FAQ

A:  All work is proposed to occur on Parcels H130006020 and H120012021 which currently have no identifiable owner and will be taken by the City of Pittsfield via eminent domain. No work is proposed on the property currently owned by living private citizens. Adjacent property owners and residents in the area of the project site will be impacted by short-term construction activities, including those listed below. It is not anticipated that any long-term impacts to adjacent property owners will occur from the project.

• Short-term impact to vehicle and pedestrian traffic on Wahconah Street during construction would occur due to the presence of construction equipment traveling on the street and the potential need for a lane closure. This impact will be mitigated through the preparation of a Traffic and Pedestrian Management Plan.
• Short-term impacts to air quality in the project area could result from the temporary operation of machinery associated with construction activities. Best management practices to control the construction emissions would be implemented to minimize visible fugitive dust emissions at the property line.
• Short-term impacts to air quality could occur due to stockpiling and on-site management of contaminated sediments before transport out-of-state for final disposal. This impact will be mitigated through implementation of dust control such as watering and continuous air quality monitoring during construction.  If air exceedances of chemical constituents in the sediment are detected, then construction activities will halt while measures are implemented to assess and address the exceedances.
• Short-term impacts to noise levels in the project area would be present during dam demolition and sediment removal from construction machinery. Mitigation measures will include scheduling work during daytime hours outside of weekend days.
• Short-term impacts to water quality could occur due to erosion and sedimentation during construction. This impact will be mitigated through use of sediment and erosion controls on-site, phasing of work in water, preparation of a Stormwater Pollution Prevention Plan, and compliance with US EPA Construction General Permit requirements.
• Short-term impacts to vegetation and habitat will occur due to clearing of trees, shrubs, and vegetation during construction area. However, post-construction, reseeding and revegetation efforts using native species will be implemented to restore and improve this habitat.

A: MassDCR and the City of Pittsfield will post periodic updates on the Bel Air Dam website (BelAirDamRemoval.com).

A: There is a 2017 Emergency Action Plan (EAP) regarding Bel Air Dam which is administered by the City of Pittsfield Emergency Management Agency and has recently been updated. The EAP serves as a guide to local and state emergency responders in the event of a possible failure and includes description of the potential inundation area that may be impacted in the event of failure, which can be used for evacuation planning purposes. If a dam failure were to occur or believed to be imminent, the City has a “Code Red” reverse 911 alert system to notify potentially affected residents of the need to evacuate. More information about the City Emergency Management Agency is at https://www.cityofpittsfield.org/departments/emergency_management/index.php, and includes information about registering for “Code Red”.

A: DCR Office of Dam Safety (ODS) periodically inspects dams and includes Bel Air Dam in their patrols.  DCR conducts minor repairs and maintenance as needed.  In the past, DCR has added riprap slope protection to a section of the center embankment’s downstream slope to stabilize the sluiceway discharge.  In addition, debris is removed as needed from sluice gate openings to facilitate maximum flow through the sluice gate and maintain the lowest possible water level in the impoundment, to reduce risk of dam failure.

A: Contingency plans will be developed for implementation during construction, to address issues such as detection of elevated air pollutants, occurrence of storm flows in excess of those that can be by-passed around construction, and elevated water column turbidity.

A: It is anticipated that water flow will be managed using a flow bypass system to move water away from the active construction area to the extent possible. Flow bypass may be accomplished via a diversion channel along the east side of the existing stream and impoundment by constructing a temporary cofferdam parallel to the exiting stream and diverting flow into the stream via either gravity or pumping.  Alternatively, the contractor may elect to surround sub-areas of the site with portable dams to divert flow around active work areas.   The Contractor will also be required to monitor for potential significant rainfall event, and to remove equipment, construction materials and stockpiles from construction area and floodplain in case of flooding emergency.

