From: thughes@hughesenvr.com Sent: Tuesday, November 23, 2021 5:08 PM To: Rob Moore Cc: 'Geilen, Alicia (DEP)' Subject: [EXTERNAL]38/58 Railroad Haverhill, DEP file number Warning! External Email. Exercise caution when opening attachments or clicking on any links. . . Hi Rob, as you are aware we have received DEP comments as well as feedback from NHESP. I just found this was stuck in y outbox so I have updated the language to be a little more current. Unclear if project meets performance standards for redevelopment in Riverfront. Stormwater management is required, and therefore does not count as "improvement" under 10.58(5)(a). While we respectfully disagree with the comment regarding the improvements to riverfront functions from the stormwater management, there are other improvements to riverfront function, including the removal of invasive species and increasing the setback from Mean High Water to building on site which improves the ability of the riverfront to provide the important functions that are described in 310 CMR 10.58(5). Currently, the existing building is located 29 feet from MHW and existing degraded riverfront extends as close as 22 feet to MHW. Our proposal increases the distance to the nearest altered riverfront area to 25 feet (the proposed rail trail) and increases the distance to building to about 40 feet. This overall shift in impervious and altered areas away from the river, along with establishing native vegetation in those areas where degraded conditions are restored will improve riverfront functions. I note that we are developing a detailed vegetation plan for the riverfront area after consulting with NHESP that will result in an improvement in the function of the riverfront and address many of the concerns expressed by DEP in their comments. With regards to whether the improvements that result from stormwater management, which we acknowledge is a regulatory requirement for any redevelopment, however there is still an improvement to the riverfront and its function that is a direct result of the current degraded condition and the proposed redevelopment and this should be considered under this section. The requirement under 5(a) has to do with the improvement, not whether it is required. For example it is possible to have a degraded condition with stormwater management existing that would not yield such improvements to riverfront function. Additionally, if the project does not happen then no such improvements occur. I note that the next subsection of the redevelopment regulations (b) specifically references stormwater management, even though it would be required by other sections of the regulations regardless. Our project improves water quality and habitat, and increases vegetative coverage closes to the river. These are threshold questons under 10.58(5)(a). However, we do not take credit for stormwater under the mitigation subsections (e) or (f) under the redevelopment section of the regulations. Regardless even without the improved water quality that results from stormwater treatment, the vegetative work and increased setback to mean high water of the developed portion of the site provides such improvements. A rail trail does not count as "mitigation" under 10.58(5), as it does not add to the protection of the interests of the WPA, but addresses public access. Point noted and we acknowledge this. To clarify, while we mentioned the rail trail in the regulatory discussion, we did not take credit for it in our calculations under this section. This was clarified in our presentation to the Commission. I also note we did not take credit for the invasive control work under subsection (f) of 10.58(5) 2:1 either. No mitigation planting plan is provided, or details on invasive plant removal (e.g., species, approximate numbers, sizes, locations, etc.). Native plant species listed in Narrative do not appear to provide sufficient structural or species diversity. Separately I am submitting a landscape plan and invasive management plan that addresses this comment. We have had one meeting with NHESP and are working to develop a plan that provides structural and species diversity, and that no longer contributes to the invasive seedbank that populates the banks of the Merrimack along its length. Our NHESP review period was hold while we developed this. As part of this work we are located significant trees (>6” dbh) on the slope between the armor stone and the existing development. There is no discussion of why bank must remain armored, and cannot be at least partially restored. Under 310 CMR 10.58(5) we are not required to evaluate the removal of any of the revetment, however, as the Commission is aware, and has been evident at other hearings during our last meeting, there are several areas of the river that have been experiencing significant erosion. The armored bank is a well- established structure with large armor stone and not something easily removed. This revetment was installed when the sewer main was installed in the bank of the river years ago in order to protect it. Removal of even a portion of the armoring would result in an increased risk of erosion as well as significant disruption to the vegetated bank in addition to jeopardizing the City’s infrastructure. We are proposing to maintain vegetation within the voids between the stone where the slope is generally vegetated within invasive plants now. Our approach will involve live staking as well as some restoration grade plants that will not put the sewer line or the revetment that protects it at risk.. We expect to include dogwoods and pussy willow in this area in addition to any native plants that are present. See the separate submission. Invasive removal is "unquantified", so there is no way to determine if 1:1 mitigation is proposed. All areas of invasive removal will be revegetated if they are within the planting footprints shown or on the slope on the waterside of the proposed rail trail. We did not include the invasive work separately in our mitigation calculations, but do count the areas that will be vegetated sitewide with native vegetation, when the project is done and compare that to the existing vegetated areas to come up with our 1:1 mitigation under 10.58(f). Unclear what "trees damaged by invasive plants" means. 10.58(5)(f) requires retaining trees and mature vegetation as part of RA mitigation, but the Narrative notes that trees will be removed from Bank and the slope above it. Most, if not all of the removal of the trees are on the slope above the top of bank and within the armor stone. However, as the Commission observed during the site visit multiflora rose and bittersweet have used the native vegetation on site as trellises and killed of much of their canopies. In some cases the trees have been outright killed. Our intention would be to identify the trees that are unlikely to recover from the invasive growth and replace them. This approach is described in our invasive management document that is being submitted separately. The Checklist for Stormwater Report notes that the project will "minimize disturbance to existing trees and shrubs", but no landscaping plan was provided to confirm tree/shrub retention. Native trees in RA and especially on/above Bank should be retained. Where they must be removed, they should be replaced. See our separate submission of our invasive management methodology and landscape plan that addresses retention of native trees and plants. Unable to determine if stormwater standards are met. Locations for soil test pits not shown on the plan, so it is unclear if they were installed in locations for infiltration units. Unclear if minimum 2' separation is provided from the bottom of the infiltration units and the top of estimated seasonal high groundwater. If the bottom of infiltration units are <4' to groundwater, a mounding analysis is required. DEP has been copied on our engineering submissions since the comment was received. Also it is important to note that since our stormwater and overall engineering is being peer reviewed by the City and the test pit issue has been addressed in those submissions. Please let me know if you have any questions, Tom Thomas G. Hughes, BS, MA Hughes Environmental Consulting 44 Merrimac Street Newburyport, MA 01950 Tel. (978) 465-5400 Fax (978) 465-8100 PO Box 392 Concord, MA 01742 Tel. (978) 369-2100 Cell (978) 289-0605