TABLE 2.

Sediment characteristics of contaminated and background subsurface sitesa

SampleDry/wet ratioPorosityDensity (g/cm3)LOIb (%)pHNitrate (μmol/cm3)Fe-HCl extract (μmol/cm3)Fe-dithionite extract (μmol/cm3)
302-020.750.361.45.15.41.02-1.03 × 10−24.36503.5
302-050.730.491.84.55.71.84 × 10−5-2.40 × 10−326.1302.3
270.890.231.94.63.69.8-54.913.5260.7
280.840.291.94.93.4137-18011.3329.6
300.860.2924.24.222.7-31.515.2414.4
310.870.261.94.73.80.1-91.710.8376.4
320.850.322.14.54.40.02-17.218.9407.9
330.840.291.94.53.613.6-29514.5467.7
340.860.2624.33.83.3-70.516.3325.0
  • a Background sediments are sample numbers 302-02 and 302-05 and were collected 61 to 344 cm below the surface, and contaminated sediments are sample numbers 27, 28, 30, 21, 32, 33, and 34 and were collected 308 to 576 cm below the surface. Values are averages of duplicate samples from two to four sediment cores or the range of values for duplicate samples from two to four sediment cores.

  • b LOI, loss on ignition.