A: A significant amount of H&H modeling has been completed; however, the final design is not complete.  A separate H&H report has not been compiled, however the H&H modeling results that have informed the design are summarized in the permit applications, which are available on the Bel Air Dam website (BelAirDamRemoval.com).  In addition, H&H information will be included within the construction bid documents and specifications to provide the contractor with data that they can use to evaluate water flow and associated management during construction.

A: The 100-year floodplain elevation is predicted to decrease in the immediate vicinity of project, between Wahconah Street and the dam.  A No-Rise Certificate will be submitted to the City of Pittsfield to confirm that the 100-year floodplain elevation will not increase, and is predicted to decrease, as a result of the project. After the project is complete, a Letter of Map Revision (LOMR) request will be submitted to FEMA to change the Flood Insurance Rate Map (FIRM) designed 100-year floodplain boundary.  This process includes notifying homeowners if they are being affected and publication of a public notice in the newspaper. The current FEMA FIRM 100-year floodplain elevation in the West Branch of the Housatonic River is 1038 NAD88 and extends to the rear portion of some private residences along Lenox Avenue, on the east side of the current impoundment/stream.  Based on current modeling result, topographic survey data, and a 2024 property boundary survey, it is expected that the 100-year floodplain after the project will be lowered such that it will be relocated beyond the boundary of private residential parcels along Lenox Avenue.

A: The only changes to water elevation along the West Branch of the Housatonic River will occur between Wahconah Street and the dam, where water levels will be lower after the dam is removed.  There will be no change to the amount of water or height of water discharging downstream as a result of the project.  Under current conditions, the impoundment above the dam provides minimal storage due to the sediment that has accumulated in the impoundment.  As a result, removing the dam will not remove water storage capacity and flows downstream are expected to be the same in the future as they are now.

A: The grading adjacent to the new stream channel will increase flood storage capacity – particularly in the area of the current impoundment, which currently does not provide storage of additional water during flooding conditions. Grading that will occur at the project site will create flood storage volume adjacent to the stream channel that is currently filled with water and therefore is currently not available for flood storage. Flood storage does not occur solely within the boundaries of a water body – low areas adjacent to the stream play a critical role in storing floodwaters. Overall, there will be an increase in the resource area identified as “Bordering Land Subject to Flooding”, or BLSF, which is defined in the Massachusetts Wetlands Protection Act regulations as the maximum lateral extent of flood water equivalent to the FEMA 100-year flood event.  As a result of the project, the area of BLSF will increase.

A: There will be no change to the amount of water or height of water discharging downstream as a result of the project.  Under current conditions, the impoundment above the dam provides minimal storage due to the sediment that has accumulated in the impoundment.  As a result, removing the dam will not remove water storage capacity and flows downstream are expected to be the same in the future as they are now.  Therefore, velocities downstream will not increase as a result of the project.  There will be an increase in velocity along portions of the stream between Wahconah Street and the dam, and the project design incorporates reinforced streambed materials to withstand the predicted velocities.  Scour calculations have been completed to document that there are no adverse erosion impacts predicted to occur to the upstream culvert below Wahconah Street where the East Branch of the Housatonic River enters the project site.

A: The City of Pittsfield will repair existing drainage infrastructure (pipes and drain manholes) as necessary to prevent leaks that have caused the displacement of soil. All existing areas that have experienced soil loss due to this condition will be restored to match existing grade and appropriately vegetated.  The City may consider the addition of low-impact development BMPs in the future for this drain network through the relocation of the discharge.

A:  The proposed project will not result in any changes to the annual releases from Pontoosuc Lake.  The project work schedule will be developed in consideration of annual releases from Pontoosuc Lake, which typically include water releases in the late fall to achieve a three-foot drawdown of Pontoosuc Lake over the winter months.

