CME Water & Wastewater Systems Flashcards
6 cards from real CME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CME Water & Wastewater Systems flashcards as text
What design standard is most commonly used for potable water distribution system hydraulics in the US?
Answer: Ten States Standards (Recommended Standards for Water Works)
The Ten States Standards (Recommended Standards for Water Works) is the most widely used guidance document for potable water system design across the Midwest and Northeast US.
Which federal regulation sets the primary drinking water standards that municipal water systems must meet?
Answer: Safe Drinking Water Act (SDWA)
The Safe Drinking Water Act authorizes EPA to set National Primary Drinking Water Regulations (NPDWRs) that municipal water systems must comply with.
What is the minimum residual chlorine level (free chlorine) EPA recommends maintaining throughout a distribution system?
Answer: 0.2 mg/L
EPA recommends maintaining at least 0.2 mg/L free chlorine residual throughout the distribution system to prevent microbial contamination.
What does the Hazen-Williams equation calculate in water distribution design?
Answer: Head loss due to friction in pipes carrying water
The Hazen-Williams equation is an empirical formula used to calculate friction head loss in water-carrying pipes for distribution system design.
What is the primary purpose of a water system's storage tank (elevated or ground-level)?
Answer: Equalize diurnal demand fluctuations and provide emergency fire flow storage
Water storage tanks equalize daily demand variations, maintain system pressure, and provide reserve capacity for fire fighting and emergencies.
Under the Lead and Copper Rule (LCR), what action level for lead triggers required system mitigation?
Answer: 15 µg/L
The EPA Lead and Copper Rule sets an action level of 15 µg/L (ppb) for lead; if exceeded at 10% of sampled taps, utilities must take corrective action.