how do you test if soil is contaminated

The only sure way to tell if soil is contaminated is to sample the soil and have a certified laboratory test it. A certified local soils engineer or professional should be employed to conduct soil sampling. Exhaustive testing may be exorbitantly expensive, however, but tests for the most common contaminants are usually affordable.

Full Answer

Should I get my soil tested for contamination?

There are many other reasons that could cause your soil to be contaminated, so if you're worried about it, you should definitely look into getting it tested. What Can You Do if Your Soil is Contaminated?

What does soil test results mean?

Contaminants in soil that is taken up by plants or comes in contact with garden fruits and vegetables can cause health problems. Soil test results will indicate the quality of the soil and the causes of soil contamination, if any.

Why is soil testing so difficult?

Soil is notoriously hard to test, because the contaminant absorbed to the soil must be extracted into a liquid carrier in order to be available for feeding into a spectrometer or for reacting with a reagent that can indicate the presence of the contaminant by color change, one of the most common tricks of test kits.

How do you test for metals in soil?

The "gold standard" for testing metals in soil is to extract the metals and analyze the extract by atomic absorption or atomic emission spectrometers.

What are the steps for soil testing?

Four steps associated with soil testing include: 1) soil sample collection, 2) laboratory analysis, 3) interpretation of results, and 4) fertilizer or other management recommendations.

How do I know if my soil is safe?

Signs of healthy soil include plenty of underground animal and plant activity, such as earthworms and fungi. Soil that is rich in organic matter tends to be darker and crumbles off of the roots of plants you pull up. A healthy, spread-out root system is also a sign of good soil.

How do I test my soil for pesticides?

The first option is to send a soil sample to a lab for analysis. Chemical screens are performed by many labs for a wide array of herbicides. However, lab analysis may be costly, time consuming, and misleading.

How can I test the health of soil at home?

Use a shovel to dig up about 1 cubic foot of soil. Put the soil on a piece of cardboard, break it apart, and look for earthworms. If your soil is healthy, you should find at least 10 earthworms! If your soil has fewer than 10 worms, add more organic matter—compost, aged manure, leaf mold.

How do you remove toxins from soil?

However, it turns out that the best way to clean contaminated soil is to grow plants that have evolved mechanisms for decomposing and removing toxic residue from soils. These plants are called hyperaccumulators because they are able to take up 100 times more metals and petrochemicals than other plants.

What should I test my soil for?

At the very least, test your soil's pH, which is a measure of how acidic your soil is. If the pH level isn't in the correct range, plants cannot take up nutrients in the soil. You should also test for phosphorus and potassium because plants require both of these nutrients in relatively large amounts.

How long does poison stay in soil?

If weed killer was still present in the soil, you would not be able to grow anything. This is why most weed killers are designed to evaporate within 24 to 78 hours. This means that for the most part, it is safe to plant anything, edible or non-edible, in a place where you have sprayed weed killer after three days.

What is considered contaminated soil?

Soil contamination occurs when hazardous chemicals are buried or spilled or have migrated into uncontaminated soil. Contamination can take place during improper disposal of hazardous chemicals, during the application of pesticides and fertilizers, or through chemical and industrial processes.

How long do chemicals stay in soil?

These are low (less than 16 day half-life), moderate (16 to 59 days), and high (over 60 days). Pesticides with shorter half-lives tend to build up less because they are much less likely to persist in the environment. In contrast, pesticides with longer half-lives are more likely to build up after repeated applications.

How can I test my soil without a kit?

Fortunately, you can test your garden soil pH without a soil test kit for a fraction of the price. Collect 1 cup of soil from different parts of your garden and put 2 spoonfuls into separate containers. Add 1/2 cup of white vinegar to the soil. If it fizzes, you have alkaline soil, with a pH between 7 and 8.

How do farmers test their soil?

There are three commonly used methods of testing soilless media using water as an extracting solution: 1:2 dilution method, saturated media extract (SME), and leachate Pour Thru. The values that represent each method of testing are different from each other.

What are the three types of soil testing?

You will also see how to test the soil using three of the most common methods: the plasticity test, the thumb penetration test, and the pocket penetrometer test.

Is my soil safe to grow vegetables?

Unless your soil has exceptionally high levels of lead or cadmium (which you can find out by testing—see below), it's probably safe to eat vegetables after washing them thoroughly. Wash with cold running water just before eating, cutting or cooking.

Should you test your soil before gardening?

Testing soil — especially new garden soil — helps guarantee your vegetables and other plants will do their best during the growing season. And springtime, just before you begin planting, is the best time to do it. Home kits are not only effective but make soil testing easy.

What should soil look like?

