11.   Close and drain the parts of the plumbing system that are vulnerable to the cold like pipes supplying water to outside faucets.

12.   Corroding copper and lead from pipes in plumbing systems in individual buildings can leach into tap water.

13.   Computer networks link computers together kind of like a plumbing system.

14.   For one thing, developers are balking at putting in a second plumbing system to handle gray water.

15.   Masters tried the friendly approach, but the company refused to install a plumbing system to control the toxic substances.

16.   Networking companies, whose mecca is the Bay Area, are the plumbing systems that link computers together.

17.   Norwalk, Connecticut-based Emcor constructs and services mechanical and electrical systems such as power, lighting and plumbing systems.

18.   Nobody foresaw the impact of the vast manmade plumbing system.

19.   Older plumbing systems may still have lead soldering.

20.   Other irritating household noises can be traced to the plumbing system.