The proposed stadium is marked with a red X. 
It is directly in line with the San Jose Airport flightpath.
The distance from the runway is about 13,000 ft.
That blue line is the 65 Decibel CNEL which stands for Community Noise Equivalent level. That is the Federal governments way of saying this area is noisy..really noisy. The site is surrounded by noise monitoring stations that take samples 24/7/365. You can see the monitoring system live by clicking here. The map is posted on the San Jose Airport site here.
OK, 65 decibels is not very loud, but that is an average level.
The noise levels will peak with each passing plane at 90 decibels!
Now its great entertainment to get the other team a yardage penalty by making a lot of noise. Its another thing altogether to have the home team play calls drowned out by a passing plane.
Can you imagine paying for seats at a concert when you know planes will be going overhead every few minutes? What self respecting artist would even book the venue?
Location Location Location
The 13th Man
In football, the home crowd is often called the “twelfth man”. The home team’s players will signal the crowd to cheer as loud as they can to drown out the other team’s verbal play calls and to be silent when the home team has the ball in the huddle. The proposed Santa Clara stadium site has something that no other NFL stadium has : A thirteenth man.
You see, because it is dead center on the flightpath of the San Jose airport , the proposed stadium is surrounded by noise-monitoring stations.. one at the end of Old Mountain View Alviso, another at Cheeney St, and another in the middle of Avenida Del Las Arboles. It takes a jet aircraft only a few seconds to travel from the airport to the site. Since the aircraft are still under full power the noise levels peak around 90db at the proposed site. So from only a few feet away, it would be impossible to hear someone yelling directly at you.
Wikipedia has this to say about the Shea Stadium, a venue situated similarly to the proposed stadium in Santa Clara: “The stadium was located close to LaGuardia Airport. For many years, interruptions for planes flying overhead were common at Shea, and the noise was so loud that radio and television broadcasts couldn't be heard."
So, this is what Santa Clara stadium proponents see as a "first class" NFL experience? How was this overlooked? It wasn't.. In fact, it was buried in a mound of illegal actions by the City of Santa Clara. The law states the Airport Land Use Commission (ALUC) is required to advise the city council about proposed plans (PUC code 21674a).
When the City of Santa Clara entered into a Term Sheet with the 49ers, they claimed that the site was indeed comparable to other NFL stadiums. They backed this up with some income projections, but with not much else. Since this was before the Enviromental Impact Report(EIR) was completed they set aside some rights to amend the Term Sheet at a later time if the California Environmental Quality Act (CEQA) reports told a different story.
Sounds reasonable, right? The fact is that that the ALUC had not reviewed the project yet and had no legal obligation to respond to the CEQA report request. You can look through the thousands of pages of the EIR but you will not find a report or comment directly from the ALUC. So the City of Santa Clara did indeed determine the outcome of the EIR and other reports before they actually started them.
So what is being hid from the public? Contrary to the Stadium EIR the ALUC found the Stadium did not fit within thier general guidelines. The ALUC fell back onto a stop-gap policy called N-4 that allows the ALUC to review a project on a case by case basis. Here is what they passed off as policy N-4
"New land Uses other than residential within the areas deemed incompatible based on the Land Use Compatibility Charts ( Table 1), are subject to case-by-case review, and can only be approved if the ALUC finds that: Adequate insulation for the control of interior noise levels is designed into the plans, or: The single event noise level for that new land use is compatible with the type of use proposed, and does not pose public health or safety issues".
The quotes are not mine but come directly from the Santa Clara County Department of Planning and Development. The color on the word "or" was added by me.
The County claimed that N-4 says that a case by case review can be done if a project is "adequately insulated for noise OR safe for aircraft and the people on the ground." Yikes! Read another way, in practice the ALUC can allow an unsafe stadium to be built if the noise levels are OK.
However, The actual text of the policy states that the project must be adequately insulated AND safe. The County literaly typed in the word "OR" to the policy just for that meeting in order to pass the stadium plans. Here is the actual text:
“N-4. New land uses other than residential proposed within in areas deemed incompatible based on the Land Use Compatibility Charts (Tables 1 and 2, pages 42-43) are subject to case-by-case review, and can only be approved if the Commission finds that:
a. Adequate insulation for the control of interior noise levels is designed into the plans.
b. The single event noise level for that new land use is compatible with the type of use proposed, and does not pose public health or safety issues. “
The same a. b. notation is used throughout the document to depict a list of items, for example a. Open hearing b. ALUC staff presentation c. Public agency staff presentation. So there is no ambiguity on what the policy meant and words like “OR” don’t get popped into quoted Santa Clara County policy on accident.
The City of Santa Clara could have made an override of any ALUC objections and that would have been the end of it, so what was the need for the fraud? The nuance is in the numbers. Just the wording of the stadium ballot measure had to get pushed though on a 4-3 vote of the City Council. An override of the ALUC would have required a supermajority 5-2 vote or the stadium project was dead, are you getting the picture?
Now there are a lot of upstanding Santa Clara residents claiming this will be a first class stadium and that the process has been public and fair. I repectfully disagree, a second class stadium brought on with dirty politics is what we are voting on.
Too Many People at Risk...
This chart shows the population density per acre for the stadium when
viewed against the ALUC published limits.
But What About.....?
The HP Pavillion?
Its 8000 feet from the nearest runway but its not on the direct flightpath. Its 750 feet to the South West, less than 1/3 the seating, and it has a dome.
Wow, its like they planned it that way!
Shoreline Amphitheatre?
It is way off the flightpath and Moffet Field is barely operating anymore.
Buck Shaw Stadium?
Is not in the flightpath of any jet aircraft.
Any other NFL stadium?
None...not one has the same noise issues.
Each stadium is shown by Lat/Long on Google Maps.
The Noise Contour maps can have large file sizes.
City Stadium......................Noise Contour map from nearest airport(s)
San Francisco (existing) ......49ERS MAP
Atlanta GA............................Falcons N/A Domed Stadium
Baltimore MD .......................Ravens MAP
Foxborough MA ...................Patriots 5.5 miles from Norfolk Airpark
Orchard Park NY ..................Bills MAP
Charlotte NC .........................Panthers MAP
Chicago IL .............................Bears MAP
Cincinnati OH ........................Bengals >MAP #1 MAP #2
Cleveland OH ........................Browns MAP #1 BKL (no contour)
Irving TX ..............................Cowboys (New Stadium is Domed) old stadium MAP
Denver CO ............................Broncos MAP
Detroit MI .............................Lions N/A Domed Stadium
Green Bay .............................Packers MAP
Indianapolis IN ....................Colts N/A Domed Stadiums (old and 2008 stadium )
Jacksonville FL ....................Jaguars 10+ miles to nearest airport
Kansas City MO ...................Chiefs 7+ miles to nearest airport
Miami Gardens FL ...............Dolphins MAP
Minneapolis MN ...................Vikings N/A Domed Stadium
Nashville TN .........................Titans MAP
East Rutherford NJ ...............Giants \ Jets MAP #1 MAP #2 MAP #3
New Orleans LA ....................Saints N/A Domed Stadium
Oakland CA ...........................Raiders MAP
Philadelphia PA .....................Eagles MAP
Glendale AZ ...........................Cardinals MAP
Pittsburgh PA .......................Steelers MAP
St Louis MO ..........................Rams N/A Domed Stadium
San Diego CA .........................Chargers MAP
Seattle WA .............................Seahawks MAP
Tampa FL ..............................Buccaneers MAP MAP
Washington DC ......................Redskins 5 miles from Andrews AFB
Houston TX........................... Texans N/A Domed Stadium