Comments from the City of…

Comments from the City of Hamilton Environmental Laboratory

Protocol of Accepted Drinking Water Testing Methods Version 3.0 Draft

1. Introduction, consider defining drinking water as water intended for human consumption as per Part 1 of SDWA. Often when the term drinking water is used, it is thought to be treated water. However raw water also falls under the requirements of the Regs, lab licensing and these guidance documents. Labs are required to be licensed to analyze private well water also – any water intended for human consumption. Defining the term would clarify the scope of this document.

1.2.1 Criteria for Licensing – Accepted Reference Method

Method Detection Limit (MDL)
Consider providing guidance document or reference method for determining matrix effects on MDL. Specifically for the following: “The laboratory must validate the MDL and determine any impacts of the matrix effect from drinking water and any preservative(s)”.
“Calculate the MDL in accordance with the laboratory’s policies and at a minimum it should follow the criteria in AWWA Method 1020 B “Quality Control””. Consider allowing labs to follow MISA protocol for MDLs. Most labs in Ontario follow the MISA Estimation of Analytical Method Detection Limits 1991.

Data Reporting

Reporting Overgrown Microbiology Tests

Using this definition only applies to selective agars. There is no overgrown condition in P/A. In MPN the tray limit is reached, but this isn’t considered the same as what is described. This would be better if “where appropriate” was added, like what CALA does for microbiology tests.

1.2.2 Additional Criteria – Alternate Reference/In-house Methods
b) Selectivity “For microbiology methods, selectivity can be demonstrated through testing target organisms for positive results and potentially interfering non-target micro-organisms for negative results” - This only applies to selective tests and not to HPC. “Where appropriate” could be added here.

2.1.1 Methods for both Total Coliforms and Escherichia coli (E. coli)
Method E2561 Presence-Absence Test for Coliform Bacteria, including Escherichia coli, in Drinking Water by Colilert® Quanti-Tray®.
- The title of this method indicates that Colilert® Quanti-Tray® is a Presence/Absence test, however, it is not since Quanti-Tray produces a result in MPN/100mL.

2.4 Cryptosporidium and Giardia
Recommend adding LaSB method for PCR: MECP 3512.

3.1 (VOC’s)- spelling error (should be “xylene”); RDL for xylenes applies to the sum of ortho zylene

3.2 Trace Metals US EPA Methods and throughout various methods section:
Recommend removing revision number and replace with “ latest addition”. Several of these reference methods have newer revision numbers than the one’s listed here.

3.22 Sodium
Add reference method EPA 200.8.

Appendix C MECP Sample Collection and Handling Requirements

Inorganic Parameters, Mercury. Alternate preservation should be included. For example, the preservation listed in Version 2 of the practices for the collection and handling of DW samples for Mercury, “preserve 5 mL/L HNO3 to pH<2 then add 2 mL/L 20% (w/v) K2Cr2O7 solution (prepared in lab grade water)” This is equivalent to the preservation listed in the draft document.

Volatile Organic Compounds- clarify that holding time for unpreserved samples includes those dechlorinated with thiosulphate. Consider that raw water with low bacteria populations can be dechlorinated using thiosulphate without preservation. It is beneficial to have one type of VOC sample vial for the sampler to use for the collection of drinking water rather than two different vials with different preservatives.

Inconsistent wording for dechlorinating agents in Preservative section:

Triazines: preservative sodium thiosulphate for chlorinated water
Carbamates: Sodium thiosulphate for dechlorination
Microcystin: sodium thiosulphate

Practices for the Collection and Handling of Drinking Water Samples, Version 3.0 Draft

Administrative Comments:

2.0 Representative Samples and Representative Data, paragraph 2, missing a word in the last sentence. “These will be discussed in detail in Section 3”.

3.3 Sample Containers, Container Type, paragraph 2, remove “the” from the sentence, “For these methods, the laboratory will require a specific the type of vial with a Teflon septum cap”.

3.4.3 Sample Preservation, Dechlorination, typo in the following sentence, deepening should be depending, “There are different types of preservatives for this purpose depending on the laboratory and the testing method.

Items For consideration:

2.0 Representative Samples and Representative Data, last paragraph, last sentence contradicts 5.0 Summary. 2.0 states, “In summary, the test results are only as good as the sample that was collected”.

5.0 Summary states, “In short, the test results will only be as good as the sample that was tested”.

3.2 Sampling Location, paragraph 1, consider changing sampler to owner/operator as used in other parts of the document.

3.3 Sample Containers, Sample Volume, the document interchangeably uses travel blank and travelling blank, pick one and use it consistently.

3.3 Sample Containers – in our experience travel blanks are not opened in the field. Blanks that ARE opened in the field are called field blanks

3.3 Sample Containers, Sample Volume, paragraph 2, “Travelling blanks are typically high performance liquid chromatography (HPLC)-grade water or equivalent.” However, section 3.4.1 uses the term analyte free water. Recommend the use of analyte free water throughout the document. This term is more generic.

3.4.2 Sample Filtering
• Consider adding statement: Drinking water samples are not filtered unless required by the method of lab analysis”. This applies to analytes like DOC or to analytes analysed by IC. The Lab had an inspection finding in 2005 to add the following statement to all of our test methods “ Drinking water samples are not filtered, unless required by the method of analysis as per section 3.7 of the MOE document “Practices for the Collection and handling of DW Samples version 1”.

• Regarding “pre-analysis filtration for non-routine tests”- please define non routine tests?

• Regarding “This can be applied for using the Drinking Water Laboratory Testing Licence application form”. The link does not open that form, rather it opens a warning that the central forms repository has moved.

Also, currently for dissolved metals, a directors direction form or R&MD form is required to gain approval to test for dissolved metals. This section requires the use of a license application form instead. Does this mean that labs can once again be licenced for dissolved metals?

3.5 Specialized Sampling Techniques, 3.5.1 Volatile Organic Compounds (VOCs), paragraph 2 interchangeably uses travel and travelling blank, pick one and use it consistently.

3.5.2 Microbiological, paragraph 3, “To prevent further bacterial growth in the sample after it has been collected, the sample should be refrigerated and transported to the laboratory on ice, but not frozen”. However, section 3.7, says “ice should not be used in coolers for micro samples”. In practice, the verbiage in section 3.7 is correct – ice should not be used

3.5.3 Lead in Plumbing O. Reg 243/07 and Schedules 15.1 and 15.2 of O. Reg. 170/03
Regarding the list of information that should be recorded on either the sample label or on an accompanying chain-of-custody form”, specifically the street address : If the sample is taken from a sampling station in the distribution system, some sampling stations may not have street addresses. For example the location may be Sampling Station King St W opposite Central Park.