Underground Storage Tanks Program
Northwest Total Petroleum Hydrocarbon Analytical Methods
The UST Cleanup Rules (OAR 340-122-0218(d)(A)) require the use of
the Northwest Total Petroleum Hydrocarbon (NWTPH) Analytical Methods
for samples "used to demonstrate compliance with remediation
levels." The NWTPH methods were developed to satisfy UST cleanup
rules in both Oregon and Washington. These methods include:
which is a qualitative and semi-quantitative screen to determine
the presence and type of petroleum products that may exist in water
or soil. This method may be used in place of the current TPH-HCID.
which is a qualitative and quantitative method for volatile
petroleum products such as aviation and automotive gasolines,
mineral spirits, Stoddard solvent and naphtha. This method may be
used in place of the current TPH-G.
which is a qualitative and quantitative method for semi-volatile
petroleum products such as jet fuels, kerosene, diesel oils,
hydraulic fluids, mineral oils, lubricating oils and fuel oils. This
method may be used in place of the current TPH-418.1 Modified or
For more information:
- View the
Northwest TPH Analytical Methods on the DEQ Laboratory's Web Site.
- To obtain a printed copy of the Northwest TPH Analytical
Methods, please call the UST Cleanup Program's information request
line, 1-800-742-7878 (toll-free within Oregon), or DEQ's Land
Quality Division, 503-229-5913. Copies may also be obtained from UST
Program staff in any of the DEQ Regional Offices.
- Laboratory personnel with specific technical questions about the
methods should contact the manager of DEQ's Organic Analytical and
General Chemistry Lab, at 503-693-5745.