A: The goal of the design is that there will be a minimal chance that a large amount of sediment being transported downstream. Temporary cofferdams and silt curtains will be moved periodically to suit the selected method of sediment removal.  It is anticipated that at some deeper locations, hydraulic dredging may be preferred by the Contractor, while in shallower areas mechanical dredging, may be more efficient. Temporary cofferdams and silt curtains will be positioned to allow phasing and sequencing of the dredging operation.  The project design includes post-construction stabilization of the streambed with natural colored rock of various sizes to protect against erosion and stabilization of areas adjacent to the streambed with planting and installation of erosion control blankets.  Long-term monitoring is planned to document site conditions after construction and confirm that the restored areas remain stable.

A: It is anticipated that days may be required for sediment to dry on-site sufficiently for transportation out-of-state. A chemical agent will be added to solidify material before loading into dump trucks. The overall construction period is anticipated to extend over 9 – 12 months.

A: The entire project area within the limit of work will be cleared of vegetation, both native and invasive, and all vegetative debris will be properly disposed of off-site in accordance with applicable regulations. Removal of large vegetation, such as tree trunks, will mitigate the potential for downstream transport of this material during construction. Any salvageable tree trunks that could be re-used on site as part of the final habitat restoration would be temporarily stored at the staging area downstream of the dam (parcel H120012021) during the construction period.

A:  The sediment contains elevated levels of chemical parameters exceeding Massachusetts Contingency Plan (MCP) reporting limits for chromium (Cr), lead (Pb), arsenic (As), Polycyclic aromatic hydrocarbons (PAH), and Extractable Petroleum Hydrocarbons (EPHs).  Based on laboratory analyses, the sediment does not exceed Resource Conservation and Recovery Act (RCRA) hazardous waste thresholds and is therefore classified as solid waste, but not hazardous waste.   At this time, all of the 35,500 cubic yards of sediment is planned to be disposed of out-of-state at a receiving facility in either New York or Pennsylvania.  Consideration is underway for implementing additional sampling to determine if some sub-sets of the sediment could be considered non-hazardous and eligible for disposal at an upland landfill within the Commonwealth of Massachusetts.  However, the budget estimate for the project includes an assumption that the entire volume that will be excavated to create the stream channel is hazardous and therefore will be transported out-of-state for final disposal.

A: Dewatering may be passive or via geotubes.  In either case, sediment would be placed on an area lined with polyethylene sheeting and decant water will be collected and sampled prior to discharge back into the West Branch of the Housatonic River. Sampling would be done to confirm that the effluent meets the discharge requirements of the US EPA Dewatering and Remediation General Permit (DRGP) and if sampling results indicate that water quality of the decant water exceeds the DRGP mandated levels, treatment will occur to meet those levels prior to discharge.

During in-water dredging, Information related to the project construction status, including dewatering operations will be posted on the Bel Air Website (BelAirDamRemoval.com).

The greatest potential impact to water quality is related to turbidity. The turbidity (solid sediment particles) and any contaminants sorbed onto the sediment particles have to potential to affect water quality. Therefore, the project will include steps to monitor and control turbidity and operations would cease if excess turbidity were detected downstream of construction activities, which will mitigate the potential for resuspended sediments to travel downstream.

Another potential effect on water quality would be if the contaminants in the sediment dissolve in the water. Measures to control turbidity would not necessarily be effective in controlling dissolved constituents. The constituents of concern at the project site (chromium, lead, arsenic, PAHs, EPHs) all have relatively low solubility and have much more affinity to remain sorbed onto the sediment particles rather than dissolving in water. This is reflected in the fact that they have remained in the sediment and have not previously been flushed or dissolved out.

The metals in the sediments are present as components of minerals, which require specific geochemical conditions to dissolve at concentrations above background. Low pH (acidic conditions) is needed to dissolve lead and chromium minerals; depleted oxygen is needed to dissolve the iron minerals which contain the arsenic. Neither of these geochemical conditions is likely to occur in the surface water.

