Soil shall be classified as either category S-1, S-2 or S-3.
The site, receptor and exposure information identified in
310
CMR 40.0904 through
310
CMR 40.0929, considering both the current and
reasonably foreseeable Site Activities and Uses identified in
310
CMR 40.0923, shall be used in conjunction
with the criteria listed below to categorize the soil.
(1) The soil categories shall be applicable
to specific volumes of soil which shall be described in written and graphic
form in the documentation of the Risk Characterization.
(2) The three soil categories describe a
range of the potential for exposure to that soil: Category S-1 soils are
associated with the highest potential for exposure, Category S-3 soils have the
lowest potential for exposure. While one and only one category is applicable to
a specified volume of soil, soils in different areas of a disposal site may be
classified in different categories, depending upon their exposure
potential.
(3) The Table in 310 CMR
40.0933(9) contains a matrix summarizing the criteria used to categorize
soil.
(4) For the purpose of soil
categorization, the potential for exposure is described by a qualitative
analysis of the accessibility of the soil in combination with the information
about the Site Activities and Uses determined pursuant to
310
CMR 40.0923. The following definitions shall
be used to describe exposure potential for the purposes of categorizing soil:
(a)
Frequency of Use
shall indicate how often a receptor makes use of, or has access to, the
disposal site. Receptor access to and use of the areas around the disposal site
are often strong indicators of potential site access and thus should be
considered in determining frequency of use for the site under investigation.
Frequency of use shall be described as either "High", "Low" or "Not Present",
using the following criteria:
1. Children's
frequency of use shall be characterized as high if:
a. any children reside, attend school or
attend day care at the disposal site; or
b. large numbers of children visit the
disposal site, regardless of any one child's frequency of visitation.
2. Adults' frequency of use shall
be characterized as high when they reside at the disposal site, or when they
work at the disposal site on a continuing basis [ i.e., full
days or shifts of eight or more hours per day on a continuing basis].
3. Children's or adults' frequency of use
shall be characterized as low when they are present at the disposal site, but
only as infrequent visitors; or when workers are present at the disposal site
for only short periods of time [ i.e., less than two hours per
day on a continuing basis, or for full days or shifts on a sporadic
basis].
4. It shall be presumed
that children may be present at the disposal site, unless it can be
demonstrated that access by children younger than 15 years old is specifically
restricted or that such children are highly unlikely to be present, in which
case children may be considered to be "Not Present". Disposal sites which are
residential properties shall presume the presence of children, unless there is
clear and convincing evidence to the contrary.
5. The frequency of use for activities not
described above shall be characterized in the documentation of the Risk
Characterization as either high or low.
(b)
Intensity of use
shall describe the nature of the Site Activities and Uses which could
potentially result in exposure to the receptor. Intensity of use shall be
described as either "High" or "Low", using the following criteria:
1. Site Activities and Uses which have the
potential to disturb soil and thus result in either direct contact with the
soil itself or inhalation of soil-derived dust shall be characterized as high
intensity use. Examples of such activities include, without limitation,
gardening, digging, and recreational sports.
2. Passive activities which do not disturb
the soil, such as walking, shopping, and bird watching shall be characterized
as low intensity use.
3. The
intensity of use for each identified Site Activity and Use shall be
characterized in the documentation of the Risk Characterization as either high
or low with appropriate justification.
(c)
Accessibility of
the soil to potential receptors shall be characterized as either "accessible",
"potentially accessible", or "isolated" using the following criteria:
1. Soil shall be characterized as
"accessible" if it is located less than three feet below the surface, and the
surface is not completely covered by pavement. For buildings having earthen
floors, the floor shall be considered as the soil surface.
2. Soil shall be characterized as
"potentially accessible" if it is located at a depth of three feet to 15 feet
below the surface (with or without pavement), or if the soil is located less
than three feet from the surface in an area completely paved.
3. Soil shall be characterized as "isolated"
if it is located at a depth greater than 15 feet below the surface, or if the
soil is covered completely by a building or other permanent structure which
does not have earthen floors, regardless of depth. Soil located at a depth
greater than three feet below the earthen floor of a building or other
permanent structure shall also be characterized as "isolated".
(5)
Category
S-1. Soil shall be classified as category S-1 if either:
(a) the soil of concern is accessible,
pursuant to 310 CMR 40.0933(4)(c)1., and either:
1. the soil is currently used for growing
fruits or vegetables for human consumption or, if it is reasonably foreseeable,
that the soil may be put to such use; or
2. a child's frequency or intensity of use is
considered to be high, pursuant to 310 CMR 40.0933(4)(a) and (b); or
3. an adult's frequency and intensity of use
are both considered to be high, pursuant to 310 CMR 40.0933(4)(a) and (b);
or
(b) the soil is
potentially accessible, pursuant to 310 CMR 40.0933(4)(c)2., and a child's
frequency and intensity of use are both considered to be high, pursuant to 310
CMR 40.0933(4)(a) and (b).
(6)
Category S-2.
Soil shall be classified as category S-2 if either:
(a) the soil is accessible, pursuant to 310
CMR 40.0933(4)(c)1.; and
1. a child's
frequency and intensity of use are both considered to be low, pursuant to 310
CMR 40.0933(4)(a) and (b); or
2.
children are not present at the disposal site and either (but not both) the
adults' frequency or intensity of use is considered to be high, pursuant to 310
CMR 40.0933(4)(a) and (b); or
(b) the soil is potentially accessible,
pursuant to 310 CMR 40.0933(4)(c)2.; and
1.
either (but not both) a child's frequency or intensity of use is considered to
be high, pursuant to 310 CMR 40.0933(4)(a) and (b); or
2. children are not present at the disposal
site and an adult's frequency and intensity of use are both considered to be
high, pursuant to 310 CMR 40.0933(4)(a) and (b).
(7)
Category S-3.
Soil shall be classified as category S-3 if either:
(a) the soil is accessible, pursuant to 310
CMR 40.0933(4)(c) 1., and children are not present at the disposal site and an
adult's frequency and intensity of use are both considered to be low, pursuant
to 310 CMR 40.0933(4)(a) and (b); or
(b) the soil is potentially accessible
pursuant to 310 CMR 40.0933(4)(c)2.; and
1. a
child's frequency and intensity of use are both considered to be low, pursuant
to 310 CMR 40.0933(4)(a) and (b); or
2. a demonstration has been made that
children are not present at the disposal site, and either an adult's frequency
or intensity of use is considered to be low, pursuant to 310 CMR 40.0933(4)(a)
and (b); or
(c) the soil
is isolated pursuant to 310 CMR 40.0933(4)(c)3., regardless of any receptor's
frequency or intensity of use.
(8) Whenever and wherever reasonable doubts
exist over the selection of the appropriate soil category, the soil category
associated with the highest exposure potential (among the soil categories being
considered) shall be selected.
(9)
Table listed in 310 CMR 40.0933(9) contains the Soil Category Selection Matrix.
Table 40.933(9)
SOIL CATEGORY SELECTION MATRIX - HUMAN EXPOSURE
POTENTIAL
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