Practice Test Geeks(WTO) Water Treatment Operator Certification Practice Test
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Source Water Characteristics Flashcards

7 cards from real WTO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Source Water Characteristics flashcards as text

  1. In the context of source water, what are humic and fulvic acids?

    Answer: Natural organic compounds from decomposing plant and animal matter

    Humic and fulvic acids are naturally occurring organic compounds formed from the microbial decomposition of organic matter in soil and water.

  2. Which watershed land use practice most significantly increases the risk of nitrate contamination in a groundwater source?

    Answer: Heavy application of nitrogen fertilizers on cropland

    Nitrogen-based fertilizers applied to cropland leach into groundwater as nitrate, especially in sandy or permeable soils.

  3. What is the term for the layer of sediment at the bottom of a reservoir that can release nutrients and metals under low-oxygen conditions?

    Answer: Hypolimnion sediment / benthic zone

    The benthic zone sediments release iron, manganese, phosphorus, and other substances into the hypolimnion when bottom-water oxygen is depleted.

  4. Which source water parameter is used to estimate the potential for calcium carbonate scale formation or corrosion in distribution systems?

    Answer: Langelier Saturation Index (LSI)

    The Langelier Saturation Index calculates whether water is scale-forming, corrosive, or balanced, based on pH, alkalinity, hardness, temperature, and TDS.

  5. What does 'color units' (CU) measure in source water, and what is the typical regulatory concern threshold?

    Answer: It measures apparent color from dissolved organics; EPA secondary standard is 15 CU

    Color units measure the yellowish-brown tint from dissolved organics; the EPA secondary maximum contaminant level for color is 15 color units.

  6. A source water sample shows dissolved oxygen (DO) levels near zero. This condition is most associated with:

    Answer: Anaerobic decomposition in deep, stratified reservoir bottoms

    Near-zero DO results from bacterial decomposition of organic matter consuming all available oxygen, typically occurring in the hypolimnion of thermally stratified lakes.

  7. Which factor most directly determines whether a surface water source is classified as 'highly vulnerable' under the SWTR (Surface Water Treatment Rule)?

    Answer: Evidence of significant pathogen contamination or high turbidity in the watershed

    Under the SWTR, surface water vulnerability is assessed based on watershed contamination indicators including pathogen presence, land use impacts, and turbidity history.