Technical and Regulatory Guidance for In Situ Chemical ... - ITRC

Follow-up Actions
A second round of permanganate injections was performed in early August of 2000. A permit for
operating Class V injection wells was obtained from KDHE's Bureau of Water (see Appendix ).
For this event, the concentration of permanganate was increased to 15%, and a total of 1,472 gallons
of oxidant solution was injected through an array of 64 probes in an area of 270 by 120 feet directly
adjacent to the building. The injection of oxidant in each probe was targeted at specific depths, with
3_4 gallons of oxidant injected at five-foot intervals between 15 and 40 feet below ground surface.
Post-treatment sampling was conducted at 5, 10, 17, 30, and 60 days after injection, with a sampling
event 90 days after injection pending.
The results from the early post-treatment sampling events do not present a clear picture of the effects
of the injection event. One monitoring well showed a 99% decrease in contaminant concentrations,
while the remaining wells showed increases in contaminant concentrations of up to a factor of ten.
Analysis of titration data for permanganate in the monitoring wells and injection points indicates that
the radii of influence of the injection points probably did not overlap in most cases. A full analysis
of t he p erformance of the second injection event will be conducted after all post-treatment
monitoring data is available.
Point of Contact
Robert Jurgens
Kansas Department of Health and Environment
(785) 291-3250
4. Former Isleta Chevron Filling Station, Albuquerque, NM
Background
This site was a gasoline filling station that had closed. In 1994, the New Mexico Environmental
Department (NMED) had the building demolished and removed five underground storage tanks
(USTs) from the property. These tanks, as well as the dispenser islands, showed evidence of longterm
leakage that had created substantial volumes of contaminated soil. Monitoring wells on the site
showed concentrations of benzene in excess of 10,000 parts per billion (ppb). Approximately 1500
tons of contaminated soil were removed, as well as 5000-6000 gallons of a mixture of water and free
product. The excavations were backfilled, and a air sparging and soil vapor extraction system was
installed over the source area. However, the system was never operated due to problems with utility
hookups.
Approximately four months after the removal of the source material, the monitoring wells were
resampled. The contaminant concentrations had decreased markedly with the removal of the source,
to levels of 1000-3000 ppb. This reduction was attributed to natural attenuation processes. It was
decided not to activate the sparging / extraction system, and the vacant site sat in this condition for
the next 5 years. Periodic sampling showed a relatively constant concentration of the contaminants
in groundwater.
In 1999, this site was selected for a pilot test of in situ chemical oxidation using a variant of Fenton’s
reagent (hydrogen peroxide and iron catalyst). This pilot test was intended in part to gain state
acceptance for this process.
Site Hydrogeology
B9