Laserfiche WebLink
SUSL a i L ca <br /> C&T Page Two <br /> ®® I <br /> Tank Backfill --.. . . . . . . . . . . . . ' . . Monitoring Well <br /> ' a a Lost <br /> Product <br /> vtih�`%^��\M'\'%��+/ 'tir'.-� ,,s,_-r.•r•.,...,��...{-•".;:' '%rr•.'•.,'::r::r.':•:••.':, c-r'..r:':�r>..t+.�� t �•Vr <br /> 1\1\/\/vY1•V\�v V•J'.?�/.T'r i!s�/`r •ti - •' � ... •t 'i� •- �..'\. /�. `. <br /> 3 - <br /> TPH <br /> EXAMINING the TOTAL M TPH <br /> Presently, total petroleum hydrocarbon analy- The 'Total" in total petroleum hydrocarbons is a. <br /> ses (TPH's) are required for many site investiga- misnomer., as few, if any, of the TPH procedures <br /> :ions evaluating subsurface contamination by are actually capable of measuring all the hydro- <br /> zvdrocarbons. These analyses are often needed carbons present in soil samples. There are <br /> =o assess the environmental impact stemming several variables affecting analytical perform- {-- <br /> ;:om leaking product delivery lines, spills, and ance between methods for TPH analysis. In <br /> Defective subsurface storage tanks. Curtis & general, the two main factors are the strength <br /> =ompkins has performed a variety of TPH of the extractant, and the abilitv of the tech- <br /> analyses for these investigations, and' has been nique to quantify the larger molecular,weight <br /> LYposed to numerous questions that result fractions. The strength of the extractant will <br /> : om TPH analyses. The following presents determine which hydrocarbon:species are solu- <br /> 3ome pointers anda synopsis of the most com- bilized (stripped from the soil) and are subse- <br /> nonly applied analytical methods forTPH quently available for ,:quantitation. Stronger <br /> a aivsis used at Curtiss and Tompkins. We have extractants will effectively remove greater quan- <br />;nalyzed TPH samples obtained at sites ranging titles of larger molecular weight species. <br /> om service stations to large petroleum refining <br />.and storage facilities. We believe our experience • The quantitation technique also plays an im- <br />�nables us to better serve the needs of the portant role. Most methods rely on gas chroma- <br />-mvironmental investigator. tography, which may'vary between techniques <br /> as a function of column types, operating tem- <br /> -7valuating the extent of soil contamination by peratures and the type of detectors. TPH tech- <br /> petroleum hydrocarbons requires consideration piques based upon gas chromatography will:not <br /> )f 1) the types of hydrocarbons present at the detect hvdrocarbons with boiling points in <br /> site: 2) the soil tvpes: 3) the distribution of excess of 350 C. Additional methods that may <br />:zvdrocarbons in the soil matrix; and.:4) the quantitate larger molecular weight species (if <br />:imitations of the available methods for petro- quantitate <br /> by the extractant) include infrared <br />_eum hydrocarbon analysis. These aspects spectrophotometry (after Freon.extraction) and , <br /> mould be considered in selecting analytical gravimetric analysis. Though, these latter <br />-nethods to assess contamination by hydrocar- techniques cannot speciate hydrocarbon com- <br />�ons. ponents. <br /> II ,,I <br />