Clean supply water versus water that has degraded

The restoration industry commonly sorts water into categories, often described in the IICRC S500 standard. In plain terms:

Generally treated as clean

  • Comes straight from a pressurized supply line
  • Addressed quickly, within the first day or so
  • Has not crossed soil, a crawlspace or a dirty floor
  • Many porous materials can be dried in place

May be treated as contaminated

  • Sat for days, especially in a warm space
  • Ran through a crawlspace, under a slab or across soil
  • Mixed with a drain, toilet bowl or appliance discharge
  • More porous materials removed rather than dried

Why the category changes the job

Water from a split copper line is drinking water, and if it is caught early, carpet, drywall and wood can often be dried and kept. As time passes, bacteria grow, especially in warm, dark places such as wall cavities and under flooring. Water that travels through a dusty crawlspace or down into a basement with old debris picks up whatever it crosses. A pipe that broke while a house was empty for a week presents a different situation from one caught the same morning.

When water is considered contaminated, the usual response shifts. Carpet pad, carpet and other porous materials are more likely to be removed. Surfaces are cleaned and may be treated with an antimicrobial product. Workers may wear more protective gear. The estimate grows, and the timeline lengthens.

A drain line failure, a toilet overflow with waste, or anything that mixes with sewage is a separate problem. That water should be treated as contaminated from the start, and nobody without protective equipment should handle it.

Clues to raise with whoever assesses the damage

  • IfThe break was found days after it startedThenAsk how the elapsed time affects which materials can be kept.
  • IfWater flowed through a crawlspace or dirt floorThenAsk whether the water is being treated as contaminated and how the crawlspace will be cleaned.
  • IfThere is a musty odor alreadyThenMention it. Odor can indicate microbial growth that changes the scope.
  • IfA drain line or toilet was involvedThenTreat it as contaminated water and keep people away from it.

Common questions

How long before clean water is no longer considered clean?
There is no fixed hour. Temperature, what the water touched and how long it sat all matter. A contractor following industry standards will assess the situation rather than rely on a single number.
Does the category affect insurance?
It can affect the scope of the work, which affects the estimate. Coverage decisions remain with your insurer and depend on the policy.

General information for Denver, not a quote or professional advice. In an emergency, call 911.