The Importance of Proper Sample Collection

Field Sampling, Measurement & Sensor Technology
Oral Presentation

Prepared by J. Monroe
MWRDGC, 6001 Pershing Road, Cicero, Illinois, 60804, United States

Contact Information:; 708-588-4161


Samples are collected daily at wastewater treatment facilities across the country to be analyzed for myriad components. The resulting data are then used by several distinct, yet interrelated, groups. Treatment plant operators review the results of analyzed samples to evaluate plant efficiency and identify where to make operational adjustments. Research and development scientists require sample data while testing prospective processes and emerging technologies. Treatment works use data to determine surcharges imposed on significant industrial users to discharge high strength waste. The Environmental Protection Agency reviews sample data provided by treatment plants to ensure discharge permit limit compliance. Publicly owned treatment works may also provide analytical results to its rate payers along with environmental activist groups. With so many depending on reliable data, it is paramount that the results of analyses are accurate and precise.

The process of collecting samples can have a significant impact on the accuracy and precision of analytical results, regardless of the diligence of the laboratory analyzing them. Sample contamination prevention, proper containers/labels, and thorough documentation are essential for generating accurate data. Failure to train new technicians using a documented procedure can lead to inconsistent sample collection and thus lead to imprecise data. Implications of using inaccurate data can range from improper plant process adjustments to receipt of noncompliance fines from the Environmental Protection Agency.

General safety, documented standard operating procedures, representative samples, preservation, contamination, chain of custody, accountability, and repercussions of improper sample collection are topics that will be covered. Chemical analysis of samples is dependent on variables. As the audience's awareness and control of these variables increases, so too will the reliability and reproducibility of data. This informative presentation will be of value to entry level treatment works employees as a training tool and to seasoned technicians as a refresher course.