Pax River Noise Zones and Your St. Mary's Home: What the 2026 AICUZ Study Means

The 2026 AICUZ study for NAS Patuxent River is the Navy's updated map of aircraft noise and accident potential around the base. It is planning guidance, while local zoning rules and parcel-specific approvals determine how property can be used or changed. The Navy's official AICUZ page says the study received final approval on July 31, 2026; the Southern Maryland Chronicle reported its public release on August 13, replacing the 2009 study. Where it can matter is new building, subdividing, and the questions buyers ask.

Here's what the maps show, how to read the noise numbers, what changed in 2026, how St. Mary's County uses the study in zoning, and how I'd use it whether you're buying or selling in St. Mary's County.

What Is the AICUZ Study?

AICUZ stands for Air Installations Compatible Use Zones. It's the Navy's study of how flight operations at a base affect the land around it, and the program's stated purpose is to protect the public's health, safety and welfare, according to the NAS Patuxent River AICUZ page. The 2026 study uses current data on aircraft, flight activity and mission needs.

It maps two things:

• Noise contours: lines showing average aircraft noise levels, measured as Day-Night Average Sound Level (DNL), at 60, 65, 70, 75 and 80 decibels.
• Accident Potential Zones (APZs): areas where an aircraft accident would be more likely if one happened. The Navy is clear that an APZ does not mean an accident is expected.

How Do I Read the Noise Numbers on the Map?

DNL is an average of all the noise from individual flights over 24 hours, with a 10-decibel penalty added to flights between 10 p.m. and 7 a.m., when people are more sensitive to noise, according to Navy AICUZ program material. So a 65 DNL line doesn't mean it's 65 decibels outside all day. It means the average, weighted for nighttime flights, works out to 65.

How the Navy Groups Noise Levels

Navy AICUZ noise zones, by DNL

Noise Zone 1

• Under 65 DNL
• Low or no noise impact

Noise Zone 2

• 65 to 75 DNL
• Moderate impact, some land use controls

Noise Zone 3

• Over 75 DNL
• Most impacted, greatest land use control

The Navy describes Zone 1 as low or no impact, Zone 2 as moderate impact where some land use controls are needed, and Zone 3 as the most impacted area with the greatest need for land use control. Those labels describe planning guidance for future development, not a rating of any existing home.

What Do the Accident Potential Zones Mean?

There are three zones at the ends of a runway. The Clear Zone sits right off the runway end, then APZ I, then APZ II. For a standard Navy Class B runway, the Clear Zone runs 3,000 feet, APZ I runs 5,000 feet and APZ II runs 7,000 feet, each about 3,000 feet wide, according to a 2015 NAVFAC report on how APZs were developed.

Runway End Zones, Closest to Farthest

Standard Navy Class B runway dimensions

Clear Zone

• 3,000 feet long
• Should stay undeveloped

APZ I

• 5,000 feet long
• About 3,000 feet wide

APZ II

• 7,000 feet long
• About 3,000 feet wide

The real shapes at Pax River follow actual flight tracks, so use the 2026 footprint map for any specific address instead of these standard dimensions.

What Changed in 2026?

The headline change is a new Accident Potential Zone over part of Drum Point in Calvert County, across the Patuxent. According to the Southern Maryland Chronicle's report on the study, flight data showed many departures from Runway 32 turning right, and those flight tracks cross the southern part of Drum Point.

On the St. Mary's side, the study identifies new noise contours across the county, drawing on data from a 2019 noise study, according to SoMdNews in August 2026. The article said annual operations have increased over the years, which means slightly more noise but not more crash areas.

The Navy approved the study on July 31, 2026. The installation's AICUZ page posts three documents you can open yourself: the full 2026 study, the NAS Patuxent River footprint map, and a separate footprint map for Webster Outlying Field in St. Inigoes.

Why Does the Map Sound Different From What I Hear?

Because DNL is an average, and you hear single flights. A home outside the 65 contour can still hear loud flyovers on a busy test day, and a home inside it can have quiet stretches. The contour tells you about long-term exposure. Your own visit tells you what a Tuesday morning sounds like.

A modeled contour doesn't predict the noise at every moment or inside every home, and a home outside a contour isn't free of aircraft noise. Flight patterns, weather, aircraft type and the day's operations all change what you hear. Use the maps as one source, not a guarantee. (Navy AICUZ page and documents checked October 8, 2026.)

Flight schedules also change with the mission, so one visit isn't the whole story. Go twice, at different times, and pay attention to how the sound comes through the windows, not just how it sounds in the driveway.

Does the AICUZ Study Change Zoning or My Property Rights?

No. The study is advisory, and zoning stays with local government. St. Mary's County was one of the first places in the country to put an AICUZ overlay in its zoning ordinance, according to the Maryland military compatibility program. That overlay is Chapter 43 of the county's Comprehensive Zoning Ordinance, and it has four tiers, from clearly compatible to clearly incompatible uses.

