Beneficial Reuse of Sand on the Fox River Sediment Remediation Project Neil Geevers (Stuyvesant/Boskalis) Richard J. Feeney, P.E. (Tetra Tech) Terri L. Blackmar, P.E. (Tetra Tech)
Project Team Client: Lower Fox River Remediation LLC Engineering Design & Construction: Tetra Tech Dredging & Capping: J.F. Brennan Co., Inc. Desanding & Dewatering: Stuyvesant Projects Realization Inc., affiliate of Boskalis Dolman • Anchor QEA, LLC: assist with design • URS: assist with modeling • Numerous local construction subcontractors
• • • •
Project Scope OU 2 – 5 // 13 MILES (21 KM) // COMBINED REMEDY // THE GOAL OF THE PROJECT IS TO REMEDIATE PCB BEARING SEDIMENT BY DREDGING, CAPPING, OR COVERING // HYDRAULIC DREDGING // SEDIMENT PROCESSING & SAND REUSE // WATER TREATMENT // OFFSITE T&D
Processing Facility DESIGN STARTED IN MARCH 2008// BEGAN PROCESSING APRIL 2009// UNIQUE SINGLE STREAM PROCESS // 150‐250 IN‐SITU CY/HR (190 M3/HR) // 6000 GALLON/MIN. (1,400 M3/HR) // 6 ACRE BUILDING (2.4 HA) // AIR QUALITY CONDITIONED
Objective One objective of the Fox River processing facility is to minimize the contaminated volume disposed of at the landfill by beneficial use of the separated coarse fractions (sand) and by dewatering the fine (contaminated) fraction
Three phase treatment 1) PRE‐CONDITIONING // 2) SAND SEPARATION AND POLISHING FOR BENEFICIAL USE (ABOUT 19% SAND), TWO SAND FRACTIONS ARE SEPARATED // 3) MECHANICAL DEWATERING
Why Separate Sand? • Prevent additional wear and tear on downstream process equipment • Reduce the dewatering cycle time from not having to process the sand • Avoid unnecessary expense for T&D as waste • Avoid consuming landfill space • Various beneficial reuse opportunities
Separated Sand Parameters • • • • • •
~ 18,000 tons of sand separated in 2009 ~ 56,000 tons of sand separated in 2010 ~ 22,000 tons of sand separated in 2011 ~ 19,000 tons of sand projected for 2012 Coarse sand ranges from 150 µm to 6 mm Fine sand ranges from 63 µm to 150 µm
Recovered sand outside of processing facility
Stockpiled & covered; awaiting load‐out for reuse
Sampling Parameters • Fine & coarse sand sampled once each 1,000 cy for the first 10,000 cy • Then one sample/10,000 cy for 10,000 to 50,000 cy • Then one sample/50,000 cy thereafter • 2009 chemistry: 27 fine sand samples and 10 coarse sand samples • 2010 chemistry: 39 fine sand & 32 coarse sand • 2011 chemistry: 11 fine sand & 12 coarse sand
Chemical Testing Criteria for Sand Proposed Constituents
Project-Specific Maximum Allowable Contaminant Concentrations (mg/kg)
PCB, Total . Total 2,3,7,8 TCDD Total 2,3,7,8 TCDF DDT (and its metabolites DDD & DDE) Arsenic Barium Cadmium Chromium Copper Cyanide Iron Lead Manganese Mercury Nickel Selenium Zinc
0.49 (mg/kg) 0.19 (ug/kg) 0.19 (ug/kg) 1.0 9.8 500 7.8 14.5 150 100 20,000 50 1100 4.7 250 63 1500
Additional Notes – Sand Testing Criteria • Geotechnical Properties Î For information only: – – – –
Grain size Percent solids Total organic carbon Moisture content
• WDNR provided Project Specific Maximum Allowable Contaminant Concentrations in December 2008 Î The concentrations shown pertain to sand that is not capped in place, and are therefore conservative if applied to sand that will be capped.
Chemical Characteristics Average PCB Concentration (ppm) vs. target of 0.49 ppm
2009
2010
2011
Fine sand (63 µm to 150 µm)
0.262
0.181
0.137
Coarse sand (150 µm to 6 mm)
0.353
0.111
0.075
Running average (combined fractions)
0.280
0.148
0.100
Beneficial Reuse Process • Prepare and submit Low Hazard Waste Exemption Request naming specific offsite projects (*one Request per project) • Public works projects are preferred • Address WDNR comments to the Request • Participate in public meeting concerning the Request • Finalize commercial arrangements • Provide appropriate temporary erosion controls at the beneficial reuse site • Track and report on sand shipped for beneficial reuse.
Win ‐ Win for 2 Major Regional Projects