Project Planning
What is usually the main goal of a remediation project?
To get contaminants below health-based guidelines.
What soil depth should you sample if you’re growing vegetables?
About 12 inches.
Metals are what type of pollutants?
Elemental/inorganic
What does ppm stand for?
Parts per million.
Name one way contaminants can enter your body.
Skin contact, inhalation, ingestion.
Name one of the first steps in planning a bioremediation project.
Build a team, set goals, assess the site, test the soil, or research.
Name one soil characteristic that affects contaminants
pH, structure, infiltration capacity, CEC, % organic matter.
Give one example of an organic contaminant.
Diesel, gasoline, pesticides, DDT, etc.
What is the relationship between ppm and mg/kg?
They are equivalent units.
Which PPE should you wear to avoid inhaling dust?
N95 respirator mask.
Why is it important to plan for toxic byproducts?
They may need safe storage/disposal at a hazardous waste facility.
Why is site history and current land use important?
It reveals past contamination sources and human/environmental interactions.
Why can metals not be broken down?
They are elements; they can only be moved, bound, or extracted.
About how much does one lead soil sample cost at a lab?
Around $80.
What’s one tool used for soil sampling?
Trowel, auger, shovel, hammer, tape measure, Ziploc bags, etc.
What are two things to consider when choosing a remediation approach?
Type of contaminant (organic or metal), concentration, site conditions, long-term impacts, or disposal method.
What is the difference between composite and individual soil samples?
Composite = mix from multiple spots for average; Individual = one location, specific info.
Which type of contaminant can microbes help transform into less toxic forms?
Organics (carbon-based)
Why are composite samples sometimes used?
To reduce testing costs.
What plants and fungi are used in the installation demo?
CA Buckwheat, CA Telegraph seeds, mycorrhizal fungi.
What should you do if plant biomass used for remediation contains high concentrations of lead or arsenic?
Seal in bins for ~6 months, reduce to sludge, and dispose at a hazardous waste facility.
Name three environmental factors that should be mapped at a site.
Sun, wind, slope, water flow, existing plants/microbes, neighbors, or cultural use.
What’s a key difference in exposure between residential land use and agriculture?
Agriculture can expose people through eating contaminated crops.
Why are soil test results sometimes confusing?
Allowable limits vary by city/agency, results only show sampled spots, and interpreting units can be complex.
What are the main steps in the double-digging protocol?
Dig trench, pile soil, loosen subsoil, add/mix organic material, flip grass, break it up.