  |
|
|
Through a network of more than 1500 wells, scientists keep track of groundwater contamination at Hanford. This brochure outlines Ecology's main concerns regarding groundwater. The Pacific Northwest National Lab prepares an annual report on Hanford Site Groundwater Monitoring. The tables below show the contaminants of greatest concern.
|
Contaminant |
General Location |
Approximate Plume Size |
Reached the Columbia River |
Observed Concentration in Wells Nearest River (Over drinking water standard) |
Highest Plume Concentration (Over drinking water standard) |
Remedy in Place |
|
Strontium-90 |
Mainly N, B, C Reactor areas (river corridor) and 200 East Area |
.4 Square Miles |
YES |
9,000 pCi/L Pico curie per liter (measure of radioactive decay) |
18,000 pCi/L in N area |
Yes, Pump and Treat in N area to stop Sr-90 entering river |
|
Iodine-129 |
Sitewide |
33 Square Miles |
NO |
None |
24.8 pCi/L in 200 W (ZP-1) |
No, no practicable treatment technology for dispersed plume |
|
Tritium |
Sitewide |
70 Square Miles |
YES |
39,100 pCi/L in aquifer tubes in N area |
2,320,000 pCi/L in 300 area |
No, disperse with short half life |
|
Uranium |
300 and 200 West Areas |
.4 Square Miles |
YES (300 area) NO (200 W) |
127 pCi/l in 300 area |
2,258 pCi/L |
Yes, Pump and Treat in 200 West No, source control only in 300 area |
|
Technetium-99 |
200 West Area |
.3 Square Miles |
NO (predicted within 80 years) |
None |
22,867 pCi/L |
Yes, Pump and Treat for containment and mass reduction |
|
Contaminant |
General Location |
Approximate Plume Size |
Reached the Columbia River |
Observed Concentration in Wells Nearest River (Over drinking water standard) |
Highest Plume Concentration (Over drinking water standard) |
Remedy in Place |
|
Chromium |
Mainly H, D, K reactor areas (river corridor) |
1 Square Mile |
Yes |
390 ppm |
2,130 ppm |
Yes, Pump and Treat in H, D, K and ISRM barrier in D to prevent Cr-6 from entering the river |
|
Carbon Tetrachloride |
200 West Area |
4.2 Square Miles |
No (predicted within 80 years) |
None (expected to be 3,000 ppb in 100 years) |
6,500 ppb |
Yes, Pump and Treat and vapor extraction for containment |
|
Nitrate |
Sitewide |
16 Square Miles |
Yes |
491 ppm in aquifer tubes in N area |
3,430 ppm in 200 West Area |
No, extent and dispersion of plume makes treatment impracticable |
Copyright © Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.html.
