The Commonwealth of Massachusetts Executive Office of Energy and Environmental Affairs 100 Cambridge Street, Suite 900 Boston, MA 02114 Charles D. Baker GOVERNOR Tel: (617) 626-1000 Karyn E. Polito Fax: (617) 626-1081 LIEUTENANT GOVERNOR http://www.mass.gov/eea Kathleen A.Theoharides SECRETARY
August 30, 2021
CERTIFICATE OF THE SECRETARY OF ENERGY AND ENVIRONMENTAL AFFAIRS ON THE NOTICE OF PROJECT CHANGE
PROJECT NAME : Neponset River Greenway: Tenean Beach to Morrissey Boulevard PROJECT MUNICIPALITY : Boston PROJECT WATERSHED : Boston Harbor EEA NUMBER : 15286 PROJECT PROPONENT : Department of Conservation and Recreation DATE NOTICED IN MONITOR : June 23, 2021
Pursuant to the Massachusetts Environmental Policy Act (MEPA) (M.G. L. c. 30, ss. 61-62I) and Section 11.10 of the MEPA regulations (301 CMR 11.00), I have reviewed the Notice of Project Change (NPC) submitted for this project and hereby determine that it does not require an Environmental Impact Report (EIR).
Original Project Description
The original project proposed to construct a 1,400-foot-long multi-use pathway beginning at Victory Road in Dorchester and extending northerly across land owned by Boston Gas Company to an existing sidewalk on Morrissey Boulevard. The length of the project consisted of approximately 1,000 linear feet (lf) of a new paved 10-foot-wide pathway and a 400-foot-long elevated pile-supported boardwalk across salt marsh. The boardwalk would be supported by 14-inch driven piles and would have an elevation of 16.25 ft NAVD88. The boardwalk included one centrally located overlook deck. The project also included the resurfacing of an additional 500 feet of sidewalk on Morrissey Boulevard as a transition from the pile-supported boardwalk. Once completed, the pathway would connect the Lower Neponset River Trail with the Harbor Walk at the University of Massachusetts (UMass) Boston EEA# 15286 NPC Certificate August 30, 2021 via the informalized use of Freeport Street. The project is part of the Lower Neponset River Master Plan, which was reviewed by MEPA (EEA #10664) in 1996 and 1998.
Project Change
The project change includes revisions to the originally reviewed “northern section” from Victory Road to the William T. Morrissey Boulevard, and the addition of a new “southern section” which runs parallel to and to the west of the I-93 corridor between Victory Road and Conley Street. Together, both sections would comprise approximately 3,620 lf of trail including a 670 lf pile-supported boardwalk portion, elevated over a small section of salt marsh and tidal flats in a cove within Dorchester Bay. In addition, approximately 500 lf of sidewalk along Morrissey Boulevard will be resurfaced.
Northern Section: Since the Certificate on the ENF was issued on December 24, 2014, the boardwalk design for the previously reviewed northern section has been realigned, extended and brought to Massachusetts Department of Transportation (MassDOT) structural and construction standards. The length of the boardwalk has been increased from 400 lf to 670 lf and the height of the deck has been raised an additional 2 feet to elevation 18.4 feet NAVD88. At the approximate center of the boardwalk crossing, a 750-sf, concrete deck overlook (“central overlook”) with seating is proposed. A second overlook (“northern overlook”) is proposed near the northern-most extent of the trail. A total of approximately 39 piles are proposed to support the piers at the boardwalk and overlooks.
The boardwalk connects to the sidewalk at Morrissey Boulevard and ramps down to grade through two pile-supported wingwalls (35-ft and 40-ft long) and stub abutment with aluminum railing. At the southern extent, the boardwalk returns to grade with two pile-supported wingwalls (40-ft and 11- ft long) and stub abutment. Further adjustments to the northern portion of the boardwalk allows continuity of the sidewalk and improves and formalizes pedestrian access across the I-93 exit ramp at Morrissey Blvd, while reducing the potentially obtrusive height of the wall at the coastal interface. The project change also includes the expansion of the central overlook and the addition of a smaller northern overlook to better accommodate boardwalk angle/direction change and provide an additional staging area for trail users. Coastal bank impacts have also increased due to the realignment of the boardwalk and abutment at Morrissey Boulevard. Along with significant debris removal, approximately 2,800 square feet of a manmade berm will be restored. As described below, DCR is considering several refinements to the boardwalk design to respond to comments received during the MEPA review period on this NPC.
Southern Section: The new southern section of the shared-use pathway was added to the project to formalize the connection between the northern section and the Lower Neponset River Trail. As originally envisioned, trail users would utilize existing pedestrian accommodations along Freeport Street. However, due to the numerous curb cuts, a formalized shared-use path is proposed. The shared- used path will consist of a 2,050 lf paved 10-ft wide pathway with two-ft wide shoulders. The pathway will be located within a vegetated corridor at the base of an embankment between Interstate-93 (I-93) to the east and commercial development to the west. A 2- foot infiltration trench is also proposed for stormwater management along this section of the pathway. Trail construction will remain at grade where feasible with the exception of raising the profile 2 to 2.5 feet for 400 linear feet near Conley St. This is intended as a climate resiliency measure to decrease the frequency of flooding of the pathway.
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EEA# 15286 NPC Certificate August 30, 2021
Due to the addition of the southern section, the project now includes small areas of existing road realignment and park improvements within the boundaries of the Neponset River Estuary Area of Critical Environmental Concern (ACEC). Connectivity improvements and roadway realignment are proposed at trail interfaces for approximately 500 ft along Conley Street and 450 ft along Victory Road. Impacts to other wetlands (land subject to coastal storm flowage (LSCSF)) have increased above MEPA review thresholds due to the development of the southern section of trail.
Landscaping and ornamental elements such as wayfinding signs, benches, and granite posts are also proposed throughout this extension of the Greenway. The southern section also includes the replacement of a broken flap valve on a drain line located within the limits of the Project, to the west of the I-93 embankment near the Boston Bowl property.
Project Site
The 4.45-acre project corridor will extend from Tenean Beach to Morrisey Boulevard with the southern section extending from Tenean Beach and the northern section extending from Victory Road to Morrissey Boulevard. The southern section will follow a sidewalk along Conley Street from Tenean Beach, where it turns north and continues parallel to and west of the embankment of Interstate 93. The trail connects to the northern section at Victory Road.
This proposed phase of the project is an important link in the larger, multi-phase, 10.5-mile Neponset River Greenway that extends from the Blue Hills in Milton to Boston Harbor.1 It expands upon a heavily used bicycle/pedestrian network in the Boston area, creating healthy transportation options and connections between diverse communities and links to job centers, higher education institutions, and recreational opportunities. Uniting the communities of Dorchester, Hyde Park, Mattapan and Milton, the trail connects a series of parks and provides an opportunity to access and appreciate the outdoors in an otherwise urban area. There are still some missing formal links with the proposed project being one of the most important.
The project corridor includes wetlands resource areas associated with the Neponset River and Dorchester Bay including coastal beach, LSCSF, salt marsh and coastal bank. The site is not located within any areas mapped as Priority Habitat of Rare Species or Estimated Habitat of Rare Wildlife by the Natural Heritage and Endangered Species Program (NHESP). Portions of the project are located within the Neponset River Estuary Area of Environmental Concern (ACEC).
