The Hudson River near One River Street
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In 2003, New York State Department of Environmental Conservation (NYSDEC) issued a proposed remedial action plan (PRAP) calling for the removal of sediments contaminated with PCBs or copper within 100 feet of the shoreline of One River Street.

After more than a year of extensive fieldwork conducted in conjunction with NYSDEC, Atlantic Richfield Company (AR) presented a comprehensive technical feasibility study on the clean-up of the Hudson River that recommends an ambitious $44 million dredging and capping project. The thorough study presents the key findings from its investigation and lays out the remediation alternatives for various parts of the site. The alternatives include extensive dredging along with the placement of permanent caps on river sediments.

The study presented several key findings:

1. Much of the contaminated sediment is found in submerged fill material, pilings and debris along the shoreline adjacent to the site. This fill slopes down to the natural river bottom 40 feet deep. The existing riverfront was built out into the river in the 19th century using this fill material. This submerged material along the shoreline is an integral part of the structure that holds the riverfront site in place. Any remedy option must take into consideration the necessity of leaving much of this fill material in place or risk undermining the riverfront.
2. Part of the remedy for the riverfront includes the creation of a bulkhead along the entire shoreline. In the northwest corner, this bulkhead will anchor a containment system for PCBs found at depths of nine to 12 feet below the surface as required by NYSDEC for the riverfront (OU-1) remedy. To make the bulkhead stable along the shoreline, a supporting berm of clean material will have to be placed along the river bottom.
3. Most of the PCB mass (99 percent) in the river is found in the river is found in a three-acre area (three percent of the total area) along the northwest shoreline of the site. Moreover, most of that contamination is located within a few feet of the shoreline in the top seven to nine feet of sediment and fill material (60 to 75 percent). In fact, 99% of the mass is in only two percent of the 140 total river acreage of the site.
4. Elevated levels of copper and other metals above AR's proposed remedial goals are concentrated in a relatively small area of approximately 20,000 square feet along the shoreline. Sediment pore water samples showed that metal levels in the water itself were below NYSDEC water quality standards This and other data about the nature of the sediments demonstrate that the sediments are binding the metals in place, making them not harmful to aquatic life.

Based on the on-site investigation, the feasibility study lays out remedy options for four areas of the river: a three-acre area near the northwest corner of the site, the southern shoreline area, the old marina/boat slips area and the larger offshore area deeper in the river.

The study recommends a $44 million dredging and capping project focused on the three-acre site near the northwest corner that would remove the majority of PCBs found there and place the remaining PCBs under a cap and berm system. The plan also recommends further capping as needed in the southern shoreline area to address the small area of elevated metals concentrations as well as some dredging and capping in the old marina and north boat slip area.

The remedy selected by NYSDEC for the river from among the alternatives presented will have a significant impact on the timetable for completing the riverfront remediation project and, ultimately, redeveloping this property for re-use by the community.

In 2007 and 2008, AR returned to the field to conduct further investigations in the River at the request of NYSDEC.