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Municipalities

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    Exams

    Wisconsin DNR’s Operator Certification program will be hosting in-person paper exams coordinated and facilitated by Wisconsin DNR staff in 2025.Exams will be held approximately four times a month for four months of the year. All 2025 exam dates and…

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    Laboratory services

    The DNR receives laboratory data from many sources for environmental monitoring. This environmental monitoring is done for compliance with state and federal rules, investigating environmental problems, determining baseline quality, verifying cleanup…

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    Laboratory certification & registration program

    The Wisconsin Department of Natural Resources (DNR) Laboratory Certification Program was created in 1986 to help ensure that laboratories submit reliable and consistent data to the department's various environmental programs. The program currently…

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    PFAS certification

    The Wisconsin Department of Natural Resources is offering certification for PFAS in drinking water (potable water), aqueous (non-potable water), and non-aqueous matrices.Labs that currently hold WI DNR PFAS certification can be found here: WI PFAS…

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    BOD troubleshooting

    What's causing bias? Contamination? Calibration?

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    BOD Toxicity

    Sample toxicity Often referred to as "sliding" BODs BOD decreases as sample volume increases (i.e., less dilute) Occurs frequently in systems receiving industrial waste Amounts to killing off (or severe shock to) "the bugs" Results in under-…

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    BOD seed

    Seed preparation and addition De-ionized water kills - Adding a seed capsule to deionized water causes an osmotic imbalance that will kill seed organisms. The purified water —containing no salts— rushes across the bacterial cell walls. The bacteria…

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    Sampling and sample handling for BOD

    Water and wastewater samples are biologically active, and the BOD will quickly deteriorate. Minimize the time between sampling and analysis to obtain the best BOD results. Take the following precautions when sampling and handling BOD samples.…

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    BOD resources

    Websites Field Training Manual for Laboratory Analysts: Chapter 7 - BOD Biochemical Oxygen Demand Source: http://home.windstream.net/mikeric/Chap1to9/Chap7%20Biochemical%20Oxygen%20Demand.htm-->

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    BOD quality control

    Limit of detection (LOD) BOD detection limits are theoretically based. A key assumption which the concept of detection for BOD is based is that the LEAST amount of depletion allowable is 2 mg/L. The LOD is also based on the highest volume of sample…

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