The organics are sorbed onto the organic carbon in the sediments. Each constituent has measurable physical property, known as the organic carbon partitioning coefficient (Koc), which characterizes its affinity to sorb onto organic carbon. Koc values have been compiled in the MCP program (MCP Toxicity.xls Numerical Standards spreadsheets. https://www.mass.gov/doc/mcp-numerical-standards-development-spreadsheets/download). PAHs and EPHs have relatively high partitioning coefficients, indicating that much higher concentrations are likely to remain sorbed onto the organic carbon in the sediment than to dissolve in water.

It is anticipated that turbidity monitoring will occur.

A: .  Sediment may be dewatered on-site on the parcel between Wahconah Street and the existing dam (Parcel H130006020) or at the staging area on the downstream parcel at 370 Wahconah Street (Parcel H120012021). The staging area parcel includes remnant concrete pads that would be used for dewatering operations to the extent possible.  In addition, polyethylene sheeting will be installed to line the area used to stockpile and dewater sediment.

A: The addition of solidification/stabilization reagents such as Portland cement, Calciment™, or lime kiln dust may be used to enhance the dewatering process.

A: MassDCR completed a Due Diligence review of the watershed upstream of the project site as part of the 401 Water Quality Certification application, which is available on the Bel Air Dam Removal website (BelAirDamRemoval.com).  However, the specific source of contaminants identified in sediment samples is not known.  MassDCR and the City of Pittsfield are not aware of any studies that have been done to identify the source of contaminants identified in sediment samples collected and analyzed as part of the proposed project.

A: Yes, air monitoring will be continuous, and construction would be stopped immediately if any exceedances are noted, and these would be posted on the website in real time.

A: A stream channel will be created to restore the connectivity of the West Branch of the Housatonic River. The project will remove contaminated material and add clean topsoil, remove invasive species, and install native herbs, shrubs, and trees.

A: The proposed project includes removing the volume of sediment needed to create the new stream channel – which will transition from a high point just downstream of Wahconah Street to a low point at the location of the dam.  In addition, some floodplain benches will be created adjacent to the riffle sections of the new stream.  Creating the new stream channel profile and floodplain benches requires removing sediment to create the new, lower elevations.  Some sediment will remain on-site, and will be covered with an impenetrable cap.

A: There will be a loss of open water habitat. Overall, the project has ecological benefits, but a change in habitat types is unavoidable.  Given the large expanse of Pontoosuc Lake 1 mile upstream, it is anticipated that ample alternative open water habitat will still exist in the area.

A: The bridge will be demolished with the dam as it is beyond repair and would be very challenging to reconstruct.

A: Yes, all the structures will be taken down and removed. If there is contaminated sediment it will be removed.

A:  The City will be updating the Phase 1 investigation of the property and is also planning to undertake a Phase 2 inspection of the soils. Information gathered during these studies will help to inform the future use of the property.

A: The city recognizes that there will be traffic flow impacts during certain periods of construction, especially along Wahconah Street.  Every attempt will be made to minimize the impacts while maintaining safety and critical circulation, i.e, school bus stops.

A: The project site is about a half a mile upstream of the Wahconah Ball Park. There are no anticipated impacts to the ballpark. The only changes to water elevation along the West Branch of the Housatonic River will occur between Wahconah Street and the dam, where water levels will be lower after the dam is removed.  There will be no change to the amount of water or height of water discharging downstream as a result of the project.  Under current conditions, the impoundment above the dam provides minimal storage due to the sediment that has accumulated in the impoundment.  As a result, removing the dam will not remove water storage capacity and flows downstream are expected to be the same in the future as they are now.

This project will not specifically address flooding at the ballpark, but it is creating more floodplain storage. There will be an increase in Bordering Land Subject to Flooding (floodplain) at the project site.  The City of Pittsfield has a separate ongoing project at Wahconah Park which will improve flooding at Wahconah Ball Park – Jim McGrath at the City of Pittsfield has information available on this if City residents would like to know more.