Introduction

This factsheet is for gardeners, homeowners, and landscapers who want to understand the impacts of lead in soil. It covers where soil lead comes from, why it matters for children and adults, current EPA and Connecticut guidelines, how to sample the yard and garden soil, what the soil test result means, and steps to take if soil is contaminated.

The goal is to help households decide whether to test, how to interpret what comes back, and what practical steps to take to reduce exposure.

What is lead?

Lead is a naturally occurring blue-gray metal, found in small amounts in the Earth's crust. It has been mined and used for thousands of years because it is dense, durable, and easy to shape. Lead was once common in paint, gasoline, pipes, solder, ceramic glazes, and pesticides. Today it is still used in some batteries, ammunition, radiation shielding, and industrial materials.

Lead is toxic if swallowed or inhaled. It can affect the brain, nervous system, kidneys, blood, and other organs. No safe level of lead in children has been identified.

Where is lead found, and what is a normal background level?

Lead occurs naturally in soil. Native, undisturbed Connecticut soils typically contain 10 to 60 parts per million (ppm), or milligrams per kilogram (mg/kg), of lead from the parent rock, well below the levels found at contaminated sites.

Higher levels usually point to human influence, such as the presence of older buildings with lead-based paint, high traffic areas due to the historic use of leaded gasoline, fill material, industrial activity, or former orchard use where lead arsenate pesticides were applied.

In soil, lead strongly attaches to soil particles and usually remains in the upper several inches under normal environmental conditions, rather than moving quickly downward.

How did soil become contaminated with lead?

In New England, the most common sources of elevated lead in yard and garden soils are lead-based paint, leaded gasoline, and lead arsenate pesticides.

Lead-based paint

Homes built before 1978 are more likely to contain lead-based paint. The federal government banned consumer use of lead-based paint in 1978, but many older homes still have lead paint under newer layers of paint. When exterior paint peels, chips, chalks, cracks, or is disturbed during renovation, lead dust and paint chips fall into nearby soil. Soil lead levels are often highest within a few feet of the foundation, and decrease farther from the house.

Leaded gasoline

Lead was added to gasoline starting in the early 1920s to boost octane. Although leaded gasoline for on-road vehicles was banned effective January 1, 1996, decades of vehicle emissions left elevated lead in many roadside soils, especially along busy roads, older roadways, intersections, and urban streets. Some piston-engine aircraft still use leaded aviation gasoline, but historic on-road gasoline use is the main reason many roadside soils still contain elevated lead.

Lead arsenate pesticides

Growers used lead arsenate for decades as an insecticide in apple, peach, and other fruit orchards. Use declined sharply after DDT became available in the late 1940s, and the EPA banned lead arsenate in 1988. However, both lead and arsenic remain in many old orchard soils. Some former orchard sites may now be house lots, schools, parks, or community gardens.

Fill, demolition debris, and urban soils

Many urban and older residential soils contain imported fill, ash, brick fragments, demolition debris, or mixed soil from earlier construction. These materials may contain lead or other metals. Testing is especially important before starting a vegetable garden, school garden, or community garden on land with an unknown history.

Who is most affected by lead?

Lead can affect people of any age, but children under six are the highest-risk group. Young children absorb lead more readily than adults, and their brains and nervous systems are still developing. They are also more likely to swallow soil and dust because of normal hand-to-mouth behavior.

During pregnancy lead ingestion is also a concern. Lead stored in the body can be released during pregnancy and breastfeeding, and may reach the developing fetus or infant.

Adults may be exposed through gardening, renovation, construction, stained glass work, shooting ranges, ammunition reloading, fishing sinkers, pottery glazes, and other jobs or hobbies that involve lead.

How does lead affect children and adults?

Lead exposure can affect children's learning, attention, behavior, hearing, speech, growth, and school performance. At higher levels, lead can damage the nervous system, kidneys, blood, and other organs.

The Centers for Disease Control and Prevention (CDC) uses a blood lead reference value of 3.5 micrograms per deciliter (µg/dL) to identify children with higher blood lead levels than most U.S. children. This is a reference value, not a safe level.

