CES - Certified Environmental Scientist Solid and Hazardous Waste Questions and Answers 1 — Questions and Answers
Question 1: A solid waste is determined to be a hazardous waste under the Resource Conservation and Recovery Act (RCRA) if it exhibits certain characteristics. Which of the following is NOT one of the four characteristics of a hazardous waste?
- Infectiousness (Correct answer)
- Ignitability
- Corrosivity
- Reactivity
Correct answer: Infectiousness
Under RCRA, a solid waste is considered hazardous if it exhibits at least one of four characteristics: ignitability, corrosivity, reactivity, or toxicity. Infectiousness is a characteristic of medical or biomedical waste, which is regulated under a different framework.
Question 2: An environmental scientist is evaluating two federal environmental statutes for a contaminated site. One statute, RCRA, focuses on managing solid and hazardous waste from generation to disposal, while the other, CERCLA, deals with the cleanup of abandoned or uncontrolled hazardous waste sites. What is the common term for the RCRA framework?
- Gate-to-Gate
- Source-to-Sink
- Cradle-to-Grave (Correct answer)
- Well-to-Wheel
Correct answer: Cradle-to-Grave
The Resource Conservation and Recovery Act (RCRA) establishes a 'cradle-to-grave' system for managing hazardous waste. This means the waste is tracked from the moment it is generated ('cradle') through transportation, treatment, and storage, to its final disposal ('grave'). CERCLA, or Superfund, is primarily for remediating past contamination.
Question 3: A manufacturing facility is implementing a new waste management plan to align with the Pollution Prevention Act of 1990. According to the EPA's Waste Management Hierarchy, which of the following actions should be given the highest priority?
- Implementing a comprehensive recycling program for waste materials.
- Installing an incinerator to recover energy from combustible waste.
- Re-designing a production process to use fewer toxic raw materials. (Correct answer)
- Contracting with a licensed facility for safe treatment and disposal of waste.
Correct answer: Re-designing a production process to use fewer toxic raw materials.
The Pollution Prevention Act of 1990 established a national policy that pollution should be prevented or reduced at the source whenever feasible. The EPA's Waste Management Hierarchy reflects this, prioritizing source reduction and reuse above all other options like recycling, energy recovery, and treatment/disposal. Re-designing a process to use fewer toxic materials is a form of source reduction.
Question 4: During the monitoring of a municipal solid waste landfill, the primary safety concern related to landfill gas is its potential for explosion. What is the main component of landfill gas that creates this explosion hazard?
- Hydrogen Sulfide
- Methane (Correct answer)
- Carbon Dioxide
- Ammonia
Correct answer: Methane
Landfill gas is composed primarily of methane (CH4) and carbon dioxide (CO2). Methane is highly flammable and can form explosive mixtures with air, typically between 5% and 15% by volume. While other gases like hydrogen sulfide and ammonia contribute to odor, methane is the principal cause of the explosion risk.
Question 5: A remedial action plan is being developed for a site contaminated with chlorinated solvents. The plan involves injecting a chemical oxidant into the subsurface to destroy the contaminants in-situ. Which of the following treatment technologies does this scenario describe?
- Solidification/Stabilization
- Soil Vapor Extraction (SVE)
- In-Situ Chemical Oxidation (ISCO) (Correct answer)
- Pump and Treat
Correct answer: In-Situ Chemical Oxidation (ISCO)
In-Situ Chemical Oxidation (ISCO) is a remediation technology that involves injecting chemical oxidants into the contaminated soil and groundwater to convert harmful contaminants into less toxic or harmless compounds. This method is distinct from physical removal methods like SVE or Pump and Treat, and from containment methods like Solidification/Stabilization.
Question 6: In the design of a modern hazardous waste landfill, a leachate collection system is a critical component required by RCRA regulations. What is the maximum allowable depth of leachate that can accumulate over the liner system?
- 15 cm (6 inches)
- 45 cm (1.5 feet)
- 60 cm (2 feet)
- 30 cm (1 foot) (Correct answer)
Correct answer: 30 cm (1 foot)
According to EPA regulations under RCRA (40 CFR 264.301), the leachate collection and removal system must be designed, constructed, and operated to ensure that the leachate depth over the liner does not exceed 30 cm (one foot). This requirement is to minimize the hydraulic head on the liner, reducing the potential for leaks.
CES - Certified Environmental Scientist Solid and Hazardous Waste Questions and Answers 1
A solid waste is determined to be a hazardous waste under the Resource Conservation and Recovery Act (RCRA) if it exhibits certain characteristics.
Which of the following is NOT one of the four characteristics of a hazardous waste?