observed results. Protocols will be provided for sampling of 1)
residential and non-residential units, 2) central heating, ventilation, and air conditioning (HVAC)
units, 3) identification of indoor lead sources, and 4) identification of indoor asbestos sources.
Within residential and non-residential units in buildings, dust will be collected from three areas;
1) accessible, 2)infrequently accessed, and 3 inaccessible areas.

Accessible areas are defined as areas in which exposures readily occur including soft
surfaces such as rugs and upholstered furniture, and hard surfaces such as doorknobs, walls,
and table tops.

Infrequently accessed areas are defined as areas in which dust may accumulate but which
cause exposure infrequently such as on top of bookshelves, on top of refrigerators, chests of
drawers or other tall objects.

Inaccessible areas are defined as areas in which dust may accumulate but which cause
exposure rarely such as behind refrigerators or other large infrequently moved objects.

Within HVACs, dust will be collected at air inlets, within mixing plenums, in outlets to sampled
units, and from the HVAC filter. The protocol outlined in this document provides instructions
for the identification of units within a building to sample, and then locations within units and
HVACs to obtain the samples. Two methods will be used to obtain dust samples for interior
building surfaces and are outlined herein: i) a wipe sampling method; and ii) vacuum sampling
methods including microvac and HEPA sampling methods.










2. STRATEGY FOR SAMPLING

2.1.
Selecting Units for Sampling


A sampling unit is defined as a reasonably small, confined and well defined area that will
be different for each building and building type. For example, a unit within an apartment
building would be an apartment, within a school could be a classroom, and within an office
building could be an area including several cubical and private offices. The procedure for
selecting units follows these steps:


i.
Select buildings (as detailed in the Sampling Plan)


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ii.
Identify and characterize the building and units selected (those identified in iii
below) using EPA provided checklists or survey guidance (for lead and asbestos)
for buildings, units and HVAC systems. Characterizations will include:





Descriptive information
Owner or other responsible individual or party for the building and units;
Number and location of floors sampled per bldg
Number of rooms sampled per floor
Square footage of floors and of space sampled per floor
*Location and orientation (directly facing or the side most directly facing, facing an area
perpendicular, facing in the direction opposite) to WTC of space sampled
Cleaning and renovation history since WTC collapse
*Type, number, age of windows in spaces sampled
*Number of window or wall HVAC units
Cleaning and replacement history of window or wall HVAC units since WTC collapse
*Visible WTC dust reported present in unit
Reported cleaning frequency and date of last cleaning prior to sampling
Carpet present
Carpet cleaned or replaced since WTC collapse

Attribution Information
Location and amount of friable asbestos material present in sampled space
Location and area of MMVF present, i.e ceiling tiles, pipe insulation, spray on fireproofing
Location and amount of chalking/peeling paint present
Current use of space
Significant particulate or combustion sources with sampling area, e.g. fireplace, stove, occupant
smokes
Significant particulate or combustion sources within or adjacent to the building, e.g. above fast
food restaurant, adjacent to emergency diesel generator exhaust

Central HVAC Design Information
*Location of air inlets
Location of filters or other air cleaning devices in system
Number and Location of HVAC return ducts in sampled space
Central HVAC cleaning and replacement history since WTC collapse
Whether or not the unit is served by an HVAC, and

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iii.
Solicit participation from a minimum of two units on alternating floors. These
units should be facing GZ, and preference should be given to units served by an
HVAC.


The intent behind this procedure is twofold: to identify and sample the most vulnerable
units within the building, and to sample enough units within the building so as to be able to
adequately characterize the building as a whole. Vulnerable units are those which are the most
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likely to have become contaminated based on their orientation to Ground Zero, and due to
potential impacts from an HVAC which serves their units. There may be reason to deviate from
this 3-step procedure to, for example, sample only one unit in a single story building. In such
cases, a conscious decision is made to base building decisions on the sampling of a limited
number of only the most vulnerable units.

