This map shows modeled outdoor noise across 97820 at 100-meter resolution, combining road, aviation, and rail sources. Green areas measure below 45 dBA. Orange and red exceed the EPA's 55 dBA outdoor threshold linked to long-term health effects. Use the layer toggles to view each source on its own or all together.
What the numbers sound like
- 30 dBAWhisper
- 40 dBASoft rainfall
- 45 dBAQuiet suburban street at night
- 50 dBAQuiet office
- 55 dBAEPA outdoor threshold: light traffic 100 ft away
- 60 dBANormal conversation an arm's length away
- 65 dBABusy restaurant
- 70 dBAHighway traffic 50 ft away
- 80 dBACity bus interior
Population Above the EPA Outdoor Threshold
The EPA's 55 dBA outdoor reference level is a common benchmark for residential noise exposure, especially for activity interference, annoyance, and long-term community noise concerns. About 135 97820 residents, or 15.3%, live above that level. By land area, 8.2% of 97820 is above 55 dBA.
See how noise in 97820 compares to similar-sized zip codes.
Noise by Part of 97820
Average noise levels for 97820 residents, grouped by direction from the center of 97820. Northern 97820 carries the highest population-weighted average; Western 97820 carries the lowest. Just 0% of residents in Western 97820 live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Northern 97820.
Eastern 97820
2% of people above 55 dBA
Northern 97820
21% of people above 55 dBA
Southern 97820
5% of people above 55 dBA
Western 97820
0% of people above 55 dBA
Northern 97820 sounds about 133% louder than Western 97820 to the human ear, a 12.2 dBA gap. Every 10 dBA roughly doubles perceived loudness. Within any of these directions, two homes a quarter mile apart can still differ by 10 or more dBA depending on how close they sit to a major highway.
How far back from US Route 395 do you need to be?
US Route 395 produces an estimated 61 dBA at its loudest centerline points. Noise drops logarithmically with distance, with the exact rate depending on what's between you and the road. Tree cover, walls, terrain, and pavement type all matter. At roughly a quarter mile back, traffic fades into the noise level of a soft rainfall.
Calculated from the model's calibrated attenuation formula. About 11% of 97820 sits under tree canopy (lighter than most zip codes) and roughly 16% is impervious surface like pavement and rooftops. Both are folded into the per-place decay rate above. Heavier canopy pulls noise down faster with distance; impervious surfaces slow the drop.