Joint Federal/State Application (JPA)

APPLICANT’S PROPOSED AVOIDANCE, MINIMIZATION, AND COMPENSATORY MITIGATION: Impacts to wetlands, their buffers, waterways, and the FEMA 100-year floodplain are being minimized to the greatest extent practicable at this stage of the project. Avoidance and Minimization will continue throughout the design process. Design revisions were made to avoid and minimize direct impacts to natural resources including:

• A substantial reduction in project scope resulting in a 60% or greater reduction in roadway work and a 70% or greater reduction in impacts to wetlands and waterways;
• Elimination of the collector-distributor system on I-270;
• Preliminary alignment shift designs;
• Alterations to preliminary roadside ditch and grading designs;
• Additions to preliminary retaining wall designs to minimize the roadway footprint;
• Revisions to preliminary ramp designs, construction access areas, preliminary stormwater management (SWM) facility locations, and sound wall locations;
• Relocations of preliminary managed lane access locations
• Revisions of proposed SWM facility locations; and
• Targeted avoidance and minimization of the Potomac River and Plummers Island, Thomas Branch, and other major stream crossings to the greatest extent practicable.

The Preferred Alternative includes a substantially revised project scope. The Preferred Alternative project limits include: I-495 from the George Washington Memorial Parkway in Virginia, including improvements to the American Legion Bridge over the Potomac River, to east of MD 187 on I-495, and I-270 from I-495 to north of I-370 and on the I-270 eastern spur from east of MD 187 to I-270. The original project limits included: I-495 from south of the George Washington Memorial Parkway in Virginia, including improvements to the American Legion Bridge over the Potomac River, to west of MD 5 in Maryland and along I-270 from I-495 to north of I-370, including the east and west I-270 spurs. Work which was proposed on I-495 east of the I-270 east spur to MD 5 has been removed from the project scope resulting in a 70% or greater reduction of impacts to wetlands, waterways, and Waters of the U.S.

Additionally, the Preferred Alternative would completely avoid significant stream valley parks including Rock Creek, Northwest Branch, Sligo Creek, Southwest Branch, and Henson Creek Stream Valley Parks, as well as historic parks of national significance including the Baltimore-Washington Parkway, Greenbelt Park, and Suitland Parkway.

Wetland mitigation requirements in Maryland and Virginia were developed using Corps and MDE standard practices. For the Preferred Alternative, the MDE mitigation requirement in Maryland is 4.38 acres of wetland mitigation and 7,400 functional feet of stream mitigation; and the Corps mitigation requirement in Maryland is 4.28 acres of wetland mitigation and 7,511 functional feet of stream mitigation. Several mitigation opportunities were explored including on-site mitigation for open channels, mitigation banking, in-lieu fee programs, and off-site permittee-responsible mitigation on public and private lands. Two permittee-responsible mitigation sites were chosen for the Final Compensatory Mitigation Plan based on their potential for functional uplift, construction feasibility, proximity to the study area, mitigation credits, and replacement of lost functions and values resulting from roadway improvements.

The two chosen mitigation sites include the Cabin Branch Stream Restoration and Wetland Mitigation Site (RFP-2) and the Unnamed Tributary to Great Seneca Creek Stream Restoration Site (CA-5). Both mitigation sites are located in the Middle Potomac-Catoctin HUC-8 (02070008) watershed in Montgomery County. Construction of the proposed wetland and stream mitigation sites would temporarily impact 0.08 acres (3,515 square feet) of forested nontidal wetland, 0.11 acres (4,889 square feet) of emergent nontidal wetland, 0.63 acres (27,430 square feet) of 25-foot nontidal wetland buffer, 11,860 linear feet (349,178 square feet) of perennial channel, 322 linear feet (2,126 square feet) of intermittent channel, and 27.03 acres (1,177,631 square feet) of 100-year floodplain. Of the temporary wetland impacts, approximately 0.03 acres (1,172 square feet) of forested nontidal wetland and 0.05 acres (2,378 square feet) of emergent nontidal wetland at the CA-5 Mitigation Site require replacement and will be replaced in-kind on-site. All other temporary impacts will be restored. Mitigation will include restoring approximately 721 functional feet of stream at the Unnamed Tributary to Great Seneca Creek Stream Restoration Site (CA-5) and restoring approximately 5,149 functional feet of Cabin Branch and restoring approximately 4.38 acres (190,793 square feet) of nontidal wetland, enhancing 0.01 acres (653 square feet) of nontidal wetlands, and enhancing 0.16 acres (7,115 square feet) of nontidal wetland buffer at the Cabin Branch Stream Restoration and Wetland Mitigation Site (RFP-2). The remaining 1,530 functional feet of stream mitigation requirement will be satisfied through purchase of credits from an approved Mitigation Bank.

The National Park Service and M-NCPPC will require additional mitigation/restoration for impacts to park properties. Construction of the proposed park mitigation projects would temporarily impact 2.44 acres (106,485 square feet) of forested nontidal wetland, 0.77 acres (33,500 square feet) of 25-foot nontidal wetland buffer, 915 linear feet (34,153 square feet) of perennial channel, 657 linear feet (4,779 square feet) of intermittent channel, and 4.71 acres (205,225 square feet) of 100-year floodplain.

401 Water Quality Certification (WQC) Request

Pursuant to Section 401 of the Clean Water Act, MDOT SHA is requesting a Water Quality Certification for I-495 & I-270 Managed Lanes Study Phase 1 South. Because a separate Water Quality Certification is being requested from the Virginia Department of Environmental Quality for the portion of Phase 1 South within their jurisdiction, this request is only for the Maryland portion of Phase 1 South. As required by 40 C.F.R. § 121.5 and Code of Maryland Regulations (COMAR) 26.08.02.10, the Water Quality Certification request includes project-specific information for the key elements required by the Maryland Department of Environment. Some of the specific details in this document regarding the current design (e.g., stormwater management, culverts) are subject to change as project designs are refined over the course of the design process, but any mitigation required will be provided by final design.

Public Hearings

The U.S. Army Corps of Engineers, Baltimore District (Corps) and the Maryland Department of the Environment (MDE) joint public informational hearings provide members of the public the opportunity to present views, opinions, and information that will be considered by the Corps and MDE in evaluating the Joint Federal/State Application for the Alteration of any Floodplain, Waterway, Tidal or Nontidal Wetland in Maryland (JPA) proposed for the project. As part of the public comment period, the purpose of the hearing(s) is for the Corps and MDE to receive oral or written comments that will enable them to evaluate the impacts of the proposed project on the public interest. All interested parties, including representatives of Federal, State, and local governments and private individuals and organizations, are invited to be present or to be represented. Each will be given an opportunity to express their views regarding the proposed project. One in-person hearing was held on Thursday, September 8, 2022, and one virtual hearing was held on Wednesday, September 14, 2022.