Toxic Cleanup Program
Guidance for PCS 2016
Updates
NW Remediation Conference
October 4, 2016
Kent Patton – Apex Laboratories, LLC
What are biggest changes in 2016 revision?
50 more pages of added guidance
 New subsection addressing sampling soil exposed by excavation. (Section 6.8.3).
 Revised the factors to consider when deciding whether to install monitoring wells. (Section
6.9.1)
 Updated discussion and references related to vapor intrusion. (Section 6.11)
 Updated the table summarizing applicable surface water standards and related discussion.
(Section 8.10)
 Changed the number of samples for the direct comparison test for groundwater compliance.
(Section 10.3.1)
 Added a discussion of the Toxics Substances Control Act. (Section 11.2.5)
 Added a discussion of environmental covenants. (Section 11.6)
 Added a discussion of model remedies. (Section 11.9)
 Added link to TCP webpage, “Checklists and Template for Plans and Reports” for Remedial
Investigation Reports. (Appendix A)
 Added link to TCP webpage, “Checklists and Template for Plans and Reports” for Feasibility
Study Reports. (Appendix B)
 Added instructions for using toxicity equivalency factors (TEFs) to determine compliance for
carcinogenic polycyclic aromatic hydrocarbons (PAHs). (Appendix C)
Focus – Know Your Contaminants
1.
Be informed – Read Updates
2.
What we focus on is what we see
Gasoline – Turns to Diesel?
3.
Know what the problem is
4.
For TPH with and without Silica
cleanup provides important data
Focus Sec. 7.3 TPH
1.
2011
silica gel cleanup should not be used for NWTPH-Dx
analyses of samples unless uncontaminated background
samples indicate that naturally occurring organic matter is a
significant component of the TPH being detected in the soil or
groundwater samples
2.
2016
Because most soils contain naturally occurring organic
matter, use of silica gel cleanup for soil extracts being
analyzed using the NWTPH-Dx method is generally
acceptable. …silica gel cleanup should not be used for
NWTPH-Dx analyses of groundwater samples unless…
Groundwater Extract - SSOR- 706168-05
2.2e
42.0e
NWTPH-Dx
4
2.58 mg/L
Diesel???
1.6e
41.4e
4
1.0e
48000
6000
4000
2000
0
0
10
Time (min.)
20
30
Groundwater Extract - SSOR- 706168-05
2.2e4
1.8e4
NWTPH-Dx
Silica Gel
Clean-up
1.6e4
0.341 mg/L DRO
86.7 % Reduction
1.2e4
1.0e4
6000
4000
2000
0
10
Time (min.)
20
30
6.0e4
Diesel Standard
NW-TPHdx with cleanup
<C17
5.0e4
<sur
<pr
3.0e4
<ph
10
11
12
13
Time (min.)
14
Hydrocarbons vs. Polars
Hydrocarbons contain only carbon and hydrogen
Polars contain a polar atom or functional group
Organic Acid
Ketone
Alcohol
Fuel Oil # 2 Diesel
7.0e4
CPI = 1
6.0e4
5.0e4
4.0e4
3.0e4
2.0e4
1.0e4
0
5
10
15
20
25
Fuel Oil # 2 Diesel : Close up view
7.0e4
< C-16
5.0e4
< pristane
3.0e4
< Phytane
< C-20
1.0e4
12
13
Time (min.)
14
Cell Membranes Polar
15
Why SGC is necessary to separate
hydrocarbons and polars (from Zemo and Foote 2003)
C25
(approx
C18)
a. Groundwater sample without SGC
(“TPHd” 2300 ug/l includes hydrocarbons
and polars; note mass >C14 and hump)
b. Duplicate sample after SGC
(100% “TPHd” was polars; hydrocarbons
not detectable in this sample)
Zemo & Associates
11
NW Natural Organics in Soil
1.0e5
Diesel Range = 1310 ppm
Oil Range = 8180ppm
4.0e4
0
5
10
15
Time (min.)
20
25
NW Natural Organics Soil after Silica Gel
5.0e5
C-29 >
Diesel Range = 179 ppm 86 % Reduction
3.0e5
< C-31
Oil Range = 1210 ppm 85% Reduction
CPI is large
1.0e5
C-21>
20
25
a-Amyrin
unk-acid
Sitosterol
C-31
C-29
Stigmasterol
C-35
4.0e4
C-27
6.0e4
C-25
unk-Aldehyde
8.0e4
unk-Aldehyde
1.0e5
unk-ketone
Natural Organics - Significant Compounds ID by GCMS
2.0e4
0
16
18
20
Time (min.)
22
24
The Take Away in Regards to TPH
1. Silica Cleanup is acceptable for soils (2016)
2. Silica Cleanup removes biogenic material
and allows understanding of nature of fuel
released and progress of natural attenuation
3.
Before and after Silica Cleanup is important
for water as it is for soil
4.
For natural and assisted natural attenuation
to mineralize hydrocarbons to CO2 and H20 polar
compounds must be formed.