ESTCP Project #1011, Rhizosphere
(1-[(C1/C2) * (H2/H1)]) * 100
Percent depletion of total petroleum hydrocarbons (TPH)
(1-(H2/H1)) * 100
C1 = Concentration of analyte in the sample
C2 = Concentration of analyte in the source (time zero)
H1 = Hopane concentration in the sample
H2 = Hopane concentration in the source (time zero)
Note: All depletion estimate calculations were done on an oil weight basis, which were obtained
during sample preparation. Oil weights used were the TPH-oil ((g/gram TPH) * grams dry
weight = g oil) for the samples.
Importantly, any compound or group of compounds can be normalized relative to a recalcitrant
biomarker. For statistical analyses of data, TPH, summed PAHs, and aliphatic and aromatic
fractions were all normalized using a recalcitrant biomarker.
Normalization with Respect to Climate.
By expressing changes
in the composition
relative to the recalcitrant biomarker decalin, we normalized degradation rates with respect to
concentration differences and thereby reduced concentration variability at each site. However,
each site was treated for different lengths of time and at different conditions. To account for this,
we normalized the treatment time based on temperature at the site. Due to issues common at
remote field demonstration sites, we were unable to collect reliable soil field temperature data.
As an alternative, we used air temperature data available from the National Oceanographic and
Atmospheric Administration (www.cdc.noaa.gov). Barrow and Annette Island data were
obtained from this database, but Galena data were not available. To substitute for Galena data,
we used Fairbanks temperature data for the Galena site. The latitude and air temperatures at
Galena and Fairbanks are similar.
Growing degree days (GDD) were calculated as below, using 0C as the base temperature:
GGD = ∑((average high+average low)/2)-0
3.5.8 Demobilization. This technique does not involve the use of any equipment or
structures that need to be removed. The vegetation can and should be left in place to facilitate
any further rehabilitation of the site and prevent erosion.
3.6 Selection of Analytical/Testing Methods
See Appendix A of this document and our Demonstration Plan in section 5.4 "Sampling Plan"
and Appendix D "Sampling and Analysis Plan for Annette Island and Campion."