Connecticut requires healthcare providers to test all children annually between nine and 35 months of age for lead in blood. If a child’s screening result is above 3.5 µg/dL, a confirmatory venous blood test is required. For additional testing and follow-up guidance, visit the Connecticut Department of Public Health’s Lead Poisoning Prevention and Control Program.

Soil testing does not replace blood lead testing. If you are concerned that a child may have been exposed to lead-contaminated soil, contact the child's healthcare provider or the local health department.

Lead distribution in soil and sampling

Lead is rarely spread evenly across a yard; it is usually highest near the original source. Common high-risk locations include foundations of older painted buildings, old or busy roads, areas below old fruit trees or former orchards, garages or sheds built before 1978, areas with fill or demolition debris, and bare play areas where children contact soil.

Lead stays near the soil surface in undisturbed ground. Digging, tilling, construction, erosion, or imported fill can move or mix lead through a deeper layer. For this reason, sample depth should match how the area is used.

Before collecting any sample, obtain clean plastic or stainless-steel tools and a clean plastic bucket. Avoid galvanized buckets, brass fittings, painted containers, and dirty tools, which can contaminate the sample. Remove prominent grass, plant fibers, rocks, and other debris before mixing the soil.

Sampling children's play areas

For play areas, collect soil from the top one to two inches, because children contact surface soil and dust. Take six to 12 small subsamples, from different spots in the play area. Mix them well in a clean plastic bucket and submit about one cup of the mixed soil.

Sampling around an older house

To see how lead changes with distance from the house, sample zones separately. Do not mix soil from right next to the house with soil from farther away. A practical approach: collect separate sets of samples from one to three feet, four to seven feet, eight to 15 feet, and more than 15 feet from the foundation.

For each distance zone, collect six to 12 small subsamples. Mix the subsamples for that zone together, and submit one composite sample. Repeat this process for each zone, so you end up with one composite sample per zone. Label each sample clearly, for example, ‘front of house, one to three feet’.

Sampling vegetable gardens

In vegetable gardens, collect soil from the top six to eight inches, which represents the root zone and cultivated layer. For a small bed or garden, take six to 12 subsamples. Mix them well in a clean plastic bucket and submit about one cup of mixed soil. If the garden is large or if different parts have different histories, submit separate samples from each area.

Getting your soil tested

For lead in soils, two levels of testing are typically used.

Standard nutrient analysis with lead screen

Some university and Extension soil testing laboratories in the Northeast U.S. include a lead screen with routine soil nutrient analysis. These tests often use the same regional soil extractant used for nutrient testing, such as the Modified Morgan extractant in New England.

The screen measures an extractable or reactive fraction of soil lead and uses a laboratory-developed relationship to estimate total soil lead, as measured by more rigorous EPA-recognized methods. It should be treated as a screening tool, not a substitute for a confirmatory total, or total recoverable metals test when a more definitive lead result is needed.

Total sorbed metals test

This test uses strong-acid digestion based on EPA Method 3050B with ICP detection (EPA Method 6010). Use this when you need a defensible total lead number, for example, for a real estate transaction, a community garden site assessment, or to confirm an elevated screen.

The UConn Soil Nutrient Analysis Laboratory (SNAL) offers both tests. For sampling instructions and fees, visit s.uconn.edu/soil-lab, or call (860) 486-4274. The Connecticut Department of Public Health also maintains a list of state-approved environmental labs that offer lead testing.

When is soil considered contaminated with lead?

There is no single number that defines ‘contaminated’. The EPA and Connecticut publish different lead values for different purposes, and most of those numbers were written for regulated cleanup sites, not home gardens.

A reasonable question for a homeowner is, which of these numbers should I pay attention to, and what does my soil test result actually mean for my yard?

Here is what each number is for, and how to read it as a homeowner.

EPA values

EPA's Residential Soil Lead Directive sets a screening level of 200 ppm and a removal management level of 600 ppm for lead in residential soil at federally managed cleanup sites.

