Methods for Water Research

On this page:

Per- and Polyfluoroalkyl Substances (PFAS)

  • PFAS Standard Analytical Methods
    EPA scientists are developing validated analytical methods for drinking water; groundwater; surface water; wastewater; and solids, including soils, sediments, biota, and biosolids, which may eventually become standard methods or research methods. This site includes available standard analytical methods for 1) drinking (potable) water, 2) non-potable water and other environmental media, and 3) source (air) emissions. It also includes information on other methods in development; links to other non-EPA federal analytical methods; and sampling resources data analysis, and laboratory certification resources.

Cyanotoxins

Drinking Water 

  • Drinking Water Research Methods
    Residues of unregulated contaminants may be present in drinking water, however little is known about their prevalence in the environment. To protect human health, EPA scientists have developed a number of EPA methods to detect unregulated contaminants. This site includes numerous methods listed under the following categories: 1) Per- and Polyfluoroalkyl Substances (PFAS), 2) Cyanobacteria Toxins (Cyanotoxins), 3) Volatile and Semivolatile Organic Compounds, 4) Other Inorganic Contaminants, and 5) Other Organic Contaminants.
  • Microbiological Methods and Online Publications (Bacteria, Protozoans, Viruses, and Coliphage)
    EPA scientists have developed a variety of methods to detect, characterize and study bacteria, protozoans, viruses and coliphage. These methods are used by EPA and state and regional water quality managers to protect human health by keeping drinking water and recreational water safe.

Remediation and Recovery

  • Selected Analytical Methods for Environmental Remediation and Recovery (SAM)
    SAM identifies analytical methods that can be used by laboratories performing analyses of environmental and building material samples following a contamination event. Laboratories may use this information to evaluate the nature and extent of contamination and assess decontamination efficacy. In addition to providing the SAM document in its entirety, this site contains a tool that allows users to easily query the SAM methods.

Wastewater 

Ambient/Environmental Waters

EPA's research in stream and source monitoring indicators includes fish, macroinvertebrates, periphyton, zooplankton, functional ecosystem indicators, water and sediment toxicity, and fish tissue contaminants. EPA exposure scientists regularly prepare and update field and laboratory protocol and methods manuals. They also provide technical assistance to EPA regions, program offices and states on the implementation and interpretation of these manuals. This website lists currently available manuals and protocols.

Biological Methods and Manual Development

EPA scientists conduct research to develop and evaluate analytical methods for the identification, enumeration, and evaluation of aquatic organisms exposed to environmental stressors and to correlate exposures with effects on chemical and biological indicators. Environmental measurements are required to determine the quality of ambient waters and the character of environmental stressors. Possible environmental stressors include chemical pollutants; microbes and pathogens; physical agents, such as land use; and processes, such as alteration of wildlife habitat.

Field Methods

Toxicity and Contaminant Methods

Additional Methods

  • Method 1609.1: Enterococci in Water by TaqMan® Quantitative Polymerase Chain Reaction (qPCR) with Internal Amplification Control (IAC) Assay
    Quantitative qPCR procedure for the detection of DNA from Enterococci bacteria in ambient water matrices based on the amplification and detection of a specific region of the large subunit ribosomal RNA gene (lsrRNA, 23S rRNA) from these organisms. An IAC is added to each qPCR analysis for Enterococcus DNA and is co-amplified simultaneously with the target sequence to specifically identify polymerase inhibition in the reactions. The advantage of this method over currently accepted culture methods that require 24 − 48 hours to obtain results is its relative rapidity. Results can be obtained by this method in 3-4 hours.  This method gives beach managers the ability to alert beach-goers to unsafe levels of microbial contamination on the same day that the sample is taken.
  • Method 1611: Enterococci in Water by TaqMan® Quantitative Polymerase Chain Reaction (qPCR) Assay
    Quantitative qPCR procedure for the detection of DNA from Enterococci bacteria in ambient water matrices based on the amplification and detection of a specific region of the large subunit ribosomal RNA gene (lsrRNA, 23S rRNA) from these organisms. The advantage of this method over currently accepted culture methods that require 24−48 hours to obtain results is its relative rapidity. Results can be obtained by this method in 3-4 hours. This method gives beach managers the ability to alert beach-goers to unsafe levels of microbial contamination on the same day that the sample is taken.
  • Microbiological Methods and Online Publications (Bacteria, Protozoans, Viruses, and Coliphage)
    EPA scientists have developed a variety of methods to detect, characterize and study bacteria, protozoans, viruses and coliphage. These methods are used by EPA and state and regional water quality managers to protect human health by keeping drinking water and recreational water safe.
  • Single Laboratory Validated Method for Determination of Cylindrospermopsin and Anatoxin-a in Ambient Freshwaters by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS) (pdf)
    This standardized, single laboratory validated liquid chromatography/tandem mass spectrometry (LC/MS/MS) method is used for the detection of cyanotoxins—cylindrospermopsin and anatoxin-a (combined intracellular and extracellular)—in ambient freshwaters. It requires the use of very small volumes of organic solvent and very small quantities of pure analytes, thereby minimizing potential hazards to both the analyst and the environment as compared to the use of large volumes of organic solvents in conventional liquid-liquid extractions.
  • Single Laboratory Validated Method for Determination of Microcystins and Nodularin in Ambient Freshwaters by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS) (pdf)
    This standardized, single laboratory validated liquid chromatography/tandem mass spectrometry (LC/MS/MS) method is used for the detection of cyanotoxins—microsystins and nodularin (combined intracellular and extracellular)—in ambient freshwaters. It requires the use of very small volumes of organic solvent and very small quantities of pure analytes, thereby minimizing potential hazards to both the analyst and the environment as compared to the use of large volumes of organic solvents in conventional liquid-liquid extractions.
  • Standard of Practice for Determination of Nonylphenol Polyethoxylates (NPnEO, 3 ≤ n ≤ 18) and Octylphenol Polyethoxylates (OPnEO, 2 ≤ n ≤ 12) in Environmental Waters EXIT
    Nonylphenol (NP) and octylphenol (OP) have been shown to have toxic effects in aquatic organisms. The prominent source of NP and OP is from common commercial surfactants, which are longer chain alkylphenol ethoxylates (APEOs). This practice screens for the longer chain APEOs which may enter sewage treatment plants at elevated levels and may cause violations of permitted discharge concentration of NP. It covers determination of NP and OP polyethoxylates in water by Single Reaction Monitoring Liquid Chromatography/ Tandem Mass Spectrometry using direct injection liquid chromatography and detected with tandem mass spectrometry detection. 
  • Standard Test Method for Bisphenol A in Environmental Waters EXIT
    The environmental source of BPA is predominantly from the decomposition of polycarbonate plastics and resins, which are used in a wide range of commercial products. BPA has been reported to have adverse effects in aquatic organisms and may be released into environmental waters directly at trace levels through landfill leachate and POTW effluents. This method has been investigated for use with surface water and secondary and tertiary POTW effluent samples therefore, it is applicable to these matrices only.

Water Research

Contact Us about Water Research
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on January 15, 2025