Airport Impact Overlay District CPAM

At its January 17, 2023 meeting, the Loudoun County Board of Supervisors approved changes to the county’s Comprehensive Plan, Zoning Ordinance and zoning map pertaining to land development in areas where airport noise impacts are known to occur currently and expected to occur in the future as airport traffic increases.

The Airport Impact Overlay District (AIOD) is a zoning designation for properties where airport noise is anticipated at specified levels. Properties located within the AIOD are subject to certain land use regulations. The AIOD was implemented by the Board of Supervisors in the early 1990s to mitigate impacts to prospective homebuyers in areas that would be affected by aircraft noise and to prevent residential development in areas where the highest noise impact to people on the ground is anticipated to occur. 

Why did the County Make Changes Now?

The Metropolitan Washington Airports Authority (MWAA), which operates Dulles International Airport, updated its noise exposure maps for Dulles Airport in 2019. As a result, Loudoun County’s previous AIOD was outdated. Based on the airport’s updated noise exposure maps, Loudoun County worked collaboratively with various stakeholders for more than two years to update the boundaries of the overlay district as well as the county’s land use policies and zoning regulations related to the AIOD.

Board of Supervisors’ Vote to Approve

The Board of Supervisors considered many factors, such as information provided by MWAA, input from area residents and homeowner associations, recommendations from the Planning Commission and research conducted by county staff. 

The Board ultimately voted on January 17 to:

• Adopt the proposed amendments to the county’s Comprehensive Plan and Zoning Ordinance and zoning map. The updated plan and regulations:
  • Do not add previously approved residential developments into the area designated with the highest noise impact; however, some existing homes may move into a different AIOD designation based on the newly adopted boundaries in the updated map. 
  • Prohibit new residential developments in the area with the highest noise impact. 
  • Require home sellers to disclose the property is within an AIOD at the time of sale.
  • Require specific disclosure language for homeowner association declarations in new developments, which must clearly state that the community is located near an airport, may be impacted by overflight noise, and is subject to the regulation of the AIOD of the Loudoun County zoning ordinance.

In addition, the Board voted in favor of opening a dialogue with the Federal Aviation Administration to better understand the future options available that would address community concerns regarding airplane noise.

The Board’s vote does not impact the AIOD boundaries surrounding Leesburg Executive Airport.

Who is Impacted?

The amendments to the AIOD map affect approximately 59,000 properties around and near Dulles Airport, including those removed from the overlay district.

Impacted residents may view the interactive map illustrating the adopted Airport Impact Overlay District to identify the current AIOD designation for their properties based on the Board’s vote. The map allows users to “turn on” the previous AIOD for comparison.

In some instances, the AIOD boundaries bisect individual properties. Any property owner with questions about how the adopted AIOD impacts their property may contact the Loudoun County Department of Planning and Zoning by email or by phone at 703-777-0246. 

About the Airport Impact Overlay District

Loudoun County government cannot regulate airport noise or control flight paths; however, the county can update its policies and regulations regarding the use of land around the airport. The AIOD is a zoning tool to plan appropriate land uses in the areas where airport noise is known or expected to occur.

There are three Aircraft Noise Impact Area designations within the AIOD that the county uses to indicate the level of impact. The AIOD regulations stipulate specific land use rules for each designation, which are intended to mitigate the impact of noise. The county refers to these levels using the symbol “Ldn,” which stands for “yearly day-night average sound level.” The Ldn is calculated using a specific formula specified in the county’s zoning ordinance. The designations are:

1. Ldn 65 or Higher: Properties located within this area are closest to the airport. New residential development is not permitted in this area.
2. Ldn 60-65: Properties located within this area are closer to the airport. Any residential development in this area requires disclosures at the time of sale; acoustical treatments for new residential construction and new additions to existing residences; and an easement established prior to construction of a new residence granting the right of overflight in the airspace above the property.
3. One-Mile Buffer: Properties located within this area are farthest from the airport while still being located within the AIOD. This designation requires a disclosure notice to be included with each sale of residential property.

More Information

• Learn more about the changes to the Airport Impact Overlay District at loudoun.gov/airportdistrict.
• Review detailed information in the January 17, 2023, Airport Impact Overlay District staff report posted on the county’s website. 
• Watch video of the January 17 presentation and the Board’s discussion and vote. 

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At its November 9, 2022, public hearing, the Loudoun County Board of Supervisors will consider proposed changes to the county’s Comprehensive Plan, Zoning Ordinance and zoning map that would amend the county’s policies and zoning regulations pertaining to land development in areas where airport noise impacts are known to occur. Loudoun County is mailing more than 47,000 letters (PDF) and informational flyers (PDF) to potentially impacted property owners to inform them of the upcoming public hearing. Residents who live in the vicinity of Dulles International Airport can expect to begin receiving the notices in their mailboxes in the coming days.

