Water Distribution System

The “As Built Water” drawing for Coffee Creek Condos shows 660 feet of 4-inch diameter cast iron (CI) pipe, 460 feet of 6-inch CI pipe and I estimate another 230 feet of 6-inch CI Pipe (length NOT stated on the drawing) for a total of about 1,350 feet of CI pipe.  HOWEVER, cast iron pipe was NOT installed but rather Asbestos-Cement (AC) piping was installed. The Chrysotile Institute estimates AC pipe lifespan at 70 years, but actual service life depends largely on pipe condition and working environment. This website
https://www.waterworld.com/technologies/pipes/article/16190948/the-asbestos-beneath-our-streets states that AC piping has a “typical design life of 50 years.” The AC piping at Coffee Creek was installed in 1977 (approximate date).

 Below is a drawing  showing the as-build water distribution system that has been marked to include the condo unit numbers and the location of the “known” branch shutoff valves.

Problem with the Branch Lines

For purpose of identification, the 1,350 feet of 4-inch and 6-inch diameter Asbestos Cement pipe is referred as the main lines. The branch lines are the 1-inch diameter polyethylene pipes coming from the main line to the condos. While there are 56 condos plus the swimming pool and Coffee House (58 total) served from the headers, some of these branch lines serve two condos. I estimate 50 connections to the headers. There have been at least 12 failures (split pipe–water leaks) of the branch lines which had to be dug up and the section replaced.  Below is a picture of cross section of the 1” pipe that failed and was replaced:

The reason for failure of the 1-inch branch pipe is that the material excavated from the trench while installing the pipe was used as backfill.  The trench should have been filled with material less than 1/2-inch in diameter in accordance with ASTM D2774 (see pages 32-33 in Polyethylene Piping Systems Field Manual).  Improper fill and compacting causes the pipe to be squeezed by the downward pressure to the point that the pipe splits resulting in a water leak.

The water leaks at Coffee Creek have never occurred in the Asbestos Cement pipe but in the branch lines off the AC pipe.  On August 23, 2018, a water leak occurred next to the 4-inch CI pipe in front of Unit # 42.  Here is a picture:

What Action is Needed?

So what should Coffee Creek do? It is the opinion of the writer (Paul Schmeil, unit #37) that we should (1) replace the galvanized 1″ male insert adapter with a brass adapter, and (2) install a shutoff valve in each branch line before the 1″ plastic branch line.