Evaluation Process

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Public Health Assessment Public Comment Release

Ward Transformer NPL Site

C The fence around the facility was approximately 8 feet high, topped with barbed wire, and in

good repair. Three sides around the lagoons was fenced with a tall fence in good repair, but

the west side had only a very short fence (about 2 feet high) that could easily be stepped over.

All fences had locks that could be accessed only by Ward employees.

C Most of the main yard was paved, but the pavement was aged and cracking in some areas.

Hundreds of used transformers were densely packed in the yard.

C The former Horizon Forest Products building was vacant.

C About a dozen employees were reconditioning transformers inside the warehouse building on

the Ward site.

C A number of 55-gallon drums were stored on pallets in the main yard near the burnoff oven.

C The burnoff oven was located in the main yard, between the warehouse building and the water

treatment facility.

Also, ATSDR staff drove through the area surrounding the site to better understand the

relationship between the site and the people living and working nearby. ATSDR staff observed

the following:

C Surrounding industrial facilities had many cars in the parking lots, indicating daily worker

populations in the area.

C One house was located about 300 feet northeast of the facility. This house had formerly been

reported as occupied, but ATSDR could not determine whether it was currently occupied.

C Other than the one house, the areas immediately surrounding the facility were industrial

properties, land belonging to the Raleigh-Durham airport and marked prominently with "No

Trespassing" signs, or vacant land buffering the two major highways crossing near the Ward

facility.

C Commercial and residential development is occurring on the other side of I-540,

approximately 1 mile west (downstream) of the site.

Evaluation Process

The process by which ATSDR evaluates the possible health impact of contaminants is

summarized here and described in more detail in Appendix A. The first step involves screening

data for contaminants of concern (COCs). ATSDR uses comparison values (CVs) to determine

which chemicals to examine more closely. CVs are concentrations of chemicals in the

environment (air, water, or soil) below which adverse human health effects are not likely.

Exceeding a CV does not mean that health effects will occur, just that more evaluation is needed.

ATSDR also considers sampling location, data quality and community health concerns in

determining which chemicals to evaluate further.

If a chemical contaminant is selected for further evaluation, the next step is to identify which

chemicals and exposure situations could be a health hazard. Exposure doses for children and

adults are calculated for COCs in site media (e.g., soil, groundwater, surface water, sediment,

fish or shellfish). Exposure doses are the estimated amounts of a contaminant to which people

come in contact under specified exposure situations. These exposure doses are compared with

appropriate health guidelines for that chemical. Health guideline values are considered safe

doses; that is, adverse health effects are unlikely below this level. If the exposure dose for a