Understanding The Changes To CWA Test Procedures

Some of the most important work for providing wastewater services and protecting the environment happens in laboratories dotted around the country. This is where regulators analyze wastewater samples to ensure that what’s coming out of factories and treatment plants adheres to the proper guidelines for public safety.

For instance, regulated or regulatory entities must use U.S. EPA-approved methods to determine compliance with Clean Water Act (CWA) provisions such as National Pollutant Discharge Elimination System permits. In a shakeup to the fundamental procedures used by these laboratories, the EPA has updated the list of approved test procedures used to analyze wastewater under the CWA, giving industry and municipality testers more options.

“EPA periodically updates the list of approved methods to reflect advances in technology, refine quality assurance and quality control requirements, and provide entities more choices of approved compliance methods,” an agency spokesperson said. “EPA’s administrator signed a final rule on December 15, 2016 approving additional analytical methods to be used to measure pollutants in wastewater, as well as clarifying the approval process for alternate test procedures and making revisions to the method detection limit procedure.”

The updates were an effort to improve flexibility and add methods that improve data quality and utilize newer technology.

“Data quality is improved by increasing the efficiency, performance, effectiveness, and outcomes of the methods,” said the spokesperson.

The EPA asked voluntary consensus bodies, like the standards development organization ASTM International and the Standard Methods Committee, to submit methods for target analytes. It also utilized a solicitation method built into the CWA.

“A number of methods were submitted to EPA for potential inclusion as an approved method via the Alternate Test Procedures (ATP) program,” said the spokesperson. “Those methods that met the ATP data standards were included in the Methods Update Rule for stakeholder comment and potential approval.”

Stakeholders found that commercial laboratories favored EPA Methods 608.3, 624.1, and 625.1, which haven’t been updated since they were introduced 20 years ago.  So, they were selected for revision via the Methods Update Rule and the EPA added several analytes that the methods didn’t include.

The update will also address laboratory contamination and variability issues, though the EPA pointed out that these have not been significant problems within the previous methods.

“The procedure for Method Detection Limits within the methods was improved to remove blank contamination issues,” said the spokesperson. “Laboratory contamination and variability can greatly influence method results. Increased vigilance for these issues continues to be addressed via quality assurance, quality control, and standards use in the methods.”

Ultimately, it will be up to individual regulators to decide if and when they will adopt the additional methods. For its part, the EPA seems to think that the sooner they do so, the better.

“Adoption of the methods may increase efficiency and productivity, since the methods can be both faster and more cost-effective,” the spokesperson said. “Additionally, because of the performance-based flexibility of the methods, laboratories are able to make modifications to the methods without EPA review.”