Soil Testing for Lead and Contaminants

When should I test my soil for lead and other contaminants?

Test if your property is near an older home with exterior paint, a heavily traveled road, a former industrial site, a burn pile, an old orchard or any area where fill soil was brought in. A new property with unknown history is also a good reason.

Children play in soil and put hands in mouths, so a family with young children has extra reason to test play areas and beds.

Land that was once farmed, or an older home site, can also hold residues from past pesticide use or stored materials. Ask neighbors, county records or your local historical society what the land was used for. This history, even if incomplete, helps you and the lab decide what to test for.

Where do contaminants come from?

Lead can come from chipped paint, old gasoline residues and certain old pesticides. Other metals and chemicals can come from industrial use, treated lumber, ash and dumped material. Old orchards sometimes carry persistent pesticide residues.

Soil often looks normal even when contaminated, so you cannot judge by appearance or smell.

Tools and fill matter too. Soil brought in for a raised bed or lawn may carry contaminants, and compost or mulch made from unknown sources can too. Ask suppliers what testing they do, and keep receipts and labels so you know what went where.

How do I take a good sample?

Ask the lab for its instructions first, since methods differ. In general you collect several small portions from a defined area, mix them in a clean container and send a measured amount. Sample garden beds separately from drip lines near buildings, where paint residue concentrates.

Use clean tools, label each sample and note where it came from and what you plan to grow.

Plan your sampling around how the space will be used. A play area, a vegetable bed and a decorative border may need separate samples because exposure differs. Sampling near the foundation of an older home often shows the highest values, so keep those samples apart from the rest of the yard.

• Take samples from the depth where roots grow.
• Keep a map of sampled spots.
• Ask the lab which contaminants its test covers.

Which lab should I use?

Start with your county extension office or state agriculture department, since many universities and state labs offer testing or can name accredited labs. Ask what the test covers, how the results are reported and who can help you interpret them.

Results mean little without guidance. Ask the lab or your extension office how the numbers compare with health-based guidelines for gardens and play areas.

Costs depend on what the lab tests and who runs it, so ask for a written list of tests and fees before sending samples. Some health departments, universities and conservation districts offer reduced-cost or occasional programs, so ask whether any are running in your area.

What do I do while waiting, or if the result is high?

Lower exposure in simple ways. Keep soil covered with mulch or grass, wash hands and produce well, remove shoes outside and keep children from bare soil. Raised beds with clean soil and a barrier at the bottom are a common approach when ground is contaminated.

If results are elevated, talk with your state or local health department and extension office before eating from that ground. Health questions belong with a doctor or public health office.

Keep dust down. Dry, bare soil blows into homes on shoes and pets. Doormats, shoe removal, damp-mopping and keeping bare patches covered help reduce what comes indoors. If a young child has had possible exposure, ask your doctor or local health department about testing and next steps.

What about food safety and ongoing care?

Leafy and root crops can take up or carry soil, so washing and peeling matter. Fruiting crops generally carry less, but ask a local expert for crop-specific guidance.

Retest after major changes such as new fill or construction. Keep results with your property records.

How often should I retest?

A clean result on a stable site does not need frequent repeats. Retest if you bring in fill, remodel or scrape an older building, if a flood deposits sediment, or if you change how a space is used, such as turning a yard into a play area or vegetable garden.

Keep every report in one place with a map of where samples came from. If you sell or rent the property, those records show what you tested and when. Ask your extension office or health department how long a result stays useful in your situation.

Last reviewed: November 12, 2026. Written by the Homestead & Small Farm Editorial Team. See our editorial policy.