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1,4-Dioxane in NY State – Soil Analytical Considerations

by Kevin Hoogerhyde

ny stateAlpha is reaching out to our clients, industry and the broader regulated community to solicit comments and perspective on the approach to 1,4-Dioxane monitoring and data interpretation in soil.

Part 375 Soil Cleanup Objectives were promulgated in 2006. In 2010, NYSDEC Policy CP-51-Soil Cleanup Guidance was published. It replaced TAGM 4046, Petroleum Site Inactivation and Closure Memorandum (1998) and STARS#1. The Policy applies to the Inactive Hazardous Waste Disposal Site Remedial Program, known as the State Superfund Program (SSF); Brownfield Cleanup Program (BCP); Voluntary Cleanup Program (VCP); Environmental Restoration Program (ERP); Spill Response Program - Navigation Law (NL) section 176 (SRP); and the Resource Conservation and Recovery Act (RCRA) Corrective Action Program.

Currently, 1,4-Dioxane is listed as a volatile organic compound on the Part 375 Soil Cleanup Objective list. More recently there has been a growing concern and awareness of this compound and its impact on the environment. Required reporting limits have been dropping to lower and lower levels and there have been numerous studies and debates about the most appropriate method used for the analysis of 1,4-Dioxane.

1 4 DIOXANE1,4-Dioxane can be determined by both a volatile (SW846-8260) and semi-volatile (SW846-8270) analytical technique. Variations and enhancements with both methods are used to eliminate or reduce potential interferences and to enhance the analytical performance of the compound. Just as characteristics of this compound make it very difficult to treat in the environment, so is the case for making this a very difficult compound to analyze and detect at the required reporting limits now being imposed by the regulators.

Following many discussions and research by both the regulators and the laboratory community, it is now well established that the most effective way to analyze for 1,4-Dioxane is by using the semi-volatile analytical approach. Although there are recognized limitations to this method, there are also method enhancements such as the use of Select Ion Monitoring in conjunction with Isotope Dilution that can be used with this technique to yield highly reliable results at very low reporting limits. The semi-volatile technique also eliminates any potential interferences from chlorinated volatiles with which 1,4-Dioxane is most commonly associated.

As a result of this information and research, in June, NYSDEC issued a memo (June 2019, Sampling for 1,4‐Dioxane and Per‐ and Polyfluoroalkyl Substances (PFAS) Under DEC’s Part 375 Remedial Programs) indicating the following:

  • “Special Testing Requirements for Import or Reuse of Soil: Soil imported to a site for use in a soil cap, soil cover, or as backfill must be tested for 1,4-dioxane and PFAS contamination in general conformance with DER-10, Section 5.4(e). Soil samples must be analyzed for 1,4-dioxane using EPA Method 8270, as well as the full list of PFAS compounds (currently 21) using EPA Method 537.1 (modified).”
  • “1,4-Dioxane analysis and reporting: The reporting limit for 1,4-dioxane in groundwater should be no higher than 0.35 μg/L (ppb) and no higher than 0.1 mg/kg (ppm) in soil. Although ELAP offers certification for both EPA Method 8260 and EPA Method 8270 for 1,4-dioxane, DER is advising the use of Method 8270 SIM for water samples and EPA Method 8270 for soil samples. EPA Method 8270 SIM is not necessary for soils if the lab can achieve the required reporting limits without the use of SIM. Note: 1,4-dioxane is currently listed as a VOC in the Part 375 SCO tables but will be moved to the SVOC table with the next update to Part 375.”

The dilemma: Although the INTENT is to move 1,4-Dioxane from the volatile organic list in Part 375 to the semi-volatile list of Part 375 with the next update, it remains on the volatile list. This current sampling guidance requires 1,4-Dioxane to be analyzed as a semi-volatile (Import or Reuse of Soils), and highly suggests that the semi-volatile method be used in general for other site applications (“DER is advising the use of Method 8270 SIM for water samples and EPA Method 8270 for soil samples.”).

How then is the compound to be analyzed and reported considering other factors including historical approach and evaluation of the site, new sites entering state programs and is it even a compound of concern at the site?

Alpha Analytical is currently certified by the NYSDOH Environmental Laboratory Approval Program to analyze 1,4-Dioxane in soil by 8260, 8270, 8270-SIM Isotope Dilution. Going forward we will be reporting the compound in BOTH fractions for soil analysis, Volatile Organics (8260) and Semi-volatile Organics (8270) to meet the current sampling guidance (June 2019) and Part 375 Volatile Organic list compounds. This will also address historical data that may have already been gathered on this compound and remain in effect for sites that have legacy concerns where the only existing data was collected by the volatile organic method 8260. We have also considered the possibility that the compound may show up in both fractions at varying concentrations. This is like the concerns raised when reporting Naphthalene as both a VOC 8260 and SVOC 8270 compound. However, reporting limits combined with method performance would make this highly unlikely.

As always, Alpha is committed to modifying this plan to meet any specific project requirements or to comply with existing approved Quality Assurance Project Plans. If for some reason you project requires the compound be reported only in one fraction or the other, please communicate that to us and we will accommodate that request. If you make a global decision that all data generated for this compound be reported only in one fraction or the other, please let us know that as well. We will only report the compound on the fraction you have decided on based on your anticipated use of the data.

Once the revisions to Part 375 have been promulgated and 1,4-Dioxane has been moved from the Volatile Organic list to the Semi-Volatile Organic list, Alpha will no longer report the compound in both fractions. At that time, 1,4-Dioxane will only be reported in the Semi-Volatile fraction. Again, if specific projects require a different approach, we will accommodate that technical requirement. For the foreseen future, Alpha will maintain certifications in the following categories: 1,4-Dioxane in soil by 8260, 8270, 8270-SIM Isotope Dilution. We will communicate any decisions to change our certification status regarding the analysis of 1,4-Dioxane.

Please direct comments, questions and concerns to your project manager or account manager. If you would like someone to contact you, please complete the form on the left side of this page.


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