2.2.
Selecting Locations Within Units to Sample


Sampling teams will enter sampling units with the intent of collecting individual
microvac and wipe samples from no less than 6 and no more than 20 sample locations, for
accessible and infrequently accessed COPC analysis; scaled to floor area as follows:
<1000sf = 3 samples, >1000 and <5000sf =5samples, >5000sf =7 samples, >10000sf = 10
samples (for each type of location).

Target areas for accessible hard and soft surface sampling in residential units include, if
present and in priority order:

i) area or wall-to-wall carpeting. Carpet locations include, in an order of most to least
preferred location (on the basis of exposure considerations): 1) in the main entrance used
for access and egress from the building; 2) carpet in the secondary, less heavily used
entrance to the house; 3) carpet in the center of the most frequently used play area for
children under the age of six; and 4) carpet in an acknowledged or evident route of high
traffic flow (i.e., stairs, hallway, etc.);

ii) the kitchen tiled floor, hardwood floors, or hard floors of other surfaces types
(laminate, e.g.);

iii) draperies/curtains in the living room, which is the primary location if
draperies/curtains are to be sampled, and then draperies/curtains in other rooms of the
unit;

iv) the wall at hand level for a resident child, or adult where no children occupy the unit;

v) the wall adjacent to the head of the bed in a childs bedroom, or in the adult bedroom
where no children occupy the unit;

vi) the interior handle of the door at the principal entrance and exit to the unit;

vii) kitchen counter tops;

viii) table tops for tables located in the dining room, living room, family room, or
bedroom, and the top of bureaus in bedrooms;

ix) upholstered furniture.

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Target areas for accessible hard and soft surface sampling in non-residential units include, if
present:


i) tiled, hardwood, or other hard-surfaced floors;


ii) area or wall-to-wall carpeting, and draperies/curtains;


iii) desk or table tops;


iv) the wall in the most actively used location in the unit;


v) the interior handle of the door at the principal entrance and exit to the unit;

vi) upholstered furniture;

Target areas for infrequently accessed hard and soft surfaces in residential units include, if
present:

i) the sill of a window;

ii) the top of vent ducts, or hot water pipes;

iii) on top of large appliances such as refrigerators, or upright freezers;

iv) on top of large objects of furniture such as bookcases, tall chests or beds canopys;


Target areas for infrequently accessed hard and soft surfaces in non-residential units include, if
present:

i) the sill of a window;

ii) the top of vent ducts, or hot water pipes;

iii) on top of large objects such as built in file cabinets or bookcases;

The following samples will be collected at each of the above sample locations: 1 microvac, 1
PAH wipe, 1 Metal Wipe.


Sampling teams will enter sampling units with the intent of collecting a single composite
sample from no less than 3 and no more than 10 sample locations, for inaccessible COPC and
WTC signature analysis; scaled to floor area as follows: <1000sf = 3 locations, >1000 and
<5000sf =5 locations, >5000sf =7 locations, >10000sf = 10 locations.

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Target areas for inaccessible hard and soft surfaces in residential units include, if present:

i) behind infrequently moved heavy appliances such as refrigerators, dishwashers, or
stoves;

ii) behind or underneath infrequently moved objects of furniture such as chests or beds;

iii) in corners of closets or similar small areas not frequently accessed or cleaned;

iv) above suspended ceilings.

Target areas for inaccessible hard and soft surfaces in non-residential units include, if present:

i) behind or underneath infrequently moved heavy equipment such as copying machines;

ii) in corners of closets or similar small areas not frequently accessed or cleaned;

iii) above suspended ceilings.

A single composite sample from all of the above sample locations will be collected by HEPA for
each unit.


Sampling teams will enter into the unit and, at that time, lay out a sampling plan for the
unit. They will have in their possession sampling equipment including equipment for wipe
sampling, and microvac and HEPA vacuuming. The wipe and micr