HC Estates Monitoring Data: Cornerstone:
Kennecott Utah Copper LLC

Quarterly Reports:
Bingham Canyon Mine Particulate Matter Monitoring Data:
Hi-Country Estates PM10 Concentrations (ug/m,3)

StatisticsApril 2013May 2013June 2013
Monthly Mean13.34319.08722.839
Maximum Daily PM1031.10943.80437.289
2nd Highest Daily PM1031.09137.34936.199
Quarterly Arithmetic Mean18.718
StatisticsJuly 2013August 2013September 2013
Monthly Mean27.12628.76522.547
Maximum Daily PM1046.71848.20842.280
2nd Highest Daily PM1039.81742.53941.009
Quarterly Arithmetic Mean26.342
StatisticsOctober 2013November 2013December 2013
Monthly Mean7.12638.25239.108
Maximum Daily PM1046.71865.61976.881
2nd Highest Daily PM1039.81760.05776.353
Quarterly Arithmetic Mean36.965
StatisticsJanuary 2014February 2014March 2014
Monthly Mean16.0439.08515.668
Maximum Daily PM1038.09433.86169.195
2nd Highest Daily PM1032.14517.07837.804
Quarterly Arithmetic Mean13.749
StatisticsApril 2014May 2014June 2014
Monthly Mean20.82118.90619.930
Maximum Daily PM10115.26039.72851.255
2nd Highest Daily PM1043.83829.51728.837
Quarterly Arithmetic Mean19.874
StatisticsJuly 2014August 2014September 2014
Monthly Mean26.90923.02722.698
Maximum Daily PM1066.57638.68042.421
2nd Highest Daily PM1040.76433.68738.744
Quarterly Arithmetic Mean24.267
StatisticsOctober 2014November 2014December 2014
Monthly Mean21.42218.90513.597
Maximum Daily PM1036.53175.52326.420
2nd Highest Daily PM1034.07951.56525.765
Quarterly Arithmetic Mean17.934
StatisticsJanuary 2015February 2015March 2015
Monthly Mean13.36811.79916.706
Maximum Daily PM1029.5129.77546.442
2nd Highest Daily PM1027.8427.28736.315
Quarterly Arithmetic Mean14.029
StatisticsApril 2015May 2015June 2015
Monthly Mean28.1910.86123.579
Maximum Daily PM10231.71624.15143.046
2nd Highest Daily PM1084.34520.33835.473
Quarterly Arithmetic Mean20.794
StatisticsJuly 2015August 2015September 2015
Monthly Mean22.39425.95619.192
Maximum Daily PM1041.54156.81631.026
2nd Highest Daily PM1038.50948.44430.371
Quarterly Arithmetic Mean22.647
StatisticsOctober 2015November 2015December 2015
Monthly Mean20.06912.95515.279
Maximum Daily PM1041.13631.93165.603
2nd Highest Daily PM1038.97520.02837.008
Quarterly Arithmetic Mean16.035