3.7 hazardous materials and hazardous waste - Missile Defense ...

Chapter 3—Affected Environment3.10.2.2 Grand Forks AFB—NoiseThe area surrounding Grand Forks AFB has a population densityrepresentative of a lightly populated rural area, and thus, based on table3.10-5, would be expected to have a background noise level of DNL lessthan or equal to 55 dBA.Aircraft noise at Grand Forks AFB occurs during aircraft engine warm-up,maintenance and testing, taxiing, takeoffs, approaches, and landings.Noise contours for aircraft operations were modeled for the AirInstallation Compatible Use Zone (AICUZ) Study (U.S. Air Force, 1995)for Grand Forks AFB. As can be seen from figure 3.10-2, contours withDNL values of both 65 and 70 dBA were estimated to occur outside thebase boundaries on land northwest of the base. The DNL equals 65 dBAcontour was also estimated to extent very slightly off the southern endof the base. As the land use in these areas was designated as“Open/Agricultural/Low Density,” the study did not conclude that therewere any land use incompatibility due to the estimated aircraft noise.The loudest on-base noise contours were estimated to have a DNL valueof 89 dBA and to occur at the southern end of the runway. (U.S. AirForce, 1995—AICUZ Study, Grand Forks AFB)The main highways in the vicinity of Grand Forks AFB are U.S. Highway2 and County Road 3B. Estimated traffic noise levels for segments ofthese highways are shown in table 3.10-9.Table 3.10-9: Estimated Traffic Noise Levels for the Grand Forks AFB Area (1)Segment of HighwayAverageAnnual DailyTraffic Count (2)Distance at whichLeq(1 hour) = 72 dBAoccursin meters (feet)Distance at whichLeq(1 hour) = 67 dBAoccursin meters (feet)Distance at whichLeq(1 hour) = 57 dBAoccurs inmeters (feet)CR 3B in the vicinity ofGrand Forks AFB maingateU.S. 2 in the vicinityof Grand Forks AFBmain gate (3)U.S. 2 in the vicinityof Grand Forks AFBsecondary gate (3)7,000 15 (49) 31 (102) 145 (478)10,500 16 (52) 34 (112) 158 (518)5,900 11 (35) 23 (76) 108 (353)(1)Based on the methodology of the U.S. Federal Highway Administration (1978) and assuming a trafficspeed of 105 kilometer (65 miles) per hour for U.S. 2, 89 kilometers (55 miles) per hour for CR 3B.(2)North Dakota Department of Transportation, 1996—Traffic Volume Map, Grand Forks County.(3)Traffic assumed divided evenly for divided highway, U.S. 2.Note: dBA = decibel A-weighted, Leq = equivalent sound level3-304 NMD Deployment Final EIS