These numbers apply directly only to Superfund and similar federal cleanup sites, not ordinary home gardens. However, they are useful reference points for homeowners, as they reflect the EPA's current view of lead’s risk in residential soil.

Connecticut values

Connecticut's Remediation Standard Regulations set Direct Exposure Criteria (DEC) of 400 ppm for residential soil and 1,000 ppm for industrial or commercial soil. These are legal cleanup thresholds that apply to regulated cleanup sites, real estate transactions on commercial or industrial properties, and similar regulatory situations. They do not apply to ordinary residential backyards.

For most home gardens and yards, Connecticut’s cleanup criteria are best used as reference points rather than automatic cleanup requirements. The 400 ppm residential value is an important warning marker. If soil lead is near or above this level, homeowners should take steps to reduce direct contact with bare soil, especially in vegetable gardens and areas used by childre

Additionally, the Connecticut Department of Public Health (DPH) Factsheet suggests a Target Level for lead in gardening soils of 100 ppm, noting that the Connecticut DEC for lead in residential soils is not protective enough for eating homegrown fruits and vegetables.

What this means for your yard

Most Connecticut homeowners will never deal with a regulated cleanup. For everyday gardening decisions, use the practical interpretation ranges below. They are based on current CT DPH gardening guidance, EPA residential soil lead screening guidance, and Connecticut cleanup criteria translated into plain advice for what to plant, where children can play, and when to take further action. However, they are not regulatory cleanup requirements for ordinary home gardens.

Practical interpretation ranges for home gardens

Below 100 ppm: Generally low risk for most uses, including vegetable gardens and play areas. Follow normal hygiene practices.

100 to 200 ppm: Moderate. Vegetable gardening is reasonable with extra precautions: keep pH near 6.5, add organic matter (compost, leaf mold, etc.), mulch, and favor fruiting crops over leafy greens and root crops.

200 to 400 ppm: Elevated for gardening. This range is above both CT DPH’s gardening soil target and EPA’s residential soil screening level, but below Connecticut’s residential Direct Exposure Criterion for regulated cleanup sites. Raised beds or containers with clean imported soil are strongly preferred for vegetables, herbs, leafy greens, and root crops. Cover bare soil in children’s play areas with turf, mulch, pavers, or another barrier.

400 -1000 ppm: High. Do not grow vegetables or herbs in this soil. Children should not play in bare soil at this level. Get a confirmatory total lead test, contact your child's pediatrician about blood lead testing, and either cap the soil with a barrier, replace it, or move the garden into raised beds with clean imported soil.

Above 1,000 ppm: Treat as a contaminated site. Remove and replace, cap with an engineered barrier, or restrict use. Consult a Licensed Environmental Professional (LEP) if the property may be subject to Connecticut's Remediation Standard Regulations.

Managing soils with elevated lead

The right response depends on the lead concentration, site use, cost, and whether children are present and using the area. Most homeowners do not need to remove every bit of lead-contaminated soil. The goal is to reduce exposure.

Common options:

• Cover bare soil with turf, mulch, dense groundcovers, pavers, gravel, or other barriers;
• Grow vegetables in raised beds or containers filled with clean soil, with regular additions of clean soil;
• Convert the area to lawn, ornamental shrubs, trees, or other non-edible landscape use;
• Remove and replace contaminated soil where practical;
• Avoid direct contact with bare soil in high-lead areas;
• Maintain soil pH, organic matter, and nutrients, to reduce lead availability.

Phytoremediation, or using plants to remove lead, is not a practical home-garden solution. It is slow and inconsistent, and the harvested material may require special disposal.

For most homeowners with moderately elevated lead in the soil, the practical approach is to cover bare soil, garden in raised beds with clean soil, wash produce carefully, and keep soil dust out of the home.

