Measuring and testing – Testing of material
Reexamination Certificate
2001-12-03
2003-07-15
Kwok, Helen (Department: 2856)
Measuring and testing
Testing of material
C073S152430, C436S029000
Reexamination Certificate
active
06591702
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for characterizing contaminated soils and sediments so as to permit timely determination of the likely sources of rapidly released fractions of contaminants disposed in the contaminated soils and sediments, thereby enabling accurate decisions to be made as to the soils and sediments needing to be removed and/or treated to achieve risk-based cleanup objectives. The method is sufficiently rapid to enable decisions to be made in the course of excavating a contaminated site.
2. Description of Related Art
The characterization of contaminated industrial and governmental sites can involve significant costs due to the inability to define “source” when used in describing sources of contaminants that significantly contribute to the degradation of groundwater, the inadequacy of current methods for measuring the fraction of contaminants that are available for transport to receptors such as groundwater, and the long lead times of days or weeks required for contaminant measurements to be obtained from commercial laboratories. These limitations prevent the timely definition of what constitutes a problematic source of contaminants at each site which would allow site managers to define which volumes of soil require aggressive treatment or removal and which soils are not an issue in terms of significant impact on receptors. Consequently, characterization costs of up to millions of dollars per site can be incurred without a true definition of source in terms of contaminant release rates, as a further result of which large volumes of soil are unnecessarily excavated and/or treated at substantial costs to the site owners.
Current methods for determining which volumes of soil are sources of contaminants and which soils are not range from the over-simplistic to the analytical approaches that require very long lead times of several days or weeks. One such method involves the determination of total concentrations of contaminants of concern. However, this type of data is of limited use in predicting the rates of contaminant release from various sections of the site. At such sites, decisions regarding cleanup levels and the planned removal and/or treatment of soil/NAPL (non-aqueous phase liquids) residues are guided by the total concentrations of the contaminants of concern. This results in a gross over-estimation of the volumes of soil/NAPL residues that are identified as “source” for contaminants and that are subsequently targeted for aggressive management.
Other methods currently in use are visual observations of staining believed to be due to hydrocarbon impact and olfactory detection of contaminants through “hydrocarbon” odor. However, visual and olfactory observations, as shown in Table 1 hereinbelow, are not good predictors of the potential of a soil/NAPL residue to impact groundwater or to become available to other receptors. Total concentration is also a poor indicator of contaminant availability to receptors.
TABLE 1
Comparisons of Vapor Pressure (PID) Measurements, Visual
Observations and Olfactory Determinations with Impact to Groundwater
(Benzene Levels in Water Partitioned with Soil)
Source Groundwater Impact Characterization Data
**Benzene &
**Benzene
Naphthalene
Loss in
Loss in soil
Initial Benzene
Soil leach
leach
*Old
Ground-
Depth,
Soil,
Water*
columns,
columns,
Observ-
water
Sample
feet
New PID
Old PID
mg/kg
mg/l
mg/kg
mg/kg
ations
Impact
SB1-03
6-8
9-40
87
1.14
.0007
1.01
1.58
HC
Minimal
Stained/
odor
SB1-03
9-11
0-22
~50
0.78
.0009
0.67
1.98
HC
Minimal
Stained/
odor
SB-62
10-12
9-49
no
0.28
.0056
0.27
0.51
No
Minimal
data
observation
SB-62
15.5-
8-24
no
1.47
.0036
1.47
21.37
15-16 ft
Minimal
17.5
data
no
observations
17 ft tar
observed
SB-59
4-6
65-
101
7.44
.007
5.62
86.66
MGP-
Minimal
177
like odor
with
staining
at 0.8 ft
from
bottom
SB-59
18-20
189-
400
340
3.08
209.48
1528.00
MGP-
High
480
like odor
with
visual
product
from
1.7 ft to
bottom
*Tap water in equilibrium with soil: 30 g soil + 100 ml tap water
**Losses from disturbed soils in leach columns calculated from containment concentration before and after leaching with 150 pore volumes of tap water
It is, thus, apparent that there is a need for a method which provides reliable and rapid means for defining what soil/NAPL residues constitute significantly available sources of contaminants at contaminated sites.
