Public water systems (PWS) and particularly small PWS should keep up to date with EPA announcements in the Federal Register of alternative test procedures to measure the levels of contaminants in drinking water.  Such measurements are a required step in determining compliance with the national primary drinking water regulations.

In its most recent action, the Agency approved 21 methods that can be used as alternatives to methods listed in the Safe Drinking Water Act (SDWA) regulations.  The alternatives are newer than the listed procedures and, therefore, are typically simpler and less costly.

Statutory authority

SDWA Section 1401(1) states that once the EPA has issued a regulation specifying a testing procedure, the Agency may then allow the use of “equally effective” alternative procedures, which the EPA publishes as guidance in the FR.

In 2007, the Agency initiated an expedited process that avoids rulemaking to authorize the use of alternatives.  Since then, about 270 expedited alternative methods have been approved.  The expedited methods are collected at 40 CFR 141 Appendix A to Subpart C and on EPA’s drinking water methods website.

E. coli, total coliform, and other contaminants

The most recent collection of 21 alternative methods includes:

• Fourteen standard methods developed by voluntary consensus standard bodies.  The EPA compared the most recent online versions of the 14 standard methods to earlier versions currently approved in 40 CFR Parts 141 and 143.  The revisions primarily involve editorial changes (e.g., corrections of errors, procedural clarifications, and reorganization of text).  The updated online version the EPA lists in its FR notice are the same as the earlier approved versions with respect to the chemistry and microbiology, sample handling protocols, and method performance data.  Contaminants tested by these methods include temperature, metals, fecal coliform, total coliforms, and E. coli.
• Three ASTM International methods.  The EPA compared the most recent versions of the three ASTM International methods (ASTM Methods D512–12 B, D3223–12, and D4327–11) to the earlier versions of those methods that are currently approved in 40 CFR 141 and 143.  Changes between the earlier approved version and the most recent version of each method involve editorial changes (e.g., updated references, definitions, terminology, procedural clarifications, and reorganization of text).  Contaminants tested by these methods are chloride, mercury, fluoride, nitrate, nitrite, orthophosphate, and sulfate.
• The following four expedited methods were developed by vendors:
  • IDEXX Laboratories, Inc. Colilert-18R.  Colilert-18R is an approved commercial medium capable of simultaneous detection of total coliform and E. coli.
  • Hach Company Method 10260.  This method determines chlorinated oxidants (free and total) in water using disposable planar reagent-filled cuvettes and mesofluidic channel colorimetry.
  • Palintest Ltd ChlordioX Plus Method—Chlorine Dioxide and Chlorite in Drinking Water by Amperometry using Disposable Sensors.  This method uses recyclable disposable sensors for amperometric detection of chlorine dioxide and chlorite, a disinfection by-product, in drinking water.
  • Veolia Water Solutions and Technologies Tecta EC/TC Method—Presence/Absence Method for the Simultaneous Detection of Total Coliforms and E. coli in Drinking Water.  This is a microbiological method for the simultaneous detection of total coliforms and E. coli in drinking water by broth enrichment of samples.

EPA’s latest list of expedited drinking water test methods was published in the June 19, 2014, FR.