Managing Water Quality Silver Bow Creek 2011 Update

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MANAGING WATER QUALITY SILVER BOW CREEK

2011 UPDATE REMEDY MUST PROTECT

HUMAN HEALTH AND ENVIRONMENT WATER QUALITY STANDARDS

YARDSTICK OF PROTECTION

SILVER BOW CREEK ROD Points of Compliance

GROVE GULCH SS-4 SS-5 SS-5A SS-6A SS-6G SS-07

ROD

SS-6A AT THESE STATIONS THESE AT MUST MEET STANDARDS MEET MUST HARDNESS BASED STANDARD Cd Cu Zn

STANDARD= exp{m [ln(hardness)]+ b } A A

MONITOR 2 FRACTIONS

DISSOLVED = metal ions

TOTAL RECOVERABLE = ions + suspended sediment

FEDERAL STANDARD DISSOLVED FRACTION (Direct Effect on Aquatic Life)

STATE STANDARD (DEQ-7) TOTAL RECOVERABLE FRACTION (Indirect Effect on Aquatic Life – Gut)

NUMERICALLY THE SAME SURFACE WATER MANAGEMENT

• BASEFLOW WATER QUALITY CONTROL GROUND WATER

• STORMWATER QUALITY BEST MANAGEMENT PRACTICES

BASEFLOW Includes: • Low Flow = July through February Ground Water

• High Flow = April through June Mountain Snow Melt Mountain Snow Melt Surface Water - Base Flow

ROD REQUIRES

• Capture and Treat Contaminated Ground Water to Prevent Discharge to Silver Bow Creek

• Meet Chronic Standard in Stream as Measured at POCs

USGS STATION SS-07

COMPLIANCE WITH ZINC STANDARDS - SILVER BOW CREEK

8 TR Zn Ratio Compliance D Zn Ratio 6

4 ZNCompliance STD Ratio 2

0 Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 USGS STATION SS-07

COMPLIANCE WITH COPPER STANDARD - SILVER BOW CREEK

20 TR Cu Ratio 18 Compliance 16 D Cu Ratio

6 CuCompliance STD Ratio 4

0 Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- Jan- 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 Average of 2009 2010 Data

BIGGEST REMAINING PROBLEM

RAIN AND SNOW-MELT RUNOFF

Surface Water – Storm Flows

• ROD REQUIRES – Best Management Practices (BMP) Program to Address Contaminated Storm Water Runoff – 15 Years

• ROD REQUIRES – If BMPs Don’t Achieve Acute Standards in Silver Bow Creek - Capture and Treat Contaminated Runoff STORMWATER BMP PROGRAM ITERATIVE PROCESS

MONITORING

RETENTION PONDS (CATCH BASINS)

HYDRODYNAMIC DEVICE ROUTING AND DIVERSIONS

RECLAIM SOURCE AREAS

STORM SEWER UPGRADES Storm Water BMPs To Date

• Cap Wastes

• Diversions to Berkeley Pit

• Missoula Gulch – storm water retention basins

• MSD Channel Reconstruction RECLAIM MISSOULA GULCH RETENTION BASINS MODEL BMP

2007 Wet Weather Dissolved Copper Compliance Ratio - by Event 3/6/2007

5.0 3/7/2007

5/3/2007

4.0 5/21/2007

5/24/2007 3.0

5/27/2007

2.0 6/5/2007

6/6/2007

1.0

7/18/2007 Compliance Ratio (Concentration/Acute Standard) Compliance (Concentration/Acute Ratio 9/5/2007 0.0 SS-01 SS-04 SS-05 SS-05A SS-06G SS-07 9/18/2007 Station 2007 Wet Weather Total Recoverable Copper Compliance Ratio - by Event 3/6/2007

1,000 3/7/2007

NOTE LOGRITHMIC SCALE 5/3/2007

100 5/21/2007

5/24/2007

5/27/2007 10

6/5/2007

6/6/2007 1

7/18/2007 Compliance Ratio (Concentration/Acute Standard) Compliance (Concentration/Acute Ratio 9/5/2007 0 SS-01 SS-04 SS-05 SS-05A SS-06G SS-07 9/18/2007 Station Storm Water In-Stream Dissolved Copper Data Summary - Post 2005

10 8.7

6.4

4.6

3.8 3.9 3.5 3.5

1.9 1.7 1.6 1.6 1.5 1.4

1 Legend

0.7 Maximum

3rd Quartile

Median Compliance Ratio (Concentration/Acute Standard) (Concentration/Acute Ratio Compliance

1st Quartile

Minimum Note: A compliance ratio >1 indicates exceedance of the acute standard. 0.1 SS-01 SS-04 SS-05 SS-05A SS-06A SS-06G SS-07

Station Storm Water In-Stream Total Recoverable Copper Data Summary - Post 2005

1000 695 NOTE LOGRITHMIC SCALE

292 261 192 165 119

100

26 21.1 13.9 13.4 10.0 8.2 10 Legend

4.9 Maximum

2.4 3rd Quartile

1 Median Compliance Ratio (Concentration/Acute Standard) (Concentration/Acute Ratio Compliance

1st Quartile

Minimum Note: A compliance ratio >1 indicates exceedance of the acute standard. 0.1 SS-01 SS-04 SS-05 SS-05A SS-06A SS-06G SS-07

Station

Buffalo Gulch

• Storm Sewer Network - Direct to Silver Bow Creek

• No Retention Basin

• Diversion Only Upper-Most Drainage

Buffalo Gulch Dissolved Copper

BUFFALO GULCH MOUTH Dissolved Copper Compliance With Acute Std Ratio

12 Exceedance Rate = 100% 11

5 Ratio(Conc/Acute Std) 4

0 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08

Cu D ratio Metro Storm Drain

• Channel Reconstructed 2003-2005

• Storm Sewer Network To MSD - Direct to Silver Bow Creek

• No Retention Basin

• Diversions To Pit Upper Anaconda Road

MSD Dissolved Copper

METRO STORM DRAIN Dissolved Copper Compliance With Acute Std Ratio

15 100% Exceedance Rate since reconstruction 14

Ratio(Conc/Acute Std) 5

0 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08

Cu D ratio BUFFALO STORM FLOW Sharp Peak Short Duration

MSD STORM FLOW Broad Peak Long Duration BMP Program – Next Steps

• MAJOR FOCUS –Buffalo Gulch –Metro Storm Drain • Hydrodynamic Devices • Upgrade Storm Sewers • Divert From Silver Bow Creek

•Retention Basins UNDEVELOPED AREAS IT COULD LOOK LIKE THIS REMEDY MUST PROTECT

HUMAN HEALTH AND ENVIRONMENT ROD SECTION 15 Coordination With Natural Resource Damage Restoration Actions

The EPA will work with the Trustee in the design and implementation of the remedial action to coordinate the implementation of the Selected Remedy with restoration actions to avoid duplication of effort and unnecessary costs and to maximize benefits to the area, where feasible and practical, and where coordination will not result in substantial delays to remedy implementation. STORM WATER REMEDY 15 YEARS

REQUIRES PATIENCE In Perpetuity

is a long time