Fate and transport modeling of selected chlorinated organic compounds at Operable Unit 3, U.S. Naval Air Station, Jacksonville, Florida
HERO ID
3975058
Reference Type
Technical Report
Year
2000
Language
English
| HERO ID | 3975058 |
|---|---|
| Year | 2000 |
| Title | Fate and transport modeling of selected chlorinated organic compounds at Operable Unit 3, U.S. Naval Air Station, Jacksonville, Florida |
| Authoring Organization | U.S. Geological Survey |
| Publisher Text | U.S. NAVY, SOUTHERN DIVISION, NAVAL FACILITIES ENGINEERING COMMAND |
| City | Tallahassee, FL |
| Abstract | Ground water contaminated by the chlorinated organic compounds trichloroethene (TCE), cis-dichloroethene (DCE), and vinyl chloride (VC) has been found in the surficial aquifer beneath the Naval Aviation Depot at the U.S. Naval Air Station, Jacksonville, Florida. The affected area is designated Operable Unit 3 (OU3) and covers 134 acres adjacent to the St. Johns River. Site-specific ground-water flow modeling was conducted at OU3 using MODFLOW, and solutetransport modeling was conducted using MT3DMS. Simulations using a low dispersivity value, which resulted in the highest concentration discharging to the St. Johns River, gave the following results. At 60 years traveltime, the highest concentration of TCE associated with the Area C plume had discharged to St. Johns River at a level that exceeded 1×103 micrograms per liter (µg/L). At 100 years traveltime, the highest concentration of TCE associated with the Area D plume had discharged to the river at a level exceeding 3×103 µg/L. At 200 years traveltime, the Area B plume had not begun discharging to the river. Simulations using a first-order decay rate halflife of 13.5 years (the slowest documented) at Area G caused the TCE to degrade before reaching the St. Johns River. If the ratio of the concentrations of TCE to cis-DCE and VC remained relatively constant, these breakdown products would not reach the river. However, the actual breakdown rates of cis-DCE and VC are unknown. Simulations were repeated using average dispersivity values with the following results. At 60 years travel time, the highest concentration of TCE associated with the Area C plume had discharged to St. Johns River at a level exceeding 4×102 µg/L. At 100 years travel time, the highest concentration of TCE associated with the Area D plume had discharged to the river at a level exceeding 1×103 µg/L. At 200 years traveltime, the Area B plume had not begun discharging to the river. “Pump and treat” was simulated as a remedial alternative. The concentration of TCE at Area B trended rapidly downward; however, one isolated pocket of TCE remained because of the low-permeability sediments present at this area. The concentration of TCE at Area C trended rapidly downward and was below 1 µg/L in about 16 years. The concentration of TCE at Area D also trended rapidly downward and was below 1 µg/L in about 18 years. |
| Report Number | 00-255 |
| Url | https://pubs.er.usgs.gov/publication/ofr00255 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | No |
| Language Text | English |