USGS Home
Contact USGS
Search USGS
Link to USGS Home Page Branch of Quality Systems Homepage Sediment Laboratory Quality Assurance Project
Branch of Quality Systems | Home | Access Data | Submit Data | Order Samples | Publications | Project Contacts
SLQA Home Submit Data Order Samples Publications Project Contacts
USGS PUERTO RICO (PR) LABORATORY
Suspended Sediment Concentration 
Results include determination of suspended sediment concentration. Target values are determined gravimetrically during sample 
preparation. Median percent differences are calculated using all submitted analyses by participants for each sample class.
Upper and lower control limits are +/-3 f-pseudosigma from median, respectively. F-pseudosigma = (Interquartile range)/1.349.
Reported laboratory results percent difference = (((Reported value - Target value)/(Target value)) * 100).
    Suspended Sediment Concentration Results
Class Sample Target Suspended Median Percent  Lower Control Reported Laboratory  Upper Control
  Id Sediment  Difference  Limit  Results Percent  Limit 
    Concentration (mg/L) (%) (%) Difference (%) (%)
Study 1, 1997 (Jul - Aug)
1 A2810 252 -3.60 -13.21 -3.02 6.01
1 B2930 302 -3.60 -13.21 -15.01 6.01
1 C3066 182 -3.60 -13.21 -11.54 6.01
2 A2810 500 -3.38 -14.40 -6.47 7.64
2 B2930 528 -3.38 -14.40 -7.70 7.64
2 C3066 356 -3.38 -14.40 -2.74 7.64
3 A1910 10760 -0.36 -8.85 9.67 8.13
3 B2030 11405 -0.36 -8.85 -5.30 8.13
3 C6666 7555 -0.36 -8.85 7.69 8.13
 
Study 2, 1997 (Nov - Dec)
1 A3814 255 -2.91 -10.81 -1.45 4.99
1 B3942 267 -2.91 -10.81 -5.28 4.99
1 C4070 185 -2.91 -10.81 -6.23 4.99
2 A3814 505 -3.77 -13.12 -6.34 5.59
2 B3942 529 -3.77 -13.12 -3.08 5.59
2 C4070 358 -3.77 -13.12 -10.27 5.59
3 A3814 10758 -0.72 -3.81 1.32 2.38
3 B3942 11412 -0.72 -3.81 5.15 2.38
3 C4070 6557 -0.72 -3.81 6.76 2.38
 
Study 1, 1998 (May - Jun)
1 A7727 189 -4.86 -16.80 -4.28 7.09
1 B7846 175 -4.86 -16.80 -9.96 7.09
1 C7983 254 -4.86 -16.80 -2.59 7.09
1 D0229 196 -4.86 -16.80 -4.25 7.09
1 E1060 243 -4.86 -16.80 -4.19 7.09
2 A5218 357 -5.48 -17.52 -4.96 6.55
2 B5155 328 -5.48 -17.52 -7.04 6.55
2 C5074 473 -5.48 -17.52 -3.53 6.55
2 D0229 377 -5.48 -17.52 -2.31 6.55
2 E1060 474 -5.48 -17.52 -0.14 6.55
3 A5527 7697 -1.27 -16.04 6.54 13.50
3 B7746 8127 -1.27 -16.04 -17.31 13.50
3 C7883 10081 -1.27 -16.04 -0.80 13.50
3 D0229 8148 -1.27 -16.04 -1.99 13.50
3 E8460 10089 -1.27 -16.04 57.60 13.50
 
Study 2, 1998 (Oct - Dec)
1 A7727 90 -2.06 -17.51 -2.78 13.40
1 B7866 201 -2.06 -17.51 -0.62 13.40
1 C7983 261 -2.06 -17.51 -2.60 13.40
1 D0229 207 -2.06 -17.51 1.86 13.40
1 E1060 239 -2.06 -17.51 -1.84 13.40
2 A5218 173 -2.38 -11.60 -3.21 6.83
2 B5155 353 -2.38 -11.60 -2.88 6.83
2 C5074 502 -2.38 -11.60 -36.65 6.83
2 D0229 405 -2.38 -11.60 -3.27 6.83
2 E1060 505 -2.38 -11.60 -0.85 6.83
3 A2030 4067 -0.28 -3.08 -0.79 2.52
3 B7746 8125 -0.28 -3.08 0.33 2.52
3 C7883 8437 -0.28 -3.08 8.48 2.52
3 D0229 8706 -0.28 -3.08 0.67 2.52
3 E8460 9106 -0.28 -3.08 0.28 2.52
 