Environmental Impacts and Mitigation
As originally proposed in the ENF, the project would have resulted in the alteration of 3,732 sf of salt marsh, including seven feet of permanent impacts associated with the placement of piles to support the boardwalk and 3,725 sf of temporary impacts associated with the use of timber mats during installation and construction of the piles and the boardwalk. The original project was also expected to alter approximately 45 linear feet of coastal bank and 4,523 sf of LSCSF associated with the construction of the boardwalk abutments. An additional 13,900 sf of temporary impacts to LSCSF was expected to be associated with construction period impacts. The original project included approximately
1 http://www.neponsetgreenway.org/nepmap.pdf 3
EEA# 15286 NPC Certificate August 30, 2021
0.4 acres of new impervious surface associated with the 10-foot-wide paved portion of the Greenway. The originally proposed boardwalk would result in 1,036 sf of shading impacts to salt marsh. The original project included impacts to 4,523 sf of filled tidelands.
As a result of the changes proposed in the NPC, the project will result in 3,188 sf of impacts to salt marsh (reduction of 544 sf), including 18 sf of permanent (increase of 11 sf) associated with the placement of piles and 3,170 sf of temporary impacts (562 sf reduction) associated with the placement of timber mats; 45,395 sf of permanent impacts to LSCSF (40,872 sf increase) and 30,265 sf of temporary impact to LSCSF (16,365 sf increase) associated with the construction of the southern section of the trail; 100 lf of permanent impacts to coastal bank (55 ft increase); and 18 sf of new permanent impacts to coastal beach and 855 sf of new temporary impacts to coastal beach. The project as revised will create 0.8 acres of new impervious area (0.4 acres increase) and result in 1,224 sf of shading impacts to salt marsh (188 sf increase). The project change increases impacts to tidelands to 45,395 sf (40,872 sf increase).
Environmental Justice (EJ) populations within a mile of the project area include those characterized as Minority, Minority and Income, Minority and English Isolation, and Minority, Income, and English Isolation.2 The project does not directly traverse residential land use and is a passive transportation enhancement project which will improve pedestrian access conditions in the project area for all populations. According to the ENF, this project will improve overall pedestrian design and will increase equity of access to public natural resources such as Malibu Beach, Tenean Beach, playground, and fields, and Finnegan Park. The trail and boardwalk were also designed for Americans with Disabilities Act (ADA) compliance and are accessible to all users.
Jurisdiction and Permitting
The original project underwent MEPA review and required the submission of an ENF pursuant to 301 CMR 11.03 (3)(b)(l)(a) and 301 CMR 11.03(3)(b)(l)(c) because it required State Agency Actions and consisted of the alteration of a coastal bank and alteration of 1,000 or more square feet (sf) of salt marsh. The project required a Section 401 Water Quality Certificate (WQC) and a Chapter 91 (c.91) License from the Massachusetts Department of Environmental Protection (MassDEP). The Boston Conservation Commission issued an Order of Conditions on October 21, 2015 (MassDEP File No. 006-1443) which was not appealed. The project is being undertaken by the Department of Conservation and Recreation (DCR) with funds from MassDOT.
With the project change, the project continues to exceed the ENF thresholds identified above. In addition, the project now exceeds ENF thresholds at 301 CMR 11.03(3)(b)(1)(f) and 301 CMR 11.03(11)(b) because the addition of the southern portion of the of the proposed multi-use pathway will result in the alteration of more than ½ or more acres of any other wetland (LSCF) and extend into the Neponset River Estuary ACEC. The project continues to require a 401 WQC and c.91 License from MassDEP. The project change will require a Non-Vehicular Access Permit from MassDOT as it will be constructed on land adjacent to I-93. The project change will require a new Order of Conditions from
2 The ENF referenced the MassGIS Environmental Justice (EJ) Population Data Layer (2010). EJ populations should be analyzed using the EJ Populations Mapping tool: https://mass- eoeea.maps.arcgis.com/apps/webappviewer/index.html?id=1d6f63e7762a48e5930de84ed4849212
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EEA# 15286 NPC Certificate August 30, 2021 the Boston Conservation Commission, or in the case of an appeal, a Superseding Order of Conditions from MassDEP.
Because the project will be undertaken by a State Agency, MEPA jurisdiction is broad in scope and extends to all aspects of the project that may cause Damage to the Environment, as defined in the MEPA regulations.
Review of the NPC
The NPC provided a description of existing and proposed conditions, preliminary project plans, and identified measures to avoid, minimize and mitigate environmental impacts. Based on agency feedback, DCR extended the comment period until August 20, 2021, to facilitate the distribution of supplemental information including additional alternatives that would reduce impacts to resource areas. Supplemental information was submitted on August 4, 2021. Revised supplemental information was submitted and distributed on August 12, 2021. The NPC and all supplemental information received will be referenced collectively as “NPC” herein.
Alternatives Analysis
The NPC included an alternatives analysis for the new southern section of the Greenway. Alternatives for the new southern section included: No-Build Alternative, Freeport Street Alternative, Cantilevered Structure Alternative, and Preferred Alternative were identified.
The Southern Section No-Build Alternative was dismissed because it would not achieve the goals of DCR to develop a defined Neponset River Greenway. There are currently missing sections of formalized or safe access in the overall goal to create a Neponset River Corridor between Blue Hills to Boston Harbor. Trail system users would continue to use city streets without sufficient space to travel between existing sections. Construction of the proposed sections closes a significant gap in the continuous corridor. Constructing either the northern or southern section alone contributes to the trail system, but does not provide the greater continuity that completion of both provide. For these reasons, the No-Build Alternative was dismissed.
The Freeport Street Alternative would involve directing trail users along Freeport Street from Conley Street and Tenean Beach. This would formalize the current substandard crossing but is still not ideal for directing an increased number of trail users to this location. This alternative was not found to be feasible because of the many curb cuts along Freeport Street as well as the narrow sidewalk that would prohibit the creation of a grade-separated shared-use trail. Additionally, Freeport Street is not owned by DCR or MassDOT, and therefore this alternative was dismissed.
The Cantilevered Structure Alternative would involve constructing a supported boardwalk structure cantilevered along the southern section of the greenway on the east side of I-93. A boardwalk of the length and durability required in the coastal environment would be both cost-prohibitive and have a greater impact on natural resources and permitting than the Preferred Alternative. A boardwalk/trail structure on the east side of I-93 would also be located entirely within the Neponset River Estuary ACEC and require additional piles in tidal flats, shellfish suitable areas, and likely salt marsh vegetation.
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Construction would also be required in close proximity to I-93 and would require additional traffic considerations and land closures. For these reasons, this alternative was dismissed.
Alternatives for Tide Gate Repair
The NPC also analyzed alternatives to the proposed tide gate repair located within the vicinity of the southern section of the which included a No-Build, New Vault Construction Alternative, On-Site Drainage Alternatives, Flap Gate Location Alternative and the Preferred Alternative. The No-Build Alternative would leave the tide gate in its current state of disrepair. This alternative was dismissed because of tidal events that back up the tidal gate and cause stormwater flooding for businesses along Morrissey Boulevard. The existing pipe is critical to move stormwater from this area to the Neponset River and increased tidal events will only continue to exacerbate the issues if repairs aren’t made. The New Vault Construction Alternative would involve costly structural equipment and would require acquisition of private property and therefore was dismissed. The On-site Drainage Alternative would involve eliminating the tide gate and associated stormwater discharge and developing on-site stormwater management. This alternative was dismissed because surrounding developments and infrastructure rely on this stormwater outlet. The Flap Gate Location Alternative would involve placing the flap gate directly at the drain outlet to Neponset River before water enters the pipe system. This alternative was rejected because the location (at the Neponset River) would make it very difficult for DCR to maintain. The Preferred Alternative includes excavation of the roof of the vault and demolition of several feet of the concrete walls. Shoring will be installed internally to support the lower portion of the vault. The main flap gate will be repaired and two 12” drains with their own flap gates will be directed to the vault. The drains will convey stormwater from catch basins installed for the multi-use trail. The Preferred Alternative will alleviate tide gate backups while continuing to provide stormwater management for surrounding areas.
