EPA Final Rule Revises Test Procedures For Determining Pollutants in Wastewater

By Linda Roeder  


Municipal wastewater treatment plants and companies required to monitor their wastewater discharges will have more flexibility for testing pollutants under an Environmental Protection Agency final rule scheduled for publication May 18 in the Federal Register.

The rule, proposed Sept. 23, 2010, will require new technologies and new versions of EPA-approved methods that have been in use for many years (75 Fed. Reg. 58,024; 185 DER A-15, 9/27/10).

National Pollutant Discharge Elimination System permits, which are designed to ensure compliance with the Clean Water Act's technology-based and water-quality based requirements, may include restrictions on the quantity of pollutants as well as requirements for measuring pollutants and reporting results.

To comply with the terms of the permits, permit holders must use EPA-approved test methods. Permit holders often can choose their method for analyzing pollutants because EPA has approved more than one method.

The final rule includes two updated methods for the pathogen cryptosporidium and the parasite giardia, which use filtration. The methods allow the flexibility to choose among several types of filters, quality controls, and stains, and clarify the measurement of sample temperatures, quality control sample requirements, and use of quality control sample results.

The rule adds methods for testing for pesticides in municipal and industrial wastewater and adds a standardized simulated weathering test method for predicting mine drainage quality. The rule also approves several ASTM International testing methods for existing and new inorganic compound pollutants, such as cyanide and dissolved oxygen, and revises cyanide handling instructions.

Oil, Grease Addressed.

The rule adds a new version of a method for testing for oil and grease, but EPA said it also is evaluating another method that uses a different extractant and a different measurement technique.

In addition, the rule changes current regulations to clarify procedures for obtaining review and approval for the use of alternate test procedures.

The rule clarifies that an analyst using a consensus standard method, such as ASTM International, for reporting under the Clean Water Act also must comply with the quality assurance and quality control requirements in that standard.

The final rule contains a few differences from the proposed rule. For example, in response to comments, EPA decided not to include a method for testing brominated diphenyl ethers in water, soil, sediment, and tissue. EPA said it agreed with commenters that additional validation methods are needed.

Addressing a proposed method for measuring chlorinated biphenyl congeners in water, soil, sediment, biosolids, and tissue, EPA said it is still evaluating the large number of public comments and plans to make a determination on the method at a later date.

Bisphenol A Provision Removed.

The final rule does not include the proposed rule's provisions to add two proposed ASTM methods for determining bisphenol A and other substances in wastewater. The agency said it is postponing approval for completion of a full validation study.

The final rule also removes an EPA method for measuring mercury. The agency said its inclusion was an error.

The rule will take effect June 18.

By Linda Roeder  

For more information on this rule under Docket No. EPA-HQ-OW-2010-0192, contact Lemuel Walker in EPA's Office of Science and Technology at (202) 566-1077 or at walker.lemuel@epa.gov.