Soil in a healthy garden should be a nice, dark, black color. Soil with little to no life in it looks more like dirt: brown and dry. This poor soil will turn to brown mud when it gets wet. Healthy soil absorbs moisture beautifully and should not have a muddy feel.

What makes a good soil?

An ideal soil would be made up of 45% minerals (sand, clay, silt), 5 % organic (plant and animal) material, 25% air and 25% water. The mineral portion would be loam (20 – 30% clay, 30 – 50% silt and 30 – 50% sand).

Why is heavy metals in soil dangerous?

The excess accumulation of heavy metals in most urban soil is dangerous to humans and other animals, largely because it is so chronic; these metals don’t leave the bloodstream of the plant or animal that ingests them, and they will remain prevalent in whichever food chain they pollute.

Why is it important to be mindful of the contaminants that often lace urban soil?

It’s important for city-dweller’s to be mindful of the contaminants that often lace urban soil—a problem that has plagued urban gardening initiatives for decades. Centuries of mining, manufacturing, and the use and accumulation of manmade toxins (from pesticides, paints, batteries, sludge, and more) have led to higher-than-normal concentrations of heavy metals like lead, cadmium and arsenic in most urban soils.

How to treat contaminated soil?

Contaminated soil can be excavated from the ground and treated in a lab, or a large plastic cover can be placed over the contaminated soil to prevent runoff or direct contact with other plants and organisms. High temperature treatments (which produce a granular soil that won’t leach minerals) are among the most commonly used methods to treat soil, as are solidifying agents (which cement the soil,) and soil washing.

What happens when plants grow in contaminated soil?

When plants attempt to grow in contaminated soil, they inevitably take up these hazardous compounds through their roots, which ultimately cycle back into the human population through consumption. (Meaning: if the plants you eat are contaminated, you will be, too.)

What is the best way to treat soil?

High temperature treatments (which produce a granular soil that won’t leach minerals) are among the most commonly used methods to treat soil, as are solidifying agents (which cement the soil,) and soil washing.

Why is decontamination important?

For one thing, decontamination helps identify the pH and nutrient levels of your soil, which clues the gardener in to any deficiencies that may be compromising their crops.

Do sunflowers decontaminate groundwater?

Some plants are capable of stabilizing or removing metals from surrounding areas through their roots , thus decontaminating groundwater (after the Chernobyl disaster, scientists planted sunflowers in contaminated areas for this very purpose).

What Are Heavy Metals?

Heavy metals are a class of elements that include lead, copper, arsenic, and cadmium, and can be toxic to humans and plants if ingested in high enough quantities. Soils have often been the landing spot for heavy metals, chemicals, and wastes as byproducts of industrial and agricultural pollutants. Many of these metals are present in soils naturally, usually in small amounts, although the natural level may vary.

Where Did They Come From?

There are significant correlations between soil type and land use history and heavy metal contamination. Knowing the history of the site will help explain how the contamination arrived. For example, historical use of metal-containing pesticides, industrial pollution, or dumping could be the cause of contamination. Land surrounding old houses containing lead paints commonly test high in lead. Lead pipes and motor vehicle exhaust also produce soil lead contamination. Car repair sites or garages might also be high in heavy metals. In areas where coal was burned, certain pesticides were used, or old mining sites remain in place, soils could be high in arsenic. Treated lumber can also contain arsenic, although pressure treated lumber for residential use no longer contains arsenic in the United States. Metals may be more ubiquitous in urban areas where construction, transportation, manufacturing, and fossil fuel combustion are more common.

What Can You Do to Minimize Risk?

Include the standard fertility analysis and organic matter test along with your heavy metals results to help Extension give you our best recommendation. If your soil has an elevated level of heavy metals, you can take several approaches that minimize your exposure risk.

Why do soils test positive for heavy metals?

All material is now tested before being used. Generally, all soils will test positive for heavy metals because metals are found naturally in the earth's crusts and soil parent materials.

How does soil affect metal uptake?

Soil type, pH, and how a plant grows, can have a great influence on metal uptake by plants and humans. For example, uptake of lead is generally low when pH is high because metals are locked-up (immobilized) by soils. Keeping soil pH near neutral (pH of 7.0) will help reduce exposure risks.

What is the UNH soil testing program?

The UNH Cooperative Extension Soil Testing Program offers a series of analyses for certain heavy metals. Our “Environmental Package” includes analysis for total cadmium, chromium, copper, nickel, lead, and zinc. We also offer individual analyses for total arsenic, mercury, molybdenum, and selenium. These analyses are done using EPA methods.

What are the risks of copper, nickel, and zinc in soil?

