REHABILITATION AND RENOVATION OF THE CARNEGIE LIBRARY AT MOUNT VERNON SQUARE ENVIRONMENTAL ASSESSMENT Prepared by: National Capital Planning Commission In Cooperation with: Events DC July 2017 With Technical Assistance from: CARNEGIE LIBRARY ENVIRONMENTAL ASSESSMENT This page left intentionally blank. ii CARNEGIE LIBRARY ENVIRONMENTAL ASSESSMENT EXECUTIVE SUMMARY The National Capital Planning Commission (NCPC), in cooperation with Events DC, has prepared an Environmental Assessment (EA) to evaluate impacts of alternatives for the rehabilitation of the Carnegie Library building at Mount Vernon Square in Washington, DC. This EA evaluates the impacts of the proposed rehabilitation, the Action Alternative, and a No-Action Alternative on the natural and human environment. The purpose of the proposed action is to rehabilitate and modernize the Carnegie Library to serve as a new city square for Washington, DC, where the community can come to learn, be entertained and collaborate. The project would include the rehabilitation of the interior and the restoration of the exterior of the Carnegie Library. The proposed project would also include restoration of the historic light well in the central atrium space and reconfiguration of the north entrance. The Library would be leased jointly by the Historical Society of Washington (HSW) and a retail tenant that would operate a retail, events, and educational facility in the building. The proposed project is subject to the review of NCPC under the National Capital Planning Act. This EA has been prepared in accordance with the National Environmental Policy Act of 1969 (NEPA), the Council on Environmental Quality’s Regulations for Implementing NEPA (40 Code of Federal Regulations [CFR] 1500-1508), NCPC’s implementing regulations (69 FR 41299), and the National Capital Planning Act. Questions or comments on the EA should be addressed to: National Capital Planning Commission Attention: Mr. Lee Webb 401 9th Street, NW North Lobby, Suite 500 Washington, DC 20004 Phone: (202) 482-7200 Email: [email protected] iii CARNEGIE LIBRARY ENVIRONMENTAL ASSESSMENT This page left intentionally blank. iv CARNEGIE LIBRARY ENVIRONMENTAL ASSESSMENT TABLE OF CONTENTS EXECUTIVE SUMMARY ................................................................................................................... iii Table of Contents ............................................................................................................................ v Purpose and Need for the Proposed Action .......................................................................... 1 What is Being Proposed for the Carnegie Library? ....................................................... 1 What is the Purpose of the Proposed Action? ............................................................... 2 Why is the Proposed Action Needed? ............................................................................ 2 What is the History of the Carnegie Library? ................................................................. 2 Public and Agency Involvement ...................................................................................... 3 How Were the Public and Other Government Agencies Involved in the Development of this EA? ........................................................................................................ 3 Environmental Assessment Process and Procedures .................................................. 4 What is NEPA and the NEPA Process? ................................................................... 4 What is Section 106 of the National Historic Preservation Act? .......................... 4 Alternatives Including the Proposed Action........................................................................... 5 What is Being Proposed for the Carnegie Library? ....................................................... 5 Alternatives Given Detailed Consideration .................................................................... 5 What is the No-Action Alternative and Why is it Considered? ............................... 5 What Action Alternative is NCPC Evaluating in this EA (Alternative A)? ............... 6 What Other Alternatives were Considered, but Not Studied in Detail? ..................... 10 What are the Impacts from Each Alternative? ............................................................ 10 What Mitigation Measures Would be Implemented for this Project? ........................ 14 Affected Environment and Impacts to the Human Environment ....................................... 17 What is the Affected Environment and How are Impacts Evaluated? ....................... 17 Cumulative Impacts Analysis Method .......................................................................... 17 What Impact Topics have been Eliminated from Further Analysis? .......................... 18 Geology, Topography and Soils ............................................................................. 19 v CARNEGIE LIBRARY ENVIRONMENTAL ASSESSMENT Vegetation and Wildlife .......................................................................................... 19 Threatened and Endangered Species .................................................................. 20 Water Resources .................................................................................................... 20 Air Quality ................................................................................................................ 24 Climate Change ...................................................................................................... 24 Noise ....................................................................................................................... 25 Land Use Planning and Zoning ............................................................................. 26 Population and Housing ........................................................................................ 29 Environmental Justice ........................................................................................... 29 Utilities .................................................................................................................... 30 Waste Management ............................................................................................... 31 Safety and Security ................................................................................................ 31 Impact Topics Analyzed in Detail .................................................................................. 32 Cultural Resources ........................................................................................................ 32 What is the Area of Potential Effect for the Proposed Action? ........................... 33 What Historic Districts are Located within the Area of Potential Effect? ........... 35 What Individually Designated Properties are Located within the Area of Potential Effect? .................................................................................................................... 40 How could the Carnegie Library be affected by the Proposed Action? .............. 45 How will other historic resources within the Area of Potential Effects be affected? ................................................................................................................................ 47 What Archaeological Resources are located at Mount Vernon Square? ........... 48 How will Archaeological Resources be impacted by the project? ....................... 49 Transportation ............................................................................................................... 50 What Makes Up the Local Roadway Network? .................................................... 50 How Were Impacts to the Local Roadway Assessed? ......................................... 51 How Would the Local Roadway Network be Affected by the Proposed Rehabilitation of the Carnegie Library? ............................................................................... 52 vi CARNEGIE LIBRARY ENVIRONMENTAL ASSESSMENT What Bicycle, Pedestrian, Public Transportation, and Parking Facilities Currently Exist at the Carnegie Library Site? ....................................................................................... 53 Loading .................................................................................................................................. 58 How Would Bicycle, Pedestrian, Public Transportation, and Parking Facilities be Affected by the Project?........................................................................................................ 58 Whare are the Cumulative Effects of the Proposed Action? ............................... 59 What Mitigation Measures would be Taken to Reduce the Impacts to the Transportation Network? ...................................................................................................... 59 Economy, Employment, and Income ............................................................................ 60 What are the Economic Characteristics of the Area Surrounding the Carnegie Library? 60 What Impact would the Proposed Action Have on the Local and Regional Economy? .............................................................................................................................. 63 How would the Proposed Action Affect Employment within the Area?............... 63 How would the Proposed Action Impact Taxes and Revenue? ........................... 64 What are the Cumulative Effects of the