# Addition of a Subsurface Intrusion Component to the Hazard Ranking System
**CFR Correction**
In Title 40 of the Code of Federal Regulations, Parts 300 to 399, revised as of July 1, 2017, on page 110, in the Table of Contents to Appendix A to Part 300, revise the following headings:
**Appendix A to Part 300—The Hazard Ranking System**
**Table of Contents**
7.1.1 Observed release/observed contamination/observed exposure.
7.1.2 Potential to release/potential for exposure.
7.2.3 Persistence/degradation.
7.3.3 Weighting of targets within an area of subsurface contamination.
**List of Figures, Figure number**
5-1 Overview of the soil exposure and subsurface intrusion pathway.
**List of Tables, Table number**
5-1 Soil exposure component scoresheet.
5-2 Hazardous waste quantity evaluation equations for soil exposure component.
5-11 Subsurface intrusion component scoresheet.
5-12 Structure containment.
5-13 Depth to contamination.
5-14 Effective porosity/permeability of geological materials.
5-15 Vertical migration factor values.
5-16 Values for vapor pressure and Henry's constant.
5-17 Vapor migration potential factor values for a hazardous substance.
5-18 Degradation factor value table.
5-19 Hazardous waste quantity evaluation equations for subsurface intrusion component.
5-20 Health-based benchmarks for hazardous substances in the subsurface intrusion component.
5-21 Weighting factor values for populations within an area of subsurface contamination.