Our Monitoring Program

In 2004, EPA established eight engineering and quality-of-life performance standards — the strictest ever developed for an environmental dredging project — to govern the Hudson River Dredging Project. The standards include three engineering standards — the migration of PCBs into the water during dredging (resuspension), the level of PCBs left on the river bottom after dredging (residuals), and the rate at which dredging was performed (productivity) — and five quality-of-life standards — air quality, noise, lighting, odor and river navigation. It required that dredging meet these standards consistently and simultaneously.

Despite the use of the best available dredging technology, daily oversight by regulatory agencies, and multiple modifications in the dredging process, the standards could not be met consistently and simultaneously because they are in conflict with one another. For example, attempts to achieve the Productivity Standard led to exceedances in the Resuspension Standard. Attempts to limit resuspension or to meet the Residual Standard inhibited productivity.

GE's evaluation is based on its analysis of more than 18,000 air, water and sediment samples that were collected during and after dredging. These data are described in more detail below.

PCBs in Water During Dredging (Resuspension)

EPA established two Resuspension Standards to ensure that dredging did not cause exceedances of the drinking water standard and did not release more PCBs into the river than would have happened over time without dredging. The first standard requires that during dredging the concentration of PCBs in the water not exceed the federal drinking water standard of 500 parts per trillion. The second standard requires that the total mass of PCBs resuspended during dredging, as measured at Waterford, not exceed 117 kilograms (258 pounds).

Both standards were exceeded during Phase 1: The federal drinking water standard was exceeded 10 times. And, dredging released 200 kg (440 pounds) of PCBs, as measured at Waterford 30 miles downstream, in exceedance of EPA's maximum allowable limit.

EPA had forecast that dredging would resuspend 0.13 percent of the PCBs dredged. In fact, dredging released approximately 25 times that rate — 3 percent to 4 percent of the PCBs dredged. PCB levels in water increased from 30-50 parts per trillion before dredging to 100-400 parts per trillion during dredging.

Click here to view water quality data from Thompson Island

Click here to view water quality data from Schuylerville

Click here to view water quality data from Waterford

Click here to view data regarding EPA's maximum allowable PCB limit during dredging

The level of resuspension led to significant increases in PCB levels in Upper Hudson fish. PCBs in yearling pumpkinseed and forage fish in the Thompson Island Pool increased by nearly 500 percent. At Albany and Troy, nearly 40 miles downstream of dredging activities, PCB levels in the two species rose 40 percent to 65 percent.

Click here to view fish data for pumpkinseed and forage fish

PCBs in Sediments After Dredging (Residuals)

EPA established the Residual Standard — the amount of PCBs left on the surface sediments after dredging — to reduce the amount of PCBs that are or may become bioavailable. EPA's target average for five-acre dredge areas was approximately 0.25 ppm, about one-quarter of a part per million. Sampling was required after each dredging pass to measure the mass of PCBs left behind.

The standard was not met in most areas dredged. In all but one area, despite multiple re-dredging attempts, the standard was met only with capping, i.e. putting down a clean layer of soil over parts of the area.

The Rate of Dredging (Productivity)

Nearly 290,000 cubic yards of sediment, containing approximately 35,000 pounds of PCBs, was dredged. EPA's goal for the first phase of the project was to dredge 265,000 cubic yards.

EPA's Productivity Standard required removal of 89,000 cubic yards of sediment in a single month during Phase 1. This standard was not met. In the best month for productivity in Phase 1, 77,300 cubic yards of sediment was removed.

Only 10 of the 18 areas scheduled for dredging in Phase 1 were dredged because more PCBs than forecast were found buried beneath the large volumes of debris in the Upper Hudson. About 120,000 cubic yards more sediment was removed than anticipated in those 10 areas.

Air Quality

PCB concentrations in air were analyzed near dredging activities and near the processing facility. Samples were collected from upwind and downwind locations. Even with the best dredging technology available and constant oversight by EPA and New York State, PCB levels in air during Phase 1 exceeded the project's quality standard 105 times.

Click here to view the data

Noise

Noise levels were measured in areas near the river while work was performed and around the processing facility. During Phase 1, GE's contractors collected 22 measurements that exceeded EPA's night-time residential noise standard (as measured in decibels) and two measurements that exceeded EPA's daytime residential noise standard.

Click here to view the data

Lighting

Lighting was measured when night-time activities were performed near residential properties and around the processing facility. While the majority of lighting measurements have been within EPA's standard, three exceedances were reported.

Odor

Monitoring for odor was conducted if project employees detected an uncomfortable or unusual odor, or if a complaint was lodged by the public. When dredging was being performed, odor was investigated on five occasions. Each time, the odor was determined to be short-lived or unrelated to the dredging project.

Navigation

EPA's standards required that dredging was to be conducted without unnecessarily hindering the ability of non-project related boats (e.g., recreational and/or commercial vessels) to use the river. During dredging operations, navigational issues were investigated on one occasion.