1. Radium contamination in Denver, Colorado Colin Hall

2. Radium Atomic Number 88 25 known isotopes Extremely radioactive Half-life 1602 years Decays to Radon Gas Uses included: –Self-luminous paints –Aircraft switches –Watches –Cancer treatment

3. Radium In Colorado Carnotite Sands One of a handful of sources worldwide Mines south of Denver Mining through-out early 1900’s Remediation began in 1980’s

4. The Problem With Radium Short term –Nausea –Skin Sores Long term –Replaces calcium in bones –Carcinogenic

5. Solution Demolition and decontamination of buildings, storage tanks and equipment. Excavation of heavily contaminated soils Lining affected area Capping Water not treated

6. Case Study- Home depot. Mined 1900’s until late 1920’s Several owners until 1940 Brick and tile making factory until mid 1980’s Nearly 70,000 square metres 300m from South Platte River 8000 homes within 2 miles

7. Case Study- Home depot. 3 Partners –US Environmental Protection Agency (EPA) –State Of Colorado –Home Depot Inc Problem – Soil contaminated with radium, arsenic, zinc, and lead – Buildings and materials radioactive

9. Case Study- Home depot. 8 years Completed 1996 Contaminated buildings and materials removed Excavated 97,000 tons of contaminated soil Replaced soil strengthen with cement and fly ash Capping layer added On going monitoring

11. Case Study- Home depot. Protected public health Prevented spread of radioactive materials and heavy metals $2 million increase in worth of site $65 million increase of residential property in 2 mile radius surrounding site Improved aesthetic quality of the area

12. Summary Radium and other radioactive materials cleaned up in Denver area Groundwater still contaminated Resulted in a clean usable site Rejuvenated the area Protected the health and safety of public

13. Thank You For Listening Any Questions?