352 Turnpike Road Southborough, MA 01772 508.480.9900

May 13, 2021

Town of Arlington Department of Public Works 51 Grove Street

Arlington, MA 02476

Attention: Mr. Wayne Chouinard Re: 1165R Mass Ave Comprehensive Permit March 19, 2021 Review Comments Dear Mr. Chouinard: On behalf of the applicant, 1165R Mass MA Property LLC, Bohler offers the following responses to the

comments in your letter to Kelly Lynema, Senior Planner, dated March 19, 2021. For clarity, the original comments are in italics, while our responses are directly below in bold type.

Drainage Report

Comment: The Engineering Division has reviewed the Drainage Report and finds the information acceptable in format, concept and methodology. With the exception of the following items the Drainage Report appears to be an accurate analysis:

Clarify discrepancy of the building outline of the connection between Building #1 and #3 on the Site and Subsurface Exploration Location Plan and the Proposed Conditions Watershed Map.

Response: The Subsurface Exploration Location Plan was based on an early iteration of the site plan layout. The attached site plans show a covered connection. The Applicant is currently exploring options for the connector between Buildings 3 and 4, including providing a hardscaped path only.

Comment: Clarify the location of CB-1 indicated on the Proposed Inlet Map as it conflicts with the location of CB-1 on the Operation & Maintenance Location Map.

Response: The location of CB-1 has been corrected in the enclosed Drainage Report.

Site Plan Documents

Sewer:

Comment: Details and offset dimensions to ensure proper spacing between water/sewer services, connections and crossings.

Response: Please see “Water/Sewer Crossing Detail” on plan sheet C-901 of the site plans.

Comment: Existing sewer lines should be replaced and not reused.

Response: Sewer laterals from all proposed buildings will be new. The existing Workbar building is not part of the project and is located within a separate property under different

Ownership from 1165R Mass Ave. As such, the existing sewer service for Workbar will remain as well as the existing MWRA sewer main.

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Water: Comment:

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Floor drain and sewer connection details should be provided for all garage facilities serving more than five (5) vehicles

The Plumbing Drawings will be filed with the building permit set of plans and will show floor drains in the garages of Buildings 2 & 4 connected to the sanitary system as required by code.

New sewer service lines from multi-family buildings should be a minimum of 8” diameter.

The new sewer laterals for the proposed buildings will be 8” diameter pipe, subject to approval from the MWRA.

It is recommended that an Inflow/Infiltration (1/l) mitigation fee be assessed to be used to reduce Vl of the Town sewer system in the amount equal to four (4) times the design flow of the project.

Based upon the Applicant’s investigation and discussion with various Town officials, there are no regulations for either determining when to impose an I/I mitigation fee, the methodology for determining such a fee and/or the amount of the I/l fee. A review of a number of other development projects reveals that no such I/I fee was imposed.

Here the project when completed is projected to result in a net positive cashflow to the Town. In the Fiscal Impact Analysis prepared by Fougere Planning & Development, Inc., a copy of which is enclosed, it is estimated total tax revenue from the project will be $593,291. Municipal costs are estimated to be $330,759, resulting in the project having a positive net revenue of $262,532 annually. This will be a substantial increase in net revenue to the Town from this site.

Moreover, the Applicant is, among other things, substantially improving the environmental conditions on the site, providing a significant, much needed, infusion of affordable and market rate housing, creating community space and implementing the goals outlined in the Master Plan prepared by the Town.

Thus, the Applicant respectfully suggests that: (a) in the absence of objective, codified regulations, providing for when and how I/I should be imposed; (b) in the absence of I/I rates uniformly adopted and imposed on all development projects in the Town; (c) based upon the significant improvements the Applicant is making to the site as detailed above; (d) in view of the substantial net positive tax flow to the Town from the property once developed; and (e) in light of the fact that this project is being permitted through the Comprehensive Permit Law, M.G.L. c.40B, no I/I mitigation fee should be imposed or, in the alternative, it should be waived.

All connections to the Town water system require a triple gated connection to provide maximum shut-off and distribution control. Triple gated connections are shown at the connection to the Town water main in Massachusetts Avenue. Additionally, separate domestic and fire water services are proposed from Massachusetts Avenue to the proposed buildings. Please see drawing C-501 within the site plan set.

Connections to the Town water main requires a tee connection.

Tee connections have been provided. Please see plan C-501 within the site plan set.

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Existing water meter vault near Mass Ave. should be removed and new water meter/s should be located within each building.

The water vault cannot be removed because it serves other buildings near the site and this will be investigated by the contractor during construction. New separate water lines will be installed for the project from the main in Massachusetts Ave to the proposed buildings, bypassing the existing water meter vault, and meters will be installed inside the buildings.

