A cross-connect is any connection between facilities provided as separate units by the datacenter. In other words, if you rent a cage, you can run cables betweeen your various racks and they are not really considered cross connects. But typically a user facility is a rack. Consider the uplink to a network provider. The line that runs from you to the telco's rack is a cross-connect. Any other between-rack cable run falls in this category. Even if the datacenter is bundling network access, it's still a cross-connect. (It's also typical to have a meet-me room that is the center of all the cross-connects, it's a patch-panel room or cage.)
Water recycling is the process of taking effluent (wastewater and sewage) and treating it so that it can be reused. For potable (drinkable) use, the recycled water has to be treated to a sufficiently high level that it's suitable for human consumption.
The most common source of lead in drinking water is the corrosion, or wearing away, of household plumbing fixtures and water system components that contain trace amounts of lead.