NYC-WTC_000233682

NYC 9/11 Public Portal Document

response guidelines

site investigation. Consideration should also be given to whether or not the new information available at this stage corroborates the information about the threat. If the threat is determined to be ‘credible,’ response actions may include measures to limit or prevent exposure of the public to the suspect water, such as public notification. Actions taken to continue the investigation at this point may include analysis of samples collected from the site, continued site characterization activities, and an analysis to estimate the spread of the contaminant.

The new information available at the confirmatory stage may include the results from laboratory analysis, including QA/QC data to support the interpretation of the results. If a specific contaminant is identified, then additional information about that contaminant can be used to further evaluate the nature of the threat as well as implications to public health. The findings of continued site characterization activities may also help to confirm the incident. The basis for confirming a contamination incident can be analytical results that identify a specific contaminant or other definitive evidence that a contaminant is present in the water. If a contaminant has been identified, consideration should be given to the health effects associated with exposure to that contaminant. It may be necessary to revise the sampling and analysis plans if a contaminant was not positively identified through laboratory analysis but the threat is still deemed ‘credible.’ Response actions potentially initiated once a contamination incident has been confirmed include characterization of the contaminated area, revision to public health protection measures, provision of alternate water supplies, and planning for remediation and recovery activities.

69 Interim Final - August 2004

CITY_21MC100_004992408

NYC-WTC_000233751