New Bedford Harbor is getting cleaner year by year, thanks in part to scientists at Battelle.
The Battelle Environmental Services team supports the U.S. Army Corps of Engineers (USACE) at one of the Environment Protection Agency’s (EPA) largest Superfund cleanup sites. New Bedford Harbor, off the coast of Massachusetts, was placed on EPA's National Priorities List in 1983 due to high levels of contamination with polychlorinated biphenyls (PCBs) and heavy metals. PCBs are organic chlorine compounds that were commonly used in electronics production until they were banned by EPA in the 1970s. They are highly persistent in the environment and have significant ecological and human health concerns.
The remedy includes dredging and disposal of more than 900,000 cubic yards of PCB-contaminated sediments from the bottom of the harbor as well as cleanup in surrounding wetlands. Battelle provides environmental monitoring, assessment and analytical testing services for the project under a contract with USACE New England District, North Atlantic Division (NAE). The Battelle team delivers comprehensive services including field data collection, laboratory analysis, database management and planning support. The team monitors sediment to confirm PCB concentrations during and after dredging. They also monitor water quality to assess the impact of dredging operations on water. Testing includes physical and chemical analyses, bioassay testing, benthic infauna analyses and in situ water quality measurements.
Battelle has been involved with the site in various capacities since the 1980s. During the 80s and 90s, Battelle performed physical and chemical modeling to characterize PCB transport patterns. The data generated helped to inform the creation of the original 1998 cleanup plan. Battelle has supported USACE NAE through four environmental consulting services contracts since 1996. Under the latest contract, awarded in 2012, the Battelle team provides a broad range of services, including:
- Water quality monitoring: During dredge season, field scientists collect data on weekly boat-based surveys. Data is also collected 24/7 from sensors attached to moorings in the harbor. Sensors send data back via telemetry and provide email alerts if readings are above a set level.
- Sediment coring: The field team collects sediment cores before (pre-dredge), during (progress-dredge) and after (post-dredge) dredging to monitor contaminant levels in thein situ sediment column.
- Wetland coring: For the intertidal portion of the cleanup, cores were taken from nearby wetlands, including a major saltmarsh habitat on the east side of the upper harbor. From November 2014 through November 2015, Battelle collected over 400 sediment cores in intertidal areas—including saltmarshes, mudflats, beaches and residential properties—to delineate the horizontal and vertical extent of intertidal areas requiring excavation.
- Sample analysis: At the Battelle analytical labs in Norwell, Massachusetts, the analytical team performs PCB immunoassay analyses for rapid PCB characterization and confirmatory analysis for PCB congeners. The lab developed and validated modified analytical methods for more accurate analysis of sediment cores.
- Passive sampling: A passive sampler study was conducted in the outer harbor to understand the flux of contamination from sediment to water.
- Plume tracking: A plume tracking study was conducted to assess the presence, extent and concentration of suspended sediment plumes resulting from disposal of navigational dredged material by the City of New Bedford into the city’s confined aquatic disposal (CAD) cell.
In addition to field collection and laboratory analysis, the Battelle team provides strategic planning support. Planning activities have focused on determining how to sequence the cleanup activities to prevent recontamination of dredged areas, as well as how and when to perform the confirmatory sampling that will allow EPA to close the site. Battelle also designed, implemented and continues to maintain the database, which now contains more than 500,000 individual records.
Battelle also provides long-term monitoring (LTM) support for the project. Battelle conducted the 2004 and 2014 LTM studies to evaluate chemical and ecological conditions before, during and eventually after dredging. Battelle has also conducted groundwater monitoring at the Confined Disposal Facility (CDF) to evaluate the integrity of the CDF.
The project has required the long-term support of more than a dozen team members, not including staff at the analytical lab in Norwell. From 2004 through June 2015, Battelle logged over 250 field days; analyzed more than 1,000 physical, chemical and biological samples; and prepared more than 100 field, technical and compliance documents to support pre-dredging design, construction monitoring, long-term monitoring and intertidal sampling in New Bedford Harbor. The Battelle team is led by Project Manager Deirdre Dahlen and Technical Lead Patty White. Senior Research Scientist Lisa Lefkovitz is the Contract Manager for the USACE NAE contract.
The New Bedford Harbor cleanup project was significantly accelerated in 2013 thanks to a settlement with AVX Corporation, one of the largest settlements in the history of the Superfund program. Battelle has provided significant planning, data collection and analytical support to assist EPA and USACE NAE with the acceleration of the cleanup project. The Battelle Environmental Services team will continue to support the New Bedford Harbor cleanup effort at least through 2017, when the current contract period expires.