Laserfiche WebLink
estimate the daily Ldn. It is assumed that the plant operates from <br /> 7 : 00 am to 7: 00 pm and that the noise levels during non operations <br /> hours is 45db(A) . Both these assumptions are conservative and <br /> result in an estimated Ldn probably higher than actual. This is <br /> because the plant will most likely not operate as late as 6: 00 pm <br /> and because the ambient noise levels are generally below 45db(A) . <br /> Ldn values <br /> Table 2 lists the projected Ldn values at receptors assuming a <br /> worse case condition where all three sources are operating. Actual <br /> operations only require mining 20 out of every 90 days. <br /> Only one site shows an Ldn value at or above 60. This is at <br /> receptor R13 . This Ldn value occurs only when receptor R13 is <br /> impacted by both traffic on Waverly Road and mining activities <br /> occur within 500 feet. This combination is expected to occur less <br /> than 5 percent of the time. Additional attenuation due to the berm <br /> created by the mining process can be expected to reduce the noise <br /> impact by 5-20 decibels. <br /> BACKUP ALARMS <br /> During the noise field study of E1 Rancho it was observed that <br /> backup alarms were barely audible. Due to both the low measured <br /> levels (at property line) and the short duration of the alarms it <br /> is expected that the impact will be minimal. <br /> PLANT MODIFICATIONS <br /> The possibility exists for modifications to the plant to increase <br /> the process rate by 1000 tons/day. Increasing the plant capacity <br /> is not expected to result in any increased noise levels. Some <br /> older, noisier, equipment will be replaced by newer, quieter. <br /> equipment. The increase efficiency will allow the plant to operate <br /> more consistency with less downtime. The results will be increased <br /> capacity without necessarily an increase in equipment. <br /> RELEVANT REGULATIONS <br /> The "San Joaquin County General Plan 2010, Section V, subsection. D- <br /> Noise" states as the objective "To ensure acceptable noise <br /> environments for each land use. <br /> Policy 1 states: The following exterior noise levels shall be <br /> considered acceptable: <br /> (a) 65 db Ldn or less for residential development. <br /> (b) 60 db Ldn or less for schools, group care facilities and <br /> hospital. <br /> Tables 1 and 2 show that the 65 db Ldn limit for residential areas <br /> will be met. The stricter 60 db Ldn limit for schools etc. , while <br /> 3 <br /> CONDOR <br />