LESSON Lead Safe University · Free

Easy Wins · 14 · Play Areas & Soil

Fifteen feet from the house is where the lead is.

Leaded gasoline was banned in 1996. The lead it dropped is still in the top 2–4 inches of soil, concentrated near old exterior paint and along traffic corridors. Within 15 feet of a pre-1978 house, bare dirt routinely tests at 400–2,000 ppm, well above the EPA residential action level. Mulch over it, grass on it, raised-bed garden with imported soil. Pick one.

Pre-1978 US homes: ~33M
EPA action level (residential): 400 ppm
Typical near-house bare soil: 500–3,000 ppm
Topsoil cap to fix: 4–6 in

EPA residential soil-lead hazard standards; UMass Extension and Cornell Garden Soil Project residential databases; USGS urban soil studies; HUD lead-hazard guidance.

Pre-1978 house + bare soil + kid = assume 400+ ppm until tested.

Two things put lead in your yard: (1) old exterior paint chalking off the siding for 50 years and concentrating in the soil at the drip line; (2) leaded gasoline, banned for cars in 1996 but still sitting in the top 2–4 inches of soil along old traffic corridors. The first is the bigger contributor near the house.

Within roughly 15 feet of any pre-1978 home, EPA-funded surveys consistently find bare-soil lead at 400–2,000 ppm, 1–5× the residential action level. The numbers go up sharply right at the foundation and drop off as you move away.

Three cheap fixes: mulch (4–6 inches of wood chips), grass (a healthy lawn caps it), or a raised-bed garden with imported soil. Pick one for the play area. Don’t let kids eat dirt within 15 feet of the house. A $20 mail-in soil test (UMass, Cornell, K-State) tells you the truth for your specific yard.

The 15-foot rule

Why the lead concentrates right next to the house.

Pre-1978 exterior paint was lead-based by default, typically 5–40% lead by weight in the dry film. Over decades, that paint chalks, weathers, peels, and sheds onto the soil immediately below it. RRP-rule renovations after 2010 contain the dust, but most pre-2010 painting and demo did not. The result is a contamination band roughly 0–15 feet from the foundation, with lead concentrations highest right at the drip line and falling off with distance.

Inside 3 feet of an old painted exterior, you can see soil-lead readings of 1,000–3,000 ppm. By 15 feet out, levels are usually closer to background. By 30 feet, most yards are at the rural-soil baseline.

The actionable shape: 15 feet from any pre-1978 painted wall is the perimeter to fix. That’s where kids dig, where dogs lie, where bare patches form against the house, where rainwater splashes dirt onto siding and back. Cap it.

The leaded-gas legacy

Old highways and old urban centers carry a different signal.

From 1923 to 1996, US gasoline contained tetraethyl lead. Roughly 7 million tons of lead were emitted from vehicle exhaust over those decades, and most of it landed within 50–100 feet of the road. That deposit didn’t move, lead binds to soil organic matter and stays in the top few inches. Leaded gas was banned for road vehicles in 1996, but the soil burden is still there.

USGS and city studies (Boston, Baltimore, New Orleans, Detroit, Chicago, LA) all show the same pattern: inner-city soil along pre-1990 traffic corridors runs 200–800 ppm, with the highest readings within 30 feet of the curb. If your home is in a dense urban area, this is layered on top of any old-paint contamination near your house.

The fix is the same: cap with mulch, grass, or imported topsoil. You don’t need to dig the lead out, it’s in the top 2–4 inches and stays there. A 4–6-inch cap of clean material puts your kid’s play surface above it.

What soil-lead numbers look like by context

The ranges, not the headlines.

Treat these as typical ranges from the published residential databases (UMass Extension, Cornell Garden Soil, USGS urban studies, HUD lead-hazard surveys). Your specific yard could be lower or several times higher. The only way to know is a $20 mail-in test.

Soil context	Typical lead range	vs. EPA action level (400 ppm)	Source
Inner-city pre-1978 home, near foundation	700–2,000 ppm (median ~900)	2–5× over	USGS urban soils studies (Boston, Baltimore, New Orleans, Detroit)
Suburban pre-1978 home, near foundation	400–800 ppm	1–2× over	HUD lead-hazard guidance + state extension data
Pre-1978 home, drip-line of exterior paint	500–3,000 ppm (highly variable)	1–7× over	EPA lead-paint hazard guidance (RRP)
Rural pre-1978 home	150–400 ppm	at or below action level	UMass Extension residential soil database
Within 50 ft of pre-1980 highway corridor	200–800 ppm	0.5–2× over	USGS leaded-gasoline legacy studies
Urban vegetable garden, post-1990 fill	100–400 ppm	at or below	Cornell Garden Soil Project
Post-1978 home, suburban/rural	<100 ppm	well below	EPA background soil estimates
Imported topsoil / raised-bed mix	<50 ppm typically	well below	Bagged soil products generally test clean; verify supplier

Ranges are typical, not guaranteed. EPA lead in soil, UMass Extension Soil and Plant Nutrient Testing, Cornell Healthy Soils, USGS urban soil studies. Your specific yard could be lower or 5× higher, only a soil test for your address tells you.

The vegetable-garden case

Why raised beds with imported soil are the right answer near old houses.

If you garden in-ground within 30 feet of a pre-1978 house: leafy greens (lettuce, spinach, kale, chard) accumulate the most soil lead, followed by root vegetables. Fruiting vegetables (tomatoes, peppers, squash) accumulate the least. None of them load up enough to deliver headline-making doses, but the dirt that splashes onto the produce during watering is the bigger contributor than uptake.

The fix: a raised bed lined with landscape fabric, filled with imported topsoil + compost. You bypass the legacy soil entirely. Cornell and UMass have both published guides on this exact setup. Cost is a few hundred dollars for a 4×8 bed, and it lasts a decade.

You don’t need to remediate the soil. You need to cap it.

Lead in residential soil sits in the top 2–4 inches and doesn’t migrate. A 4–6 inch cap of clean material, mulch, grass, or imported topsoil, puts your kid’s play surface above the contaminated layer. The expensive solution (full soil excavation) is overkill for almost every residential case. The cheap solution (mulch this weekend) actually works.

The three easy wins

What to actually do this weekend.

Cover bare soil within 15 feet of the house with mulch or grass this weekend.

Bare dirt against the foundation is the high-concentration zone. A bag of cedar mulch is $5; you need maybe 8–12 bags for a typical 50× perimeter at 4 inches deep. Cap it. Top it up annually as it breaks down.

If you prefer grass: overseed the bare patches, water for two weeks, and let the canopy fill in. A healthy lawn is also a soil cap, the leaf litter and root mass pin the lead-bearing dust in place.

Vegetable garden? Raised bed with imported soil. Not in-ground near a pre-1978 home.

Build (or buy) a raised bed at least 12 inches deep. Line the bottom with landscape fabric. Fill with bagged topsoil + compost from a verified supplier. You’re now gardening in clean dirt, regardless of what’s in the legacy soil below.

If you must garden in-ground, stick to fruiting vegetables and wash everything thoroughly. Skip the leafy greens in any in-ground bed within 30 feet of an old painted exterior.

$20 mail-in soil test tells you the truth for your specific yard.

UMass Extension, Cornell, K-State, and most state ag-extension labs run residential soil-lead panels for $15–$30. Sample technique matters: composite from several spots in the play zone, top 2 inches, no leaves or rocks, mail it in.

If the result is <100 ppm, relax. 100–400 ppm: cap as a precaution. 400+ ppm: cap, fence, or move the play area. The number for your address replaces the guesswork.

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