15.1 Soil-Lead Hazards and Sampling Interpretation for Supervisors
Key Takeaways
- A soil-lead hazard exists in a play area when a composite sample of bare soil is ≥ 400 ppm, and in the rest of the yard when the arithmetic mean of composite sample(s) of bare soil from non-play areas for each residential building on a property is ≥ 1,200 ppm (40 CFR 745.227(h)(4)).
- Both prongs apply only to bare soil. Intact grass, mulch, or pavement is not the (h)(4) sample. A 900 ppm play-area composite is a soil-lead hazard; 900 ppm at the back of the lot that is not a play area is not a rest-of-yard hazard.
- Risk-assessment soil samples are collected where bare soil is present in exterior play areas, the rest of the yard (non-play), and dripline/foundation areas (745.227(d)(8)). Do not average a play-area composite with a rest-of-yard composite.
- Soil samples under 745.227(f) are collected only by a certified inspector or risk assessor and analyzed by an EPA-recognized (NLLAP / TSCA 405(b)) laboratory. A supervisor reads those results to write the work plan and does not collect RA soil unless also certified in that discipline.
- Supervisor curriculum 745.225(d)(3)(x) is soil and exterior dust abatement or LBP hazard-control methods (hands-on). Exterior paint chips on the dripline after paint abatement are a cleanup duty under 745.227(e)(8)(v)(C), not a substitute for reading the RA soil table.
400 ppm is not 1,200 ppm, and only bare soil counts
Quick Answer: A soil-lead hazard is present (i) in a play area when the soil-lead concentration from a composite play-area sample of bare soil is ≥ 400 parts per million (ppm), or (ii) in the rest of the yard when the arithmetic mean lead concentration from a composite sample (or arithmetic mean of composite samples) of bare soil from the rest of the yard (non-play areas) for each residential building on a property is ≥ 1,200 ppm (40 CFR 745.227(h)(4)). Risk-assessment soil is taken where bare soil is present in exterior play areas, the rest of the yard, and dripline/foundation areas (745.227(d)(8)). The supervisor reads those results. Paint, dust, and soil samples under 745.227(f) are collected only by a certified inspector or risk assessor and analyzed by an EPA-recognized (NLLAP / TSCA 405(b)) laboratory.
This is the sorting table for soil work. A 900 ppm play-area composite is a soil-lead hazard. A 900 ppm composite from the back of the lot that is not a play area is not a rest-of-yard hazard, because rest-of-yard uses 1,200 ppm. Mixing those two numbers — or applying 400 ppm to the whole property — is the classic exam miss. Intact sod over 2,000 ppm is not an (h)(4) sample of bare soil; the hazard language is bare soil, not every cubic yard on the tax parcel.
Supervisor curriculum topic 745.225(d)(3)(x) is soil and exterior dust abatement or LBP hazard-control and reduction methods, including hands-on. You still do not become the risk assessor by owning a soil corer. Chapter 7 taught you to read the RA. This section is how to read the soil rows so the work plan in Sections 15.2 and 15.3 matches the hazard that actually exists.
The two prongs of 745.227(h)(4)
ppm here is the same unit as µg/g. A lab report that says 400 µg/g is 400 ppm. Do not convert it to mg/cm² (that is paint XRF) or µg/ft² (that is dust loading).
| Location | What is sampled | Hazard number | How the number is built |
|---|---|---|---|
| Play area | Composite of bare soil from the play area | ≥ 400 ppm | One composite from that play area; compare the composite to 400 |
| Rest of the yard (non-play) | Composite sample(s) of bare soil from the rest of the yard, for each residential building on the property | ≥ 1,200 ppm | Arithmetic mean of that composite (or of the composites) compared to 1,200 |
| Dripline / foundation | Bare soil at the dripline or next to the foundation | Use 400 if that strip is a play area; use 1,200 if it is non-play rest of yard | (d)(8) requires the sample whenever bare soil is present; (h)(4) still uses play vs rest-of-yard, not a third federal number |
Equal to or greater than. 400 ppm is a play-area hazard. 399 ppm is not. 1,200 ppm is a rest-of-yard hazard. 1,199 ppm is not. Do not round 1,150 up to 1,200 because it feels close.
Bare soil only. (h)(4) and (d)(8) both say bare soil. Dense grass, intact mulch, or pavement is not the sample. The RA should not composite a vegetated side yard into the play-area number, and you should not invent a soil-lead hazard from a covered surface the assessor never sampled as bare. If the cover fails later and the same soil is now bare, that is a new condition — not a license to skip the original table.
Do not average play with yard. A play-area composite of 900 ppm and a rest-of-yard composite of 300 ppm do not become a property-wide 600 ppm. Play-area (h)(4)(i) is already a hazard at 900. Rest-of-yard (h)(4)(ii) is not a hazard at 300. Averaging them is how a sandbox disappears from the work order.
Each residential building. Rest-of-yard means are per residential building on the property. Building A's yard composite does not clear Building B. A duplex with two addresses on one lot still needs the rest-of-yard read for each building the RA sampled that way.
HUD's 9 square feet is not (h)(4). HUD Guidelines Chapter 12, as a documented methodology under 745.227(a)(3), discusses a 9 square foot bare-soil extent for some yard/area hazard-control decisions, and says any size bare play area above 400 µg/g is a hazard. EPA 745.227(h)(4) does not write a 9 ft² sentence. On this exam, cite 400 / 1,200 and bare soil. Do not fail a play-area 500 ppm composite because someone measured only 8 ft² of dirt.
