We can take soil samples from suspect sites that may have petroleum contaminated soils for analysis by a certified lab. If site needs remediation oversight and official closure, we can assist with those services as well.
Non-commercial residential or farm heating oil tanks that contain 1100 gallons or less are not regulated by the EPA as long as they do not leak. Discovered leaks in these tanks automatically make them regulated. State and local governments may regulate them anyway. So buyers beware if you are looking to purchase a house that has a heating oil tank, it would be wise to check for petroleum leaks in the soil or groundwater near the tank as part of your due diligence. Once you purchase the property you become liable for any leaks and/or soil or groundwater contamination.
See link for more info. http://www.epa.gov/oust/faqs/heatoil.htm
In NC when a release is discovered, then form UST-61 should be filed with the State. As of October, 2015 the Non-Commercial UST cleanup fund was eliminated, so no more funds available for cleanups.
To rectify a small UST such as a heating oil tank release, the product, tank and contaminated soil should be removed and taken to an approved facility for remediation.
The remaining soil from the over dig can be tested for product with a photoionization detector (PID) before taking an official soil sample to the lab. For example diesel range organics (DRO) should have PID hits of less than 1 to 2 ppm before sending the soil sample to the lab for testing to fall under the 10 ppm limit. DRO is less volatile in colder weather than gas range organics (GRO) so best to get low PID readings before sampling.
When you have an excavation that appears to be clean, take a soil sample from beneath the tank and send to a certified lab for an analysis report. Should get a licensed professional (PE, PG et al.) to write a closure report that interprets the analysis and give recommendation of no further action needed for the release. This report should be sufficient for most banks and State Regulatory agencies.
Be aware that if groundwater is near the contaminated soil, then you may have to do a limited site assessment that involves groundwater monitoring wells, remediation etc.