Eden Remediation Services Kenneth Summerour, P.G.

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1 Prepared by: Eden Remediation Services Kenneth Summerour, P.G. 601 S. Madison Avenue, Suite 60 Monroe, GA Office: /Cell:

2 Overview Remedial Technologies Subsurface Injection Techniques Soil Blending Methods Case Studies

3 Overview of Remedial Technologies Chemical Oxidation (ISCO) Chemical Reduction (ISCR) Enhanced Bioremediation (ISB) Surfactant Applications

4 Chemical Oxidation (ISCO) Breaking bonds of organic molecules and inserting oxygen End products are carbon dioxide, water, and harmless salts ISCO applied via direct push rod train, injection wells, or blending methods Useful on source areas or full scale treatments Success requires contact with contaminated media (both saturated soils and impacted groundwater) 4

5 Common Chemical Oxidants Fenton s Reagent H 2 O 2 + Fe +2 OH - + OH - + Fe +3 Catalyzed Hydrogen Peroxide (iron chelation) Calcium Peroxide/Modified Fenton s (iron chelation + acidic modifier) Sodium Persulfate S 2 O activator SO (SO 4.- or SO 4-2 ) Sodium and potassium permanganate (ideal for chlorinated ethenes) Ozone (gas, requires ozone generator)

6 Chemical Reduction (ISCR) ISCR involves the addition of electronsmirror image of ISCO Abiotic reactions usually result in less daughter product formation Used on chlorinated plumes, metals, explosives, etc. Applied via direct injection and solid phase PRBs (goal of developing reducing zones) Examples: ZVI, nzvi, iron sulfides, polysulfides, dithionites, etc. 6

7 Enhanced Bioremediation (ISB) ISB involves the injection or addition of nutrients to stimulate microbial degradation Petroleum hydrocarbons commonly reduced aerobically Treatment Train : ISCO + aerobic biostimulation Sulfate reducing bacteria - petroleum fuels or add iron for treatment of chlorinated VOCs Chlorinated VOCs treated anaerobically reductive dechlorination (lactate, soybean oils, etc.) 7

8 Surfactant Treatments Surfactants are soluble in both oil (fuel) and water Used for NAPL removal by creation of emulsions Extraction required following emulsification Variety of surfactant products available depending on type of NAPL Follow-up monitoring needed to ensure surfactant impact & removal 8

9 Comparison of Remedial Technologies Speed of reaction: ISCO ISCR ISB Source area treatments: ISCO or surfactants ISCO can treat NAPL and higher dissolved Large plumes ISCR/ISB more cost effective Treatability testing aids in comparison Consider multiple technologies

10 Subsurface Injection Technologies Direct Push Injection Target discrete zones Allows higher pressure injection (ZVI/slurries) Difficult in tight formations/surfacing Additional wells often needed for monitoring Injection Wells Constructed with PVC, CPVC, Stainless Steel Grout seals better in tight formations Easier geochemical monitoring Facilitates multiple point injection Cost savings with multiple injections

11 Successful Injections Require: Source area characterization/vertical contaminant profile Good estimate of pore treatment volume Direct contact (especially ISCO/surfactants) Delivery method suited to site conditions Sufficient delivery volume/don t under dose Measure contact in the field!

12 Soil Blending Methods: In-Situ In-Situ blending performed using excavators or augers Offers maximum contact Eliminates waste generation Treat soils AND groundwater together Allows treatment of low permeability soils Green friendly alternative to off-site land filling

13 Soil Blending Methods: Ex-Situ Ex-situ blending involves removal prior to treatment Soils typically screened and blended in a pug mill Soils can be stabilized after treatment for re-use Lower cost alternative to hazardous waste landfilling

14 Select Case Studies 1) VCP Soil Blending Site (AL) 2) Dry Cleaner Texas 3) Wood Treatment Facility (South GA) 4) Industrial Site (Atlanta area) 5) Former Lagoon (Upstate NY) 6) Former Auto Dealer (NW GA)

15 Alabama VCP Site Soil Blending Overview Releases - former paint solvent ASTs Assessment identified LNAPL and VOCs (naphthalene and toluene) Highest total VOCs: 1,000-5,000 ppm ADEM required haz disposal- blending offered as an alternative Treatability study identified CHP + sodium persulfate + iron chelate Treatment performed on 300+ tons of soil from 2-10 Confirmatory sampling indicated VOC reduction to below risk target levels No costly offsite removal required Cost < $75,000, NFA received

