Groundwater Contamination at Hanford

Through a network of more than 1,500 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. 

Major groundwater radiological plumes on the Hanford Site and their impact on the Columbia River

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

 

Major groundwater chemical plumes on the Hanford Site and their impact on the Columbia River

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