Chromium-6 Data

City of Grants Pass Chromium-6 Data

Split samples were taken on April 4, 2011, and again on May 3, 2011, and were sent to both MWH Labs and Neilson Research Corporation for analysis. As of March 2012, sampling has been reduced from monthly to quarterly per EPA recommendations.

Chromium-6 Testing Results February 2011 - September 2015
LaboratoryTest DateRaw WaterFinished WaterNew Hope Pump StationMerlin / North Valley
MWH LabsFebruary 1, 20110.075 µg/L0.140 µg/L0.140 µg/L0.230 µg/L
MWH LabsMarch 1, 20110.880 µg/L1.100 µg/L0.940 µg/L0.910 µg/L
MWH LabsApril 6, 20110.081 µg/L0.100 µg/L0.120 µg/L0.210 µg/L
Neilson LabApril 6, 20110.088 µg/L0.120 µg/L0.131 µg/L0.250 µg/L
MWH LabsMay 3, 20110.087 µg/L0.110 µg/L0.140 µg/L0.230 µg/L
Neilson LabMay 3, 20110.088 µg/L0.146 µg/L0.144 µg/L0.233 µg/L
Neilson LabJune 7, 20110.087 µg/L0.122 µg/L0.135 µg/L0.266 µg/L
Neilson LabJuly 5, 20110.081 µg/L0.116 µg/L0.117 µg/L0.238 µg/L
Neilson LabAugust 2, 20110.098 µg/L0.131 µg/L0.132 µg/L0.261 µg/L
Neilson LabSeptember 6, 20110.103 µg/L0.136 µg/L0.133 µg/L0.269 µg/L
Neilson LabOctober 4, 20110.092 µg/L0.111 µg/L0.138 µg/L0.276 µg/L
Neilson LabNovember 1, 20110.099 µg/L0.136 µg/L0.169 µg/L0.305 µg/L
Neilson LabDecember 5, 20110.110 µg/L0.167 µg/L0.181 µg/L0.278 µg/L
Neilson LabJanuary 3, 20120.102 µg/L0.138 µg/L0.188 µg/L0.238 µg/L
Neilson LabFebruary 7, 20120.114 µg/L0.165 µg/L0.193 µg/L0.302 µg/L
Neilson LabMarch 6, 20120.097 µg/L0.142 µg/L0.169 µg/L0.287 µg/L
Neilson LabJune 19, 20120.099 µg/L0.134 µg/L0.134 µg/L0.238 µg/L
Neilson LabSeptember 4, 20120.097 µg/L0.133 µg/L0.137 µg/L0.295 µg/L
Neilson LabDecember 4, 20120.081 µg/L0.075 µg/L0.154 µg/L0.283 µg/L
Neilson LabMarch 5, 20130.094 µg/L0.115 µg/L0.129 µg/L0.212 µg/L
Neilson LabJune 4, 20130.061 µg/L0.130 µg/L0.117 µg/L0.202 µg/L
Neilson LabSeptember 3, 20130.109 µg/L0.168 µg/L0.145 µg/L0.299 µg/L
Neilson LabDecember 17, 20130.118 µg/L0.211 µg/L0.218 µg/L0.317 µg/L
Neilson LabMarch 6, 20140.088 µg/L0.114 µg/L0.164 µg/L0.251 µg/L
Neilson LabJune 17, 20140.110 µg/L0.160 µg/L0.150 µg/L0.310 µg/L
Neilson LabSeptember 10, 20140.105 µg/L0.118 µg/L0.115 µg/L0.286 µg/L
Neilson LabDecember 8, 20140.110 µg/L0.109 µg/L0.120 µg/L0.286 µg/L
Neilson Lab March 5, 20150.097 µg/L0.095 µg/L0.150 µg/L0.256 µg/L
Neilson LabJune 18, 20150.129 µg/L0.132 µg/L0.127 µg/L0.258 µg/L
Neilson LabSeptember 21, 20150.082 µg/L0.082 µg/L0.092 µg/L0.362 µg/L 


