• Login
    View Item 
    •   Home
    • University Colleges
    • SUNY Brockport
    • Scholarship
    • Government Documents (Water Resources)
    • View Item
    •   Home
    • University Colleges
    • SUNY Brockport
    • Scholarship
    • Government Documents (Water Resources)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of SUNY Open Access RepositoryCommunitiesPublication DateAuthorsTitlesSubjectsDepartmentThis CollectionPublication DateAuthorsTitlesSubjectsDepartmentAuthor ProfilesView

    My Account

    LoginRegister

    Campus Communities in SOAR

    Alfred State CollegeBrockportBroomeCantonDownstateEmpireFredoniaMaritimeNew PaltzOneontaOptometryOswegoPlattsburghSUNY Polytechnic InstituteSUNY Office of Community Colleges and the Education PipelineSUNY PressUpstate Medical

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Geochemistry and Microbiology of Iron-related Well-screen Encrustation and Aquifer Biofouling in Suffolk County, Long Island, New York

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    wr_misc/29/fulltext (1).pdf
    Size:
    1.092Mb
    Format:
    PDF
    Download
    Average rating
     
       votes
    Cast your vote
    You can rate an item by clicking the amount of stars they wish to award to this item. When enough users have cast their vote on this item, the average rating will also be shown.
    Star rating
     
    Your vote was cast
    Thank you for your feedback
    Author
    Walter, Donald A.
    Keyword
    Long Island
    Aquifer
    Bacteria
    Microbiology
    Date Published
    1997-01-01
    
    Metadata
    Show full item record
    URI
    http://hdl.handle.net/20.500.12648/4137
    Abstract
    Iron-related well-screen encrustation and aquifer biofouling has decreased the specific capacity of several production wells in Suffolk County, N.Y., and has forced the Suffolk County Water Authority to adopt a costly well-reconditioning and replacement program. The specific-capacity declines are the result of the precipitation of iron oxyhydroxides and the growth of iron bacteria on the well screens and in the pore spaces of the surrounding formation. Mineralogic and chemical analyses indicate that the inorganic part of the encrusting material consists primarily of amorphous ferric hydroxide (Fe(OH)3 ); minor components of the material include goethite (FeOOH), hematite (Fe2 O 3 ), and quartz (SiO 2 ). The weight percent of ferric hydroxide in the material ranged from 32.3 to 98.6 percent and averaged 64.3 percent. Equilibrium modeling indicated that during pumping the well waters were supersaturated with respect to goethite, hematite, magnetite, and quartz and were under-saturated with respect to ferric hydroxide. Theoretical Eh values computed for the ferrous/ferric-iron redox couple and the oxygen/water redox couple averaged 390 millivolts and 810 millivolts, respectively, indicating that the waters were in a state of redox disequilibrium. The disequilibrium condition arises from the mixing of ground water with a low dissolved-oxygen concentration with oxygenated ground water during operation of the well. The low pH of the ground water contributes to the disequilibrium condition by slowing the rate of iron oxidation after the introduction of oxygen. Chemical and mineralogical data indicate that most of the encrusting material in the wells was deposited while the wells were shut down, probably in response to the use of treated water of higher pH to keep pump turbines wet while the wells were not in operation; the increased pH of water in the static water column increases the rate of ferrous-iron oxidation and causes the well water to become increasingly saturated with respect to ferric hydroxide. The median half-time of oxidation in samples of untreated ground water (pH 4-5) was 4.19 days, whereas the average half-time of oxidation in treated water (pH 7-8) was 11.9 minutes Equilibrium modeling indicated that treated waters generally were supersaturated with respect to ferric hydroxide, whereas untreated well waters were not. Field and laboratory data indicate that iron bacteria play an important role in the encrustation and biofouling process in Suffolk County. Filamentous iron bacteria were common in the affected wells. The most common species was Gallionella ferruginea, an effective biofouling agent that prefers water with low, but detectable, dissolved-oxygen concentrations and high dissolved-iron concentrations; this species was more common in biofilm samples from the Magothy aquifer than in those from the upper glacial aquifer. Iron bacteria also were found in sediment cores from several locations in the aquifer and in drilling water. Lignite could act as a carbon source for heterotrophic iron bacteria, which could accelerate the formation of iron-bacteria biofilms in wells screened in some parts of the Magothy aquifer. Iron-bacteria biofilms alter the chemistry of well water by removing iron, manganese, and sulfate from solution and by increasing the pH. Sulfur-reducing bacteria and iron-sulfide mineral phases were observed in some samples of encrusting material, indicating that these bacteria could contribute to well-screen encrustation in some geochemical environments.
    Description
    USGS Water-Resources Investigations Report: 97-4032
    Collections
    Government Documents (Water Resources)

    entitlement

     

    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.