Calculator 03

Leak-likelihood estimator

Five questions produce a qualitative tier — Lower, Moderate, or Higher. Only soil testing confirms anything.

The purpose of this tool is expectation-setting. A typical clean removal runs $1,500 – $3,500; a confirmed leak reprices the job into remediation, where most NJ residential cases land at $8,000 – $10,000. Knowing which outcome is more probable before the excavator shows up is the difference between a budget and a shock. Mechanics of how leaks are found and handled: the leak and remediation guide.

Tank profile
History & site

Why age and material dominate

Most NJ residential underground tanks are bare steel, buried between the 1940s and 1980s with no cathodic protection. Steel in wet soil corrodes from the outside in, bottom first, and the process only runs one direction. Fiberglass tanks, common after the mid-1980s, don't rust; their failures are rarer and structural. That's why a 40-year-old steel tank with no records scores Higher even with no visible symptoms — and why "it still holds oil" is not evidence of a sound shell. Pinhole leaks feed the soil, not the basement.

If your tier comes back Higher and a sale is coming, sequence matters: test before you list, not after a buyer's inspector forces the issue. See selling with a tank and the suspected-leak page.