Technology: In Situ Chemical Oxidation
Daisy Fresh: Other technologies used - monitored natural attenuation, enhanced fluid recovery.
- ISOTEC’s chemical oxidation process was used
- Phase I - 46 direct push (DP) points with multiple injection intervals and 12 injections wells; Phase II - 54,190 gallons of ISOTEC reagents injected
Alpine:
- Initially, an aqueous solution of ferrous sulfate and hydrochloric acid was injected.
- This was followed by hydrochloric acid and finally by a 35% solution of hydrogen peroxide; In August and September of 2001, a total of 135 gallons of a 5.5% solution of potassium permanganate was injected at the site.
Park Avenue:
- 550 gallons of a biodegradable surfactant was injected at each injection point
- 310 gallons of a proprietary catalyst solution was injected at each point
- A mixture of a proprietary acid (total of 270 gallons) and a hydrogen peroxide solution (total of 640 gallons) was injected
Spin City:
- 550 gallons of a biodegradable surfactant was injected at each injection point
- 116 gallons of a proprietary catalyst solution was injected at each point
- A mixture of a proprietary acid (total of 295 gallons) and a hydrogen peroxide solution (total of 515 gallons) was injected
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Contaminants: Chlorinated Solvents
Daisy Fresh:
(Groundwater) Chloroform - 33 μg/l; cis-1,2-DCE - 1,600 μg/l; PCE - 20,000 μg/l; TCE - 2,300 μg/l; vinyl chloride - 18 μg/l; xylenes - 16 μg/l
(Soil) 1,1-DCE - 11 μg/kg; 1,2-DCE - 47 μg/kg; benzene - 8μg/kg; chloroform - 44 μg/kg; cis-1,2-DCE - 12,600 μg/kg; naphthalene - 16 μg/kg; PCE - 219,000 μg/kg; TCE - 560,000 μg/kg; vinyl chloride - 600 μg/kg; xylenes - 87 μg/kg
Alpine: 1,1-DCE - 5.9 μg/l; cis-1,2-DCE - 3,100 μg/l; PCE - 2,940 μg/l; TCE - 1,400 μg/l; vinyl chloride - 300 μg/l. Contaminant concentrations in soil were below cleanup standards.
Park Avenue: (Groundwater) cis-1,2-DCE - 56 μg/l; PCE - 470 μg/l; trans-1,2-DCE - 4 μg/l; TCE - 150 μg/l; xylenes - 1 μg/l. (Soil) cis-1,2-DCE- 56 μg/kg; PCE - 44,590 μg/kg; TCE - 940 μg/kg; chlorobenzene - 19 μg/kg
Spin City: (Groundwater) cis-1,2-DCE - 900 μg/l; PCE - 2,900 μg/l; trans-1,2-DCE - 140 μg/kg; TCE - 320μg/l. (Soil) cis-1,2-DCE - 130 μg/kg; PCE - 47,350 μg/kg; trans-1,2-DCE - 140 μg/kg; TCE - 1,500 μg/kg |
Type/Quantity of Media Treated: - Daisy Fresh: Soil, groundwater
- Alpine: Groundwater
- Park Avenue: Soil, groundwater
- Spin City: Soil, groundwater; volume of treated soil: 172 cubic yards; groundwater treatment area: approximately 0.74 acres |
Regulatory Requirements/Cleanup Goals:
Daisy Fresh:
- Groundwater: PCE and TCE - 5 μg/l; VC - 2 μg/l; Cis-1,2 DCE - 156 μg/l. Soil: PCE and TCE - 0.5 mg/kg; VC - 0.044 mg/kg; Cis-1,2-DCE - 78.2 mg/kg
Alpine:
- PCE - 5 μg/l; TCE - 5 μg/l; cis 1,2-DCE - 70 μg/l; vinyl chloride - 2 μg/l
Park Avenue:
- Groundwater: PCE - 500 μg/l; TCE - 500 μg/l. Soil: PCE -5,000 μg/kg; TCE - 5,000 μg/kg
Spin City:
- Groundwater: PCE - 500 μg/l. Soil: PCE - 500 μg/kg; TCE - 500 μg/kg |
Description: In situ chemical oxidation was conducted at four drycleaner sites contaminated with chlorinated solvents from drycleaning operations, with TCE and PCE as the primary contaminants in groundwater. The concentration of PCE and TCE varied between the two sites, ranging from 470 to 20,000 μg/L for PCE, and 150 to 2,300 μg/L for TCE. The remediation involved in situ chemical oxidation using hydrogen peroxide at full-scale at three sites and at pilot-scale at one site (Daisy Fresh).
Contaminant concentrations at all four sites were reduced following treatment. The percentage reduction ranged from 33 to 100 percent. At one site (Daisy Fresh), concentrations of VOCs decreased at first and then increased in two wells. This was attributed to the desorption of solvents from the soil. Cost data were not provided for any of the projects. At several of the sites, monitored natural attenuation will continue to be evaluated as a remediation technology following the application of in situ chemical oxidation. |