Sometimes pollution is easy to see, like the smog that trails from tailpipes as we drive along congested freeways.
But when toxic chemicals and metals seep into soil or groundwater, we may be walking above contaminated land without even knowing it.
A database of hazardous-waste cleanup sites compiled by the state’s Department of Toxic Substances Control reveals that some of these instances are actually at or near school sites.
We found five school sites in San Diego County that have active listings for cleanup status.
This designation doesn’t necessarily mean that toxic waste is being removed from a school right now. But it does mean that the department confirmed the existence of dangerous toxic waste at the site at some point.
Here’s what we found:
Webster Elementary School (San Diego Unified School District)
Source of Pollution
Burnt trash from a landfill that once operated at the site where Webster now sits.
Environmental hazards
The soil and ash beneath the surface contain lead and dioxins.
High concentrations of lead can be deadly, according to the Mayo Clinic, but trace amounts can also cause serious harm to children’s mental and physical development. Kids younger than 6 are most at risk of lead poisoning.
Long-term exposure to dioxins can cause cancer, according to the World Health Organization, but small amounts pose a minimal threat.
Protective measures
The toxic ash is covered by concrete, granite and asphalt, but the amount of insulation varies. In some places, the ash is 2 feet below the surface. In others, it’s 30 feet down.
Current status
The site was last inspected in August, but the Department of Toxic Substances Control has not yet posted its findings publicly.
Correia Middle School (San Diego Unified)
Source of Pollution
Portions of the school’s playground were once an illegal dumping site for burnt refuse. Ash was discovered in the soil when the district tried to build a retaining wall at the edge of the site.
Environmental Hazards
“High levels of lead” were found in some soil samples. The soil also contained lesser amounts of dioxins and the poison arsenic.
Protective Measures
The lead-contaminated soil was removed. Follow-up soil tests found no significant levels of the metal.
The district also monitored groundwater around the school for contamination. None was found in August 2007, when the district did two rounds of testing.
Current status
As of August 2011, the project is exempt from further environmental review. It’s not clear why the site is listed as active.
R. Roger Rowe Middle School Expansion Properties (Rancho Santa Fe School District)
Source of Pollution
Gasoline and diesel fuel leaked into the groundwater from underground storage tanks, tainting land near the school that the Rancho Santa Fe School District wanted to turn into athletic fields and parking lots.
Environmental Hazards
A broad range of petroleum hydrocarbons was found in soil samples, including benzene — a chemical that health researchers have strongly linked to blood-cell cancers.
Protective Measures
The tanks were removed and the Rancho Santa Fe signed an agreement with the Department of Toxic Substances Control to restrict the use of parcels on the site where the groundwater is contaminated.
The district can only build on those parcels with the department’s consent, but it has no current plans to develop them, according to Sandy Lubenow, an assistant to the district’s superintendent.
The district must also prepare and submit annual reports to show it’s complying with the land-use agreement.
Current Status
The department found that the school district is currently in compliance.
Magnolia Elementary School (Cajon Valley Union School District)
Source of Pollution
A pump that extracted wastewater from a former Ketema airplane-part manufacturing plant leaked out, polluting the groundwater and pumping toxic gas into the soil.
The chemicals have spread 7,000 feet, posing a threat to Magnolia and the surrounding community.
Environmental Hazards
The chemical trichloroethylene, which can harm the central nervous system and a variety of organs, including the kidney and the liver, according to the Environmental Protection Agency.
Protective Measures
Quarterly monitoring of the school’s soil and indoor air quality, as of July 2012.
Current Status
In May, the Department of Toxic Substances Control recommended that a pollution-monitoring firm hired by Ketema’s parent company, Ametek, expand the scope of its inquiry by testing outdoor air samples and deeper soil samples. A follow-up report on their efforts is due in November.
Proposed Alpine High School Site (Grossmont Union High School District)
Source of Pollution
Pesticides and other chemicals used for ranching and farming.
Environmental Hazards
Chlordane, a chemical that is harmful to the central nervous system in high doses, according to the EPA.
Protective Measures
The district removed and treated more than 236 tons of chlordane-infused soil before shipping it to the Copper Mountain Landfill in Arizona.
A review of eight soil samples found that the chlordane levels were below what the EPA considers hazardous under the federal Resource Conservation and Recovery Act.
Current Status
Certification of the district’s chlordane-removal efforts is set for December.