Are the cast iron pipes in San Angelo safe?

rusted pipes

by: Dusty Ellis

Posted: Feb 23, 2023 / 03:08 PM CST

Updated: Feb 23, 2023 / 03:10 PM CST

SAN ANGELO, Texas (CVHP) — Aging water systems in small towns across Texas can threaten water supply and quality, but are cast iron pipes really dangerous?

There are currently 81 miles of cast iron pipes used in water mains with more cast iron pipes used in private properties across San Angelo.

According to the U.S Environmental Protection Agency, most distribution piping installed in the United States, beginning in the late 1800s until the late 1960s, was manufactured from cast iron.

“Cast Iron probably in the sixties and seventies was one of the primary uses and a lot of it had to do with the strength of the material- It was a newer material at that point,” Water Utilities Assistant Director, Andy Vecellio said, “However it did show characteristics of, especially in sewer cases, of corrosion or rusting out which could cause problems.”

Cast iron pipes were the gold standard because of their longevity, however, over time cast iron pipes that transport water become susceptible to corrosion. The most common type of corrosion in cast iron is graphitic corrosion – (a form of selective leaching where the iron matrix corrodes, leaving behind porous graphite mass.) according to the EPA.

Graphitic corrosion generally is a slow process. It can cause significant problems since no easily apparent changes occur which are visible, yet the cast iron loses its strength and becomes brittle.

In locations where cast iron pipes had to be replaced across San Angelo, there are several methods, such as a full replacement, adding a liner and pipe bursting.

Most cities in Texas have opted to stop utilizing cast iron in new installations of pipes, according to Vecellio.

According to Whitt Inspections, cast iron isn’t inherently dangerous, stating the issues lay within the connections/joints of the pipes. Many of the municipal pipelines and commercial buildings across the US still have cast iron pipes with no problems. Along with cast irons’ longevity, another advantage is that it can withstand enormous amounts of pressure, unlike some other materials used for pipelines today.