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Toxics Cleanup Program


Landscaping and Gardening in Arsenic- and Lead-Contaminated Soils "Gardening" icon

3 Photos showing wear gloves, wash vegetables, and plant in raised beds

 

Arsenic and lead can pose a risk to people gardening, landscaping, or playing in soils.  Learn if you are at risk and what to do to protect yourself.

If you are new to the issue…


For more detailed information…


How can I be exposed in my yard?


The main way people are exposed is through swallowing contaminated soils.  Dust that is inhaled can also stick to the nose and throat and be swallowed.  Arsenic and lead are not absorbed very well through the skin.  However, soil stuck to dirty hands can often end up getting swallowed.  Read about the health effects of arsenic and lead.


Basic Safety When Working in Your Yard

  • Wear gloves and wash hands after working in the soil.
  • Wear a dust mask during dry weather or water down the soil.
  • Take off shoes and boots at the door.
  • Don’t wear dirty work clothes into the house.
  • Wash dirty or muddy clothes separately.
  • More healthy actions for your home.

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Growing Fruits and Vegetables

Most plants do not take up much arsenic or lead into their edible parts.  The greater risk can be from eating dirt or dust stuck to the outside of your produce.  Seeds and fruits tend to have lower levels than leaves, stems, or roots.  Spinach and other leafy greens take arsenic into their leaves.  Roots and tubers can have higher levels in the skin than the flesh. 


Leafy greens and root vegetables tend to take up more arsenic and lead.  If you know that your soil is contaminated, you can take the following actions:

  • Mix compost or manure into your garden bed.  This will dilute the contamination.
  • Build raised beds or garden in ceramic pots.

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Photo: person holding bunch of lettuceWashing and Peeling Your Produce

Washing removes soil and dust stuck to the outside of fruits and vegetables.  Leafy greens and other plants grown close to the ground tend to pick up more soil when harvested.  Also, leaves have a large surface area for soil to stick to.

Roots and tubers usually have higher arsenic and lead levels in the skin.  Peeling them helps remove that area, plus any dirt stuck to the outside of the produce.


Building Raised Garden Beds

  • Building the frame:  Build raised beds using cedar, plastic lumber, or concrete.  If you use salvaged wood, make sure it’s not arsenic-treated (CCA) lumber or railroad ties.
  • Preparing for your soil:  For added protection, place heavy-duty landscape fabric over the ground inside your frame.
  • Buying soil:  The state doesn’t regulate soil sellers, so ask your supplier about soil quality before you buy.  Many suppliers will test for metals, petroleum, and other contaminants.  Ask the following questions:

    • Where does the soil come from?
    • Is it blended with compost and additives?  If so, where do they come from?
    • Has it been treated for chemical contamination?
    • Will the soil support what you are planning to grow?

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Covering Bare Patches of Soil

Covering bare soils helps reduce contact with soils.  You can use low-cost landscaping materials or add on to a project you already planned to do.

Photo: Wood chips Wood chips or bark

Four to six inches of bark is good for flower gardens, under hedges, around bushes, trees, and children’s play areas.    Mulch helps hold moisture in the ground for your plants’ roots.
Photo: Decorative rocks Decorative rock and pea gravel

Line the area you want to fill with a permeable landscape fabric.  The fabric should keep soil from seeping into the gravel and reduce weeds, but still let water through.
Photo: Healty lawn

Build a healthy grass cover.

Use slow release fertilizers to keep your grass healthy and avoid chemical pesticides and herbicides.

Water your new lawn regularly to build a thick and healthy grass cover.

Photo: Wheelbarrow with soil 

Place a new layer of topsoil over existing soil.

Cover existing soil with four or more inches of topsoil.   
 
Ask your soil supplier about the soil quality to make sure you are not bringing in new contamination.

Photo: Salmonberry bush

Plant bushy or thorny plants.

Plants can discourage foot traffic in areas with contaminated soil. Native plants can also give a natural look and provide a safe haven for wildlife.
 
Examples of native plants are Oregon grape, Mock Orange, and Salal. For a list of native plants visit: http://wnps.org.

Photo: walkway pavers

Install walkways, a patio, or hard surface.

You can use permeable concrete, pavers, and asphalt. Permeable materials allow surface water to filter into the soil.  This helps the environment by keeping waterways clean and slowing runoff.

  • Lay concrete or pavers to create a patio, sport courts, or driveway.
  • Create a path or border with brick and stone pavers.

Children's Play Areas

Build or install a sandbox.

Sandboxes provide a safe place for children to play and stay out of the soil.

  • Use a cover to keep soil and cats out.
  • Use play sand that has been washed and screened for use in children’s play areas.

Place rubber mats, pea gravel or mulch under children’s play sets.  

Be sure to check that the rubber mats, pea gravel or mulch are safe for children.   Check with the Consumer Product Safety Commission and the ASTM before purchasing recycled rubber products.

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Removing and Replacing Contaminated Soils (King and Pierce counties)  

Check if your home is eligible for free soil sampling.  High levels of arsenic or lead in your yard may qualify for free soil removal through the Yard Sampling and Cleanup Program

We do not recommend doing your own soil removal unless you are planning a major landscaping or building project that involves moving soil. For further advice, visit our Technical Assistance page or contact Hannah Aoyagi at Hannah.Aoyagi@ecy.wa.gov  or (360) 407-6790.

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Environmentally-Friendly Gardening Tips