Where the new maps can matter is future development. Areas at 65 decibels or higher generally shouldn't be considered for most new residential development, and the base opposed a proposed Lexington Park subdivision in a 65 to 70 decibel contour, SoMdNews reported. The article also reported that the zones won't affect existing housing but could affect new development. The county commissioners decide whether to adopt the study into local planning.

If you plan to build an addition, subdivide or develop land near the base, ask St. Mary's County Land Use and Growth Management how the overlay applies to your parcel before you buy.

What Should I Do If I'm Buying Near the Base?

• Visit at different times of day. Flight activity varies, so drive by on a weekday morning and again in the afternoon.
• Look up the address on the 2026 maps before you write an offer, especially in Lexington Park, California and Great Mills, where homes sit closest to the base.
• Weigh noise against commute. A home a few minutes from Gate 1 can save a lot of time each day. How you weigh that is your call, and I'll give you the honest picture either way.
• Look at windows and insulation. Newer windows make a real difference indoors.

How Do I Check a Specific Address?

Check Any Address in Five Minutes

Using the Navy's 2026 maps

1. 1Open the Navy's AICUZ page
   Find the 2026 NAS Patuxent River footprint map
2. 2Use the Webster Field map near St. Inigoes
   It's a separate footprint
3. 3Find the property
   Note the noise contour and any APZ it falls in
4. 4Ask the county about building plans
   Land Use and Growth Management applies the overlay
5. 5Visit and listen
   Weekday morning and afternoon

What Should I Do If I'm Selling Near the Base?

Expect buyers to ask about the AICUZ maps, and be ready with clear answers. Don't hide the noise. Put your drive time to the nearest gate in your listing, know which contour your home sits in, and let buyers weigh the trade-off themselves. I'll walk buyers through the maps so it reads as local knowledge, not a red flag. That's part of how I market St. Mary's listings.

Pull the map before you list, so a buyer's agent doesn't surprise you with it at a showing. Your contour, your drive time to the gate and any sound upgrades you've made, like newer windows, turn a hard question into a simple fact sheet.

Talk with your agent and a real estate attorney about what to disclose. See Maryland disclosures in my seller guide.

What Questions Should I Ask Before Buying Near the Base?

• How often do aircraft fly over this street, and at what times?
• Is the home in a noise contour or an Accident Potential Zone on the 2026 maps?
• How are the windows and insulation?
• Do I plan to add on or subdivide later? If so, what does the county overlay allow?
• Will this affect resale or rentability when I move?

What Does This Look Like for a Real Search?

Example scenario: This is made up to show the steps, not a real buyer. A buyer is choosing between two similar homes, one off Three Notch Road near Lexington Park and one a few miles farther out toward Hollywood.

Before touring, we pull up both addresses on the 2026 footprint map. The closer home sits inside a noise contour, and the farther one doesn't. The buyer visits both on a weekday morning and again in the late afternoon, then compares the daily drive to the gate.

The buyer also asks whether either lot could take an addition later. For the closer home, that question goes to Land Use and Growth Management before the offer, not after. Either choice can be right. The point is that the buyer made it with the maps, the drive and the sound all in view.

What Mistakes Do People Make With the AICUZ Maps?

• Using the 2009 maps. The 2026 study replaced them, so older printouts and screenshots can be out of date.
• Reading a contour as a ruling. The maps are planning guidance. They don't condemn a house or change its zoning.
• Forgetting Webster Field. Homes near St. Inigoes have their own footprint map.
• Assuming you can add on. Additions and subdivisions are where the county overlay matters most.
• Visiting once. One quiet afternoon doesn't tell you what a test week sounds like.

Who Answers Each Question?

• The Navy's AICUZ page: the 2026 maps and the full study.
• St. Mary's County Land Use and Growth Management: how the Chapter 43 overlay applies to building, additions and subdividing.
• A real estate attorney: disclosure questions.
• A home inspector or window contractor: sound insulation in the house itself.
• Me: where a home sits on the maps, commute trade-offs and how nearby homes have sold.

Where Do I Report Aircraft Noise?

If you have a noise concern, call the Pax River noise hotline at 1-866-819-9028 or email paxnoise@us.navy.mil, both listed on the Navy's AICUZ page. More local contacts are on my community resources page.

The goal is to decide with your eyes, and ears, open. If you want a second set of eyes on a specific address, send it to me.

Frequently Asked Questions

Sources: U.S. Navy: NAS Patuxent River AICUZ · Southern Maryland Chronicle on the 2026 AICUZ study · SoMdNews: Pax River base identifies noise contours (Aug. 2026) · Maryland military compatibility: St. Mary's AICUZ overlay · NAVFAC: History and development of APZs (2015) · U.S. Navy AICUZ program: noise zones and DNL. Checked October 2026; rules and rates can change, so confirm anything that affects your decision.

This article is general real estate information, not legal, lending, tax, or insurance advice. Talk with the right licensed professional about your specific property.