# US 5,344,781 A · Detection and prevention of hydrocarbon leakage from underground storage tanks

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- Number: US 5,344,781 A
- Document ID: US5344781A
- Status: Granted
- Kind: A
- Application number: 07/687,460
- Filed: 1991-04-17
- Granted: 1994-09-06
- Earliest claimed: 1991-04-17
- Assignees: International Lubrication and Fuel Consultants, Inc.
- Inventors: Nancy E. Kitchen; Edward F. Kitchen; George H. Kitchen, III
- Web page: https://patentgrep.com/patent/US5344781A

## CPC

- G01N 33/241: {for hydrocarbon content}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

Methods and apparatuses for detecting leakage of hydrocarbons from and preventing corrosion of underground storage tanks. Soil samples near an underground storage tank are taken and analyzed in the field, preferably using hexane as a solvent to detect the presence of hydrocarbons such as heating and waste oil. The soil-to-tank potential of the tank and the presence of water within the tank are measured and, if warranted, cathodic protection provided to the tank to prevent corrosion or further corrosion.

## Claims

### Claim 1

A kit for on-site or field analysis of soil for detecting the presence of hydrocarbons in the soil, the kit comprising:
a container including; hexane as a solvent reactable with hydrocarbons in an amount sufficient to mix a desired soil sample therewith;
sealable field container means for agitating a desired soil sample with said hexane to create a mixture of said hexane and the soil sample;
filter paper for filtering soil solids from said mixture of the soil sample and said hexane; and
an evaporating dish for evaporating said extraction fluid and inspecting any residue from said evaporation for detecting hydrocarbon presence from inspection of filtered extraction fluid.

### Claim 2 (depends on 1)

The invention of claim 1 wherein said filter paper comprises size 20 micron or finer porosity.

### Claim 3 (depends on 1)

The invention of claim 1, wherein said evaporating dish comprises a cover for storage of said residue.

### Claim 4 (depends on 1)

The invention of claim 1 wherein said evaporating dish comprises label means for providing information on said evaporating dish.

### Claim 5

A method for on-site or field testing soil for the presence of hydrocarbons, the method comprising the steps of:
a) drilling at least one hole in the ground at a selected location;
b) removing soil from the hole;
c) placing the soil and hexane as a solvent reactable with hydrocarbons in a sealable field container;
d) agitating the sealable field container thereby mixing the soil and the hexane;
e) filtering solids from the mixture of soil and hexane;
f) providing an evaporation dish;
g) evaporating, in said evaporating dish, the extraction fluid to produce a residue containing hydrocarbons, if present in the soil sample; and
h) detecting the presence of hydrocarbons from inspection of filtered extraction fluid.

### Claim 6 (depends on 5)

The invention of claim 5 wherein the step of detecting the presence of hydrocarbons comprises visually detecting a colored residue.

### Claim 7 (depends on 6)

The invention of claim 6 wherein the step of detecting the presence of hydrocarbons comprises touching the residue tactually to feel the lubricating sensation caused by hydrocarbons.

### Claim 8 (depends on 5)

The invention of claim 5 further comprising the step of drilling at least one hole from which to extract the soil at a selected location relative to an underground hydrocarbon storage tank.

### Claim 9 (depends on 8)

The invention of claim 8 further comprising the step of drilling at least one hole down to a depth at least as deep as the bottom of the underground hydrocarbon storage tank.