Study 1, 1999 (Apr - May)
1 A2608 278 -2.19 -13.76 -1.26 9.38
1 B2539 298 -2.19 -13.76 -4.90 9.38
1 C5281 149 -2.19 -13.76 -4.85 9.38
2 A6646 534 -2.97 -9.67 -1.99 3.72
2 B6575 572 -2.97 -9.67 -2.43 3.72
2 C1469 300 -2.97 -9.67 0.47 3.72
3 A3663 10123 -0.43 -4.07 2.74 3.22
3 B3706 10856 -0.43 -4.07 -2.36 3.22
3 C4782 5244 -0.43 -4.07 -50.23 3.22
 
Study 2, 1999 (Sep - Oct)
1 A3447 337 -2.54 -16.98 -13.41 11.90
1 B3511 333 -2.54 -16.98 -5.83 11.90
1 C3684 281 -2.54 -16.98 -19.16 11.90
2 A3415 788 -1.25 -11.52 -9.96 9.02
2 B3572 848 -1.25 -11.52 -2.15 9.02
2 C3645 652 -1.25 -11.52 -5.95 9.02
3 A3606 14026 -0.71 -4.22 -4.67 2.79
3 B3745 14626 -0.71 -4.22 0.15 2.79
3 C3869 12415 -0.71 -4.22 -1.23 2.79
 
Study 1, 2000 (May - Jun)
1 A1111 441 -2.87 -11.78 -2.68 6.03
1 B4141 451 -2.87 -11.78 -8.27 6.03
1 C7171 379 -2.87 -11.78 -2.29 6.03
2 A1111 1120 -1.63 -8.81 -8.77 5.56
2 B4141 1171 -1.63 -8.81 -0.47 5.56
2 C7171 980 -1.63 -8.81 -2.37 5.56
3 A1717 12658 -0.05 -3.89 0.33 3.80
3 B.4141 13213 -0.05 -3.89 0.66 3.80
3 C7171 8810 -0.05 -3.89 1.36 3.80
 
Study 2, 2000 (Oct - Nov)
1 A1414 567 10.49 -105.07 1.94 126.05
1 B4141 586 10.49 -105.07 47.41 126.05
1 C7171 419 10.49 -105.07 44.47 126.05
2 A1111 1266 2.06 -45.61 45.36 49.72
2 B4141 1279 2.06 -45.61 30.31 49.72
2 C7171 914 2.06 -45.61 -4.21 49.72
3 A1111 13941 -0.92 -5.78 0.50 3.93
3 B4141 14173 -0.92 -5.78 6.54 3.93
3 C7171 10421 -0.92 -5.78 -2.12 3.93
 
Study 1, 2001 (Jul - Sep)
1 A1515 579 -2.17 -10.36 -0.43 6.02
1 B4545 590 -2.17 -10.36 -0.44 6.02
1 C7575 419 -2.17 -10.36 3.88 6.02
2 A1623 1729 -1.73 -5.96 1.16 2.49
2 B4536 1761 -1.73 -5.96 -1.73 2.49
2 C7689 1254 -1.73 -5.96 -0.69 2.49
3 A2512 13563 -0.34 -3.89 0.13 3.22
3 B3832 14044 -0.34 -3.89 -7.72 3.22
3 C7473 10000 -0.34 -3.89 3.70 3.22
 
Study 2, 2001 (Oct - Jan)
1 A2926 441 -1.44 -20.24 -10.91 17.35
1 B3851 459 -1.44 -20.24 13.93 17.35
1 C8977 331 -1.44 -20.24 -1.13 17.35
2 A0817 1399 -2.30 -8.73 2.94 4.13
2 B3842 1437 -2.30 -8.73 -3.79 4.13
2 C8368 1036 -2.30 -8.73 -3.26 4.13
3 A2823 12304 -0.46 -4.76 -0.03 3.83
3 B5152 12983 -0.46 -4.76 -0.10 3.83
3 C7072 9168 -0.46 -4.76 0.41 3.83
 
Study 1, 2002 (Jul - Sep)
1 A0514 328 -0.89 -22.90 -9.41 21.12
1 B4748 345 -0.89 -22.90 -0.75 21.12
1 C7968 245 -0.89 -22.90 9.37 21.12
2 A2808 718 -2.79 -10.92 -7.93 5.34
2 B5840 746 -2.79 -10.92 -6.51 5.34
2 C7967 516 -2.79 -10.92 0.89 5.34
3 A2926 12401 -0.89 -4.38 -2.34 2.59
3 B5153 12991 -0.89 -4.38 -0.51 2.59
3 C6373 9075 -0.89 -4.38 3.75 2.59
PR Sand Separation PR Fine Separation PR Sediment Mass Results