The Airport Impact Overlay District (AIOD) is a zoning designation that includes properties where airport noise at specified levels is anticipated. Properties within the AIOD are subject to certain land use regulations. The current overlay district was implemented by the Board of Supervisors in the early 1990s to prevent residential development in areas that would be affected by aircraft noise and to mitigate impacts to prospective homebuyers. 

Why is the County Considering These Changes Now?

The Metropolitan Washington Airports Authority (MWAA) updated the noise exposure maps for Dulles International Airport in 2019. The update reflects changes in the aviation environment over the last 30 years and prepares for future changes in airport usage. As a result, the current Loudoun County AIOD is outdated. Based on the airport’s updated noise contours, Loudoun County is working to update the boundaries of the overlay district as well as updating the county’s related policies and zoning regulations related to the AIOD. 

Changes the County is Considering

• Comprehensive Plan: The proposed changes to the county’s Comprehensive Plan consist of changes to maps within the plan that show noise contours and policy changes that would require disclosure statements as part of all future sales of properties within the AIOD. The policy changes also would allow previously approved residential rezonings to develop in accordance with their earlier approvals. 
• Zoning Ordinance: The zoning ordinance changes involve updated maps to display the new boundaries and text changes to amend the existing zoning regulations to reflect the policy changes.

Who is Impacted?

The proposed amendments to the AIOD potentially affect more than 47,000 Loudoun property owners around and near Dulles Airport. As required by law, those property owners are receiving a letter from the Loudoun County Department of Planning and Zoning notifying them that a new zoning designation is being proposed that could affect their property and notifying them of the upcoming Board of Supervisors public hearing concerning the proposed amendments. A similar letter was sent to property owners earlier this year prior to the Planning Commission’s June 28, 2022, public hearing on the proposed amendments.

Board of Supervisors Public Hearing November 9

The Planning Commission’s recommendations to the Board of Supervisors concerning the proposed changes to the AIOD will be included in the staff report prepared for the Board’s public hearing scheduled for Wednesday, November 9, 2022, at 6:00 p.m. The staff report will be posted at loudoun.gov/meetings at least three days prior to the public hearing. 

The public hearing will be held in the Board Room of the Government Center, 1 Harrison St. SE, in Leesburg. The meeting can be viewed in person, on Comcast Government Channel 23, Verizon FiOS Channel 40 and via livestream at loudoun.gov/meetings.

Members of the public may provide their comments to the Board of Supervisors by mail, email, in person or virtually during the meeting. Instructions for providing input to the Board, including how to sign up to speak in advance, are posted at loudoun.gov/signuptospeak.

About the Airport Impact Overlay District

Loudoun County government cannot regulate airport noise or control flight paths; however, the county can update its policies that regulate the use of land around the airport. The AIOD is a zoning tool to plan appropriate land uses in the areas where airport noise is known to occur.

There are three Aircraft Noise Impact Area designations within the AIOD that the county uses to indicate the level of impact. The designations indicate an approximate level of noise residents may hear from airport traffic. The AIOD regulations stipulate specific land use rules for each designation, which are intended to mitigate the impact of noise. The county refers to these levels using the symbol “Ldn,” which stands for “yearly day-night average sound level.” The Ldn is calculated using a specific formula specified in the county’s zoning ordinance. The designations are:

1. Ldn 65 or Higher: Properties located within this area are closest to the airport. New residential development is not permitted in this area.
2. Ldn 60-65: Properties located within this area are closer to the airport. Any residential development in this area requires disclosures at the time of sale; acoustical treatments for new residential construction and new additions to existing residences; and an easement established prior to construction of a new residence granting the right of overflight in the airspace above the property.
3. One-Mile Buffer: Properties located within this area are farthest from the airport while still being located within the AIOD. This designation requires a disclosure notice to be included with each sale of residential property.

• View the interactive map illustrating the current and proposed Airport Overlay Districts.

Next Steps

Following the Board of Supervisors’ public hearing, the Board will consider any action it may take to update the county’s comprehensive plan policies and zoning regulations. The Board may choose to adopt or decline to adopt the proposed updates. The Board may also choose to forward the discussion on the proposed updates to a future meeting for additional work and discussion.

Questions?

Members of the public who have questions about the letters they received or any part of the county’s current efforts should contact the Department of Planning and Zoning by email or by phone at 703-777-0246.

More Information

To learn more about the proposed changes to the Airport Impact Overlay District, including how to sign up for email and text updates on the project, visit loudoun.gov/airportdistrict.

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At its June 28, 2022, public hearing, the Loudoun County Planning Commission will consider proposed changes to the county’s 2019 Comprehensive Plan and the Revised 1993 Zoning Ordinance that would amend the county’s policies and zoning regulations regarding airport noise impacts around Dulles International Airport. 

The Airport Impact Overlay District (AIOD) indicates anticipated noise levels and related land use regulations. The current overlay district was implemented by the Board of Supervisors in the early 1990s to prevent residential development in areas that would be affected by aircraft noise and to mitigate impacts to prospective homebuyers. The current AIOD is now outdated. 

