Key EPA RSL Values from the November 2024 Tables - A Field Reference
EPA’s Regional Screening Levels (RSLs) are the default federal screening tool for soil, air, and tap water at contaminated sites. The November 2024 generic tables (TR=1E-06, THQ=1.0) cover roughly 890 chemicals across all environmental media. This post is a quick field reference for the values environmental professionals reach for most often, and a reminder of how RSLs differ from enforceable drinking water standards.
For a full explanation of how RSLs are derived and when to apply them, see our EPA RSL explained guide. For a deeper walk through the November 2024 tables specifically, see our November 2024 RSL update guide. This post is the short-reference companion to those.
What RSLs Are (and Are Not)
RSLs are risk-based screening concentrations. A result above an RSL means a chemical warrants further evaluation, not that remediation is automatically required, and not that a cleanup standard has been exceeded. They are calculated from standardized exposure assumptions and toxicity values at a target cancer risk of one in one million (TR=1E-06) and a target hazard quotient of 1.0.
Two practical points that trip people up:
- RSLs are not cleanup standards. State programs set their own cleanup numbers (see below).
- The tap water RSL is usually lower than the drinking water MCL for the same chemical, because the RSL is a risk-based screening value while the MCL is an enforceable standard that also factors in treatment feasibility and cost. When screening groundwater at a CERCLA site, the RSL, not the MCL, is generally the appropriate comparison value.
Key Values from the November 2024 Tables
The values below are drawn directly from the November 2024 RSL summary table (TR=1E-06, THQ=1.0). Residential and industrial figures are direct-contact soil screening levels; tap water is the residential tap water RSL.
| Chemical | Residential soil (mg/kg) | Industrial soil (mg/kg) | Tap water (ug/L) | Drinking water MCL (ug/L) |
|---|---|---|---|---|
| Benzene | 1.2 | 5.1 | 0.46 | 5 |
| Tetrachloroethylene (PCE) | 24 | 100 | 11 | 5 |
| Trichloroethylene (TCE) | 0.94 | 6 | 0.49 | 5 |
| Arsenic (inorganic) | 0.68 | 3 | 0.052 | 10 |
| 1,4-Dioxane | 5.3 | 24 | 0.46 | none |
| Lead and Compounds | 200 | 800 | 10 | 10 |
| Vinyl Chloride | 0.059 | 1.7 | 0.019 | 2 |
A few of these are worth calling out for site work:
Benzene has a residential tap water RSL of 0.46 ug/L, well below the 5 ug/L MCL. At a petroleum site where benzene is the driver, screening groundwater against the RSL rather than the MCL is the more conservative and generally more appropriate choice during investigation.
1,4-Dioxane has no federal MCL, so the tap water RSL of 0.46 ug/L is often the only federal screening number available for groundwater. It is a frequent co-contaminant at chlorinated solvent sites and is easy to miss because older analytical methods did not capture it well.
Lead carries a residential direct-contact soil RSL of 200 mg/kg. Note that EPA’s CERCLA and RCRA residential soil lead guidance, updated by an October 2025 OLEM directive, also uses a 200 ppm screening level alongside a 600 ppm removal management level. Those CERCLA/RCRA values are a separate framework from the TSCA Section 403 soil-lead hazard standards (400 ppm in play areas, 1,200 ppm yard-wide average), which apply to lead-based paint risk assessments and remain in effect. Be clear about which framework governs your site before applying a number.
Vinyl Chloride has a very low residential soil RSL of 0.059 mg/kg, reflecting its potency as a carcinogen. It is a common breakdown product of PCE and TCE, so it often appears at solvent sites even where it was never used directly.
How This Affects Site Assessment Work
For Phase II ESAs and CERCLA or RCRA screening, compare analytical results to the current RSLs for the relevant medium and exposure scenario. Use residential values for residential or unrestricted reuse, and commercial/industrial values where land use supports it.
A result above an RSL flags a chemical for further evaluation. It does not by itself require remediation, and it does not override a state cleanup standard. In Ohio, for example:
- Ohio VAP sites use CIDARS generic numerical standards, derived independently from RSLs.
- BUSTR sites use BUSTR action levels from the TGM, also independently derived.
- DERR-directed sites may use RSLs as screening values, with final cleanup levels set in the Director’s Final Findings and Orders.
RSLs are most directly useful as a screening tool when no specific regulatory program governs the work, for example during Phase II ESAs conducted for due diligence.
Practical Reminders
- Always document which RSL table version you applied. EPA updates the tables periodically, and stating the version (here, November 2024) avoids confusion during regulatory review.
- When EPA’s online RSL calculator is unavailable, the downloadable summary tables on the EPA RSL website contain the same pre-calculated values at the standard risk targets.
- Confirm whether your state program adopts EPA RSL updates automatically or maintains its own screening schedule before relying on a federal value.
Source
EPA Regional Screening Levels (RSLs) - Generic Tables, November 2024 (TR=1E-06, THQ=1.0). Values cited above are from the November 2024 RSL summary table. Lead soil guidance: EPA OLEM Residential Soil Lead Directive, October 16, 2025. TSCA Section 403 soil-lead hazard standards: 40 CFR Part 745.