Code of Massachusetts Regulations › 310 CMR - DEPARTMENT OF ENVIRONMENTAL PROTECTION › Title 310 CMR 40.0000 - Massachusetts Contingency Plan › Subpart I - RISK CHARACTERIZATION › Section 40.0984 - Derivation of Additional Method 1 Soil Standards for Use in Method 2

Current through Register 1525, July 5, 2024
If an MCP Method 1 Soil Standard has not been promulgated by
				  the Department, the RP, PRP or Other Person may develop an MCP Method 2
				  Standard for that oil and/or hazardous material on the basis of the following
				  assumptions and procedures:
(1) A
				site-specific background concentration in soil shall be identified for the oil
				and/or hazardous material.
(2)
				Based upon non-cancer health risk, a concentration of the oil and/or hazardous
				material associated with a Hazard Quotient (HQ) of 0.2 for each soil category
				shall be identified using the equations:
[OHM]S1 = (HQ x
				  RfDchronic x C)/((RAForal x
				  ADSES1oral) + (RAFdermal x
				  ADSES1dermal))
[OHM]S2 = (HQ x
				  RfDchronic x C)/((RAForal x
				  ADSES2oral) + (RAFdermal x
				  ADSES2dermal))
[OHM]S3 = (HQ x
				  RfDsubchronic x C)/((RAForal x
				  ADSES3oral) + (RAFdermal x
				  ADSES3dermal))
Where:
[OHM] = The concentration of oil and/or hazardous material
				  being derived, in units of milligrams per kilogram soil (mg/kg or ppm).
HQ = Hazard Quotient (HQ) of 0.2 (dimensionless).
RfD = The Reference Dose for the chemical, in units of
				  milligrams contaminant per kilogram-day (mg/(kg x day)).
RAForal = The Relative Absorption
				  Factor applicable for oral soil exposures (dimensionless).
RAFdermal = The Relative Absorption
				  Factor applicable for dermal soil exposures (dimensionless).
C =106 mg/kg conversion
				  factor.
ADSE = Average daily exposure to soil by the oral or dermal
				  pathway in units of milligrams soil per kilogram-day (mg/(kg x day)).
ADSE values are:
S1 oral = 2.4 mg/(kg x day)
S1 dermal = 21 mg/(kg x day)
S2 oral = 0.27 mg/(kg x day)
S2 dermal = 0.49 mg/(kg x day)
S3 oral = 1.2 mg/(kg x day)
S3 dermal = 13 mg/(kg x day).
(3) A concentration of the oil and/or
				hazardous material associated with an Excess Lifetime Cancer Risk equal to
				one-in-one million shall be identified for each soil category using the
				following equations:
[OHM] = (ELCR x C)/(CSF x ((RAForal x
				  LADSEoral) + (RAFdermal x
				  LADSEdermal)))
Where:
[OHM] = The concentration of oil and/or hazardous material
				  being derived, in units of milligrams OHM per kilogram soil (mg/kg or
				  ppm).
ELCR = Method 1 Excess Lifetime Cancer Risk limit of
				  one-in-one million (10-6).
CSF = The oral Carcinogenic Slope Factor in units of risk per
				  milligram per kilogram-day (mg/(kg x day))-1.
RAForal = The Relative Absorption
				  Factor applicable for oral soil exposures (dimensionless).
RAFdermal = The Relative Absorption
				  Factor applicable for dermal soil exposures (dimensionless).
C =106 mg/kg conversion
				  factor.
LADSE = Lifetime average daily exposure to soil by the oral
				  or dermal pathway in units of milligrams soil per kilogram-day (mg/(kg x day)).
				  LADSE values are:
S1 oral = 0.37 mg/(kg x day)
S1 dermal = 3.9 mg/(kg x day)
S2 oral = 0.10 mg/(kg x day)
S2 dermal = 0.19 mg/(kg x day)
S3 oral = 0.0088 mg/(kg x day)
S3 dermal = 0.095 mg/(kg x day).
(4) Considering the category determined for
				the groundwater at the disposal site per
				310
				CMR 40.0932 and an acceptable leaching model
				or test method as discussed in
				310
				CMR 40.0985, a concentration in soil which
				will not result in groundwater concentrations of the oil and/or hazardous
				material greater than the applicable MCP Method 2 groundwater standard derived
				in 310 CMR 40.0983 shall be
				identified.
(5) For each
				combination of soil and groundwater categories, the lowest non-zero
				concentration estimated in 310 CMR 40.0984(2) through (4) shall be the
				risk-based concentration for the oil and/or hazardous material of
				concern.
(6) The site-specific
				background concentration identified in 310 CMR 40.0984(1) shall be
				considered.
(7) The Practical
				Quantitation Limit (PQL) applicable to the oil and/or hazardous material using
				an appropriately sensitive analytical method for quantifying the concentration
				of the chemical in soil shall be identified.
(8) For each combination of the soil and
				groundwater categories, the highest of the three concentrations identified in
				310 CMR 40.0984(5) through (7) shall be adopted as the MCP Method 2 soil
				standard for that combination of soil and groundwater categories.
(9) MCP Method 2 soil standards identified in
				310 CMR 40.0984(8) shall be adjusted to a ceiling concentration if the
				calculated concentration is greater than the ceiling concentration. The ceiling
				concentration shall be based upon the "Odor Index" of the chemical, defined for
				the purposes of these regulations to be the ratio of the vapor pressure of the
				chemical and the 50% odor recognition level (odor threshold) for the chemical:
Odor Index = VP ÷ ORL50%
Where:
VP = The vapor pressure of the oil and/or hazardous material,
				  in units of TORR, measured at temperatures between 20° and 30°
				  Celsius.
ORL50% = The concentration of the oil
				  and/or hazardous material at which 50% of the general population would
				  recognize its odor. In units: parts per million (ppm).
(a) S-1 Standards:
1. Chemicals having an Odor Index greater
				than or equal to 100 shall be assigned a ceiling concentration of 100 mg/kg
				(ppm).
2. Chemicals having an Odor
				Index greater than or equal to one, but less than 100, shall be assigned a
				ceiling concentration of 500 mg/kg (ppm).
3. For chemicals having an Odor Index less
				than one or for which there is insufficient data to calculate an Odor Index,
				the assigned ceiling concentration shall be 1,000 mg/kg (ppm).