Noise

Current studies show that noise is well within the 67 dB design level. Monitors show that levels in all areas are less than or equal to 67 dB. Some noise is occasionally heard, but most noise is primarily from natural and man made sources. A reading of 67 dB corresponds to urban row housing on a major avenue (45 dB = agricultural land; 36 dB = wilderness; 84 dB = apartment next to the freeway).

A different rating system that uses a weighted average over a 24 hour time period, shows sound levels ranging from 52 - 62 LDN. Outdoor residential areas average about 55 LDN. EPA studies show that levels less than 55 LDN have little annoyance to people. Sleep interference occurs in the range of 45 - 70 LDN. Damage occurs at about 80 LDN.