In 2019, DCGP tested several of its garden locations for lead contamination. As expected, all tested sites were found to be below the threshold for safe gardening. DCGP strives to be transparent and, therefore, is publishing the results of those tests here. Please contact the office with any concerns.
One consideration of urban gardening is soil contamination. Unless you are gardening on a site known to be contaminated by industry or pollutants, lead is the only heavy metal likely to be found at dangerous amounts in your soil. Lead naturally occurs in all soils at a rate of 10-50 parts per million (ppm). Soil is considered safe for gardening at a rate less than 400 ppm.
At any level of soil contamination, very young children should be supervised to ensure they are not ingesting significant amounts of soil.
At low levels of contamination (150 to 400 ppm) it is encouraged to:
- Mulch exposed soil
- Wash vegetables thoroughly and peel root veggies before eating
- Enforce a clean hands policy
- Increase organic matter in soil
*A note to Strawberry Hill gardeners: SH was found to have the highest rates of lead. While still below the safe threshold, DCGP is pursuing remediation. In spring 2020, DCGP will be conducting further tests to determine the best next steps.