Subject: Superfund Proposed Plan
Escambia Wood Treating Company (ETC)
Operable Unit 2 – Groundwater, Solid Waste Management Unit 10
It is appreciated that the Environmental Protection Agency (EPA) has expanded the Proposed Plan to address the contaminants in the ground water and soils containing free phase creosote non-aqueous phase liquid (NAPL) and non-mobile residual NAPL. EPA’s plan to issue an Amended Record of Decision to address all of the contaminants and their various physical states associated with the Solid Waste Management Unit 10 (SWMU 10) is an appropriate approach.
On October 1, 2006, Citizens Against Toxic Exposure (CATE) submitted comments on the “Technical Memorandum for the Remedial Alternatives for Groundwater at the Escambia Wood Treating Site (OU2).” In the com- ments, the following was included: “Section 1.3 contaminant migration pre- sents the possibility of free product residual, free phase product and free product source area to exist in the ground water at the ETC site. The remedial alternatives fail to specifically address the remediation of the area or areas of free phase materials.” It is time that the free phase material be de- fined as consisting of NAPL and non-mobile residual NAPL in soils which are serving as the source of ground water contamination. The NAPL is pre- sent in lateral lenses in four feet to 50 feet thick layers and consists of 200,000 to 300,000 gallons of NAPL creosote. The NAPL creosote is acting as a source area of ground water contamination.
The plans for the remedy are to remove the free phase NAPL and non- mobile residual NAPL that are serving as the source area for the extensive ground water contamination. The remedy of complete removal of the sources of contamination is an appropriate approach, due to the need to return the three aquifer zone layers of contaminated ground water in the area of the Escambia site, and offsite up to 1.5 miles or greater, to their beneficial uses and original quality prior to the Escambia Treating Company locating in Pensacola.
Alternative S4 for SWMU 10 consists of Steam Enhanced Extraction (SEE) and in-situ Enhanced Bioremediation, with Surfactant Enhanced Aquifer Remediation and insitu Chemical Oxidation, if necessary. This rem- edy is the appropriate remedy to be implemented in the source area.
The alternative S4 for the Highly Adsorbed Phase Area (HAPA) consists of Surface Enhanced Aquifer Remediation, in-situ Chemical Oxidation and Enhanced Bioremediation. This is an appropriate remedy for the HAPA.
Critical to the evaluation of the performance of the remedy is the need to install injection and extraction wells over the HAPA and the installation of performance evaluation monitoring wells. These wells are critical to evalu- ating the progress of the remedial activities.
Possible Continued Contamination Migration
If the source area is not appropriately addressed, the contaminants will continue to leach into the ground water resources both laterally and vertically. This is why CATE members were so concerned in October 2006 with the presence of free phase materials under the area of the old waste water pond and landfill. These materials have continued to leach and contaminate additional ground water resources since CATE focused on the source material contamination. It is extremely important that EPA select and implement the appropriate remedy to remove the source area free phase contaminants and perform the remedy as quickly and efficiently as possible.
Other Alternative Remedies
Alternative S4 is the appropriate remedy for SWMU 10. The other pro- posed alternatives for addressing the contaminants in the Source Area are unacceptable because they would leave the contaminants in place. Even with solidification of the waste or isolation of the waste, the potential threat to groundwater from the waste remaining in place in the Source Area is un- acceptable.
During the remedial design phase of OU-2, SWMU 10, EPA needs to fo- cus on controlling air emissions of Volatile Organic Compounds and Semi- Volatile Organic Compounds and prevent the emissions from being re- leased into the air as the free phase NAPL is mobilized and extracted from the source area. Controlling the toxic air emissions is critical to protecting the health of workers on the Escambia site as well as workers and individuals in the surrounding area. Adequate vapor collection systems and ex- traction systems, as well as monitoring devices, must be designed and required to be utilized during the remedy implementation phase.
EPA must also ensure during the design phase that techniques are de- veloped and required to be implemented to control the NAPLs when the NAPLs are mobilized and brought to the surface to be recovered. Methods need to be employed that capture the mobilized NAPL waste so that the NAPL waste is not allowed to migrate out of the source area, contaminate additional ground water resources and contribute to additional ground wa- ter pollution.
EPA must be required to install and utilize sufficient ground water moni- toring wells in all three ground water zones to track contamination move- ment and insure additional contaminants are not moving into the outer ar- eas of contamination as a result of the implementation of the remedy.
Contaminants of Concern
The contaminants of concern associated with the Ground Water Oper- able Unit 2 consist of 16 chemicals. Each of the 16 chemicals has a clean- up level in ug/l based on Florida Department of Environmental Protection and Groundwater Cleanup Target Levels. All 16 of these chemical stan- dards must be applied to the Escambia ground water contaminants as cleanup criteria. The chemicals are associated with the creosote and Pen- tachlorophenol used to treat the wood products, #6 diesel fuel used to dis- solve and carry the Pentachlorophenol as a treating chemical and Dibenzo- furan, a byproduct of the manufacturing process of Pentachlorophenol. The cleanup levels in ground water range from 0.2 ug/l for Benzo(a)pyrene, a component of creosote, to 140 ug/l for 2,4-Dimethylphenol, a component of Pentachlorophenol.
The ground water contaminants are present in the three aquifer zones impacted by the ETC site. These ground water zones consist of the surficial zone, low permeability zone, and main production zone. All three ground water zones must be remediated to the clean up levels for all 16 chemicals to ensure that the aquifer water quality is returned to its beneficial use of drinking water quality.
We appreciate the opportunity to comment on the proposed plan for the Escambia Wood Treating Company Operable Unit 2 – Ground Water SWMU 10.
P. O. Box 9813
New Iberia, LA 70562
337 367 2216 firstname.lastname@example.org
Citizens Against Toxic Exposure
1120 North G Street
Pensacola, Florida 32501
850 432 2228 email@example.com firstname.lastname@example.org