24.04.2015 Views

KIRTLAND AIR FORCE BASE ALBUQUERQUE, NEW MEXICO ...

KIRTLAND AIR FORCE BASE ALBUQUERQUE, NEW MEXICO ...

KIRTLAND AIR FORCE BASE ALBUQUERQUE, NEW MEXICO ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

APPENDIX B<br />

SOP B7.2<br />

Use of NMED Soil Screening Levels<br />

This SOP just provides a general procedure for data assessment of soil analytical results using New<br />

Mexico Environment Department Soil Screening Levels (SSLs).<br />

NMED-HWB produced guidance in December 2000, with a subsequent update in January 2001, for use<br />

in evaluating the potential for human health risk at sites where there were past releases or disposal<br />

activities that may impact human health and the environment. This guidance document was modeled after<br />

guidance available from the EPA and provides a step-by-step approach to developing SSLs that can be<br />

used to assess the need for further risk evaluation. NMED developed New Mexico-specific SSLs based<br />

on parameters more appropriate for sites within the state relative to climate, exposure, and soil<br />

properties. NMED SSLs are presented in Table B7.2-1.<br />

The evaluation of analytical data for Kirtland AFB projects must follow the risk-based soil-screening<br />

approach presented in the guidance from NMED (NMED, 2000) which is described below:<br />

1. Determine the analytes detected in soil samples collected from the site<br />

2. Evaluate data for metals and radionuclides with concentrations exceeding NMED-approved<br />

background values for Kirtland AFB, or literature values available from the U.S. Geological<br />

Survey (Shacklette and Boerngen 1984), and for all organic compounds that were detected in<br />

samples<br />

3. Calculate a ratio for each metal and organic compound determined from step 2 as the<br />

appropriate exposure point concentration divided by the NMED SSL<br />

4. For each toxicity endpoint calculate a sum of the ratios for the analytes specific to each<br />

endpoint (e.g., sum of carcinogenic ratios and sum of noncarcinogenic ratios)<br />

5. Compare endpoint ratios to 1.0. If ratios exceed 1.0 there is a potential that unacceptable risk<br />

exists at the site due to exposure to soil and further risk evaluation should be considered.<br />

6. If endpoint ratios are less than 1.0 there is acceptable risk due to exposure at the site and<br />

there is no need for further risk evaluation.<br />

Data for soil samples should also be compared to groundwater protection dilution-attenuation factor 20<br />

(DAF20) values. DAF20 values were adjusted for toxic pollutants listed in the Water Quality Control<br />

Commission table for groundwater standards (NMAC 20.6.2). The DAF20 values for each chemical<br />

should be adjusted based on the number of toxic pollutants presented in soil specific to each landfill as<br />

presented in NMED guidance. DAF20 values present a value at which leaching of a contaminant from<br />

soil could occur. Although concentrations of chemicals in soil greater than DAF20 values indicates a<br />

potential for leaching, the DAF20 values do not take into account vertical contaminant migration to<br />

groundwater. Groundwater at Kirtland AFB ranges from 100 to 500 ft below ground surface; thus, a sitespecific<br />

evaluation of contaminant migration should be conducted to determine the potential for<br />

contaminant leaching from soil and subsequent unsaturated (vadose) zone migration to the water table.<br />

Several tools are available to evaluate vadose zone contaminant migration including the computer models<br />

SESOIL and VLEACH.<br />

Refer to following document for guidelines and procedures for the NMED-HWB SSL guidance. Table<br />

A-1 from the guidance document (NMED 2000) is included in this SOP as Table B7.2-1.<br />

Kirtland AFB<br />

SOPs for Field Investigations B-175 April 2004

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!