Raised beds for lead-affected sites

Raised beds are one of the best options for food gardening where the native soil has elevated lead. Use at least 12 inches of clean imported soil for most vegetables. Deeper beds are better for root crops. Place a porous landscape fabric or geotextile barrier at the bottom of the bed to reduce mixing with the native soil, while still allowing drainage.

Do not till or mix the contaminated native soil into the raised bed. Keep paths around raised beds covered with mulch, turf, gravel, pavers, or another barrier, so that contaminated soil is not splashed or tracked into the bed.

Use clean soil and compost from a reliable source. If buying bulk soil, ask the supplier where the material came from and whether it has been tested for lead or other contaminants.

Can vegetables be grown in soils with elevated lead?

Growing vegetables in soils with elevated lead depends on the lead level, the crop, and how exposure is managed. The concern is not only lead inside plant tissue; soil dust on leaves, roots, hands, and kitchen surfaces is often a bigger exposure pathway than what the plant takes up internally.

Different parts of plants accumulate lead at very different rates. Fruiting parts (tomatoes, peppers, eggplant, beans, peas, corn, squash) take up the least and are the safest choice with moderately contaminated soil. Leafy crops (lettuce, spinach, kale, chard, herbs) hold the most because lead settles on leaves as dust, and also moves into leaf tissue. Root crops (carrots, beets, potatoes, radishes) hold an intermediate amount, mostly in or just under the skin.

If soil lead is between 100 and 200 ppm, choose fruiting crops when possible, wash produce carefully, peel root crops and discard the peels, and grow leafy greens and herbs in clean raised beds.

If soil lead is 200 ppm or higher, do not grow vegetables, herbs, or other food crops directly in that soil. Use raised beds or containers with clean imported soil instead.

Reducing lead availability in vegetable gardens

Soil amendments do not remove lead, but they can reduce how available it is to plants and how much dust ends up on produce.

Maintain soil pH near 6.5

Lead is generally less soluble (i.e. less available for plant uptake) in near-neutral soil than in acidic soil. Most Connecticut soils are naturally acidic, so vegetable gardens often need limestone. Apply lime only according to a soil test recommendation. Too much lime creates other nutrient problems.

Maintain organic matter

Organic matter binds lead and reduces plant uptake. Compost, leaf mold, aged manure, and organic mulches help build organic matter and reduce bare soil. If you use composted manure regularly, retest soil because manure-based composts can push phosphorus high.

Keep phosphorus in the optimum range

Phosphorus reacts with lead to form less soluble compounds. Even so, do not add excess phosphorus. Too much moves into lakes, ponds, streams, and wetlands and degrades water quality, and it is regulated under Connecticut's lawn fertilizer law.

Follow soil test recommendations. Do not add phosphorus ‘just in case’.

Keep soil covered

Bare soil creates dust and splash. Cover exposed soil with mulch, turf, groundcovers, dense plantings, or hard surfaces, especially near older buildings, along foundations, and in children's play areas.

Good hygiene around the garden and home

Good hygiene is one of the most effective ways to reduce lead exposure from soil.

• Wash hands after gardening and before eating;
• Wash garden tools, gloves, and containers;
• Wash all produce thoroughly under running water. Soak and rinse leafy greens well and discard outer leaves. Scrub root crops, and peel them if soil lead is elevated;
• Do not eat, drink, or smoke while gardening;
• Remove shoes before entering the home after working in bare soil. Use sturdy doormats, and clean them regularly;
• Keep pets from digging in contaminated areas and wipe paws when needed;
• Keep children away from bare soil where lead is elevated, and wash toys that have touched soil.

Common mistakes to avoid

• Do not assume soil is safe because vegetables look healthy. Plants can grow normally in soil with elevated lead;
• Do not rely on home lead-paint test swabs for soil testing. Soil should be tested by a licensed laboratory;
• Do not mix contaminated soil into clean raised-bed soil;
• Do not bring in fill or topsoil from unknown construction sites, roadsides, demolition areas, or old industrial properties;
• Do not assume that compost, lime, or fertilizer makes contaminated soil safe. These practices reduce risk but do not remove lead.