Suitable calculations should be performed to verify that the 6” existing main serving the property from Mass Ave. has suitable capacity to provide the necessary domestic water supply and fire flow for the proposed project.

The results of a Hydrant Flow Test, dated 11/12/2020, show flow pressure equal to 135 psi at a rate of 1,060 GMP. Wozny/Barbar & Assoc., the Mechanical Engineer of Record, stated that the result was “excellent” and that there was “No need for a fire pump or domestic booster system”. Please see the attached results and email from Wozny/Barber. As a result, the updated design includes a 6” connection for domestic water and a separate 8” connection for fire protection.

Connections to the Town water distribution system on Ryder St. should include the replacement of the existing water main located in Ryder Street due to the existing age, condition and material as well as;.

Based on discussions with Town Staff on May 4, 2021, the Applicant is no longer proposing a water line connection to Ryder Street and the requested improvements are no longer necessary.

Connect the dead end configuration of the water main on Ryder Street by extending it to the existing water main located in Forest Street.

Based on discussions with Town Staff on May 4, 2021, the Applicant is no longer proposing a water line connection to Ryder Street and the requested improvements are no longer necessary.

Stormwater/Flood Plain

Comment:

Though not required under the Town Stormwater Mitigation Bylaw, it is recommended to use any opportunity to collect and infiltrate stormwater runoff where possible to reduce the effects of climate change and increase stormwater water runoff quality.

Response: The 1165R Development proposes to increase pervious open space by 194%, from 7,332

Comment:

Response:

sf to 21,574 sf, significantly increasing stormwater infiltration and groundwater recharge. The project will also provide water quality treatment of stormwater runoff generated within the site where there is currently none. Refer to the enclosed drainage report for a summary of the decreases in peak runoff rates and volumes.

Suitable documentation of groundwater conditions have not been provided. A verification statement should be provided to ensure that no structures are built below the estimated seasonal high ground water elevation (footings excluded).

Two geotechnical engineers provided input on existing groundwater conditions. Please see the attached from LGCI Geotechnical Consulting, Inc., summarizing the findings. The Applicant does not anticipate dewatering will be necessary. No structures will be built below the estimated seasonal high ground water elevation.

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CATV: Comment:

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Due to the proximity to the 100 year flood elevation it is recommended that the Frimpter Method shall be utilized with the observed local ground water readings and in conjunction with the USGS Groundwater Well Network. At a minimum these test pits should be installed in the proposed foot print of the buildings.

Borings were performed by two separate geotechnical engineers. The findings have been considered in the design of building foundations relative to groundwater levels. The lowest floors of all proposed buildings will be above the 100-year flood elevation and estimated seasonal high ground water elevation. It is not anticipated that dewatering will be necessary and no structures will be built below the estimated seasonal high ground waiter elevation.

Please comment on potential for scouring potential as well as concerns about runoff and erosion along the back (north) wall of Building #4 where the direction of flow of Ryder Brook is proposed to be re- directed. Provide calculations and/or analysis that stormwater flow will not erode and undermine the foundation/footings at the rear of Building #4.

The plans have been updated to show Ryder Brook being pushed further away from Building #4 to address these concerns. Additionally, stone will be installed in this area in order to prevent erosion and scouring. Please note that the proposed ditch elevation in that area will be approximately 96 feet and the bottom of footing will be at a minimum elevation of 94.5 feet, assuming a minimum four foot depth below the finished floor elevation. Please see the Grading and Drainage Plan within the site plan set.

What are the off-site upgrade requirements necessary for the CATV requirements for proposed development?

Will current utility pole and cable configurations accommodate the required cable, electric and telephone wires without the need for additional utility poles or improvements outside of the project locus? Any installation of new utility poles or underground conduit in the public right of way will require a Grant of Location from the Board of Selectmen. This information should be provided as part of the application process to evaluate the entirety of impacts and effects.

The Applicant has worked closely with Eversource and Verizon to determine how the site will be served electrically and with CATV. The electric and CATV infrastructure serving the site are owned and maintained by the utility companies. Any new poles or underground service located in the public right of way will be brought before the Board of Selectmen by the utility companies as is the normal course. The plan is to bring the electric service from Forest Street to Ryder Street and through the site driveway to a transformer serving the entire site near building 4. Secondary services will be routed from the transformer through the site to the buildings. All utility services will be coordinated with the Town as required.

Accessibility

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Comment:

The Traffic Impact Report indicates that Quinn Road is a private way. However, Town records indicate that Quinn Road is a public way. The layout for Quinn Road was approved on April 9, 1957 and the roadway was accepted on April 14, 1958 by the Board of Survey.

Comment acknowledged.

