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)

Statistics April 2013 May 2013 June 2013
Monthly Mean 13.343 19.087 22.839
Maximum Daily PM10 31.109 43.804 37.289
2nd Highest Daily PM10 31.091 37.349 36.199
Quarterly Arithmetic Mean 18.718
Statistics July 2013 August 2013 September 2013
Monthly Mean 27.126 28.765 22.547
Maximum Daily PM10 46.718 48.208 42.280
2nd Highest Daily PM10 39.817 42.539 41.009
Quarterly Arithmetic Mean 26.342
Statistics October 2013 November 2013 December 2013
Monthly Mean 7.126 38.252 39.108
Maximum Daily PM10 46.718 65.619 76.881
2nd Highest Daily PM10 39.817 60.057 76.353
Quarterly Arithmetic Mean 36.965
Statistics January 2014 February 2014 March 2014
Monthly Mean 16.043 9.085 15.668
Maximum Daily PM10 38.094 33.861 69.195
2nd Highest Daily PM10 32.145 17.078 37.804
Quarterly Arithmetic Mean 13.749
Statistics April 2014 May 2014 June 2014
Monthly Mean 20.821 18.906 19.930
Maximum Daily PM10 115.260 39.728 51.255
2nd Highest Daily PM10 43.838 29.517 28.837
Quarterly Arithmetic Mean 19.874
Statistics July 2014 August 2014 September 2014
Monthly Mean 26.909 23.027 22.698
Maximum Daily PM10 66.576 38.680 42.421
2nd Highest Daily PM10 40.764 33.687 38.744
Quarterly Arithmetic Mean 24.267
Statistics October 2014 November 2014 December 2014
Monthly Mean 21.422 18.905 13.597
Maximum Daily PM10 36.531 75.523 26.420
2nd Highest Daily PM10 34.079 51.565 25.765
Quarterly Arithmetic Mean 17.934
Statistics January 2015 February 2015 March 2015
Monthly Mean 13.368 11.799 16.706
Maximum Daily PM10 29.51 29.775 46.442
2nd Highest Daily PM10 27.84 27.287 36.315
Quarterly Arithmetic Mean 14.029
Statistics April 2015 May 2015 June 2015
Monthly Mean 28.19 10.861 23.579
Maximum Daily PM10 231.716 24.151 43.046
2nd Highest Daily PM10 84.345 20.338 35.473
Quarterly Arithmetic Mean 20.794
Statistics July 2015 August 2015 September 2015
Monthly Mean 22.394 25.956 19.192
Maximum Daily PM10 41.541 56.816 31.026
2nd Highest Daily PM10 38.509 48.444 30.371
Quarterly Arithmetic Mean 22.647
Statistics October 2015 November 2015 December 2015
Monthly Mean 20.069 12.955 15.279
Maximum Daily PM10 41.136 31.931 65.603
2nd Highest Daily PM10 38.975 20.028 37.008
Quarterly Arithmetic Mean 16.035