A recap: what to do if your soil lead level is high

1. Confirm the result with a more definitive metals test, especially for community gardens, school gardens, real estate decisions, or areas used by children;
2. Stop direct contact with bare soil. Use mulch, turf, pavers, dense plantings, or other barriers;
3. Move food production into raised beds or containers with clean soil;
4. Keep soil dust out of the home by removing shoes, washing hands, cleaning tools, and wet-cleaning entry areas;
5. If a child may have been exposed, contact the child's healthcare provider or local health department. A blood lead test is the only way to know whether a child has elevated blood lead.

Bottom line

Lead in soil does not go away on its own. The realistic goal is to know where it is and reduce exposure.

For most Connecticut gardeners, the first step is soil testing. If lead is low, continue normal gardening and hygiene practices. If lead is elevated, keep soil covered, grow food crops in cleaner areas or raised beds, maintain pH and organic matter, wash produce carefully, and keep soil dust out of the home. If lead is high, do not grow food crops directly in that soil and do not let children play in bare soil.

Use raised beds or containers with clean soil, cover contaminated areas, and reach out to the lab if you want help interpreting your results.

Resources

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Connecticut Department of Energy and Environmental Protection. (n.d.). Naturally occurring metals. https://portal.ct.gov/deep/remediation--site-clean-up/release-based-cleanup-program/naturally-occurring-metals

Connecticut Department of Energy and Environmental Protection. (n.d.). Remediation standard regulations and direct exposure criteria. https://portal.ct.gov/deep/remediation--site-clean-up/remediation-standard-regulations

Connecticut Department of Public Health. (n.d.). Lead poisoning prevention and control: For parents. https://portal.ct.gov/dph/environmental-health/lead-poisoning-prevention-and-control/for-parents

Connecticut Department of Public Health. (2025, June). What you need to know about gardening. https://portal.ct.gov/dph/-/media/dph/ehdw/tox/safe-gardening-fs-2025.pdf

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New England Lead Coordinating Committee. (n.d.). The lead problem. University of Connecticut Cooperative Extension System. http://www.nelcc.uconn.edu/lead_problem.html

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Ryan, J. A., & Zhang, P. (n.d.). Soil lead remediation: Is removal the only option? U.S. Environmental Protection Agency, Risk Reduction Engineering Laboratory.

Suffolk County Cooperative Extension. (1979). Lead in the soil: A gardener’s handbook. University of Massachusetts.

U.S. Environmental Protection Agency. (n.d.). Learn about lead. https://www.epa.gov/lead/learn-about-lead

U.S. Environmental Protection Agency. (n.d.). Method 3050B: Acid digestion of sediments, sludges, and soils. https://www.epa.gov/sites/default/files/2015-12/documents/3050b.pdf

U.S. Environmental Protection Agency. (n.d.). Protect your family from sources of lead. https://www.epa.gov/lead/protect-your-family-sources-lead

U.S. Environmental Protection Agency. (n.d.). Lead in New England. https://www.epa.gov/region01/leadsafe

U.S. Environmental Protection Agency. (1996, January 29). EPA takes final step in phaseout of leaded gasoline. https://www.epa.gov/archive/epa/aboutepa/epa-takes-final-step-phaseout-leaded-gasoline.html

U.S. Environmental Protection Agency. (2024, January 17). Biden-Harris Administration strengthens safeguards to protect families and children from lead in contaminated soil at residential sites. https://www.epa.gov/newsreleases/biden-harris-administration-strengthens-safeguards-protect-families-and-children-lead

U.S. Environmental Protection Agency. (2025, October 20). Residential soil lead directive for CERCLA sites and RCRA hazardous waste cleanup facilities. https://www.epa.gov/superfund/residential-soil-lead-directive-cercla-sites-and-rcra-hazardous-waste-cleanup-facilities

UConn Soil Nutrient Analysis Laboratory. (n.d.). Soil lead interpretation sheet. https://soiltesting.cahnr.uconn.edu/soil-lead-interpretation-sheet/