NYC 9/11 Public Portal Document
Mr. Vincent McGowan
BPCPC
January 14,2001
Page 5 of5
Cold n has determined that the concentrations of the eight elemental metals analyzed in the
composite bulk soil samples collected from the West Thames Park are within general
background levels for the Eastern United States as well as below the NYSDEC's recommended
soil cleanup objectives and USEPA limits for Arsenic and Lead soil contamination.
surface 1rq a samples (METALS)
Of the five elemental metals analyzed in the eight surface wipe samples, only Lead has a
regulatory limit for surface com..trnination. The limit for Lead is set by the New York City
Department of Health (NYCDOH) and the USEPA at 40 micrograms per square foot (ug/sq,ft.)
on floor surfaces, 250 ug/sq.ft. on widow sills and 400 ug/sq.ft, on window wells as a clearance
criterion for lead-based paint abatement activities. The clearance criteria is compared to the
average of all surface wipe samples collected from each separate surface type.
Colden has chosen the floor surfaces clearance criteria for Lead (40 ug/sq.ft.) as a criterion for
determining the extent of Lead contamination at the West Thames Park, as it is the most
stringent regulatory limit currently available.
The average of the four surface wipes for Lead was 26.925 ug/sq.ft, This average is well below
the NYCDOH and USEPA limit.
Arsenic was found to be ND or "None Detected in three of four surface wipe samples. Arsenic
was detected in the fourth wipe sample collected on the concrete footing pad under the play
structure (36.0 uglsq.ft.). Arsenic is commonly used as a preservative for pressure treated wood
used in play structures, which may be the source of tlxe'arsenic that was detected. The wooden
structure is coated with a sealant, which according to a study presented by the Connecticut
Agricultural Experiment Station reduces arsenic availability from play structures by 90 to 95%,
Colden does not believe the presence of Arsenic on the concrete footing pad is of concern, as it
will be covered with over a foot of new sand prior to the reopening of the park.
Results of all four surface wipe samples for Cadmium were ND or "None Detected",
Chromium was detected In all four surface wipes. The results ranged from 6.89 to 35.5 ug/sq,ft.
While there are no currP- ` federal, state or local standards for Chromium surface
contamination, the presence of Chromium would be expected in the samples based on the metal
and plastic substrates they were collected from Chromium is a common element used in metal
manufacturing and pigments. It is also a component of wood preservatives along with arsenic.
The Chromium concentrations found can be attributed to the playground products themselves
as opposed to external the World Trade Center collapse.
L0'd S€ 60 —9-6W
NYC-WTC 000130933
OCR can misread numbers and units. Confirm readings against the page image before using them.