NJDEP posted (on 6/20/2019) revised Evaluation of Extractable Petroleum Hydrocarbons (EPH) in Soil Technical Guidance (June 2019, Version 1.0) along with the EPH Alternative Product Limit Calculator and the EPH Category 2 Health Based Calculator.
NJDEP held training (on 07/23/2019) attended by over 450, which included discussion of key technical topics such as laboratory testing for grain size. During the training, NJDEP clarified this test method refers to ‘sieve with hydrometer’ or ASTM D7928-17 Standard Test Method for Particle-Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis, which is offered by Alpha Analytical.
As stated in Appendix 2 of the revised EPH Guidance: ‘…grain size distribution data generated via sieve and hydrometer analyses are used to derive the effective diameter “D10” input parameter for use in the Department’s EPH Alternative Product Limit Concentration Calculator’. D10, known as ‘effective diameter’ in geotechnical engineering, is the sieve diameter that passes 10% of the mass of the dry sample.
Alpha’s grain size data report provides the weight fractions for specific sieve and hydrometer particle sizes, including the effective diameter D10 which represents the equivalent particle size in millimeters where 10% by dry weight passes (i.e., is finer). Alpha calculates and reports the D10 value in the grain size data report which is then used as a data input for the EPH Alternative Product Limit Calculator.
NJDEP also clarified during the training that they do not offer NJ certification for ASTM grain size test methods, and that grain size samples may be collected and held (with no method-defined hold time) pending review of the EPH test results and subsequent use of the calculator. In summary, the revised EPH Technical Guidance provides a method to determine an AOC-specific EPH alternative product limit concentration based on the AOC-specific soil texture and the stored or discharged petroleum products. Alpha Analytical offers the test methods and data reporting formats designed to support the revised EPH Technical Guidance. Call us for more information on our products and services. For the guidance and the calculators, refer to: https://www.nj.gov/dep/srp/guidance/