Steps to Creating a Community Garden or Expand Urban Agriculture at a Brownfields Site
- Step 1. Survey the property history
- Step 2. Test your soil
- Step 3. Clean contaminants
- Step 4. Consider garden design
- Step 5. Construct the garden
The types of contaminants you are likely to find depend on the history and use of the property. As a general rule at Brownfields sites, environmental professionals look at the property history and previous uses to identify what environmental contaminants may be present for testing. They also look at nearby properties to see if their use may have created hazards that could affect neighboring areas.
Environmental professionals follow the all appropriate inquiry processes of ASTM- E1527-21 when they evaluate environmental conditions and likely contamination at Brownfields properties. Experienced professionals can sometimes look at a property for visual cues to potential contamination. Soil staining, an oily sheen on puddles, visible tanks or piping, drainage areas, or piles of debris may suggest petroleum tanks or illegal dumping but typically more than a visual investigation is needed. These steps may be useful to others interested in using and converting vacant lots or abandoned Brownfields for food production or urban agriculture facilities. If you suspect environmental contaminants, you may wish to select a different site for a potential garden.
Steps you can take to do a search in your community include:
- A librarian at your local public library may be able to help you locate historical property records, Sanborn or fire insurance maps and city directories that identify previous property uses or you may be able to find information on the internet from State, tribal or local regulatory agencies, planning or health departments as well as police or fire departments.
- Read Kansas State University’s Gardening on Brownfields: Obtaining Property Information and Site History to learn how to find historic site information and interpreting your findings.
- EPA’s Envirofacts database may assist you in finding historic site information and interpreting your findings.
- Talk with your local officials. They may be able to help you select a safer site for gardening or a location already tested and found to be safe.
- After your investigations and discussions with your local town or city officials, if your community determines you want to garden at the proposed site, you may wish to work with local officials to seek technical assistance to assess or clean a property to support any safe reuse. You may wish to encourage your local government to request technical assistance or see current and upcoming Brownfields Grant funding opportunities to assess or clean a property to support any safe reuse.
- Only governmental entities are eligible to receive Brownfields assessment grants. See the EPA Brownfields grant funding page to learn who is eligible to receive different Brownfields grants. A non-profit organization may apply for a grant to cleanup up a site they own, provided they are not liable for the contamination at the site and took certain steps, such as conducting a Phase I environmental site assessment that followed the all appropriate inquiries ASTM E1527-21 process prior to acquiring the property.
Individuals establishing a community garden typically send samples to a soil extension service lab as they employ many local soil and plant experts. Each State and territory has an extension office at the land grant university and regional extension offices. The lab will generally test for pH, nitrogen (N), phosphorus (P), and potassium (K) and may provide guidance on other important soil and plant nutrients.
Not all extension services, however, consider or test for environmental contaminants without special requests. Some test for lead in a standard soil sample while other labs require a separate request and payment to test for lead, arsenic, mercury or other heavy metals. Some also test for pesticides commonly used in agriculture. Check with your extension service to see what soil tests they provide or recommend. Individual state land grant universities and extension offices may have specific suggestions for sampling requirements, soil depths to sample based on what you plan to plant, as well as advice on whether you can combine samples into composite samples that represents soil at multiple locations and save testing costs. They may also have specific testing request forms and packaging recommendations for mailing soil samples. The U.S. Department of Agriculture's Land-Grant University Website Directory provides a map and links with the university and extension offices in your area.
Environmental testing can differ from the soil test conventionally done for soil and plant health. You may want to talk with environmental regulators about whether site history suggests environmental contaminants are likely to be present. Environmental regulatory agencies may maintain lists of environmental testing laboratories or be able to refer you to testing services. Also recognize contamination may not only be associated with industrial areas. In some residential areas with older housing stock or near heavily trafficked roads, lead from the weathering of paint or historical vehicle emissions may have resulted in elevated levels of lead in soils. In another example, naturally elevated levels of arsenic in soil, extensive use of pressure treated wood or past application of arsenical pesticides may suggest arsenic may be a concern and a focus for further soil testing.
