A phase 2 environmental site assessment is typically initiated when preliminary evaluations raise red flags about a property’s environmental condition. This stage dives deep—sampling soil, groundwater, and building materials to uncover hidden dangers. While some contaminants are expected based on the site’s past use, others sneak in unexpectedly, complicating remediation and potentially inflating costs. Let’s take a closer look at the less-expected culprits that tend to surprise even seasoned environmental consultants.
Industrial Ghosts: Heavy Metals Lurking in Soil
It’s one thing to expect petroleum residues on a former gas station site—but discovering toxic metals in soil where you’d least suspect them? That’s a whole different game.
- Lead and Arsenic from Smelters and Foundries
Legacy industries often left behind traces of heavy metals like lead and arsenic, especially in urban centers. These contaminants bind tightly to soil particles and can stay there for generations. - Cadmium and Zinc from Electroplating and Batteries
Properties once used for metal finishing or battery recycling may surprise stakeholders with elevated cadmium and zinc levels, both of which pose serious risks to human health. - Chromium from Leather Tanning Facilities
Chromium VI is notoriously carcinogenic and can show up even if records don’t list tanning activity—sometimes due to undocumented dumping or runoff from nearby operations. - Mercury Hotspots from Thermometer or Lamp Factories
Though less common, mercury contamination is still found in sites with historical links to specific manufacturing sectors.
Heavy metals aren’t just difficult to clean up—they often require off-site disposal or long-term containment. And their presence can limit redevelopment potential, especially for residential or agricultural reuse.
Underground Storage Tanks: Silent Leakers Beneath the Surface
Underground storage tanks (USTs) are classic environmental hazards—but it’s the extent of their damage that often comes as a shock.
- Fuel and Oil Residues from Leaky Tanks
Even tanks that were decommissioned decades ago may have left behind diesel, gasoline, or heating oil that seeped into subsurface soils. - Volatile Organic Compounds (VOCs): BTEX Compounds
Benzene, toluene, ethylbenzene, and xylene—the usual suspects—are common in gasoline and present both inhalation and groundwater contamination risks. - MTBE: A Long-Lasting Groundwater Threat
Once used to enhance octane in fuel, MTBE is a groundwater nightmare due to its high solubility and resistance to natural degradation. - Unmapped or Forgotten Tanks
Some tanks aren’t even in public records, buried and forgotten—until boring and sampling say otherwise.
When these tanks are discovered, the remediation can quickly escalate into a full-scale excavation or groundwater treatment project, depending on the severity of the leak.
Pesticide Residues: Farmland’s Lingering Legacy
Agricultural lands often wear a green façade, but underneath that pastoral charm could lie decades of chemical buildup.
- DDT and Organochlorines
Though banned in the U.S. since the 1970s, DDT residues still turn up in soil samples. These legacy pesticides break down slowly and bioaccumulate in the food chain. - Chlordane and Heptachlor from Termite Treatments
These were commonly used around building foundations—even outside agricultural settings—and can linger in soil for over 50 years. - Atrazine and Glyphosate Residues
Still widely used today, these herbicides can persist in soil and leach into groundwater, depending on site conditions. - Point-Source Accumulation from Improper Disposal
Some sites have “hot spots” where unused or expired pesticides were dumped or spilled, leading to localized but intense contamination.
Even if a site has changed hands many times, these residues serve as a chemical fingerprint of its agricultural past—often requiring deep-soil excavation or in-situ chemical oxidation.
PFAS and Emerging Pollutants: Tomorrow’s Headache, Today
You’d think we’d run out of new pollutants to worry about—but science keeps catching up with our industrial habits.
- PFAS (Per- and Polyfluoroalkyl Substances)
Found in everything from non-stick cookware to firefighting foam, PFAS compounds are known as “forever chemicals” for a reason—they don’t break down easily and can contaminate drinking water for miles. - Personal Care Products and Pharmaceuticals
These trace pollutants often come from biosolid application or improper wastewater treatment, disrupting local ecosystems and showing up in groundwater. - Microplastics and Nanoplastics
Though more studied in oceans, microplastics are now being detected in soils, particularly near industrial sites or landfill leachates.
Flame Retardants and Plasticizers (e.g., PBDEs and Phthalates)
Emerging concern pollutants that may have leached into soil from discarded electronics, old furniture, or construction debris.
These modern contaminants pose a real challenge—they’re often unregulated, hard to test for, and even harder to remediate effectively. Their presence could dramatically shift both regulatory compliance and cleanup cost projections.
Radioactive Surprises: Nuclear Ghosts of Sites Past
Radioactive materials are typically the last thing most environmental assessors expect to find—yet they occasionally show up, catching everyone off guard.
- Radium from Watch Dial Manufacturing or Industrial Gauges
Back in the day, glow-in-the-dark paint meant radium. Some sites with no obvious nuclear history can still be hot zones. - Uranium and Thorium Residues from Historical Mining or Labs
Some properties have old mining ties or were used for scientific research, leaving behind trace radioactive dust. - Cesium-137 or Strontium-90 from Fallout or Accidents
These isotopes can appear in regions downwind of former nuclear testing zones or in places with improperly stored lab equipment. - Naturally Occurring Radioactive Material (NORM)
Certain geological formations bring their own background radiation—especially a concern for oil and gas drilling sites.
Even when the levels aren’t hazardous by EPA standards, their presence can spark community concern and require specialized disposal or shielding measures.
So… What Do You Do When the Dirt Fights Back?
Discovering unexpected contaminants during a phase 2 environmental site assessment can quickly escalate a seemingly straightforward property transaction into a regulatory labyrinth. The key is proactive, comprehensive testing and a remediation plan that’s adaptable to whatever surprises your soil might throw at you.
From toxic metals and leaky tanks to pesticide ghosts and modern chemical nightmares, knowing what might be lurking underground ensures you’re not just buying property—but peace of mind.