ACEC
A small portion of the southern extent of the pathway coincides with the boundary of the Neponset River Estuary ACEC. However, the work within this area is limited to the reconstruction of an existing roadway and sidewalk area. In addition, a small amount of the proposed work at Victory Park/Victory Road falls within the ACEC. The Victory Park work includes sidewalk extension and regrading of the parking lot to eliminate low spots and improve drainage. The gravel lot will not be paved. A small gravel area will be restored with loam and seed. The proposed work will improve public access to the Neponset Estuary, which is consistent with the goals of the Neponset River Estuary ACEC Resource Management Plan by providing public benefits, recreational opportunities, and stormwater management improvements.
Wetlands and Stormwater
The project will result in impacts to 3,188 sf of salt marsh (18 sf permanent/3,170 sf temporary); 75,660 sf of LSCSF (45,395 sf permanent/30,265 sf temporary); 100 lf of coastal bank (permanent), and 873 sf of coastal beach (18 sf permanent/ 855 sf temporary). MassDEP will review the project for its consistency with the Water Quality Regulations (314 CMR 9.00). The Boston Conservation Commission will review the project for its consistency with the Wetlands Regulations (310 CMR 10.00) and associated performance standards.
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EEA# 15286 NPC Certificate August 30, 2021
As described in comment letters from MassDEP and CZM, the width to height ratio of the proposed boardwalk, which ranges from 0.9:1 to 1:1, cannot be further maximized to reduce shading impacts without increasing direct impacts to salt marsh from larger support piles. DCR determined that it is not possible to meet height to width ratio of 1.5 to 1, as recommended by the Division of Marine Fisheries to reduce shading impacts to salt marsh. If the boardwalk were to be raised to meet a 1.5:1 ratio, it would require an additional seven to eight feet in height for a deck surface greater than elevation 25 feet NAVD88. This increased height would also require an increase to the diameter of the supporting piles resulting in additional direct impact to salt marsh. The boardwalk is oriented north to south which will reduce shading.
The project proposes mitigation for wetlands impacts in the form of removal of a manmade berm consisting of approximately 2,800 sf (140 cubic yards) of fill material from area categorized as coastal beach to restore salt marsh and intertidal habitat. Comments from MassDEP and CZM note that this area functions as a barrier beach as defined in and regulated by 310 CMR 10.29 and is therefore subject to the Performance Standards for work on a coastal beach at 310 CMR 10.27(3) through (6). The Wetlands Regulations at 310 CMR 10.27(3) specifies that “Any project on a coastal beach, except any project permitted under 310 CMR 10.30(3)(a), shall not have an adverse effect by increasing erosion, decreasing the volume or changing the form of any such coastal beach or an adjacent or downdrift coastal beach.” As indicated in comments from MassDEP and CZM, to avoid impacts to the dune and barrier beach and reduce the accumulation of debris, the addition of compatible sediments to the dune and planting it with erosion control vegetation would provide a better buffer that can reduce the accumulation of debris in the cove.
In response to feedback provided by MassDEP and CZM, DCR will also evaluate the option of building up the barrier beach/berm with appropriate substrate and planting with species that provide erosion control and stabilization. The feasibility of this restoration option will be more fully vetted in upcoming permit applications. Restoration under with the berm removal or building up the berm will include management of invasive species such as black locust (Robinia pseudoacacia), Asiatic bittersweet (Celastrus orbiculatus), multiflora rose (Rosa multiflora) and others as identified per Massachusetts Invasive Plant Advisory Group (MIPAG), within the project footprint. Native coastal plantings are proposed as depicted in the landscape plans provided with the NPC. New plugs would not be installed in the area of the berm if removal is prohibited, due to consistent observation of sparse vegetative cover at the existing elevations and substrate.
As described by DCR, if consultation with the regulatory agencies determines the fill removal associated with reconstruction of the vegetated berm is not permittable, mitigation will focus on debris removal as previously planned. Debris removal within coastal wetland resource areas is proposed to be conducted by personnel on-foot with hand tools to the maximum extent practicable. Heavy machinery will be used to remove larger pieces of debris (e.g., timbers, wharf remnants). If necessary, machinery will be staged in adjacent upland areas where feasible and the construction mat access can also provide a means to remove these larger pieces.
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EEA# 15286 NPC Certificate August 30, 2021
The proposed stormwater management system has been designed to comply with MassDEP’s stormwater management standards that were incorporated into the Massachusetts Wetland Protection Act Regulations on January 2, 2008 (310 CMR 10.05(6)(k)). Since the project consists of a boardwalk and footpath, stormwater standards are allowed to be met to the extent practicable per 310 CMR 10.05(6)(m)6. A Stormwater Management Report has been prepared for submittal with the Notice of Intent and a copy has been provided with these supplemental materials. The report documents how the Project as a whole, meets or exceeds the ten Stormwater Standards as well as the DEP Stormwater Handbook. The project has incorporated LID design features into the overall Stormwater Management, including the use of infiltration trenches along the trail. The stormwater management system provides attenuation of the peak runoff rates from the 2,10, and 100-year, 24-hour storm events, maximizes infiltration to groundwater, and provides 80% TSS removal prior to discharge. The proposed stormwater system consists of a 2-foot-wide subsurface infiltration trench to be constructed parallel to the trail length in the northern and southern sections. The trench will include 2 feet of subsurface washed stone, overtopped with 6 inches of soil seeded with low native grasses. The pathway will be graded to direct stormwater from the trail into the proposed infiltration trench. Stormwater generated by the path will be largely infiltrated with two new drop inlets conveying outfalls to the tide gate vault. No specific stormwater management measures are being proposed for the boardwalk portion of the path since planking allows for stormwater to fall through. Where overlook decking is solid, there will be no sources of pollution such as gas-powered vehicles or deicing materials.
Waterways
The project includes work within 45,395 sf of filled tidelands associated with the proposed boardwalk and paved pathway. Chapter 91 Waterways License #14395 was issued July 21, 2017, for the previous design of the 400-ft boardwalk and multi-use trail in the northern section. Since changes to the northern alignment are greater than 10% of the original design and the southern section has not been licensed, the project will require a new Chapter 91 License to approve both components. The entirety of the boardwalk and both abutments will be within Chapter 91 jurisdiction as defined by 310 CMR 9.04 within filled and flowed tidelands. Comments from MassDEP indicate that this project is a water- dependent use project pursuant to 310 CMR 9.12(2)(a)4,11, 12, and 13. The filled tidelands constitute Commonwealth Tidelands of the Dorchester Bay, as defined in 310 CMR 9.02 by virtue of it being owned/controlled by DCR which is subject to jurisdiction pursuant to M.G.L Chapter 91 per 310 CMR 9.04(1) and requires a Chapter 91 Waterways License pursuant to 310 CMR 9.05(1)(a). The removal of 140 cubic yards of fill/berm located below mean high water is considered dredging and therefore would require a Chapter 91 Waterways Permit per 310 CMR 9.05(2)(b).