The EPA’s Superfund program, health agencies like ATSDR and State and Tribal environmental regulatory programs have information and different numeric levels used to screen soil for investigation and cleanup. In most instances, those screening levels help determine whether a risk is likely or not and if likely, further information collection needed. These ‘screening’ levels are not the final standards for cleanup. Risk-based cleanup levels also depend on the site and its proposed use, the population, neighbors and those using or accessing the site and other considerations. Also, screening levels do not factor in or consider plant uptake of contaminants or deposition of contaminants on food and should not be considered as establishing safe levels of contaminants for food production.
If soil test results are of concern or indicate you have contamination, the lab can explain their testing and help interpret results. Talk with local, state or tribal Brownfield experts or seek information on health protective cleanup standards. For a community project, you may want to encourage your city, town or non-profit organization to apply for a Brownfields assessment grant to ensure review of past uses, interview neighbors, conduct site(s) sampling, plan cleanup or apply for a cleanup grant if cleanup is necessary. The state or tribal Brownfields response program can help and oversee the cleanup. You will need to explain your interest in turning the site into a garden or food production area and they will provide guidance on what levels of cleanup are recommended to ensure safe gardening. They may recommend above-ground rather than in-ground gardening to reduce exposure to unsafe soils or as an additional precaution against soil exposures.
In those instances, your state or tribal response program or local city agency may recommend using a water permeable fabric cover or geotextile to reduce exposures to soils of concern as well as path or garden walkways and play areas. They may suggest you purchase and add topsoil or clean fill from 'certified soil sources' to ensure the soil is safe for handling by children or gardeners of all ages and for food production.
Note: One important point to remember – in the building and construction trades, the term 'clean fill' is used to mean materials screened so no chunks of concrete or asphalt are in the material, it does not mean the soil is safe and healthy for gardening.
If you need soil material to add in gardening areas, you are looking for certified soils and your environmental program will be able to direct you to providers of safe certified soils.
Alternatively, you may have such limited contamination that no cleanup is necessary or can be managed by reducing exposure or access by placing equipment, sheds or other fixed objects over those specific areas of concern. Adding safe compost, certified soils or soil amendments before planting and periodically in the growing season, can improve the soil quality and help to further bind the contaminants. Consider repeat testing to ensure the soil amendments control pH and reduce contaminant levels and bioavailability and that no additional contaminated material is present.
In addition to the property specific environmental considerations, there are other factors to consider in garden design. These include: access to sunlight and water; location and proximity to homes and other structures, lighting and security for gardeners, produce and tools, as well as gardener and visitor accessibility. The Sustainable Sites Initiative focuses on creating sustainable landscapes using environmentally sustainable materials and can provide information on material selection.
Creating a garden to serve the entire community requires a number of additional considerations. Remember to design your garden entrance with paths and ramps that can accommodate children, senior citizens, and those with disabilities by:
- Gardening is a favorite hobby of people of all ages, including many retirees. By 2030, 1 out of 5 Americans will be age 65 or over. Consider ways you can make your garden accommodate their needs.
- By contrast, children under six may like a sandbox to play in, a shady spot or their own growing area in a safe location where parents and grandparents can supervise. Let the children help design their garden spot.
- Horticultural therapy uses gardens and growing plants to heal and encourage activity for those of all abilities.
- Creating pathways at least 3 feet wide between beds will allow space for wheelchairs while a 5 foot width permits a wheelchair turning radius while a 7 foot width allows two wheelchairs to pass.
- Adjusting the height and depth of raised beds to facilitate access for gardeners with restricted movement or issues of balance.
- Path materials should be firm and smooth with a texture that minimizes slipping. Minimize changes in the slope and grade of paths, where possible.
- Providing benches or picnic tables provide areas for gardeners to safely sit – preferably in the shade!
- Learn more about access requirements on the U.S. Access Board's website.
Learn more at the American Horticultural Therapy Association.