Summary of 2nd Quarter 2014 Groundwater Monitoring

Routine groundwater analysis conducted during 2nd quarter 2014 at the Clinton Landfill No. 3 facility was performed as part of the April 1, 2014 Illinois EPA split sampling event (monitoring wells G02D, G16D, G25D, and G49D), with all remaining groundwater samples being collected by May 23, 2014. Parameters analyzed during the 2nd quarter 2014 event consist of all List G, List G1 and List G2 parameters for the all permitted monitoring wells at the facility, and additional List G3 parameters were also analyzed for wells monitoring the Chemical Waste Unit. The actual parameter lists are included in the facility permit.

The 2nd quarter 2014 groundwater analytical results showed that no organic parameters were detected above their respective reporting limits. However, for several organic parameters the laboratory was required to use a higher than normal reporting limit because of sample matrix interference. In accordance with USEPA SW-846 Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, a reporting limit is the lowest concentration at which an analyte can be detected in a sample and its concentration can be reported with a reasonable degree of accuracy and precision. When a sample has to be diluted before analysis, because of sample matrix problems (typically caused by interference from other chemicals in the groundwater sample, or because of high sample turbidity) the reporting limit is raised by a factor corresponding to the dilution factor.

While the higher reporting limits were greater than the permit’s Applicable Groundwater Quality Standard/Maximum Allowable Predicted Concentration (AGQS/MAPC) value for the respective monitoring zone, the analytical results did not detect any of these constituents to be present in the groundwater samples. The affected monitoring zones and parameters include the following:

  • Upper Radnor (S-series), Lower Radnor (M-series), and Organic Soil (D-series) 1,3-Dichloropropene, reporting limit <2 µg/L vs AGQS/MAPC 1 µg/L Roxana Silt (R-series)
  • Naphthalene, reporting limit <10 µg/L vs AGQS/MAPC 5 µg/L Tetrahydrofuran, reporting limit <20 µg/L vs AGQS/MAPC 10 µg/L All monitoring zones
  • Total PCBs, reporting limit <1 µg/L vs AGQS/MAPC 0.5 µg/L

The Clinton Landfill No. 3 groundwater monitoring program requires all List G2 organic parameters be monitored on a semi-annual basis (2nd and 4th quarters). These parameters will be sampled again in the 4th quarter 2014 monitoring event and the results evaluated by the Illinois EPA after their due date of January 15, 2015. This is part of the continuing groundwater monitoring program under which the facility operates to ensure groundwater quality. A variety of inorganic parameters and water quality indicators were reported above their respective AGQS/MAPC value. The facility is required to report these exceedences in a Notice of Observed Increase and conduct confirmation sampling during the 3rd quarter 2014 sampling event.