EPA Method 334.0 is a quality control protocol for chlorine residual monitoring, published by EPA in 2009. Method 334.0 is intended for use by drinking water facilities for compliance with daily monitoring and analysis of residual chlorine (free or total) and serves as a quality control procedure used to ensure that results obtained for residual chlorine at drinking water systems are accurate and precise.
Tutorial Video Series
DEP created a series of tutorial videos to guide public water systems through the various requirements of Method 334.0:
The following are graphical instructions for the method procedures:
In addition, the following spreadsheet can be used to calculate and document the analyst Initial Demonstration of Capability (IDC) for the grab sample method
Does it apply to my water system?
Pennsylvania drinking water systems are expected to follow Method 334.0 if they use a handheld, benchtop or on-line chlorine analyzer for any of the following:
- compliance monitoring at both the entry point and in the distribution system;
- monitoring used to obtain results for calculating giardia or virus inactivation;
- chlorine monitoring required as a permit condition.
In short, all community water systems, all nontransient noncommunity water systems using chlorine and any transient noncommunity water system with a surface water source or that use chlorine to achieve 4-log treatment of viruses are required to follow Method 334.0.
How does my water system become Method 334.0 compliant?
Method 334.0 applies to both the individual conducting chlorine analysis, and the analyzer used to obtain results. The following portions of the method are required for a water system to be compliant with Method 334.0:
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- The field sampler initial demonstration of capability (Method 334.0 Section 10.1.2) is required for any individual who conducts chlorine analysis at the water system. (DEP FORM ID: 3900-FM-BSDW0544)
- The initial calibration verification (Method 334.0 Section 10.1.1) is required for any handheld or benchtop analyzer used for chlorine analysis or used for comparison grab sampling within Method 334.0. (DEP FORM ID: 3900-FM-BSDW0545)
- Routine calibration verifications (Method 334.0 Section 11.1) are required quarterly for any handheld or benchtop analyzer used for chlorine analysis or used for comparison grab sampling within Method 334.0. (DEP FORM ID: 3900-FM-BSDW0546)
Note: The next two requirements are applicable to on-line analyzers only.
- An initial demonstration of capability (Method 334.0 Section 10.2.2) is required for any on-line analyzer used for compliance monitoring and analysis or to obtain results used for calculating giardia or virus inactivation. (DEP FORM ID: 3900-FM-BSDW0561)
- Routine grab sample comparisons are required, at a minimum of once every seven days, between a Method 334.0 compliant handheld or benchtop analyzer and any on-line analyzer used for compliance monitoring and analysis or to obtain results used for calculating giardia or virus inactivation. (DEP FORM ID: 3900-FM-BSDW0548)
In addition to the required portions of the method specified in the bullets above, the use of secondary standards with the handheld or benchtop analyzers used for chlorine analysis and comparison sampling is recommended by Method 334.0 (Method 334.0 Section 11) and encouraged by DEP (DEP FORM ID: 3900-FM-BSDW0547).
How do I document my water system's compliance with Method 334.0?
DEP has developed six forms for the five required and one recommended portions of Method 334.0 described above which can be used to properly document compliance with the method. Follow the hyperlinks in the previous section to download each applicable form.
The IDC Calculation spreadsheet can also be used to document the analyst IDC for the grab method. Follow the hyperlink in the Job Aids section above to access the spreadsheet.