Why is This Occurring Now?

The Metropolitan Washington Airports Authority (MWAA) updated the noise exposure maps for Dulles International Airport in 2019. The update reflects changes in the aviation environment over the last 30 years and prepares for future changes in airport usage. Based on the airport’s updated noise contours, Loudoun County is amending its 2019 Comprehensive Plan and Zoning Ordinance to update the policies and zoning regulations that are related to the AIOD. Over the last year, Loudoun County has been studying MWAA’s noise exposure maps and developing recommendations for consideration by the Planning Commission and Board of Supervisors.

Who is Impacted?

The proposed amendments to the AIOD that are under consideration by Loudoun County potentially affect more than 50,000 property owners around and near Dulles Airport. The Department of Planning and Zoning distributed letters directly to affected property owners. Virginia law requires the county to provide notice to property owners any time new zoning designations are proposed as that action may impact future development on the property. The purpose of the letter is to notify affected property owners about proposed amendments to the AIOD that would impact their property and notify the affected property owners about the upcoming public hearing concerning the proposed amendments. 

Public Hearing, June 28

Members of the public have the opportunity to provide input to the Planning Commission that will inform its recommendation to the Board of Supervisors. The Planning Commission’s public hearing on this topic is scheduled for Tuesday, June 28, 2022, at 6:00 p.m. in the Board Room of the Government Center, 1 Harrison St. SE, in Leesburg. The meeting also may be viewed on Comcast Government Channel 23, Verizon FiOS Channel 40, and via livestream at loudoun.gov/meetings.

Members of the public may provide their comments to the Planning Commission by mail, email, in person, or virtually during the meeting. Instructions for providing input to the Planning Commission, including how to sign up to speak in advance, are posted on the county’s website here. 

• View Planning Commission agendas and minutes.

What Do I Need to Know?

Loudoun County government cannot regulate airport noise or control flight paths and the construction of a fifth runway; however, the county can update its policies that regulate the use of land around the airport. The AIOD is a zoning tool to plan appropriate land uses in the areas where airport noise is known to occur.

There are three Aircraft Noise Impact Area designations within the AIOD that the county uses to indicate the level of impact. The designations indicate an approximate level of noise residents may hear from airport traffic. The AIOD regulations prescribe specific land use rules for each designation, which aim to mitigate the impact of noise. The county refers to these levels using the symbol “Ldn,” which stands for "yearly day-night average sound level." The Ldn is calculated using a specific formula specified in the county’s zoning ordinance. The designations are:

1. One-Mile Buffer: Properties located within this area are farthest from the airport while still being located within the AIOD. This designation requires a disclosure notice to be included with each sale of residential property.
2. Ldn 60-65: Properties located within this area are closer to the airport. Any residential development in this area requires disclosures at the time of sale; acoustical treatments for new residential construction and new additions to existing residences; and an easement established prior to construction of a new residence granting the right of overflight in the airspace above the property.
3. Ldn 65 or Higher: Properties located within this area are closest to the airport. New residential development is not permitted in this area.

View the interactive map illustrating the current and proposed Airport Overlay Districts.

Understanding these designations will help property owners interpret how the proposed changes to the AIOD would impact their properties. Property owners in the impacted areas may want to note:

• New residential development on properties within the Ldn 65 or higher is not permitted. As a result, any property moving into the Ldn 65 or higher area would see a reduction in development potential. This area is generally located west and south of Washington Dulles International Airport. 
• Under the proposed amendments, approximately 600 existing homes that are not currently located within the Ldn 65 or higher area would become located within the new Ldn 65 or higher area. If the proposed amendments are adopted, the homes could continue as they existed on the adoption date of the proposed amendments; however, any additions to the property after the adoption date would be subject to the new zoning rules.

The letters sent to impacted property owners indicate their current AIOD designation and the proposed AIOD designation. 

What is Proposed to Change?

The current process is intended to update the boundaries of the overlay district based on updated maps of noise contours for Dulles International Airport. The currently adopted noise contours for the airport are based on a 1992 noise study. MWAA published an updated noise study in 2019 to reflect current airport operations and flight paths. No change is proposed for the Leesburg Executive Airport.

The county is also seeking to clarify the overlay district regulations. The proposed update would clarify that disclosures of the AIOD areas for a property are required for each sale of a home within the overlay district, not just the initial sale. The proposed update also clarifies that changes to the boundaries do not invalidate previously approved residential rezonings.

Next Steps

Following the Planning Commission’s June public hearing, the commission will submit its recommendations to the Board of Supervisors for consideration. Pending any additional work on this initiative that the Planning Commission chooses to conduct, the Board of Supervisors could consider the proposed AIOD and associated policies as early as September 2022.

More Information

To learn more about the proposed changes to the Airport Impact Overlay District, including to sign up for email and text updates on the project, visit loudoun.gov/airportdistrict.

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