Elevated levels of copper, nickel, and zinc can cause plant toxicity, while cadmium and arsenic can be of concern to human health. Any metal testing positive in soils at a high rate should be of concern, but each case is unique based on characteristics of the site.

How does soil contamination affect the environment?

Humans can be harmed by contact with toxic and hazardous materials on a contaminated site via exposure to contaminated land, air, surface water, and ground water.

What is a site contaminated by?

Sites contaminated by improper handling or disposal of toxic and hazardous materials and wastes. Sites where toxic materials may have been deposited as a result of natural disasters or acts of terror. Sites where improper handling or accidents resulted in release of toxic or hazardous materials that are not wastes.

What are the two ROE contaminated land indicators?

The two ROE contaminated land indicators focus on Contaminated Ground Water Migration at Cleanup Sites and Human Exposures at Cleanup Sites.

Why are contaminated sites of concern?

Other contaminated sites are of greater concern because of the chemicals that may be present and their propensity to persist in or move through ...

What is RCRA cleanup?

Resource Conservation and Recovery Act (RCRA) cleanup facilities: These facilities are subject to cleanup under RCRA due to past or current treatment, storage, or disposal of hazardous wastes and have historical releases of contamination.

What is the Department of Defense contaminated with?

Military bases and defense sites: Some of the millions of acres of land used by the Department of Defense are contaminated from releases of hazardous substances and pollutants ; discarded munitions, munitions constituents, and unexploded ordnance; and building demolition debris. Similarly, as part of its defense mission, the Department of Energy owns numerous facilities that have been contaminated from releases of hazardous chemical and/or radioactive substances.

What is brownfield property?

Brownfields: Brownfields are real property where expansion, redevelopment, or reuse may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. Cleaning up and reinvesting in these properties protects the environment, reduces blight, and takes development pressures off green spaces and working lands.

What happens if you overuse fertilizer?

Overuse of Fertilizers and Pesticides in Agriculture: Synthetic fertilizers and pesticides release toxins into the soil of the field they're applied to, and in surrounding fields if they're applied too liberally .

How to prevent toxic chemicals from destroying plants?

Shifting your focus to organic gardening and adding rich organic matterto the soil will also help negate the impact of the toxic chemicals and protect your plants.

What is the biggest contributing factor to soil contamination?

Industrial Waste: Liquid and solid waste released into the environment is the biggest contributing factor to soil contamination.

What are the causes of soil contamination?

Industrial Waste: Liquid and solid waste released into the environment is the biggest contributing factor to soil contamination. Deforestation: Trees being cut down leaves the soil exposed to the elements, which in turn leaves it more susceptible to contaminants.

How long does it take for garbage to decompose?

Garbage Pollution: Litter that is disposed of carelessly not only pollutes the land, but can take hundreds, or even thousands, of years to decompose.

When are blog comments checked?

All blog comments are checked prior to publishing

Is arsenic in soil?

Meanwhile, some soils may be naturally high in lead or arsenic, although this is usually at relatively small amounts.

Why are colorimetric tests false positive?

These tests are susceptible to false positives -- indicating the presence of a contaminant when there is really some other, often benign, chemical in the soil that can also react with the color-changing reagent -- as well as false negatives -- indicating no contaminant, most often because the contaminant was insufficiently extracted from the soil or because the contaminant is part of a larger molecule that fails to react with the color changing agent.

Why is soil hard to test?

Soil is notoriously hard to test, because the contaminant absorbed to the soil must be extracted into a liquid carrier in order to be available for feeding into a spectrometer or for reacting with a reagent that can indicate the presence of the contaminant by color change , one of the most common tricks of test kits.

What are the factors that affect the results of soil extraction?

This extraction process significantly affects the test results. Soil composition and pH, the presence of multiple contaminants, and other factors can all influence the completeness of the extraction. It is necessary for a repeatably consistent percentage to be extracted in order to quantify how much contaminant exists in the amount of soil used for the test or no numerical estimate of contamination can be reached.

Why is it important to have a small sample size?

Small sample sizes -- which are typically necessary to keep the costs down in consumer test kits -- further complicate the testing, because it is very difficult to get a "homogenous sample" of soil (a sample which would give the same results no matter where you pull out the little bit that will actually get tested).

How many PPM is a lead test?

Although there are reliably certified lead test kits on the market (certified not to produce more than 5% false negatives), these kits are intended to operate in the range of 5000 ppm, well above the level of interest for contaminants in soil.

Why is XRF used?