Climate Change Adaptation and Resiliency
The NPC provided an assessment of the project’s vulnerability to climate change including sea level rise (SLR). The Dorchester waterfront is projected to experience 9 inches of sea-level rise by 2030 and 40 inches by 2070, according to Climate Ready Boston (2016). The neighborhood-scale Coastal Resilience Solutions for Dorchester report (2020)3, identifies a specific flood pathway at Morrissey Boulevard South near the location of the raised boardwalk. Water entering through this pathway could flood a large portion of land from the waterfront, inland to McMorrow Playground and south to Garvey
3 https://www.boston.gov/sites/default/files/file/2020/10/Climate%20Ready%20Dorchester- Final%20Report%20%28Spreads%20for%20web%29_3.pdf 8
EEA# 15286 NPC Certificate August 30, 2021
Playground. According to the Boston-Harbor Flood Risk Model (BHFRM), the project site is vulnerable to increasing levels of coastal flooding over time. Morrissey Boulevard, at the northern extent of the project site, is vulnerable to a 10-year coastal flood event as early as 2030 with the open space around the road at risk of being inundated during high-tides. Victory Road is vulnerable to a 100-year coastal flood event in the near term (2030). As a long-term project (2050), the report proposes a raised harborwalk on a landscape berm (DFE 16.1 ft NAVD88) around Morrissey Boulevard to close the flood pathway, maintain waterfront access, and to maintain this uninterrupted transportation pathway.
With an elevation of 18.4’ (NAVD 88), the flat surface of the elevated boardwalk has been raised several feet in comparison to the original design and is located above the projected design flood elevation even accounting for sea level rise conditions as of 2070 which ranges between 16 and 16.1 ft NAVD88. This design flood elevation includes site-specific wave information plus one foot of freeboard. Other portions of the trail, including the paved pathway are below current 1% annual chance flooding (100-year storm event) elevations and some fill is proposed to raise the area in the vicinity of the tide gate vault. This will raise the area profile between 2 to 2.5 feet over approximately 400 linear feet which is intended to decrease the frequency of flooding, but not eliminate it. The expected design life of the project corresponds to 2050 at which point DCR will need to evaluate additional elevation changes and/or location of the southern section of the greenway. DCR should continue to work with the City to ensure that the project is consistent with climate change adaptation and resiliency efforts proposed for the area.
Construction Period
All construction and demolition activities should be managed in accordance with applicable MassDEP’s regulations regarding Air Pollution Control (310 CMR 7.01, 7.09-7.10), and Solid Waste Facilities (310 CMR 16.00 and 310 CMR 19.00, including the waste ban provision at 310 CMR 19.017). The project should include measures to reduce construction period impacts (e.g., noise, dust, odor, solid waste management) and emissions of air pollutants from equipment, including anti-idling measures in accordance with the Air Quality regulations (310 CMR 7.11). I encourage the Proponent to require that its contractors use construction equipment with engines manufactured to Tier 4 federal emission standards or select project contractors that have installed retrofit emissions control devices or vehicles that use alternative fuels to reduce emissions of volatile organic compounds (VOCs), carbon monoxide (CO) and particulate matter (PM) from diesel-powered equipment. Off-road vehicles are required to use ultra-low sulfur diesel fuel (ULSD). If oil and/or hazardous materials are found during construction, the Proponent should notify MassDEP in accordance with the Massachusetts Contingency Plan (310 CMR 40.00). All construction activities should be undertaken in compliance with the conditions of all State and local permits. I encourage the Proponent to reuse or recycle construction and demolition (C&D) debris to the maximum extent.
Conclusion
Based on a review of the NPC and comments received, and in consultation with State Agencies, I have determined that the NPC has adequately described and analyzed the proposed project change, and assessed its potential environmental impacts and mitigation measures. I have determined that an EIR is not required for this project change.
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EEA# 15286 NPC Certificate August 30, 2021
August 30, 2021 ______Date Kathleen A. Theoharides
Comments received:
07/08/2021 Neponset River Watershed Association 08/16/2021 Division of Marine Fisheries 08/17/2021 Office of Coastal Zone Management (CZM) 08/19/2021 Massachusetts Department of Environmental Protection (MassDEP) Northeast Regional Office (NERO) 08/19/2021 Massachusetts Department of Environmental Protection (MassDEP) Waterways Regulations Program (WRP)
KAT/EFF/eff
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July 8, 2021
Secretary Kathleen Theoharides, Executive Office of Energy and Environmental Affairs 100 Cambridge Street, Suite 900 Boston, MA 02114 Attn: MEPA Office
RE: Notice of Project Change-EEA #15286 Neponset River Greenway: Tenean Beach to Morrissey Blvd
Dear Secretary Theoharides:
Thank you for the opportunity to comment on the Notice of Project Change for the extension of the Neponset River Greenway Trail between Tenean Beach and Victory Road. We have been a staunch advocate for this trail, which has created safe public access to the Neponset River. We wholeheartedly support the trail’s extension by the Department of Conservation and Recreation (DCR) to connect more Neponset River communities to each other and to the river.
The Neponset River Estuary is a unique resource; and one of the primary goals in the NepRWA’s nomination of the ACEC was to preserve and protect this resource not only for its ecological value, but also its recreation potential. Extending the Neponset Greenway Trail advances those goals and provides a safe space for people to enjoy the river. Additionally, we appreciate the restoration measures identified in the MEPA application, including removal of debris in the salt marshes.
We note that this area has already begun to experience the impacts of climate change, including storm surges and flooding. We would ask that during the construction of this extension, careful planning be made to minimize the effects of these climate impacts on the path and the surrounding neighborhoods. And while we understand an infiltration trench is proposed along the path, we encourage the proponent to investigate other opportunities to incorporate LID along the path and associated sidewalks and roadways. Not only will these significantly contribute to the safety and experience of users, they could be used to demonstrate green stormwater management strategies to the public.
We also encourage the comprehensive management of invasive species along the trail. We understand that knotweed and other invasive plants often obstruct the existing portions of the trail, and so encourage the proponents to think carefully about the long-term maintenance of the vegetation along the Greenway.
Finally, we support the suggestions submitted by the Neponset River Greenway Council to MassDOT (attached hereto). These suggestions specifically speak to
several public safety issues and identify some problem flooding that occurs regularly that might be addressed through this project.
Thank you again for the opportunity to comment on DCR’s MEPA application. We support this project as a means to realize some of the goals of the Neponset River ACEC RMP, bringing more people to the river and restoring some degraded salt marsh. Should you have any questions, please don’t hesitate to contact me.
Sincerely,
Kerry Malloy Snyder, JD Advocacy Director
Attachment
Page 2 of 2
Neponset River Greenway Council 92 Neponset Avenue Boston, MA 02131-2155
June 16, 2021
Patricia A. Leavenworth, P.E. Chief Engineer, MassDOT Suite 6340, 10 Park Plaza, Boston, MA 02116
RE: Highway Design, Project File No. 608943 Boston - Neponset River Greenway Construction
Dear Ms. Leavenworth,
We at the Neponset River Greenway Council have been advocating for the construction and maintenance of the Neponset Trail since 1991. We are very grateful to MassDOT, DCR, Boston PWD and BTD and our legislative delegation for collaborating to move this segment of the trail forward, and we are eager to see this built soon.
We would like to offer some suggestions that we believe will help make the trail better for all users.
The Neponset River Watershed Association (NepRWA) agrees with these suggestions as this project will help attract more people to the river.
On behalf of the entire Neponset River Greenway Council, we thank you very much for your consideration and efforts on this project.