It is unclear how safe access and egress to Mass Avenue, Forest Street and the Minuteman Bike path is intended to occur based on the site plans. It is recommended the Applicant provide clear depiction of access and egress from the project site for all modes of travel, including vehicles, cyclists and pedestrians. The current plan simply provides access off the project property into a complex and confusing assortment of driveways within Mirak Innovation Park.

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Response:

Similar comments were made by the Transportation Advisory Committee and the applicant has responded to the TAC comments separately.

Comment: The Traffic Impact Report indicates that “Pedestrian and bicycle accommodations and safety

Response:

are paramount for a successful development in an urban area.” It is recommended that the project be required to provide connectivity for both pedestrians and cyclists including:

A clear connection and accessible pedestrian path to Forest St. by installing necessary sidewalks and curb ramps from the Ryder Street driveway exit to Forest Street, also;

a clear connection and accessible pedestrian path to Mass Avenue by installing necessary sidewalks and curb ramps along the expected pedestrian routes towards Mass Ave. Currently there are Easements “A and B” connecting to Quinn Road indicated on the ALTA plans, but no proposed work for improving pedestrian accessibility.

Update the deteriorated and poor condition roadway along the Ryder Street private way to provide a smooth and safe route for vehicles to access Forest Street and bicycles to access the Minuteman Bike Path.

Pedestrian improvements should be considered in Mirak Innovation Park West Driveway. The area is immediately adjacent to 1171 Mass Ave. as this is the shortest and most direct route to connect pedestrians to Mass Avenue.

The Applicant has submitted an extensive Traffic Impact Report which has been supplemented based upon comments provided by the BETA Group, Inc., the Town’s peer reviewer.

BETA Group has provided two extensive Traffic Peer Review letters to which the Applicant’s traffic consultant, Nitsch Engineering, has provided additional information and responses after discussion with representatives of BETA Group. Accordingly, please refer to the revised Traffic Impact Report and the twenty-two page letter from Nitsch Engineering. On May 6", the BETA Group provided their final comments accepting the Applicants approach to transportation analysis and design with a few minor comments that will addressed by Applicant.

Landscaping:

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Lighting: Comment:

If possible, street tree plantings should be provided in a grass strip along Quinn Road as part of the pedestrian accessible path to Mass Avenue.

The Applicant does not own land on Quinn Rd and will not be planting street trees along Quinn Rd.

Project should provide screening of parking areas and buildings from the immediate residential abutters if possible.

Parking will be almost entirely located within parking garages in Buildings 2 and 4. There are only 11 outside parking spaces proposed, of which only four (4) are located on the driveway leading to Ryder Street (nearest the residential abutters). Screening of those four spaces is not possible because of the limited width of the driveway which also includes the proposed Mill Brook sidewalk. Those four (4) parallel parking spaces are consistent with the parallel parking that currently exists on Ryder Street. The other seven (7) spaces are at least 170 feet from Ryder Street or will be obscured from view from Ryder Street by the proposed building.

Additional lighting should be considered and included along any defined and improved pedestrian pathways connecting to Forest St. and/or Quinn Road. Night sky reduction, light pollution, cut off fixtures and glare should be ensured through the approved Lighting Plan.

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Response: As stated above, the Applicant does not own land on Forest Street or Quinn Road (both are public streets) nor the portion of Ryder Street where the existing pedestrian path connecting to Forest Street exists. Therefore, no lighting improvements are proposed for those areas. The proposed site lighting for 1165R takes into consideration night sky, light pollution, and glare. Please refer to the Lighting Plan within the site plan set.

Traffic: Comment: Additional comments pertaining to the Traffic Impact Report is deferred to the Transportation Advisory Committee.

Response: The applicant has received and responded to comments to the TAC separately.

In addition to the above, the Applicant has coordinated with the Fire Department to ensure that access for their fire trucks is adequate. Attached is an exhibit demonstrating the truck travel path of Ladder Tower Truck #1 as specified by the Arlington Fire Department.

Should you have any questions or require additional information, please do not hesitate to contact either of us at (508) 480-9900. Thank you.

Sincerely, Bohler

., / ig cat. ae Andrew Platt Randy Miron

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APPENDIX TO COMPREHENSIVE PERMIT TOWN ENGINEER RESPONSE LETTER

Exhibit No. Exhibit

1 Drainage Report, by Bohler Engineering, dated 5/5/21

2 Civil Site Plan Set, 16 plan sheets, by Bohler, revised 5/13/21

3 Hydrant Flow Test & Email, dated 11/12/20 and 11/24/20, respectively 4 Geotechnical Report, by LGCI, dated 1/22/21

5 Fiscal Impact Analysis, by Fougere Planning & Development, Inc.

6 Fire Truck Exhibit, by Bohler, dated 5/13/21

END of ATTACHMENTS LIST