You determine that the average total VOHAP concentration, as defined in
§ 63.7957, of the remediation material managed in the remediation material management unit material is less than 500 ppmw. You must follow the requirements in
§ 63.7943 to demonstrate that the VOHAP concentration of the remediation material is less than 500 ppmw. Once the VOHAP concentration for a remediation material has been determined to be less than 500 ppmw, all remediation material management units downstream from the point of determination managing this material meet the requirements of this paragraph unless a remediation process is used that concentrates all, or part of, the remediation material being managed in the unit such that the VOHAP concentration of the material could increase. Any free product returned to the manufacturing process (e.g., recovered oil returned to a storage tank at a refinery) is no longer subject to this subpart.