SU0004564 SSNL - Laserfiche WebLink

Home Browse Search

SOIL AND WATER TABLE ANALYTICAL TEST RESULTS EAST SOIL NITROGEN CONTENT and WEST SOIL NITROGEN CONTENT and TEST PIT WATER TABLE NITROGEN TEST PIT WATER TABLE NITROGEN CONTENT CONTENT 2 Ft Depth 3 ppm as NO;N 1029 ppm TKN 2 Ft Depth 12 ppm as NO,N 657 ppm TKN 8 Ft Depth 47 ppm as NO,-N 570 ppm TKN 8 Ft Depth 13 ppm as NO,-N(?) 401ppm TKN 12 Ft Depth 20 ppm as NO3 N 579 ppm TKN 13 Ft Depth 58 ppm as NO,N(?) 698 ppm TKN Water Table- 224 ppm as NO, Water Table- 168 ppm as NO, 15 Ft Depth 15 Ft Depth The nitrate concentrations with the soil profile yielded interesting results and illustrates the variability in nitrate concentrations found in virtually every agricultural environment. Considering that the East Test Pit was thought to be "background," the soil and water table nitrate concentrations are roughly equivalent to those found in the West Test Pit. The 20 ppm NO3-N at the 12-ft depth for the East Test Pit, which was at the capillary fringe illustrates the apparent capacity of the soil to denitrify to a great extent(over 100% from 8 ft to 12 ft). The upper soil profile for the West Test Pit from 2 feet down to 8 feet indicate comparatively low concentrations of nitrate-nitrogen and may be an indication of the denitrification potential of the f soil. It is a possibility that there may have been a laboratory error for the West Test Pit analysis. ! The 8-foot depth test result may have been transposed with the 12-foot test result, since it would j have been expected for the nitrate concentration to decrease with soil depth. However, if the results are correct, then it is theorized that for the 13-foot depth in the West Test Pit,the nitrate-nitrogen content is higher because the sample was retrieved right on top of the water table. This nitrate concentration may be from the actual water table concentration. Nitrate not only moves horizontally with the groundwater flow, it can also move upwards, with a "wetting front." Total Kjeldahl Nitrogen(TKN) measures the organic and ammonium fractions of nitrogen. The test results are normal and what would be expected under agricultural soils, except the 2-foot East Test Pit. This TKN concentration can be considered on the high side and may be attributed to the annual grass growth on the soil surface leaching the organic and ammonium fractions of nitrogen, which is settling on top of the cemented silts stratum. Additional soil samples were obtained for chemical analysis from the proposed leachfield area for APN 191-230-08. The test results are referenced on the Soil Analysis Report as LF42" for the sample from 42 inches in depth, LF1.5, for 1.5 feet in depth and LF-T for the seven-foot depth. Chemistry on these soil samples was done to analyze several constituents that influence nitrate loading. The important parameters for nitrate loading assessment are the organic matter, pH, cation exchange capacity (CEC), and nitrate-nitrogen content. As noted, the organic matter in the soil profile is low for agronomic purposes, but in sufficient amounts to contribute some 4 CFtemq Consi&ing