Pesticide distribution in water, sediment, and fish of the Occoquan Watershed

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dc.contributor.authorHall, Ellen L.en
dc.contributor.committeechairDietrich, Andrea M.en
dc.contributor.committeememberGodrej, Adil N.en
dc.contributor.committeememberGrizzard, Thomas J.en
dc.contributor.departmentEnvironmental Engineeringen
dc.date.accessioned2014-03-14T21:46:03Zen
dc.date.adate2008-09-18en
dc.date.available2014-03-14T21:46:03Zen
dc.date.issued1996-04-25en
dc.date.rdate2008-09-18en
dc.date.sdate2008-09-18en
dc.description.abstractAbout 50 synthetic organic chemicals (SOCs), including pesticides and polyaromatic hydrocarbons (PAHs), have been identified as possible contaminants in the Occoquan Watershed. Since 1982, water, sediment, and fish samples have been collected from the streams and reservoirs of the watershed 2-4 times per year. The Occoquan Watershed Monitoring Laboratory (OWML) collected samples and analyzed for a targeted set of compounds. Beginning in 1993, new SOC screening methods consisting of solid-phase extraction (SPE) followed by gas chromatography with mass spectrometric detection (GC/MS) were developed for water and sediment samples. A similar method for fish tissue was developed in this study using methanol extraction with C-18 and alumina SPE cleanup. Method detection limits (MDLs) ranged from 0.03-0.37 mg/kg wet weight and recoveries in matrix spikes ranged from 15-92%. Very few SOCs in OWML's database were found at levels above method detection limits. In water, atrazine was the most commonly detected compound (87 detections out of 610 samples analyzed). It was also found in 8 sediment samples and 1 fish organ sample. Atrazine concentrations were highest in the spring; summer provided the most frequent detections. Detections occurred at multiple locations during the same sampling period; stations furthest west (nearest to agricultural areas) tended to show the highest values. Rainfall events were associated with 23% of atrazine detections. The raw and finished water samples from the two water treatment plants in the basin showed that the average atrazine removal by conventional treatment was 37%.en
dc.description.degreeMaster of Scienceen
dc.format.extentxi, 107 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-09182008-063530en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-09182008-063530/en
dc.identifier.urihttp://hdl.handle.net/10919/44829en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1996.H355.pdfen
dc.relation.isformatofOCLC# 34923181en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectpesticidesen
dc.subjectmonitoringen
dc.subject.lccLD5655.V855 1996.H355en
dc.titlePesticide distribution in water, sediment, and fish of the Occoquan Watersheden
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineEnvironmental Planningen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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