# ARCO - SILVER BOW CREEK/BUTTE AREA
> **Judicial** · FY1991 · — · Combined With Another Case(s)
## Case
- **Activity ID:** `48950`
- **Case Number:** 08-1991-0121
- **Type:** Judicial
- **Lead:** EPA
- **Outcome:** Combined With Another Case(s)
- **Penalty assessed:** —
- **Cost recovery:** —
- **Compliance action $:** —
- **Multimedia (multi-env):** N
## Defendants
- ANACONDA MINING COMOANY (complaint) (settlement)
- ARCO (complaint) (settlement)
## Summary

THE CLARK FORK BASIN SUPERFUND SITES ARE A SERIES OF FIVE    GEOGRAPHICALLY CONNECTED SUPERFUND SITES IN SOUTHWESTERN     MONTANA. THE SILVER BOW CREEK/BUTTE AREA (ORIGINAL PORTION)  SUPERFUND SITE (SBCO) IS PART OF THE CLARK FORK BASIN        COLLECTION OF SUPERFUND SITES. THE SITE BEGINS AT THE        HEADWATERS OF SILVER BOW CREEK NEAR BUTTE IN SOUTHWEST       MONTANA, PROCEEDS DOWN SILVER BOW CREEK TO THE WARM SPRINGS  PONDS, WHERE IT NOW ENDS. AT ONE POINT, THE SITE CONTINUED   DOWN THE CLARK FORK RIVER TO THE MILLTOWN RESERVIOR FIVE     MILES EAST OF MISSOULA.                                      MINING, MILLING AND SMELTING ACTIVITIES, CONDUCTED FOR OVER  100 YEARS IN THE AREA, PRODUCED SUBSTANTIAL QUANTITITIES OF  WASTE CONTAMINATED WITH HEAVY METALS. THESE WASTES WERE      DISCHARGED OR DUMPED INTO SILVER BOW CREEK, WARM SPRINGS     CREEK, AND THE CLARK FORK RIVER. THE CONTAMINATED WASTE      ENTERED THE RIVERS IN THE FORM OF SUSPENDED SEDIMENTS        PRIMARILY FROM TAILINGS AND SMELTER WASTE AND DISSOLVED      METALS PRIMARILY FROM ACID MINE WATER.  THE WASTES CONTAIN   CONCENTRATED ARSENIC, LEAD, CADMIUM, ZINC, AND COPPER, AS    WELL AS OTHER METALS. IN ADDITION TO CONTAMINANTS FROM THE   BUTTE MINING OPERATIONS, THE MONTANA POLE AND ROCKER WOOD    TREATING FACILITIES CONTRIBUTED TO THE CONTAMINANT LOAD OF   SILVER BOW CREEK. BOTH WOOD TREATING OPERATIONS USED         PENTACHLOROPHENOL AND CREOSOTE WHICH SEEPED INTO SILVER BOW  CREEK. THE ROCKER PLANT SITE ITSELF 

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*Source: [EPA ECHO](https://echo.epa.gov/) · AI Analytics · CC0 1.0*