As we discussed in my previous blog, sometimes the Category of water damage (i.e., the presence or absence of contamination in water and its risk to building occupants) can’t be determined by the water damage restoration technician’s preliminary determination. In such situations, Indoor Environmental Professionals (IEPs) are required to determine things like the water’s cleanliness, the water’s location, the type of building materials impacted, the potential for risk to workers and other building occupants, and the protocol for remediation (i.e., a corrective action plan) where contaminated water is observed. Such a determination of water cleanliness and its potential to cause harm to occupying persons may include a single-phased laboratory analysis of sample(s) collected by the IEP or may include a multi-phase laboratory analysis. For example, when a known sewage backup has occurred and the extent of its impact on the indoor environment is needed, a simple sewage-screening analytical method may be appropriate; however, if a question arises over whether a Category 1, 2 or 3 water damage exists due to a potential or suspected source or deterioration of water (e.g., water entering through the roof during a hurricane), a multi-phase laboratory approach (e.g., sewage-screening, Heterotrophic Plate Count (HPC), and/or Bacteria Genus ID per organism (BGI)) may be required to reliably determine whether the waterborne pathogens are present, to what extent, and to what risk exists in the impacted rooms.

Specific Bacterial Species. Sometimes the question has to do with whether a specific bacterial species exists. In such cases, the IEP sample and the laboratory analysis are centered on answering the question of whether that species is present or not. An example of this are samples and analysis for Enterococcus species (sp.). The sample methodology includes water or surface (e.g., swab, bulk materials, or wipes) sampling followed by a laboratory analysis. Analysis includes the identification of Enterococcus bacteria through a chromogenic substrate test method. This analytical method, usually, only detects the presence or absence of these bacteria and does not provide enumeration.

Sewage Screening. This is a common method of sampling that seeks to determine if sewage indicator organisms are present or absent in the tested water. The sample methodology includes water or surface sampling followed by a laboratory analysis. Analysis, usually, includes identification of Total Coliforms, Escherichia coli (E. coli), and Enterococcus bacteria through a chromogenic substrate analysis. (These bacterial species are indicator organisms for sewage contamination.) This analytical method, usually, only detects the presence or absence of these bacteria and does not provide enumeration.