Sincerely, Jessica Mink, President Vivian Ortiz, Treasurer Lee Toma, Secretary Andres Ripley, Facilitator and NepRWA representative
Cc: Senator Nick Collins, Representative Dan Hunt Neponset River Greenway Council – Feedback for MassDOT Project File Number 608943
Project Overall:
We would like to see the trail paved to a twelve foot width rather than ten feet. This allows more space for people to pass, which is helpful for groups and improves safety for people with small children or pets.
Please include a trail traffic counter at some point along the trail. Alternatively, it would be nice to have a live webcam showing conditions on the trail and the Expressway so we could do manual counts.
Please include lighting along the trail, and security cameras and/or an emergency call box. Many trail users are uncomfortable using the existing trail when it gets dark out. This is important because parts of the trail are remote and secluded, and the sun sets as early as 4:11 pm in the winter.
Invasive species management: Please address this - there is currently a very large outcrop of poison ivy at the corner of Conley Street and the gas line right-of-way. Other parts of the trail are plagued by knotweed, which grow to block the trail and disrupt the trail surface.
Please ensure that the guardrails include rails on both the road and the trail side to protect users from hitting the vertical posts.
Wayfinding signage would be helpful at the rest stop on Victory Road, at Tenean Beach, and at the Morrissey Boulevard terminus.
Please coordinate with the Climate Ready Boston group. What are the elevations of Conley St and Victory Rd beneath the Expressway, and will these be raised to protect the inland neighborhood from storm surges?
Southern Project Limit / Conley Street:
The presentation did not clearly define the trail treatments at the project limits.
Thank you for coordinating with Boston BTD/PWD on Conley Street and Victory Road work. We would like that collaborative work to show a trail entrance curb cut at the northern Tenean Beach entrance, and more detail about how people biking southbound would transition from the trail across Conley Street to the southbound travel lane.
Figure 1. Need curb ramps at the entrance to the trail at Tenean Beach, and a treatment for southbound cyclists to cross to the southbound travel lane.
Neponset River Greenway Council – Feedback for MassDOT Project File Number 608943
At the intersection of Conley Street and the gas line, there is a curb cut. We expect this will remain for maintenance and emergency vehicle access. Please address the trail design in this area. Will there be a crosswalk for people to get from the trail to the southbound travel lane?
Figure 2. The trail needs to be protected from snowplows pushing snow in from adjacent parking lots. The poison ivy outcrop on the right will need to be removed. Will the curb cut remain, and if so, how will southbound trail users be directed to follow the trail or cross the road and take the southbound travel lane?
Will Conley Street be raised to protect the inland neighborhood from storm surges? Or would the trail be placed on a berm to reduce flooding? One reason many trail users stay on the road is because the trail at Tenean Beach floods frequently.
Conley Street needs several improvements. The drainage in this area is poor. Vehicles traveling northbound splash water from a large puddle onto the sidewalk. Many of these northbound vehicles also cross the center line into the other travel lane.
Please fix the drainage problem under the highway and/or install a splash guard to protect trail users. Drivers also stray into the opposing lane to avoid the puddle.
Please install a center line rumble strip or other infrastructure to discourage northbound drivers from straying into the southbound lane at the curve.
Figures 3 and 4. Conley Street drainage needs improvements. The splash created a hostile environment for sidewalk users, and the puddle encourages drivers to cross the centerline into oncoming traffic..
Neponset River Greenway Council – Feedback for MassDOT Project File Number 608943
The trail width under the highway is described as 12 feet. Is this the actual trail width, or does this include the guardrail?
Please consider signage or other measures to discourage speeding on Conley Street at the curve where visibility is limited.
If the whole trail doesn’t include lighting, there should be lighting under the highway. Please note that as of June 12 the electrical cable for the existing lighting system is hanging several feet below the overpass and appears likely to be caught and damaged by a passing truck.
Conley Street to Victory Road
We would like to see more plantings in this area. To improve the user experience and reduce maintenance costs, please select plants with roots that will not disrupt the paved trail surface.
Please consider adding a few gentle curves to the trail, similar to those between Central Avenue and the Harvest River Bridge in Milton.
At locations adjacent to parking lots, please coordinate with abutters and include protection to help ensure that snowplows do not dump snow on the trail or damage trail fences or greenery.
Please coordinate with BPDA and the developers of 780 Morrissey Boulevard to connect that site to the trail, and ask them to include lighting and video security overlooking the trail.
Please include an informational kiosk and wayfinding signage at the rest stop space beside Victory Road.
Victory Road Crossing
The Council prefers the first alternative, with the crosswalk on the east side of the highway.
We would prefer to see a red light, either a traditional intersection or a HAWK signal. If that is not warranted, we would like the stopsigns at the highway offramp to include flashing red lights or have a red light triggered by the pedestrian crossing. If a red light is not possible, please analyze how visible the RRFB signal will be for drivers at the end of the offramp.
Please include signage warning of the trail crossing on Victory Road and the offramp, and yield to pedestrians in crosswalk signage.
Please use video detection to trigger the trail crossing signs, with pushbuttons as a backup. We find this to be helpful in places like the Upper Charles River Trail crossing at Route 85.
If the whole trail doesn’t include lighting, there should be lighting under the highway.
We would prefer that the slip lane at the Freeport Street intersection be eliminated. A four way stop would reduce traffic conflicts.
Neponset River Greenway Council – Feedback for MassDOT Project File Number 608943
Victory Road to Morrissey Boulevard and Northern Limit
Please use a textured surface on the boardwalk for safety. The wooden decking on the Harvest River Bridge is slippery when wet. We also recommend avoiding sharp turns, and would like to see more detail about the transition from the boardwalk to the sidewalk.
Please provide more details about the crosswalk at the end of the Expressway offramp. We would like to see signage on the ramp warning drivers of pedestrian traffic, and a RRFB or HAWK signal at the crossing. Will the crossing be accessible?
We believe it would be helpful to have wayfinding signage at the boardwalk entrance to direct people away from the offramp.
What is the elevation and grade at this section of the trail?
Please define the exact limits of the project. This was not clear from the presentation. We expect that this segment will extend only as far as the southern end of the Beades Bridge.
Thank you very much for your consideration and your efforts to design and build this project.
From: DMF EnvReview-North (FWE) To: Flaherty, Erin (EEA) Subject: RE: Supplemental Infromation: EEA# 15286 NPC Neponset River Greenway - Boston Date: Monday, August 16, 2021 1:56:55 PM
Hi Erin, Thank you for forwarding the supplemental information. We’ve reviewed the responses to shading impacts to salt marsh. As it’s not feasible to raise the boardwalk to 1.5:1 H:W ratio and due to ADA requirements deck spacing cannot be larger than ¼”, we have no additional comments at this time. Let me know if you have any questions. Kate
Kate Frew Environmental Analyst MA Division of Marine Fisheries 30 Emerson Avenue Gloucester, MA 01930 phone: 978-282-0308 x157
From: Flaherty, Erin (EEA)
All –
Please see attached supplemental information for the project filing.
From: Flaherty, Erin (EEA) Sent: Wednesday, July 14, 2021 10:08 AM To: MEPA (EEA)
The comment period has been extended to 8/20/21. The Certificate will be issued 8/30/21. Supplemental information will be forthcoming.
From: Flaherty, Erin (EEA) Sent: Tuesday, July 13, 2021 5:18 PM To: MEPA (EEA)
The comment period for this project has been extended. The comment period now closes on 8/12/21. A certificate will be issued on 8/23/21. Supplemental information will be forthcoming.