What 745.227(d)(8) actually sampled
The RA is required to collect and analyze soil in three locations where bare soil is present:
- Exterior play areas
- The rest of the yard (non-play areas)
- Dripline/foundation areas
Play area is occupant-use language from the RA's background step (745.227(d)(3)): where children under 6 play — sandbox, swing set, packed dirt by the back steps, a daycare outdoor classroom. It is not “any grass the owner mows.” If the RA labeled the packed dirt under the swing set as play area, you do not relabel it rest-of-yard because it is inconvenient.
Dripline is sampled because paint chips and wash-off concentrate at the foundation. That strip is often the highest number on the page. It is not automatically a third hazard threshold. Read how the RA classified the use: a child's play strip along the south wall is a play area at 400 ppm; a narrow unused drip strip that the RA put in non-play is in the rest-of-yard mean at 1,200 ppm. Do not invent a “dripline = 400 ppm always” rule, and do not ignore a 2,000 ppm drip strip the RA listed as a play-area composite.
Sampling uses documented methodologies with quality control (745.227(d)(9)). HUD Guidelines and EPA residential soil-sampling protocols are the usual (a)(3) methods: composite cores from the top of the bare patch, not a single scoop from the neighbor's garden. 745.227(f) is the hard stop: those cores are collected by an inspector or risk assessor, not by the abatement crew on lunch break.
How a supervisor reads one soil table
You do not collect confirmatory cores. You do check that play, rest-of-yard, and dripline rows exist when the visual described bare soil, that the lab is NLLAP, and that nobody averaged unlike areas.
Worked example — 900 ppm is not one answer
| Row on the RA | Result | (h)(4) read | What the abatement work plan must not do |
|---|---|---|---|
| Play area (sandbox / swing set), composite bare soil | 900 ppm | Hazard. 900 ≥ 400 | Ignore it because 900 is below 1,200, or plant rye grass and call it abatement |
| Rest of yard (back of lot, non-play), composite bare soil | 900 ppm | Not a rest-of-yard hazard. 900 < 1,200 | Apply the play-area 400 ppm number to the whole lot and excavate the back fence line “to be safe” without a contract for that scope |
| Play area, composite bare soil | 350 ppm | Not a play-area hazard | Treat 350 as “close enough” to 400 and open a soil-abatement notice |
| Rest of yard, arithmetic mean of composites | 1,200 ppm | Hazard. Equal to 1,200 counts | Call 1,200 a pass because it is not “over” 1,200 |
| Dripline, bare soil, RA classified as play (kids dig along the south wall) | 800 ppm | Play-area hazard (800 ≥ 400) | File it under 1,200 because it is “just the dripline” |
| Dripline, bare soil, RA classified as non-play and folded into the rest-of-yard mean | Mean 600 ppm | Not a rest-of-yard hazard | Invent a third federal dripline number |
| Side yard under intact sod; RA notes no bare soil | Not sampled as (d)(8) bare soil | No (h)(4) sample from that cover | Composite the sod into the play-area number, or skip a later bare patch the RA did sample |
Field traps on this page:
- 900 ppm is a play-area hazard and not a rest-of-yard hazard. Same number, different prong.
- Bare is the adjective that keeps vegetated or paved soil out of (h)(4).
- Dripline is a sampling location, not a third ppm standard.
- Do not collect the cores. If the table is missing a required bare-soil location, send the RA back; do not fill the blank with a supervisor sample (745.227(f)).
- HUD 5,000 µg/g language in Guidelines Chapter 12 (when soil abatement is “most appropriate” versus interim controls) is not the EPA hazard definition. A play area at 900 ppm is already a soil-lead hazard under (h)(4). HUD's 5,000 figure is a method-preference discussion, not a pass.
What you do with a complete soil table (and what you do not)
Use the table to name which bare-soil areas are hazards before you pick removal and replacement (Section 15.2) or permanent covering (Section 15.3). Put those areas in the occupant protection plan, the five-business-day notice quantities, and later the abatement report. Do not drop a prioritized play-area soil hazard because the crew is a paint crew (Chapter 7).
Do not:
- Treat a lead hazard screen as a full soil RA (Chapter 7.3).
- Use interior dust-lead action levels (5 / 40 / 100 µg/ft² on or after January 12, 2026) as soil numbers.
- Call mulch over 900 ppm play-area soil soil abatement — that is Section 15.3.
- Leave paint chips in the dripline after exterior paint work and pretend the RA's 350 ppm play-area row still describes the yard. 745.227(e)(8)(v)(C) is cleanup after exterior paint abatement: horizontal surfaces in the closest outdoor living area cleaned of visible dust and debris, and paint chips on the dripline or next to the foundation removed from the site and properly disposed. That visual is not soil abatement, but chips left in play-area soil are how you create or continue a soil-lead hazard the RA did not write.
Official sources: 40 CFR 745.227(d)(8), (e)(8)(v)(C), (f), (h)(4); 40 CFR 745.225(d)(3)(x); HUD Guidelines Chapter 12 (soil-lead evaluation discussion; 9 ft² / 5,000 µg/g method-preference language is HUD, not the EPA (h)(4) text).
A certified risk assessor reports a play-area composite of bare soil at 900 ppm and a rest-of-yard (non-play, back-of-lot) composite of bare soil at 900 ppm for the same residential building. Which reading of 40 CFR 745.227(h)(4) is correct?
Under 40 CFR 745.227(d)(8) and (f), where are risk-assessment soil samples taken, and who may collect them?
Which statement correctly states the soil-lead hazard rule in 40 CFR 745.227(h)(4)?