1.   No one knows how many chronic, undetected leaks exist on hazardous liquid pipelines.

2.   The federal Office of Pipeline Safety removed several sites, including maps that it said illustrated places where hazardous liquid pipelines flowed through unusually sensitive environmental areas.

3.   The first in a series of tough new rules to protect Texans from natural gas and hazardous liquid pipeline disasters were adopted Tuesday by state officials.

4.   The problem, they say, is that hazardous liquid pipelines have the thinnest wall requirements of any major piping code.

5.   Yet they are concerned that leaks on hazardous liquid pipelines occur five times more often on a per-mile basis than those on natural gas transmission lines.

6.   The Transportation Department proposed Friday requiring most oil and hazardous liquid pipeline operators to test their lines every five years to make sure they are safe.