SUMMARY OF THE INVENTION
It is, thus, one object of this invention to provide a method for defining soil/NAPL residues that constitute significantly available sources of contaminants at contaminated sites.
It is another object of this invention to provide a method for defining sources of contaminants in contaminated soils and sediments that significantly contribute to the degradation of groundwater and other contaminant receptors.
It is yet a further object of this invention to provide a method for measuring the fraction of contaminants in contaminated soils and sediments that are available for transport to receptors such as groundwater.
It is still a further object of this invention to provide a method for defining sources of contaminants in contaminated sites that reduces the amount of time required for obtaining such information in comparison to the days and weeks required by conventional methods.
It is yet a further object of this invention to provide a rapid method of estimating the mass of rapidly released hydrocarbon contaminants in each section of a site so as to quantify the spatial mass distribution of significant sources of rapidly released contaminants.
It is a further object of this invention to provide a method for defining sources of contaminants in contaminated sites that can be carried out at such contaminated sites.
These and other objects of this invention are addressed by a method for identifying and characterizing contaminated sources in a site comprising contaminated soils and sediments in which the vapor pressure at a plurality of subsurface soil sampling locations of the site is measured, producing a plurality of subsurface vapor pressure measurements with depth, which measurements are then mapped, resulting in generation of a subsurface vapor pressure map. The vapor pressure mapping indicates the spatial distribution of the total mass of rapidly releasable contaminants.
Commercially available instrumentation that provides contaminant-specific vapor pressures would yield a mapping of the rapidly releasable mass of only a specific contaminant. Concomittently, soil samples are analyzed in the laboratory for contaminant mobility using mobility test procedures such as the Synthetic Precipitation Leaching Procedure (SPLP), leaching tests and resin enhanced desorption of the soil. The results of these tests may be used to calibrate vapor pressure instrumentation. Using vapor pressure measurements together with total concentration measurements, contaminants in fast release compartments and slow release compartments in the contaminated soils and sediments are identified and the fraction of the contaminants in the fast release compartments and the slow release compartments rapidly determined in the field.
REFERENCES:
patent: 2165440 (1939-07-01), Bays
patent: 2183964 (1939-12-01), Horvitz
patent: 2305384 (1942-12-01), Hoover
patent: 2349472 (1944-05-01), Taggart
patent: 2386832 (1945-10-01), Zaikowsky
patent: 2725281 (1955-11-01), Bond
patent: 2918579 (1959-12-01), Slobod
patent: 3033761 (1962-05-01), Brown
patent: 3120428 (1964-02-01), McDermott
patent: 3180983 (1965-04-01), Hall
patent: 3307912 (1967-03-01), Davis
patent: 4573354 (1986-03-01), Voorhees et al.
patent: 4809790 (1989-03-01), Manchak, Jr.
patent: 4834194 (1989-05-01), Manchak, Jr.
patent: 5063519 (1991-11-01), Zison
patent: 5137830 (1992-08-01), Milly
patent: 5328849 (1994-07-01), Smith
patent: 5435176 (1995-07-01), Manchak, III
patent: 5687093 (1997-11-01), Long et al.
patent: 5766953 (1998-06-01), Kennedy
patent: 5813798 (1998-09-01), Whiffen
patent: 5862512 (1999-01-01), Voorhees et al.
patent: 5873049 (1999-02-01), Bielak et
Hayes Thomas D.
Srivastava Vipul J.
Fejer Mark E.
Gas Technology Institute
Kwok Helen
Politzer Jay L
LandOfFree
Method for identifying sources of rapidly released... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for identifying sources of rapidly released..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for identifying sources of rapidly released... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3023858