Erin Flaherty Environmental Analyst Massachusetts Environmental Policy Act Office [email protected] c: (617) 874-0589
MEMORANDUM
TO: Kathleen A. Theoharides, Secretary, EEA ATTN: Erin Flaherty, MEPA Office FROM: Lisa Berry Engler, Director, CZM DATE: August 17, 2021 RE: EEA #15286, Neponset River Greenway: Tenean Beach to Morrissey Blvd.; Boston
The Massachusetts Office of Coastal Zone Management (CZM) has completed its review of the above-referenced Notice of Project Change (NPC), noticed in the Environmental Monitor dated June 23, 2021, and offers the following comments.
Project Description Since the issuance of the Secretary’s Certificate for a segment of the Neponset River Greenway from Morrissey Boulevard to Victory Road, the project scope has been expanded to include the development of a trail segment from Victory Road to Tenean Beach. The project proposed by the Department of Conservation and Recreation (DCR) consists of the construction of 3,620 linear feet (LF) of a 10-foot-wide multi-use paved pathway, including approximately 670 LF of pile-supported boardwalk across tidal habitat in an inlet of Dorchester Bay. The northern section of the project comprises approximately 900 LF of a 10-foot wide, multi-use paved pathway with two-foot shoulders. The pathway transitions to a 10-foot-by-670-foot pile-supported boardwalk with hardwood decking and aluminum railings. Piles will be 20-inch diameter, concrete-filled steel pipe driven into the ground. At the approximate center of the boardwalk crossing, a 750-square-foot (SF) outlook with seating is proposed. A second 240 SF overlook is proposed near the northern-most extent of the trail. The boardwalk connects to the sidewalk at Morrissey Boulevard and ramps down to grade through two pile-supported wingwalls (35 feet and 40 feet long) and stub abutment with aluminum railing. At the southern extent, the boardwalk also returns to grade with two pile-supported wingwalls (40 feet and 11 feet long) and stub abutment. The project will include grading as well as construction of a two-foot stormwater management infiltration trench along the pathway. An additional 500 LF of sidewalk along Morrissey Boulevard will be resurfaced to accommodate the transition from the proposed pile- supported boardwalk. Sidewalks will also be extended from Victory Road into DCR’s Victory Park with some parking improvements that enhance safe pedestrian access to the greenway.
A revised alignment of the previously reviewed boardwalk section is also proposed; this includes small areas of existing road realignment and park improvements within the boundaries of the Neponset River Estuary Area of Critical Environmental Concern (ACEC). Impacts to other wetlands, such as Land Subject to Coastal Storm Flowage, have increased beyond review thresholds due to the development of the southern section of the trail. Coastal Bank impacts have also increased due to the realignment of the boardwalk and abutment at Morrissey Boulevard. Along with significant debris removal, approximately 2,800 SF of a manmade berm will be removed to restore salt marsh and intertidal habitat.
Project Comments Supplemental information from the proponent demonstrates that the proposed alignment of the shared use path has balanced resource protection of the salt marsh with the improvements to public safety. Part of the proposed mitigation for the impacts to salt marsh included removal of sediment from a berm that meets the definition of coastal dune and barrier beach under the Wetlands Protection Act (WPA) Regulations. Removing sediment from the dune, as proposed, would have adverse impacts on the form and volume of the dune as well as reducing its ability to provide storm damage protection and flood control functions, which would not meet the standard of no adverse impact of the WPA Regulations. To avoid impacts to the dune and barrier beach and reduce the accumulation of debris, the addition of compatible sediments to the dune and planting it with erosion control vegetation would provide a better buffer that can reduce the accumulation of debris in the cove. Local organizations may be interested in helping remove debris after significant storms to avoid future impacts to the restored wetland behind the barrier beach.
Federal Consistency Review The proposed project may be subject to CZM federal consistency review, in which case it must be found to be consistent with CZM's enforceable program policies. For further information on this process, please contact Robert Boeri, Project Review Coordinator, at [email protected], or visit the CZM web site at https://www.mass.gov/federal-consistency-review-program.
LBE/ts/rh/elh cc: Rachel Freed, Jill Provencal, Daniel Padien, Chrissy Hopps, Pam Merrill, MassDEP
Charles D. Baker Kathleen A. Theoharides Governor Secretary
Karyn E. Polito Martin Suuberg Lieutenant Governor Commissioner
Memorandum
To: Erin Flaherty, MEPA Office
From: Susan You, Waterways Regulation Program (WRP), MassDEP/Boston
Cc: Daniel Padien, Program Chief, Waterways Regulation Program, MassDEP/Boston Frank Taormina, Waterways Regulation Program, MassDEP/Boston
Re: Comments from the Chapter 91 Waterways Regulation Program - EEA #15286 NPC, Neponset River Greenway: Tenean Beach to Morrissey Blvd, Boston, Suffolk County
Date: August 19, 2021
The Department of Environmental Protection Waterways Regulation Program (the “WRP”) has reviewed the above referenced NPC (EEA #15286) and supplemental information submitted by the BSC Group on behalf of the Massachusetts Department of Conservation and Recreation (DCR or the “Proponent”) for the project changes to the construction of the extension of the Neponset River Greenway trail system connecting Victory Road to the Tenean Beach through Morrissey Boulevard in, on, and/or over filled and/or flowed Tidelands of the Dorchester Bay, Boston (Dorchester), Suffolk County (the “project site”). Said trail system consists of the Northern Section, which was previously reviewed under EEA # 15286, and the Southern Section, which is newly proposed in the current NPC being reviewed.
The following changes, as detailed in Section 1.3 of Attachment A of the NPC, were made to the proposed project: - Northern Section: 1. Construction of approximately 900 linear feet of a 10-foot wide, multi-use paved pathway with 2-foot shoulders; 2. Construction of a 10-foot wide by 670-foot long pile-supported boardwalk with hardwood decking and aluminum railings, of which 270-feet of the boardwalk is
This information is available in alternate format. Contact Michelle Waters-Ekanem, Director of Diversity/Civil Rights at 617-292-5751. TTY# MassRelay Service 1-800-439-2370 MassDEP Website: www.mass.gov/dep Printed on Recycled Paper
elevated to 18.4 feet (NAVD88), rather than constructing approximately 400 feet, as previously authorized in DEP Waterways License no. 14395. 3. Expansion of the previously proposed center outlook to a 750 square feet outlook with seating and construction of a 553 square feet new outlook near the northern- most extent of the trail. 4. Increase the diameter of piles from 14 to 20 inches. 5. Construction of two pile-supported wingwalls (35 feet and 40 feet long) and stub abutment with aluminum railing at the connection between the boardwalk and Morrissey Boulevard and two pile-supported wingwalls (35 feet and 40 feet long) and stub abutment at the southern extent. 6. Construction of a 2-foot stormwater management infiltration trench along the pathway 7. Associated regrading/ raising elevations, resurfacing, and parking improvements
- Southern Section newly added to the project 1. Construction of a 10-foot wide by 2,050-foot long shared-use paved pathway with 2-foot shoulders that runs parallel to and to the west of the I-93 corridor between Victory Road and Conley Street 2. Installation of a 2-foot infiltration trench for stormwater management along the pathway 3. Raising the trail construction 2 to 2.5 feet for 400 linear feet near Conley Street 4. Connectivity improvements and roadway realignment at trail interfaces from approximately 500 feet along Conley Street and 450 feet along Victory Road 5. Associated landscaping and installation of ornamental elements such as wayfinding signs, benches, and granite posts throughout the Section 6. Tidal gate repairs including replacement of a 54-in broken flap valve on a drain line owned by the DCR and installation of two 12-in drains to stop the flow of high tides up the drain lines located to the west of the I-93 embankment near the Boston Bowl property 7. Removal of approximately 140 cubic yards of fill/berm from flowed tidelands near the northern approach to Morrisey Boulevard to meet adjacent grads and restore 2,800 square feet of salt marsh
Water Dependency: The WRP has determined that this project is a water-dependent use project pursuant to 310 CMR 9.12(2)(a)4,11, 12, and 13.