16 Soil Concentrations (mg/kg) VCP Site (cont.) Soil Blending Results 1,000 PRE AND POST SOIL BLENDING RESULTS Methyl-2-Pentanone Ethylbenzene Isopropylbenzene Methylcyclohexane Naphthalene Tetrachloroethene Toluene Xylenes (total) Baseline Post Blending

17 Former Dry Cleaner - Montgomery Co., Texas Overview Release of PCE and daughters, max VOCs >1,000 ppb DTW ft-bgs, water bearing silty-sand confined by SC/clay PCE degradation products suggested past reductive de-chlorination Risk based treatment goal: < PCLs (protective concentration limits)

18 Former Dry Cleaner - Montgomery Co., Texas Results ISCO treatment designed utilizing iron activated sodium persulfate (15-20% solution) Three injection treatments performed targeting source area and down-gradient Confirmatory sampling indicated results <PCLs A NFA later received allowing redevelopment

19 Wood Treatment Facility Overview Site Former Impoundment Site in Coastal Plain Province near Okefenokee Swamp Creosote and pentachlorophenol (PCP) impact in surface impoundment NAPL present & dissolved PAHs to Proposed Corrective action includes ISCO-soil blending & down-gradient PRB

20 Wood Treatment Facility (cont.) Treatability Approach A treatability study indicated either soil blending or ISCO would be most effective using CHP followed by potassium permanganate 350, , ,000 TREATABILITY RESULTS Anthracene Benzo(a)pyrene Chrysene 200,000 Fluoranthene 150, ,000 50,000 0 Control 15% H2O2 15% H2O2 and 0.1% PMG

21 Wood Treatment Facility (cont.) Soil Blending An initial soil blending pilot in 2010 resulted in NAPL removal from CHP-permanganate oxidation Follow-up pilot in 2012 used high volume dose of CHP only with significant reduction observed < target goals Full scale treatment pending following PRB installation

22 Industrial Facility Overview A small PCE solvent plume was identified in an industrial park outside Atlanta, GA Maximum PCE concentrations ppb Iron-rich saprolite at a depth of feet Goal was PCE reduction < MCL (5 ppb) Treatability study indicated sodium persulfate with natural iron activation most effective Injection performed into 15 delivery wells 22

23 Industrial Facility (cont.) Treatment Results Confirmatory sampling conducted 45, 90, and 120 days post injection indicated non-detect concentrations of PCE and degradation products after a single injection Pre Injection Post Injection

24 Former Lagoon, Upstate NY Overview IW -5 IW -4 Lagoon Well 2 Lagoon Well 1 IW -1 IW -3 IW -2 Site contains two former solvent disposal lagoons (1,1,1-TCA, DCE etc.) Limited soil excavation performed in the source area Groundwater pump-and-treat system installed VOCs detected in alluvial sediment and fractured sandstone formation (15-20 feet)

25 Former Lagoon (cont.) Treatment Process ISCO treatment performed using alkaline activated persulfate to lower source area VOCs (1,000-5,000 ppb) Geochemical monitoring indicated significant oxidant impact (see graph) Confirmatory sampling indicated VOC reduction Further treatment is pending 25

26 Former Auto Dealer Overview Auto dealership constructed in low lying swamp Valley and Ridge Province, Conasauga Formation (limestone) Groundwater depth 4-13 ft-bgs in silty-clay/sandy-silt soils Separate releases of gasoline and waste oil/chlorinated VOCs discovered, plume >200 LNAPL detected in 22 wells, thicknesses >1 Site

27 Former Auto Dealer (cont.) Geologic Cross-Section

28 Former Auto Dealer (cont.) ISCO Treatment Summary ISCO injections performed using CHP and activated persulfate Separate ISCO injection performed using potassium permanganate to treat vinyl chloride Results indicated complete LNAPL removal and desired reduction in dissolved phase Leading edge of plume treated/controlled Vinyl chloride eliminated with one injection NFA achieved allowing sale of the property

29 Former Auto Dealer (cont.) MW-10: south end under building

30 Subsurface Remediation is Attainable! Keep at it, and remember to: Measure contact in the field Start with a good estimate of cleanup mass and volume Choose the right chemistry treatability testing is always recommended Design a best-fit strategy (i.e. soil blending, injection, and down-gradient PRB) Follow a performance monitoring plan to expedite site closure

31 Eden Remediation Services Services We Offer PRB Design and Implementation Remedial Design/System Optimization Rapid Closure Strategies Chemical Injections (ISCO/ISCR) Enhanced Bioremedial Approaches Surfactant Applications