The Categories and Classes of Water


The Many Classes of Water

Did you know there are three categories and four classes of water? Understanding each type, it’s sources and the risks associated with water damage is very important. When dealing with water inside your home or property, time is always of the essence.

The Categories of Water


This category is made of liquid from a clean and sanitary source. While this water may start as clean water it can turn into category 2 rather quickly if not dealt with immediately.

Category 1 sources include water from:

  • Faucets
  • Water fountains
  • Toilet tanks


Greywater is the gently used water that goes down the drain of your bathroom sink, shower, bathtub, washing machines, and/or utility sinks. As a rule, grey water has not come into contact with human waste, but rather may contain dirt, food, hair, soap, grease and oil, and miscellaneous cleaning products. Grey water may contain levels of contaminants that can cause illness when ingested.

Category 2 sources include water from:

  • Washing machine overflows
  • Dishwashers
  • Flush from kitchen and bathroom sink drains


Blackwater is the worst category of water and could cause illness or even death if not dealt with properly. Blackwater usually refers to water that comes from toilets and can contain human waste and toilet paper.

Category 3 sources include water from:

  • Sewer backup
  • Toilet overflows that contain feces and toilet paper
  • Standing liquid that contains bacterial growth
  • Flooding from rivers or streams

The Classes of Water


Only part of a room is affected in a class 1 water loss. This class is the easiest to deal with and has a slow evaporation rate. Affected materials will contain little to no carpet and only consist of low permeance materials like concrete or plywood.


With a fast evaporation rate, class 2 will affect an entire room that contains carpeting where moisture has traveled up the walls at least a foot. Moisture remains in structural materials.


The fastest evaporation rate of the four classes, class 3 usually has a source that has started from above. The entire room will be saturated including ceilings, walls, insulation, sub-floors and carpet.


Specialty drying situations when there has been enough time and water to saturate materials like brick, stone, or hardwood make up class 4.

Water Damage from Any Water Source is an Issue

In all cases, standing water in your home or property can cause water damage and needs to be dealt with quickly! Even flooding from clean water sources can create thousands of dollars in costly repairs if not dried out properly the first time. Mold can grow quickly behind walls, in ductwork and throughout your flooring. Trust the professionals at Mammoth Restoration to ensure your property is dried effectively the first time. At Mammoth Restoration, we understand what your going through and how important it is to remove all of the water and restore your home after water damage. With over 15 years of water restoration services in Flagstaff and northern Arizona, we can get your home back to normal in no time. We are available 24/7!

Call us today for a consultation.


Mammoth Restoration works with home and business owners throughout Flagstaff and Northern Arizona, insurance companies, the State of Arizona, various law enforcement entities, and other licensed contractors. Call us today for your restoration and remediation needs.


Mammoth Restoration works with home and business owners, insurance companies, the State of Arizona, various law enforcement entities, and other licensed contractors

Call us today for your restoration and remediation needs: (928) 714-0050