Mixed Deck — All CME Topics Flashcards

In the Rational Method, which factor primarily reflects the land use and surface characteristics of a drainage area?

Answer: Runoff coefficient (C)

The runoff coefficient (C) represents the fraction of rainfall that becomes surface runoff and varies by land use — for example, C ≈ 0.90 for impervious pavement versus C ≈ 0.25 for lawns with sandy soil.

Which greenhouse gas has the highest 100-year Global Warming Potential (GWP) relative to CO₂?

Answer: Sulfur hexafluoride (SF₆)

Sulfur hexafluoride has a 100-year GWP of approximately 23,500, the highest of any gas regulated under the Kyoto Protocol.

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.

Which system is commonly used to treat municipal wastewater?

Answer: Wastewater treatment plants

Municipal wastewater, which includes sewage from homes and businesses, contains various contaminants that must be removed before it can be safely discharged. Wastewater treatment plants are specialized facilities designed to purify this water through a series of physical, chemical, and biological processes. This comprehensive treatment ensures the water meets strict regulatory standards, preventing pollution and protecting public health and aquatic ecosystems.

A municipal engineer is evaluating air quality impacts from a new transit bus depot. Under the Clean Air Act, a 'criteria pollutant' does NOT include:

Answer: Polychlorinated biphenyls (PCBs)

PCBs are regulated as hazardous air pollutants (HAPs) under CAA Section 112, not as criteria pollutants, which include the six NAAQS-regulated pollutants.

During construction of a city hall renovation, the contractor submits a request for equitable adjustment (REA) claiming unforeseen subsurface conditions. For the claim to be valid under a standard Differing Site Conditions (DSC) clause, the contractor must demonstrate:

Answer: The conditions differed materially from those indicated in the contract documents

Under a DSC clause, the contractor must show the actual subsurface conditions materially differed from what the contract documents indicated or what a reasonable contractor would have expected.

What is the purpose of a subdivision ordinance in municipal planning?

Answer: Govern the division of land into parcels, setting standards for streets, utilities, and plat recording

Subdivision ordinances regulate the process of dividing land, establishing standards for street design, utility installation, lot configuration, and the required review and plat recording process.

Which urban design principle promotes mixing residential, commercial, and civic uses within walkable distances to reduce automobile dependency?

Answer: Mixed-use development

Mixed-use development integrates different land uses in close proximity, enabling residents to walk or bike to daily destinations.

Under the National Bridge Inspection Standards (NBIS), how frequently must publicly owned bridges over 20 feet in length be inspected?

Answer: Every 2 years

NBIS requires routine inspections of public highway bridges at intervals not to exceed 24 months (2 years), with underwater and fracture-critical inspections having separate requirements.

Which design standard governs accessible pedestrian facilities, including sidewalk width and curb ramp slopes, in the United States?

Answer: ADA Standards for Accessible Design

The ADA Standards for Accessible Design set federal requirements for pedestrian infrastructure accessibility, including curb ramps, crosswalks, and sidewalk dimensions.

What is the primary concern with combined sewer overflows (CSOs) in older US cities?

Answer: Discharge of untreated sewage and stormwater to waterways during rain events

CSOs occur when combined sewers overflow during storms, releasing untreated sewage mixed with stormwater directly into receiving waters, causing significant water quality impairment.

In sewer system design, what does 'peaking factor' account for?

Answer: Ratio of peak instantaneous flow to average daily flow used for sizing sewers

The peaking factor is applied to average daily flows to size sewers and treatment facilities for the highest expected instantaneous or peak-hour flows.

Which pipe material is most commonly specified for new gravity sanitary sewer mains in urban areas due to its corrosion resistance?

Answer: PVC

PVC is widely used for gravity sanitary sewers because it resists corrosion from hydrogen sulfide and sewage acids.

Which of the following best describes green infrastructure in the context of stormwater management?

Answer: Practices that mimic natural hydrology by infiltrating, evapotranspiring, or harvesting stormwater near its source

Green infrastructure uses natural processes — such as bioretention, rain gardens, green roofs, and permeable pavements — to manage stormwater at or near its source, reducing runoff volume and improving water quality.

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.

Which document formally authorizes a project manager to apply organizational resources to project activities?

Answer: Project charter

The project charter is the formal document signed by the sponsor that authorizes the project and empowers the project manager to use organizational resources.

What is 'design-build' project delivery and its primary advantage for municipalities?

Answer: A single entity is responsible for both design and construction, providing single-point accountability and often faster delivery

Design-build contracts one firm for both design and construction, reducing coordination gaps, shortening schedules through overlapping phases, and providing single-point responsibility.

What is the purpose of a slip joint or expansion joint in concrete structures and pavements?

Answer: Allow for thermal expansion and contraction, preventing cracking due to temperature-induced stress

Expansion joints create intentional gaps that accommodate thermal movement, preventing uncontrolled cracking in rigid concrete structures and pavements.

Which U.S. regulatory program requires large municipal separate storm sewer systems (MS4s) to obtain permits controlling stormwater runoff?

Answer: Clean Water Act Phase I and Phase II MS4 rules

EPA's Phase I (1990) and Phase II (1999) MS4 rules under the CWA NPDES program require municipalities to reduce pollutants in stormwater discharges.

What is the primary purpose of a traffic impact analysis (TIA) in urban development?

Answer: To evaluate the effect of proposed development on surrounding transportation networks

A TIA assesses how a proposed development will affect traffic operations on nearby roads and intersections.