The following tables summarize data collected for NAWQA studies during 1992-1995 by showing results for the Lower Susquehanna River Basin Study Unit compared to the NAWQA national range for each compound detected. The data were collected at a wide variety of places and times. In order to represent the wide concentration ranges observed among Study Units, logarithmic scales are used to emphasize the general magnitude of concentrations (such as 10, 100, or 1,000), rather than the precise numbers. The complete data set used to construct these tables is available upon request. The groups of compounds analyzed for were selected on the basis of national usage of pesticides and other criteria. This summary includes compounds that may not be registered for use in Pennsylvania or Maryland. Some of the compounds analyzed for have previously been registered in Pennsylvania or Maryland, but either have not been renewed or have had the registration revoked.
Water samples: Compounds detected || Compounds not detected
Fish tissue and bed sediment samples: Compounds detected || Compounds not detected
[mg/L, milligrams per liter; µg/L, micrograms per liter; pCi/L, picocuries per liter; %, percent; <, less than; - -, not measured; trade names may vary]
2,4,5-T (Fruitone A)
2,4,5-TP (Silvex, Fenoprop)
Bromoxynil ( Bromotril)
Dacthal mono-acid (Dacthal metabolite)
Picloram (Grazon, Tordon)
Triallate (Far-Go, Avadex)
3-Hydroxycarbofuran (Carbofuran metabolite)
Aldicarb sulfone (Standak)
Aldicarb sulfoxide (Aldicarb metabolite)
Aldicarb (Temik, Ambush)
Oxamyl (Vydate L)
Phorate (Thimet, Granutox)
Propargite (Comite, Omite)
1,1,2-Trichloro-1,2,2-trifluoroethane (Freon 113, CFC 113)
1,2-Dibromoethane (EDB, Ethylene dibromide)
Chloroethene (Vinyl Chloride)
Benzo [c] cinnoline
Aldrin (HHDN, Octalene)
Chloroneb (Tersan SP)
alpha-HCH (alpha-BHC, alpha-lindane)
cis-Permethrin (Ambush, Pounce)
trans-Permethrin (Ambush, Pounce)
a Selected water-quality standards and guidelines (Gilliom and others, in press).
b Rates of detection are based on the number of analyses and detections in the Study Unit, not on national data. Rates of detection for herbicides and insecticides were computed by only counting detections equal to or greater than 0.01 µg/L in order to facilitate equal comparisons among compounds, which had widely varying detection limits. For herbicides and insecticides, a detection rate of "<1%" means that all detections are less than 0.01 µg/L, or the detection rate rounds to less than one percent. For other compound groups, all detections were counted and minimum detection limits for most compounds were similar to the lower end of the national ranges shown. Method detection limits for all compounds in these tables are summarized in Gilliom and others (in press).
c Detections of these compounds are reliable, but concentrations are determined with greater uncertainty than for the other compounds and are reported as estimated values (Zaugg and others, 1995).
d The guideline for methyl tert-butyl ether is between 20 and 40 µg/L; if the tentative cancer classification C is accepted, the lifetime health advisory will be 20 µg/L (Gilliom and others, in press).
e Selected sediment-quality guidelines (Gilliom and others, in press).