9.0 Fourth Record of Decision (ROD): 2003

9.0 Fourth Record of Decision (ROD): 2003

Record of Decision:  September 30, 2003

Document: Located under Record of Decision Links

The fourth ROD was signed on September 30, 2003 in order to address remediation of site-wide soil, sediments in the Delaware River and Crafts Creek, and groundwater.  It also amended the Record of Decision for OU-3, the slag area.

9.1 Areas of Concern (OU-5):

• Soils
• Sediments
• Groundwater

9.2 Human Health Risk Assessment/Environmental Risk Assessment:

For the soil and sediment component of OU-5, the remedial action needed to prevent human exposure to the site-wide soils, sediments and slag material based on current and future uses.  The remedy needed to reduce risk to ecological receptors from exposure to contaminated soils and sediments. As well as minimize migration from soil, sediments, and slag material to the groundwater and surface waters.  The groundwater needed to be restored to the drinking water standard within a reasonable time frame.  EPA Region 2 has determined that it is technically impracticable to restore groundwater to meet ARARs and invoked a Technical Impracticability waiver for the Site.

9.3 Description of Alternatives

Soils

• Alternative SL1: No Action
• Alternative SL2: Limited Action
• Alternative SL3: Containment
• Alternative SL4: Source Removal/Off-Site Disposal
• Alternative SL5: Excavation/Soil Washing/On-Site Backfill
• Alternative SL6: In Situ Stabilization/Containment

Sediments

• Alternative SD1: No Action
• Alternative SD2: Limited Action
• Alternative SD3: Containment
• Alternative SD4: Dredging/Dewatering/Off-Site Disposal
• Alternative SD5: Dredging/Dewatering/On-Site Backfill

Groundwater

• Alternative GW1: No Action
• Alternative GW2: Limited Action
• Alternative GW3: Containment via Barrier Walls
• Alternative GW4: Restoration (Extraction Wells for Pump-and-Treat)
• Option (a): with source removal
• Option (b): without source removal

9.4 Selected Remedy

OU-5 (Taking into consideration the amendment of the OU-3 Remedy):

The selected remedies for OU-5, included SL3, SD5, and GW2. 

Soils:

• Capping of site-wide contaminated soil (includes both the slag area and main plant area) with storm water management system and erosion controls along the shoreline
• Dredging the contaminated sediments in the Back Channel and Crafts Creek,
• Implementation of a long-term maintenance and monitoring program to ensure integrity of the capped areas
• Institutional controls to restrict the future excavations through the soil cap and limit future land uses

Sediments:

• Dredging of the contaminated sediments in the Delaware River and Crafts Creek
• Dewatering and capping of the dredged on-site sediments
• Backfill by placement of a sandy loan soil with organic matter and restoration of dredges areas by re-establishing wetlands

Groundwater:

• Implementation of a long-term groundwater sampling and analysis program to monitor the contaminant concentrations at the Site, and assess migration and attenuation of contaminants over time
• Institutional controls to restrict the installation of wells and use of contaminated groundwater in the vicinity of the Site

9.5 Construction Completion/Underway:

Operable Unit 5 (OU-5):

The soil component of the remedial action for OU-5 has been completed.  Soil capping of 5 acres and construction of the New Jersey Transit River Line station stop at Roebling was completed in 2005.  A deed notice was placed on NJ Transit River Line station stop portion of the Site to limit any alteration, improvement, or disturbance of Site soils. 

Ongoing activities include:

• Construction at Isolated Parcel:
• Soil capping and shoreline stabilization of the isolated parcel (area east of Crafts Creek).  Construction activities are underway.
• Design of Sediment Dredging:
• Dredging of approximately 240,000 cubic yards of contaminated sediments is currently underway, and may take several years.  Once complete the slag area will be capped with a soil cover
• Groundwater Pre-design Investigation:
• Is currently underway to develop a groundwater baseline for assessing potential groundwater impacts to surface water and identify future monitoring needs.

Operable Unit 3 (OU-3):

Final Design:

Passive recreation:

• All graded areas will receive a loam and seed cover
• 12 foot wide sidewalk has been provided along the Delaware River side of the site, which also provides maintenance access to storm water bioretention basin
• 2 walkways provide linkage to adjacent neighborhoods, one from end of Ninth Avenue, the other at the intersection of Riverside Avenue and 5th avenue
• Walkway at 9th ave. 12feet wide and provides additional potential vehicular maintenance.

Drainage:

• Includes water quality improvements for offsite runoff from the residential area south of OU3 site, as well as on-site runoff
• Design includes off-site drainage collection and storm water management facilities needs to be compatible with and allow room for sediment placement