An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »


Mold Course Chapter 7:

Evaluating the Remediation

  1. Completing Mold Remediation - Fix the Water Problem and Clean Up the Mold
  2. Considering Bioaerosol Sampling

Previous ChapterNext Chapter

Lesson 1 - Completing Mold Remediation - Fix the Water Problem and Clean Up the Mold

How do you know when you have finished remediation? Ultimately, it is a judgment call. People should be able to occupy or work in the building without health complaints or physical symptoms. The most important action, if mold growth is to be controlled in a building, is to eliminate the source of moisture that caused the mold problem. No matter how good the mold cleanup is, if the water problem is not solved, mold will return. Therefore, determining whether moisture in the building is being controlled is key in assessing the effectiveness of the remediation effort. If moisture is not being controlled, even removing all the mold growing in the building will be only a temporary solution.

A visual inspection of the area that has been remediated should show no evidence of present or past mold growth. There should be no moldy or musty odors associated with the building, because these odors suggest that mold continues to grow. If mold or moldy odors are present in the building, the remediation has not been effective.

Keep in mind that remodeling, cleaning and construction may have introduced new building materials or chemicals capable of causing upper respiratory irritation that, in some individuals, may mimic the symptoms caused by exposure to mold.

Top of Page

Lesson 2 - Considering Bioaerosol Sampling

Bioaerosol sampling (air sampling for mold or other biological contaminants) usually is not necessary to determine remediation effectiveness. In fact, bioaerosol sampling may be less effective at determining the success of remediation than visual and sensory surveys of the area.

Although sampling may be of some help in judging remediation effectiveness, remember that a negative sampling report must not be used in place of a visual survey. Factors that may dramatically reduce or increase the spore levels within a building include:

  • Barometric pressure
  • Inside and outside temperatures
  • Activity levels
  • Humidity

Air sampling for mold provides information on what was in the air only for the moment when the sampling occurred. It is important, therefore, that sampling not replace visual inspection.

Top of Page

Previous ChapterNext Chapter