CEI Environmental Monitoring & Testing Flashcards

What does a turbidimeter measure in water quality monitoring?

Answer: Cloudiness caused by suspended particles

A turbidimeter measures turbidity, the optical clarity of water, by quantifying light scattered by suspended particulate matter.

Which chain-of-custody requirement is most critical when collecting environmental samples for legal proceedings?

Answer: Sample custody must be documented and unbroken from collection to analysis

An unbroken, documented chain of custody ensures sample integrity and admissibility in legal or regulatory proceedings by tracking possession at every transfer.

What does a passive air sampler measure compared to an active air sampler?

Answer: It collects contaminants by diffusion without a pump over an extended period

Passive air samplers collect airborne contaminants through diffusion alone — no pump required — allowing time-weighted average concentrations to be measured over days or weeks.

In ambient air quality monitoring, what does the acronym 'NAAQS' stand for?

Answer: National Ambient Air Quality Standards

NAAQS are EPA standards that set maximum allowable concentrations for six criteria pollutants in outdoor air to protect public health and welfare.

Which sampling method involves collecting water from a stream at regular time intervals to create a representative composite sample?

Answer: Time-integrated composite sampling

Time-integrated composite sampling combines sub-samples collected at fixed intervals, producing a sample that represents average water quality over the sampling period.

What is the purpose of a field blank in environmental sampling quality control?

Answer: To detect contamination introduced during sample handling and transport

A field blank uses clean water or media that is opened, exposed to field conditions, and processed identically to samples to identify cross-contamination during collection or transit.