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Learn more. Learn about benefits of river restoration.

Options for Baker and T&H Dams - their costs, benefits & detriments.

Detailed analysis of impacts and benefits of river restore project. 

What are PCBs, and how can they affect me?

Speak up. Do you or don't you support dam removal on the Neponset River? Contact Steve Pearlman.

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Neponset River

Restoration

Public Meetings

 
 

 

At late-April and early-May public meetings, MassDEP presented new data from the results of their PCB-testing on upland soils along the banks of the Neponset River. The results of this testing do not show elevated levels of PCBs or other contaminants in upland soils along the River. DEP also recapped data previously presented by the US Geological Survey on PCB contamination found in Neponset River's river-bottom sediments. A MassDEP risk evaluation expert was on hand to discuss the human health and environmental risk implications of the new testing data on upland soils, as well as the USGS data on the contamination of the river itself. Finally, MassDEP discussed how the river-bottom PCBs might need to be managed under various fishery restoration scenarios such as full or partial dam removal of the Baker Dam or the T&H Dam, if the state decides to pursue one of these options.

For questions regarding these meetings, feel free to contact the NepRWA Office at 781-575-0354 x304 (Steve) or x305 (Ian), and/or Chris Pyott of MassDEP at 978-694-3353 or Christopher.Pyott@state.ma.us. 

View a full copy of the DEP press release.

Background

Several years ago, investigations by the Riverways Programs, the US Geological Survey and the US Army Corps of Engineers uncovered high levels of hazardous polychlorinated biphenyls or "PCBs" in river-bottom sediments of the Neponset River in Hyde Park, Mattapan, Dorchester and Milton in the area downstream of Mother Brook. The contaminants were discovered in the course of studying options for restoring herring, shad and other fish runs on the Neponset River. Follow-up studies confirmed that these pollutants are concentrated behind the Tileston and Hollingsworth Dam in Hyde Park and to a lesser degree, behind the Baker Dam in Lower Mills. They also found that significant quantities of PCBs are getting into the water and moving out into the estuary through slow diffusion and when stirred up by storms. Finally, they found elevated levels of PCBs in the tissues of some fish living in the Neponset River and consequently the MA Dept. of Public Health has issued a health warning on eating certain species of fish caught in the freshwater portion of the river. The discovery of PCBs in the river-bottom has significant implications for any potential plan to restore fisheries along the Neponset.

During the 1960s, the former Metropolitan District Commission (MDC) dredged and channelized the Neponset River as part of a land reclamation project. The MDC removed sediments from the river-bottom and deposited them in a variety of "dredge spoil piles" in wetland areas along the river. More recently, this raised a concern that PCBs might have been deposited in what are now upland areas along the banks of the Lower Neponset River. In the fall of 2007 and in the spring of 2008, the MassDEP, undertook additional PCB-testing of these upland areas along the river banks to evaluate what, if any, problems may exist.

 

Summary of January 2008 Public Meeting on Lower Neponset River Restoration

The Mass Department of Fish & Game’s Riverways Program held a public meeting on January 9, 2008 in Dorchester to unveil results from its two final studies on cleaning up and restoring the lower Neponset River from Hyde Park and Milton to the mouth of the Neponset River in Dorchester Bay. The two main speakers were scientist Robert Breault from the U.S. Geological Survey (USGS) who spoke on his studies of PCB contamination and James MacBroom of Milone & MacBroom, the firm hired by the Riverways Program to study alternatives for achieving PCB cleanup and for restoring fish passage and overall habitat in and along the River. Ian Cooke of NepRWA spoke last regarding ongoing efforts to build consensus on a “preferred” alternative.

First to speak was Rob Breault, who published a study in 2004 identifying areas with the greatest quantities and concentrations of PCBs in the sediments below the River. These areas were directly behind the Baker Dam in Lower Mills, Dorchester and Milton, and behind the Tileston & Hollingsworth (T&H) Dam in Milton and Hyde Park The study also contained initial information on the types of PCBs that were found and their possible sources. However, Breault spoke mostly about his new unpublished findings, based on sampling done in 2005. Breault stated that:

PCBs in sediments behind the dams were found to be highly unstable and to become suspended in the water column after storms;

PCBs were found in the flesh of freshwater fish at levels that are deemed to pose a significant risk to human health. (The Massachusetts Department of Public Health has now issued an Advisory telling people not to eat fish caught in this area of the river);

Storms have regularly washed large quantities of PCBs over the dams and into the Neponset River Estuary. PCBs were found in the water column of the Estuary from lower Mills all the way to the mouth of the River at Dorchester Bay ;

PCBs were found in the flesh of salt water fish in the Estuary, though not yet at levels which pose a risk to human health.

Most of Breault’s presentation was an explanation of his efforts to fingerprint the precise types of PCBs that he found behind the dams and to see which companies along the River used those types of PCBs before the chemical was banned in the 1960s. Breault concluded that most of the PCBs probably came from sites along Mother Brook, a tributary that enters the Neponset River at Hyde Park . [The Department of Environmental Protection is now using Breault’s data to try to identify “potentially responsible parties” who could be required to help pay for the cleanup of the River.]

The second speaker at the meeting was James MacBroom, a dam expert from Connecticut. MacBroom’s firm published a report in November 2006 which looked at all possible alternatives for PCB remediation as well as fish passage and habitat restoration. Based on the identification of “preferred alternatives” by a “Technical Advisory Committee” (TAC) established by the Riverways Program, MacBroom has also done a more detailed, but as yet unpublished, Supplemental Report on these alternatives.

MacBroom spent most of his presentation discussing why certain options were discarded as technically infeasible and then explaining the advantages and disadvantages of the remaining alternatives. For every option, state law requires that PCBs be fully remediated behind the dams before any other restoration work begins, although MacBroom found that doing this remediation at the same time as the cleanup would save a lot of money. For Baker Dam, MacBroom noted that building a “fish ladder” was infeasible because it would increase flooding in this already flood-prone area. The remaining feasible options were to repair and maintain the dam indefinitely without providing for fish passage; to build a gradually sloping rock ramp which would make it possible for some fish species to swim over the dam; and dam removal. Dam removal was the alternative identified by the TAC as best meeting the goals of river restoration as well as costing the least over the long-term.

At T&H dam, feasible options were found to be more numerous, although cost differences were considerable. The TAC’s “preferred alternative” (and, again, the least expensive one) for T&H Dam was also dam removal. It was noted, however, that the TAC has no legal authority to decide which option should be implemented, so that issue remains unsettled.

People attending the meeting then asked questions and made comments. Everyone agreed that PCBs need to be cleaned up as soon as possible if they pose a risk to human health, though a number of individuals from Lower Mills, Dorchester, were opposed to removing Baker Dam due to the historic significance of this area (the dam itself was actually built in the 1960s, though dams have been located at or near this site since the seventeenth century). The President of the Massachuset-Ponkapoag Tribal Council who attended the meeting also pointed out, however, that before the first dam was built, anadromous salt water fish had been going up the Neponset River for millennia to lay their eggs, and that Native Americans had built weirs in the Lower Mills area to catch these fish.

The final speaker of the evening was Ian Cooke of the Neponset River Watershed Association. Ian pointed out that unless everyone can work together to find an acceptable solution, it was highly unlikely that the necessary funding could be raised to even clean-up the PCBs, much less restore the River. Cooke said that NepRWA is in the process of establishing a Citizens Advisory Committee to see if a consensus can be reached among the affected communities on how to proceed forward. The “CAC” will begin its work in March 2008.

Learn more about the Lower Neponset River Restoration Project.

Updated March 2008