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An investigation using an x-ray fluorescence (XRF) field meter was conducted on an old Navy vessel into the source of dissolved copper in stormwater discharges. The vessel was moored at the Suisun Bay Reserve Fleet in Benicia, California. Though source control is the preferred method of reducing or eliminating contamination in stormwater. In this case, that was not practical as the source of the copper was a giant Single Anchor Leg Mooring (SALM) mounted on the deck of the vessel. Following the investigation, custom stormwater BMPs were installed to remove dissolved copper from the stormwater discharges.
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Copper Source Tracking Using X-Ray Fluorescence and Design of Custom
Stormwater BMPs Suisun Bay Reserve Fleet, California
StormCon Portland, OR August 6, 2014
Ryan Janoch, PE David Elias, CEG, CHG
Mapistry California Water Board
Overview
• Site History/Stormwater Background
• Site Specific Target Concentrations
• Exceedance Investigation
• Custom BMPs
• Applications
Suisun Bay Reserve Fleet
▪ Aka “Mothball Fleet” or “Ghost Fleet”
▪ Benicia, California
▪ Operated by US DOT Maritime Administration (MARAD)
▪ Retention and non-retention vessels (USCG, Navy, MARAD)
Suisun Bay Reserve Fleet 4
Suisun Bay Reserve Fleet 5
Conditions in 2006
6
Water Quality Concerns
• Discharge of metals during in-water hull cleaning
• Metals accumulation in sediments
• Metals discharge from exfoliated paint and metals in stormwater
7
Enrollment in the California
Industrial Stormwater Permit
8
Sweeping/Vacuuming
9
Data were Collected
• Before: original condition
• After sweeping
• After both sweeping and
hydroblasting
10
Questions asked
1. Does sweeping work?
2. Does hydroblasting work?
3. Sweeping vs. Hydroblasting?
4. Realistic target concentrations?
11
Original Conditions Collected from October 2009 to April 2010, total metals
Results in µg/L Average Maximum Target
Copper 77 520 63.6, 3.1
Lead 125 1,200 81.6, 2.5
Zinc 2,079 12,000 117, 81
Post Sweeping
Collected from Dec. 2010 through March 2011
Results in µg/L Average Maximum
Copper 28 (down 64%) 110
Lead 24 (down 81%) 210
Zinc 1099 (down 48%) 5,300
Roanoke
Results in µg/L Start Sweep Hydroblast
Copper 97 14 (86 %) ND (100 %)
Lead 6.6 0.5 (93 %) ND (100 %)
Zinc 1,700 370 (79 %) ND (100 %)
Setting Target Concentrations
Step 1 results Average (µg/L) Maximum (µg/L)
Copper 37 210
Lead Total 23 290
Zinc Total 499 3,500
Step 2 targets New (µg/L) Old (µg/L)
Copper 210 63.6, 3.1
Lead 290 81.6, 2.5
Zinc 3,500 117, 81
Response to Site Specific
Target Concentrations
Site Specific Target Concentrations
• Copper 210 ug/L
• Lead 290 ug/L
• Nickel 31 ug/L
• Zinc 3,500 ug/L
Exceedance
▪ Mt. Washington
▪ November 2012 sampling event
▪ Total Copper 3,000 ug/L
▪ Dissolved Copper 2,600 ug/L
Mt. Washington Historical Data
Target
(ug/L)
Sampling Results (ug/L)
Mar-14
2011
Mar-13
2012
Oct-22
2012
Nov-28
2012
210 1,100 2,800 2,900 3,000
Current BMPs ▪ Non-Structural Controls
▪ Sweeping ▪ Structural Controls
▪ Coconut mats ▪ Perlite wattle ▪ Walnut shell wattle ▪ Oil adsorbents ▪ Scupper screens
▪ Focus ▪ Solids ▪ Petroleum ▪ Metals
Investigation
▪ Potential sources: grease, lubricants
▪ Screening using X-Ray Fluorescence (XRF)
XRF - Field Screening Tool
Commonly used for:
▪ Metals in soils
▪ Lead paint in toys
▪ Contaminated dry wall (strontium)
Results
▪ 19 surfaces screened
▪ Equipment and superstructure surfaces (non-detect to 10,000 ppm)
▪ Elevated levels on SALM
SALM
▪ Single Anchor Leg Mooring ▪ Underwater anchor for
fueling operations ▪ Allows for fueling in higher
seas ▪ Mt. Washington is off-shore
fueling tanker ▪ SALM is 55’ by 140’ ▪ Mt. Washington is 100’ by
700’
SALM Copper Leaching
▪ Ablative paint coating
▪ Confirm leaching
▪ Distilled water on SALM surface
▪ 640 ug/L dissolved copper
Options ▪ Source Control
▪ Re-paint ▪ Cover (shrink wrap)
▪ Treatment ▪ BMPs ▪ Existing
▪ Considerations ▪ Environment ▪ Costs ▪ Human health ▪ Applicability ▪ Feasibility ▪ Scraping schedule
Column Test
Modified zeolites Dissolved Copper
Influent 640 ug/L Effluent <100 ug/L >80% removal rate
Customized BMPs
▪ Two media types for metal removal
▪ Two configurations
▪ Filter bags
▪ Filter socks
▪ Check dams and over
scupper drains
Planned Wet Season Monitoring ▪ Hydraulics ▪ Treatment Performance ▪ Maintenance/longevity ▪ Deployment
Major Source Control ▪ Mt. Washington scrapped prior to wet
season
Similar Approach Petroleum Exceedances
▪Source Investigation ▪Custom BMPs ▪Wet Season Monitoring
Custom BMPs
Wet Season Monitoring
Program Highlights
• Site specific target concentrations
• Regular monitoring of stormwater discharges
• Routine inspection, sweeping, and BMP replacement
• Aggressive exceedance investigations
• Innovative BMP implementation
Applications
▪ Facilities’ Industrial stormwater permits
▪ Pollutant source tracking
Closing
Acknowledgements Bryan Vogel, Erick Lawlor, and Joe Pecoraro (MARAD) Andrea Brown (Terraphase Engineering) Mike Dieckhaus (Tetra Tech)
Questions?
Ryan Janoch Mapistry
David Elias California Water Board
