The story of Home Depot is a tale of greed, grift, and civil procedure. It centers on a scheme that involved three companies: Home Depot, Citibank, and Carolina Water Systems Inc. Here’s how it allegedly worked. Representatives from Home Depot or CWS called homeowners and claimed that “contaminants” were found in nearby tap water. They urged homeowners to let them perform a test for “contaminants,” which was really just a test for water hardness; almost all tap water tested positive, even if it was perfectly safe. But CWS told homeowners the positive result proved their water was unsafe and required a $9,000 water purification system that other companies sell for $1,400. The company then told homeowners they had been approved for a Home Depot–branded Citibank credit card, which they could use to pay for the system with deferred interest.