remove rising groundwater and surface runoff before it has a chance to seep into the home. Accumulated water can cause interior damage and encourage the growth of mold, mildew, and fungus. Pumps should be maintained and equipped with all the necessary components in order to ensure their reliability. Some models are equipped with a battery backup to prevent flooding during a power outage.