Urban Soils

ACCD works with citizens and community partners to better understand the challenges of working with urban soil in farm and garden projects.

Soil is an essential resource. While often overlooked in urban environments, soil plays a central role in the functioning of healthy towns and cities. Urban soils are the base from which natural and constructed environments are built. Urban soil plays an important role in infiltrating stormwater, especially in developed areas with impervious surfaces such as roads and buildings. 

Urban soil also provides a foundation for recreation in playgrounds, parks, soccer fields and gardens that give children and adults spaces to enjoy the outdoors.   

The Urban Soils Program focuses on lead and contaminant research, soil testing outreach and technical assistance. ACCD’s expertise also extends to urban farm and garden resources, policy planning and networking.  

ACCD offers the following services: 

  • Soil testing formation and technical assistance
  • Soil Contamination mapping and research
  • Urban Agriculture: A Zoning Guide for Municipalities  

Benefits of Urban Soil

Soil in cities provide habitat for untold numbers of microbes, insects, fungi, plants, trees and animals (including us). Much of this plant life (healthy lawns, gardens, and trees) also improves air quality, reduces heat island effect and provides additional rainwater capture.
It is not just the rainforest that stores carbon. Urban soils, both exposed and covered by concrete, store a surprising amount of carbon. This provides a key function in combatting climate change and supporting the natural carbon cycle.
Urban soil can be used for urban farms and gardens that assist with food security and sovereignty, serve as spaces of community interaction, and increase the health of individuals and families.
In impervious city spaces, urban soils are a key source of rainwater infiltration. Healthy soils can take on water and reduce the pressures of stormwater flows to stormwater infrastructure. Examples of green space that assists with stormwater management include rain gardens, lawns, parks and community gardens.

Common Problems with Urban Soils

Urban soils also pose a unique set of limitations and risks that are important to understand. Urban soils reflect the legacy of human activity and environmental degradation. Understanding the issues that face urban soils, as well as the strategies for improving their health and ecosystem services, will allow communities to gain the most from a key urban resource. 
Stemming from topsoil loss and low-quality urban fill, low organic matter results in reduced soil fertility and can minimize the ability of soils to infiltrate and store water.
High pH (>7) can often result from road salts and treatments along the edges of roadways. Foreign materials in soil, like bricks and concrete, can also raise the pH – making it unsuitable for plant life.
Heavy metals such as lead and arsenic are common in Pittsburgh soils. Heavy metals result from historic demolition practices that spread lead-based paint chips throughout the soil. These contaminants tend to stay with the soil for a long time and are exceedingly difficult to remove.
Demolition practices and urban wear and tear have left behind rubble in the form of bricks, concrete, pipes, wood debris, foundation and other materials buried in our urban soils. These items cause a host of issues such as low fertility, high pH, low organic matter and obstructions that reduce infiltration. Rubble can also make it difficult to physically plant trees and crops.
Activity (everything from bulldozers to human feet) often causes urban soils to be extremely compacted. At high enough rates, compaction can prevent roots from moving through the soil and inhibit the ability of water and nutrients to flow properly.

Soil Testing

The best way to know what is in soil is to test it. Several laboratories will test soil for fertility, structure and possible heavy metal contamination.
ACCD most frequently uses Penn State Agriculture Analytics Laboratory for soil testing. This lab provides fertility testing and recommendations for agricultural soil amendments, as well as heavy metal and environmental testing. Reach out to ACCD for technical support and assistance with understanding the soil sampling and lab submission process.



Get Farm Assistance

Submit a question about ACCD’s Agriculture and Soils Program, including Farmland Preservation, Urban Soils and Livestock Compliance and Regulations.