WA-813_11174_CA_O_20240730_Plume Stability

Evaluation Date:Job ID:
Facility Name:Constituent:
Conducted By:Concentration Units:ug/L
Sampling Point ID:MW-2 MW-1 MW-3 MW-11 MW-13 MW-23 MW-22
Sampling SamplingEventDate
1 2-Mar-11 3340 1630 7700 156
2 26-Sep-11 7470 2170 13400 63.8 701
3 1-Nov-12 5630 1340 9170 1 172418-Sep-13 4290 6970 1 1310
5 3-Apr-14 1580 1350 1580 34.8 14.8
6 6-Jan-15 5760 2030 5510 1 3.7
7 12-Jan-21 5060 937 3900 1 104
8 23-Mar-22 3460 1180 1480 1 11.8
9 27-Sep-22 1770 2340 795 538 10.41026-Jan-23 5190 28901116-Apr-24 1540 927
12
13
14
15
16
17
18
19
20
Coefficient of Variation:0.48 0.31 0.82 1.99 1.63Mann-Kendall Statistic (S):-17 -2 -39 -6 -16Confidence Factor:89.1%54.8%99.9%69.4%96.9%
Concentration Trend:Stable Stable Decreasing No Trend Decreasing
Notes:
1.At least four independent sampling events per well are required for calculating the trend. Methodology is valid for 4 to 40 samples.
2.Confidence in Trend = Confidence (in percent) that constituent concentration is increasing (S>0) or decreasing (S<0): >95% = Increasing or Decreasing;
≥ 90% = Probably Increasing or Probably Decreasing; < 90% and S>0 = No Trend; < 90%, S≤0, and COV ≥ 1 = No Trend; < 90% and COV < 1 = Stable.
3.Methodology based on "MAROS: A Decision Support System for Optimizing Monitoring Plans", J.J. Aziz, M. Ling, H.S. Rifai, C.J. Newell, and J.R. Gonzales,
Ground Water , 41(3):355-367, 2003.
DISCLAIMER: The GSI Mann-Kendall Toolkit is available "as is". Considerable care has been exercised in preparing this software product; however, no party, including without
limitation GSI Environmental Inc., makes any representation or warranty regarding the accuracy, correctness, or completeness of the information contained herein, and no such
party shall be liable for any direct, indirect, consequential, incidental or other damages resulting from the use of this product or the information contained herein. Information in
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GSI Environmental Inc., www.gsi-net.com
BENZENE CONCENTRATION (ug/L)
2-Jan-23
Everetts Grocery Benzene
GSI MANN-KENDALL TOOLKIT
for Constituent Trend Analysis
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