Chapter 91 Jurisdiction: Said work will be undertaken in, on, and/or over filled and/or flowed Commonwealth Tidelands of the Dorchester Bay, as defined in 310 CMR 9.02 by virtue of it being owned/controlled by DCR. which is subject to jurisdiction pursuant to M.G.L Chapter 91 per 310 CMR 9.04(1) and requires a Chapter 91 Waterways License pursuant to 310 CMR 9.05(1)(a). The removal of 140 cubic yards
Page 2 of 3 of fill/berm located below mean high water is considered dredging and therefore also requires a Chapter 91 Waterways Permit per 310 CMR 9.05(2)(b).
Chapter 91 Comments: The NPC states that the entirety of the boardwalk and both abutments will be located within Chapter 91 jurisdiction. Approximately 110 linear feet of the multi-use trial in the northern section will also be in jurisdictional filled tidelands. In the southern section, portions of the connectivity improvements, sidewalk formalization and roadway realignment proposed along Victory Road including regrading and resurfacing of a parking area in DCR’s Victory Road Park are located on filled tidelands. Approximately 800 linear feet of the total southern section is located within filled tidelands. Up to 3,170 square feet of temporary construction mats will also be required in flowed tidelands/intermittently flooded intertidal areas for long-reach equipment to install the piles and boardwalk components. An additional 4,780 sf of construction mats will be used for access on flowed tidelands. Total project-related fill within Chapter 91 jurisdiction has been calculated at 409 cubic yards. Cuts/excavation within jurisdictional areas have been calculated at 279 cubic yards. The remainder of the proposed greenway construction activities are located outside of Chapter 91 jurisdiction. Temporary in-water work is limited to the construction mats and installation of piles and abutment for the boardwalk.
Since changes to the northern alignment are greater than 10% of the original design and the southern section has not been licensed, the Proponent is seeking a new Chapter 91 License to approve both components. The Department notes that an application for the new Chapter 91 Waterways License is attached to this NPC but is missing a request for a Permit also for dredging described above. Furthermore, the Proponent should clarify how long the temporary structures, such as construction mats, are intended to remain in place below mean high water, so that the Department can determine whether said activity requires a Permit or License. Please note, that if dredging exceeds 100-cubic yards, then this project will also require a 401 Water Quality Certificate from the MassDEP Wetlands Program.
The Department will initiate its review of the license application to ensure it meets the minimum filing standards as set forth in 310 CMR 9.11(3), which includes the Secretary’s Certificate concluding the MEPA review process and a copy of Notice of Intent filed with the Boston Conservation Commission. The Department notes that most of the project sits within and near the edge of a minority population area and the Application shall meet Environmental Justice requirements during licensing.
If you have any questions regarding the WRP’s comments, please feel free to contact me at (617) 556- 1198 or at [email protected]
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Charles D. Baker Kathleen A. Theoharides Governor Secretary
Karyn E. Polito Martin Suuberg Lieutenant Governor Commissioner
August 20, 2021
RE: Boston Kathleen A. Theoharides, Secretary Neponset River Greenway: Tenean Beach to Executive Office of Morrissey Boulevard Energy & Environmental Affairs EEA # 15286 100 Cambridge Street Boston MA, 02114
Attn: MEPA Unit
Dear Secretary Theoharides:
The Massachusetts Department of Environmental Protection Northeast Regional Office (MassDEP-NERO) has reviewed the Notice of Project Change (NPC) for the proposed Neponset River Greenway: Tenean Beach to Morrissey Boulevard in Boston. MassDEP provides the following comments.
Wetlands
A Notice of Project Change (NPC) has been filed with the Executive Office of Energy and Environmental Affairs (EOEA) by BSC Group on behalf of the Massachusetts Department of Conservation and Recreation (DCR) for construction of the Tenean Beach to Morrissey Boulevard extension of the Neponset River Greenway trail system in the Dorchester neighborhood in the City of Boston. The project previously underwent MEPA review in 2014, receiving a Secretary’s Certificate dated December 24, 2014. The project did not require the filing of an Environmental Impact Report (“EIR”), and it was found that the potential impacts of the project identified in the Environmental Notification Form (“ENF”) dated November 24, 2014 warranted no further environmental review.
This information is available in alternate format. Contact Michelle Waters-Ekanem, Director of Diversity/Civil Rights at 617-292-5751. TTY# MassRelay Service 1-800-439-2370 MassDEP Website: www.mass.gov/dep Printed on Recycled Paper
The 2014 Certificate considered impacts resulting from construction of a 1400-foot long multiuse pathway beginning at Victory Road in Dorchester and extending northerly across land owned by Boston Gas Company to an existing sidewalk on Morrissey Boulevard. The extension consisted of approximately 1,000 linear feet of a new paved 10-foot-wide pathway and a 400-foot elevated pile-supported boardwalk across salt marsh. The boardwalk was approved by a 401 Water Quality Certification from MassDEP (Transmittal #X271887), a Section 404 Permit from the USACE (NAE-2016-0280) and an Order of Conditions (DEP #006-1442) issued by the Boston Conservation Commission. These permits allowed alteration of approximately seven (7) square feet (sf) of Salt Marsh from the installation of seven 14-inch diameter piles and 3725 sf of temporary salt marsh alteration from the placement of construction mats.
The current application includes an alternate design/realignment of the previously proposed “Northern Section” from Victory Road to the William T. Morrissey Boulevard crossing over Dorchester Bay, which was reviewed under the Secretary’s Certificate EEA #15286. The Northern Section has been revised to an approximately 1,570-foot-long multi-use pathway and boardwalk beginning at Victory Road in Dorchester and extending northward across the Boston Gas Company, d/b/a National Grid (“National Grid”) liquefied natural gas (“LNG”) storage facility and solar array at Commercial Point, where it will connect with the existing sidewalk on Morrissey Boulevard. This will eliminate a dangerous, substandard crossing of the I-93 exit ramp pedestrians currently use to reach the sidewalk at Morrissey Boulevard. The project also proposes the construction of the “Southern Section” of 2,050 linear feet of new multi-use trail connecting Victory Road to Tenean Beach off Conley Street, which was not previously reviewed through the ENF filing for EEA#15286. The Southern Section will follow a sidewalk along Conley Street from Tenean Beach, where it turns north and continues parallel to and west of the embankment of Interstate 93. The trail connects to the Northern Section through roadway and connectivity improvements at Victory Road. Wetland resources are associated with the tidal portion of the Neponset River and Dorchester Bay.