City of Grants Pass Total Chromium Data

For the total chromium testing performed on June 4, 2013, the laboratory reported a sensitivity problem that raised the minimum reporting level (MRL) for the tests performed on that day from the usual 0.05 micrograms per liter (ug/L) to 0.4 ug/L. It is estimated that the results that would have been obtained, should the MRL have been lower, would be similar to the results above. When the MRL for a test is set excessively high, levels below that point (in this case 0.4 ug/L) will not be known. If you have questions about how labs set MRLs for specific tests please take a look at the following websites for more information:

Laboratory
Test Date
Raw Water
Finished Water
New Hope Pump Station
Merlin / North Valley
Total Chromium Testing Results
Brooks Rand
January 26, 2011
0.841 µg/L
0.193 µg/L
No data
No data
Brooks Rand
March 1, 2011
0.317 µg/L
0.160 µg/L
0.178 µg/L
0.244 µg/L
Brooks Rand
April 5, 2011
0.909 µg/L
0.163 µg/L
0.151 µg/L
0.256 µg/L
Neilson Lab
April 5, 2011
0.678 µg/L
0.140 µg/L
0.140 µg/L
0.260 µg/L
Brooks Rand
May 3, 2011
0.375 µg/L
0.154 µg/L
0.161 µg/L
0.235 µg/L
Neilson Lab
May 3, 2011
0.340 µg/L
0.160 µg/L
0.200 µg/L
0.250 µg/L
Neilson Lab
June 7, 2011
0.509 µg/L
0.516 µg/L
0.200 µg/L
0.320 µg/L
Neilson Lab
July 5, 2011
0.395 µg/L
0.278 µg/L
0.266 µg/L
0.330 µg/L
Neilson Lab
August 2, 2011
0.347 µg/L
0.318 µg/L
0.340 µg/L
0.415 µg/L
Neilson Lab
September 6, 2011
0.421 µg/L
0.234 µg/L
0.248 µg/L
0.378 µg/L
Neilson Lab
October 4, 2011
0.652 µg/L
0.190 µg/L
0.148 µg/L
0.270 µg/L
Neilson Lab
November 1, 2011
0.233 µg/L
0.149 µg/L
0.169 µg/L
0.326 µg/L
Neilson Lab
December 5, 2011
0.232 µg/L
0.194 µg/L
0.192 µg/L
0.330 µg/L
Neilson Lab
January 3, 2012
0.416 µg/L
0.207 µg/L
0.297 µg/L
0.338 µg/L
Neilson Lab
February 7, 2012
0.483 µg/L
0.311 µg/L
0.362 µg/L
0.411 µg/L
Neilson Lab
March 6, 2012
1.280 µg/L
0.132 µg/L
0.330 µg/L
0.234 µg/L
Neilson Lab
June 19, 2012
0.499 µg/L
0.647 µg/L
0.687 µg/L
0.102 µg/L
Neilson Lab
September 4, 2012
0.400 µg/L
0.257 µg/L
0.246 µg/L
0.378 µg/L
Neilson Lab
December 4, 2012
2.450 µg/L
0.206 µg/L
0.287 µg/L
0.411 µg/L
Neilson Lab
March 5, 2013
0.330 µg/L
0.183 µg/L
0.214 µg/L
0.248 µg/L
Neilson Lab
June 4, 2013
No data
No data
No data
No data
Neilson Lab
September 3, 2013
0.803 µg/L
No data
No data
0.499 µg/L
Neilson Lab
December 17, 2013
0.542 µg/L
0.706 µg/L
0.704 µg/L
0.846 µg/L
Neilson Lab
March 6, 2014
No data
No data
No data
No data
Neilson Lab
June 17, 2014
No data
No data
No data
No data
Neilson LabSeptember 10, 2014No dataNo dataNo dataNo data
Neilson LabMarch 05, 2015No DataNo DataNo DataNo Data
Neilson LabJune 18, 20150.444 µg/L
 No DataNo DataNo Data
Neilson Lab
September 21, 2015
No Data
No Data
No Data
0.624 µg/L