Another technique that has recently been gaining attention is XRF (X-ray fluorescence spectrometers), because certain consumer organizations have started to scan products for the presence of toxic materials by XRF. These devices also need to be used only by highly trained personnel, as much due to the safety of the use of x-ray sources as for the accuracy of the technique. Generally, the cheaper the device, the less able it is to distinguish between various metals in a complex sample like soil.

What is the gold standard for soil testing?

The "gold standard" for testing metals in soil is to extract the metals and analyze the extract by atomic absorption or atomic emission spectrometers.

What is Soil Contamination?

Before you begin to plan and construct your garden, it’s always wise to have a soil sample analyzed. The quality of soil can be affected by many things. It is important to determine what nearby land was used for in the past and assess the impact of any nearby industry.

What is the key to growing a healthy garden?

Image by megaflopp. The key to growing a healthy garden is clean, healthy soil. Contaminants in soil can quickly lead to an array of problems, so determining possible causes of soil contamination beforehand and learning how to clean contaminated soils is very important.

What is the best way to treat contaminated soil?

Contaminated soil treatment also includes adding plenty of rich organic matter to the soil and a healthy top-dress of peat moss, compost, or aged manure. This practice will help protect plants from damage. Always be sure to wash any fruits or vegetables before you eat them.

How to reduce the negative impact of soil contamination?

While cleaning contaminated soil is not “literally” possible, some things can be done to reduce the toxic impact. Adjusting the soil pH to as close to neutral as possible will help reduce the negative impact of contaminants.

What are the most common contaminants in soil?

Possible Contaminants in Soil. Urban dwellers should be particularly concerned with a number of possible soil contaminants including lead, which has been used in paint and as an additive to gasoline; cadmium, which results from burning coal and garbage; arsenic, which is used in wood preservatives, weed killers, pesticides, and fertilizers.

What chemicals are used to detect gas leaks?

If you live close to an industrial or commercial site, it’s wise to have your soil checked for metals and cyanides, benzene, toluene, and other chemicals associated with gas station leaks. Rural residents should also check for past and present industries and pesticides.

Can you plant fruit in raised beds?

Always be sure to wash any fruits or vegetables before you eat them. If contaminants are a problem, you can also plant in raised beds made with untreated lumber. This will allow you to add your own healthy soil.

Why Doesn’t Commercial Hot Composting Break Down Synthetic Auxin Herbicides?

If synthetic auxin herbicides are broken down by soil microbes, heat, moisture and exposure to air, shouldn’t they degrade quickly in commercial composting facilities which use hot composting systems which have all of these factors in abundance and are able to degrade many synthetic organic chemical contaminants?

How Long Do Synthetic Auxin Herbicides Really Last in the Soil?

To clear up any misconceptions about the potency of these herbicides, and any marketing misinformation downplaying their persistence, I randomly selected one of the agricultural formulations, and examined the directions on the label, which are very extensive as the manufacturers spell out the facts very clearly to avoid legal liability.

How to get rid of herbicide residue?

Remove contaminated material when contaminated manure or mulch has been applied, as the material will keep releasing herbicide residue as it breaks down. Scrape off any loose manure or compost and put it into the landfill waste bin (not the green waste recycle bin!) or spread it on grassland. 8.

What is auxin herbicide?

These synthetic auxin herbicides bind to the lignin in pasture grasses. Lignins are a class of polymer compounds that most plants use in their cell walls and other tissues for structural support. When animals graze they ingest the herbicides, which passes straight through their digestive tract without breaking down, and are excreted out in urine and manure. These herbicides remain bound to the large amounts of undigested grass residues which are present in the manure, and are released into the environment as the plant matter decays.

What are the names of the herbicides that are used in the production of grass clippings?

The herbicides (weedkillers) involved in nearly every case of herbicide contamination of commercial manure, compost and soil, as well as the contamination of grass clippings and hay on farms, are aminocyclopyrachlor, aminopyralid, clopyralid, picloram, fluroxypyr and triclopyr , which belong to a class of herbicides known as synthetic auxin herbicides, as they mimic the natural plant hormone auxin and disrupt plant growth of sensitive broadleaf plants – they don’t affect all broadleaf plants and do not affect most grasses.

How long does it take for hay to deactivate?

Some field reports have indicated that complete deactivation can take several years, and hay has been reported to have residual herbicide activity after three years when stored in dry, dark barns. Breakdown of these herbicides is particularly slow in piles of manure and compost, , due to lack of oxygen.

What does it mean when a plant has leaf cupping?

If herbicidal symptoms appear, such as leaf cupping, distorted new growth and twisted stems, then that is indicative that synthetic auxin herbicide contamination has occurred. Do not plant sensitive plants, plant grasses instead, then test again the following year to determine if the herbicide is still present in the soil.