30 Apr. 19

Cross Connection

This photo below shows a plumbing pipe connected to an underground sprinkler system. The pipe is disconnected right now.

Once water leaves the supply side it is considered waste water and we have to make absolutely positively sure there is no chance that water can re-enter the supply system. The use of anti-back-flow devices are usually installed here. In this case there is no back-flow prevention device present.

It takes one of those “planets-in-alignment” moments for waste water to be siphoned into the drinking water. I get it. BUT WHY TAKE THE CHANCE?!?

So how can this happen?

  1. The water needs to be flowing into the sprinkler system.
  2. Something such as a water main break, fire department drafting water, or even a burst water heater has to create a negative pressure in the supply side of the water pipes.
  3. Water in the pipes can then flow backwards.
  4. If there are any poisonous substances such as pesticides in the ground of the photo above, they stand a chance to be brought into the drinking water pipes.
  5. If we, or our family members, drink this water, illness can occur.
  • Anti-siphon and anti-back-flow devices stop the waste water from re-entering the water system.
  • I personally believe this is incredibly important and pretty affordable to repair. Many people, home inspectors included, never heard of a cross connection. Many people have gotten sick and some have died from drinking water with poisons in it.

    I hope this helps people understand the importance repairing, correcting, cross connections that are found and documented.