Private home water service connected to sewer line!

Whenever I get a customer who complains that backflow prevention isn’t needed, I like to pull out stories like this one.

Some of us on the inside of the backflow industry (those of us who don’t have a life and think this kind of stuff is cool) knew much of the details of the incident as they were unfolding a couple of years ago. We were just not able to talk about it.

Now that the trial is over, here’s what we know…kinda.

Several years ago a Commerce City family had a contractor install a water softener on the main water service to their home. Soon after the install the family noticed taste and odor issues with the drinking water. One of the family members was diagnosed with Chrone’s disease less than a month later. After several years of investigation and a jury trial, the contractor was found responsible.

The following are excerpts of recent news releases from Channel 4 and 7 News in Denver, Colorado:

Channel 4 reported on October 26, 2012 that a jury had awarded a Commerce City family “nearly $1 million in damages after drinking water contaminated with raw sewage”. Channel 7 had reported two days earlier that a jury awarded the family $465,000.00 and $462,000.00 for “negligent infliction of emotional distress and extreme and outrageous conduct”.

So…what happened?

In one sentence, the installer directly connected the water softener drain line to the sewer.

Those of us in the backflow industry would immediately identify this as a cross connection that MUST be protected by an air gap (an adequate physical separation between the water softener and the sewer). This isn’t just a good idea; this physical separation is required by both the International Plumbing Code and the Uniform Plumbing Code.

Those of you who have not been trained in cross connection control might wonder how the drinking water became contaminated. There are actually three ways the sewage can get back into the drinking water lines:

1) A siphon may be created by a city water pipe break or high water usage. The sub-atmospheric pressure within the city pipes would cause the sewage to be sucked into the water softener.

2) Capillary action causes water to move against gravity due to the combination of surface tension of water and adhesive forces between the liquid and container that act to lift the water (Thank you Wikipedia for a simple explanation). If the water has come in contact with sewage then microbiological contaminates can move with the water back into the water softeners.

3) One of the things that cause backflow through backpressure is elevation. If the level of sewage is above the softener then backpressure could fill the drain line of the softener. Sewage backup flooding a basement is not unusual. Another cause of backpressure would be if the water softener’s drain line was attached to the sewer line that ran along the ceiling of the basement above the softener. It is common for the sewer pipes to be above the basement floor in older houses. Now we have a situation where sewage can move from the sewer line to the softener constantly.

How the sewage actually came in contact with the softener’s resin tank is open to question. Court transcripts may be the only way to find out. We do know that a simple air gap would have prevented the whole problem.

This article can be found on Fred Spengler’s new blog at: www.backflowconsulting.com. Come join in the conversation and give us your ideas and comments on this story and others.