Wetlands Impacts
The Northern Section proposes a redesigned 670-foot-long boardwalk section between the National Grid energy facility parcel and Morrissey Boulevard that will extend over land located seaward of the original shoreline Historic MHW and within Chapter 91 jurisdiction. At the approximate center of the boardwalk crossing, a 750-sf outlook with seating is proposed. A second 553 sf overlook is proposed near the northern-most extent of the trail. The boardwalk is proposed to be built with prefabricated 50-foot-long aluminum trusses and a hardwood deck. The majority of the elevated boardwalk decking will be located at approximately elevation 18.4’ NAVD 88, above the established 100-year floodplain Velocity Zone, or VE, breaking-wave height of 14’. Only 75 linear feet of the 670-foot-long boardwalk passes directly through salt marsh. Direct impacts from the boardwalk to 18 sf of salt marsh will result from installation of eight 20-inch diameter concrete- filled steel pipe piles providing foundational support to the boardwalk structure. Four of the eight piles in salt marsh are to support a 209 sf portion of the 553 sf overlook that will be located directly over saltmarsh. The remaining four piles support the boardwalk where it crosses over 75 linear feet of salt marsh. Two of those four piles also support 115 sf of the 750 sf central overlook that will be located over salt marsh. The number of spans and piles that are necessary to support the structure in jurisdictional and resource areas has been reduced where feasible. A total of approximately 39 piles are proposed to support the piers at the boardwalk and overlooks. The decision to drive the piles will
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eliminate drilling spoils. Long reach equipment will be used to drive piles and to install the boardwalk superstructure itself.
Temporary placement of construction mats will be necessary for access to install the driven piles, pile caps and the boardwalk structure. Approximately 7,950 sf of construction mats will be placed seaward of Historic MHW, which will provide equipment access during the boardwalk installation. Approximately 3,170 sf of temporary salt marsh impacts are required for the construction matting. The temporary impact areas will be restored in kind after the removal of the construction mats. An additional 18 sf of permanent pilings will be required in the narrow boundary between the delineated salt marsh and the highest high tide (astronomical high tide) at elevation 6.8’ NAVD 88. There will be almost 12 feet of clearance between the bottom of the boardwalk deck and the highest high tide elevation. The remaining 23 piles (50 sf) supporting the elevated boardwalk will be in Land Subject to Coastal Storm Flowage (LSCSF) and downgradient from the coastal bank. Approximately 854 sf of temporary matting is proposed within coastal resources (beaches/flats).
Approval of the revised boardwalk design centers upon interpretation of 310 CMR 10.32(4):
“Notwithstanding the provisions of 310 CMR 10.32(3), a small project within a salt marsh, such as an elevated walkway or other structure which has no adverse effects other than blocking sunlight from the underlying vegetation for a portion of each day, may be permitted if such a project complies with all other applicable requirements of 310 CMR 10.21 through 10.37.”
The alternatives analysis provided in the NPC and supplemental materials shows that only 75 feet of the 670-foot long boardwalk passes through saltmarsh. An additional 324 square feet of decking from the two overlooks, 115 square feet of the central overlook and 209 square feet of the second overlook, will be located over salt marsh. Helical piles, micropiles, and driven piles (including concrete-filled steel pipe piles, concrete-filled fiberglass-reinforced pipe piles, and timber piles) were all evaluated for supporting the boardwalk. Support types were reviewed for durability in the marine environment, load carrying capacity, constructability, and environmental impact. 20- inch concrete-filled steel pipe piles were selected for long span, load carrying capacity and life span in the marine environment.
The height of the boardwalk over the salt marsh has been detailed. It has been determined that it is not possible to meet height to width ratio of 1.5 to 1, as recommended by the “Massachusetts Division of Marine Fisheries Environmental Recommendations for Small Docks and Floats” and the Massachusetts Office of Coastal Zone Management (CZM). If the boardwalk were to be raised to meet a 1.5:1 ratio, it would require an additional seven to eight feet in height for a deck surface greater than elevation 25 feet NAVD88. This increased height would also require an increase to the diameter of the supporting piles resulting in additional direct impact to salt marsh. The boardwalk is oriented north to south which is recommended by CZM to reduce shading.
The supplemental alternatives analysis provided on August 12, 2021 shows that project has minimized the square footage of the boardwalk and overlooks over salt marsh and minimized the number of piles in salt marsh. It has provided justification for the use of the 20-inch concrete filled
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steel pipe pilings. It has also provided justification that the design height to width ratio, ranging from 0.9 to 1 to 1:1 cannot be further maximized without increasing direct impacts to salt marsh from larger support piles.
Approximately 100 linear feet of the previously reinforced coastal bank located at the northernmost point of the pathway will be altered through the addition of the concrete abutments and ramps as the elevated boardwalk makes landfall at Morrissey Boulevard. These changes will not affect the stability of the bank. Alteration will also be required in LSCSF for the installation of the boardwalk and access to the northern section of the pathway, the improvements to Victory Road Park, and in roadway redevelopment and trail development in the Southern Section of the pathway. Approximately 400 linear feet of the Southern trail route will be filled to raise the profile between 2 to 2.5 feet in LSCSF. LSCSF impacts have increased the most in the revised project, including exceeding the threshold of a ½ acre or more of “other wetland” alteration. This increase is due to sections of Victory Road, Conley Street, and portions of the Southern Section of trail being located in LSCSF. Finally, the proposed repair/partial reconstruction of the existing 13 ft by 8.5 ft tide gate vault will also occur in LSCSF.
Proposed mitigation includes cleaning up the large debris, timbers, and trash along the coast and in the currently degraded areas of salt marsh in the vicinity of the Greenway. Any salt marsh grasses and root systems affected by the pilings are proposed to be transplanted to bare or sparsely vegetated areas in the appropriate tidal elevations.
The applicant has proposed removal of a “manmade berm” consisting of approximately 2800 sf and 140 cubic yards of fill material from an intertidal area to restore salt marsh and intertidal habitat. This area functions as a barrier beach as defined in and regulated by 310 CMR 10.29 and is therefore subject to the Performance Standards for work on a coastal beach at 310 CMR 10.27(3) through (6). 310 CMR 10.27(3) specifies that “Any project on a coastal beach, except any project permitted under 310 CMR 10.30(3)(a), shall not have an adverse effect by increasing erosion, decreasing the volume or changing the form of any such coastal beach or an adjacent or downdrift coastal beach.” The applicant should therefore construct an alternative to removing barrier beach to create salt marsh. The applicant has identified mitigation alternative “B” as described in the revised supplement which focuses on debris removal to be conducted by personnel on-foot with hand tools to the maximum extent practicable, with heavy machinery used only to remove larger pieces of debris such as timbers or wharf remnants. Debris removal without the removal of beach sand, sediments or soils, is projected to enhance or restore approximately 3,000 sf of salt marsh, coastal beach and/or LSCSF. The supplement states that “Direct planting in debris removal areas is not proposed, with the exception of any coinciding native wetland and upland coastal plantings depicted on the landscape plans. Supplemental salt marsh grass plugs will also be considered in areas with existing suitable substrate, where debris cover had prevented growth.”
The supplement appends mitigation alternative B with a third option as follows: “After further discussion with the agencies, DCR will also evaluate the option of building up the barrier beach/berm with appropriate substrate and planting with species that provide erosion control and stabilization. The feasibility of this restoration option will be more fully vetted in upcoming permit applications.” This option was suggested by CZM in discussions relative the alternative supplement
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and may also be explored as an alternative to removal of beach materials. Both alternative “B” options include management of invasive species. MassDEP advises implementation of the alternative “B” options.
The MassDEP appreciates the opportunity to comment on this proposed project. Please contact [email protected] at (978) 694-3258 for further information on wetlands issues. If you have any general questions regarding these comments, please contact me at [email protected] or at (978) 694-3304.
Sincerely,
John D. Viola Deputy Regional Director
cc: Brona Simon, Massachusetts Historical Commission Eric Worrall, Rachel Freed, Jill Provencal, Phil DiPietro, MassDEP-NERO
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