Suspected or Confirmed Leak
The stakes
A leak reprices everything. Removal of a clean tank is a $1,500–$3,500 job; confirmed contamination moves you into a $3,000–$15,000 band, with most residential remediations landing at $8,000–$10,000 and severe cases exceeding $100,000. The spread inside that band is decided by data — how far the oil traveled, how deep, and whether it reached groundwater — which is exactly why no honest number exists before sampling.
Two other stakes run in the background. Plumes migrate: oil in soil moves over time, and contamination that reaches groundwater or crosses a property line escalates both the cleanup and the oversight. And the leak follows the house — once known, it carries disclosure obligations at sale, so an unresolved leak quietly becomes a future transaction problem on top of a present environmental one.
What changes the decision
Suspicion vs. lab confirmation. Oil odor in the yard or basement, a sheen on sump or surface water, and failing furnace lines are grounds for testing — not conclusions. Only laboratory soil results confirm a leak, and everything expensive should wait for them.
Groundwater proximity. Shallow groundwater — common in coastal and low-lying areas — raises the chance that contamination has spread and adds cost and oversight if it has.
Time since the tank was last used. A tank out of service for decades has had decades to release residual oil through a corroding shell. Long-idle tanks are precisely the ones where "it was fine when we stopped using it" means least. The leak-risk tool converts age, material, and history into a rough probability tier before you spend on sampling.
The sequence
- Soil sampling ($300–$1,000). Samples around and beneath the tank, analyzed by a laboratory. This one purchase converts every later decision from guesswork to scope.
- If confirmed: NJDEP reporting and case setup. Confirmed contamination falls under NJDEP's Site Remediation Program; regulated cleanups proceed under that oversight with the required professionals. The leak and remediation guide walks the regulatory mechanics.
- Remediation scope from data, not a sales pitch. The excavation plan should cite your lab results and delineation — specific depths, specific extents. A scope that arrives before the data does was written for a different property.
- Confirmatory samples and closure documentation. Post-excavation samples prove the contamination is gone; the closure paperwork is what future buyers, lenders, and insurers will ask to see.
A firm remediation price quoted before sampling is a red flag — nobody knows the scope yet, including the person quoting it. So is a "free, state-funded" cleanup pitch: NJDEP explicitly warns about contractors advertising free removal or remediation, and the state fund behind those pitches is backlogged, with new applications date-stamped but not processed until funding is available. Read the grant and UST Fund reality before signing anything built on "no cost to you."
Documents to walk away with
- Initial laboratory soil results establishing the leak and its extent
- NJDEP case number and reporting records, if contamination was confirmed
- Remediation scope and disposal manifests for excavated soil
- Confirmatory (post-remediation) laboratory results
- Final closure documentation for the case
- Contractor and oversight professionals' license information
Contractor matching is not running yet. When it is, the plan is to check independent, licensed contractors for licensing and compliance, and match you with one equipped for contamination work. We don't perform the work, set the price, or guarantee outcomes — remediation scope and cost are set by your soil data and NJDEP requirements, not by anyone's pitch.
If you're not yet sure a leak is even likely, run the leak-risk tool first; if you're weighing testing against doing nothing, the remove-vs-close calculator will sequence it for you.