| Chicot Aquifer, which covers a large area of south Louisiana. Pile driving or excavation operations, with the potential to puncture the existing, confining claybed, are the most significant project components with regard to potential contamination of the Chicot Aquifer from hazardous waste. Hazardous waste sites have been documented to exist in the project corridor and hazardous material could be allowed to enter the aquifer if documented and/or currently unknown contaminated areas are excavated and the confining clay layer is punctured creating a point of recharge.
None of the alternatives would impact primary recharge areas of the Chicot Aquifer, which are located in Beauregard, Allen, and Evangeline Parishes.
Construction impacts to the Chicot Aquifer would be dependent of the depth to the water bearing strata of sand and gravel underlying the Selected Alternative. Utilizing idealized geologic sections prepared by the United States Geological Survey, none of the alternatives would be anticipated to impact the Chicot Aquifer. This determination is further substantiated by recent construction of the University Avenue underpass at the Union Pacific Railroad. This project included a railroad bridge on piles and excavation for the roadway underpass, neither of which penetrated the aquifer. Avoidance of impacts to the Chicot Aquifer, which is a sole source aquifer, will continue to be coordinated with the EPA and LaDEQ as the I-49 Connector project continues to develop.
COMMITMENT:
The potential for contamination through ground water/surface water interchange will be minimized through special design techniques and plan review procedures that continue to involve the EPA, LaDEQ, and other appropriate agencies. Through such coordination, adequate safeguards will be instituted to assure compliance with state and federal regulations.
The actual aquifer layer will be identified at the time of the design phase when borings are obtained for design purposes. Design measures and construction techniques will be utilized to guard against contamination of the aquifer. See Wastes Sites.
During the construction phase of the project, close coordination with LaDEQ and EPA will be maintained to assure that adequate protection is maintained for the Chicot Aquifer.
STATUS:
See table below.
CHICOT AQUIFER
| Commitment/Mitigation Tasks | When to Occur* | Status | Date Completed | Links to Relevant Resources |
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| Coordination with EPA, LaDEQ, and other appropriate agencies | F,C | No Activity | N/A | N/A |
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| Field borings to identify precise location of Chicot Aquifer | F | No Activity | N/A | N/A |
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| Design details to guard against contamination | F | No Activity | N/A | N/A |
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| *Note: P = Preliminary Design Phase, F = Final Design Phase, C = Construction Phase |
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