As the New Year approaches, I propose we make two commitments: We must commit to using the scientific method, and we must rely on testing to make decisions and recommendations. As scientists, we should always use the scientific method when we approach a situation. Some professionals rely on their experience and regulatory monitoring to develop a solution. This is not the scientific method. The evidence and experience should be used to generate a hypothesis and develop a means of testing. This assessment phase provides an opportunity to use field testing equipment or even water testing services that are accurate and reliable, but may or may not be “certified.”
Because of the regulatory climate and “cookbook” nature of some governmental guidance documents and operational permits, our approach to operating water facilities has been focused on meeting regulatory monitoring benchmarks. This approach tends to rely on routine operational monitoring and some regulatory performance monitoring using only certified testing data. Routine performance monitoring has a regulatory role, but it is reactive and provides a limited snapshot of the system performance.
We may have many permitted facilities, but this approach to evaluating and tracking a system does not help with initial design, troubleshooting or diagnosing a problem. Therefore, we need multiple available avenues for water testing that may include field testing supplies and equipment, low-cost water quality screening testing, high-quality laboratory testing, and certified laboratory testing. These should be parts of our toolkits.
Because certified laboratory testing can be expensive and time consuming and provide limited information, field testing and screening can be used to cost-effectively and proactively track a system and, if necessary, diagnose a problem. Consider adding more field testing and screening to your diagnostic and operational toolkit. Initially, taking this approach may not make you friends with some regulators, but your clients will be happy that you are using a fact-based method that can be confirmed using certified water quality testing to identify and solve problems.
When taking this approach, we must be able to address the what, why, who and how.
What is the nature of the system? Is it a private drinking water system or source, or part of a public water supply, bottled water operation or industrial application?
Why are we evaluating this problem? Are we troubleshooting a malfunction within the system or are we addressing a new issue?
Who needs to be part of this assessment, and are we getting all the background information?
How will the testing be conducted, and what is the level of accuracy and precision that is needed? For example, can I use a field screening test for manganese, or do I have to collect samples and submit them for certified analysis?
Field Testing in Action
To better explain this approach, here is an example.
A small, transient, non-community restaurant water source that uses well water tested positive for E. coli. The owner contacted the local state representative, who recommended the owner call the Water Research Center. After the state had completed an inspection and assessment of the system and put the restaurant on a boil-water advisory, we were hired. The state strongly suggested that the system install 4-log disinfection to control E. coli. Upon being hired, we did the following:
- Reviewed all the documentation and where samples were collected;
- Inspected the system and all sampling sites;
- Conducted a limited pumping test of the well and field-monitored water quality monitoring during this testing, and collected water samples when there was a significant change in pH, conductivity, turbidity, temperature, appearance or the oxidation reduction potential (ORP);
- Submitted field samples for informational water testing to check the levels of major cations and anions in the water, heterotrophic bacteria, and nuisance bacteria, and certified testing for total coliform and E. coli counts, not a presence/absent method;
- Conducted field monitoring of the interior distribution system, which include monitoring for pH, conductivity, turbidity and ORP, and then used these findings to develop a sampling plan; and
- Implemented a sampling plan that included a combination of informational and certified water testing. The informational bacterial testing was done using Biological Activity Reaction Testers and presence/absence media with MUG. Some certified testing utilized the standard total coliform plate count method with confirmation testing for E. coli and testing for heterotrophic bacteria. We found the following:
- State-approved sampling sites were not appropriate because of issues related to the presence of backflow issues, dead-end service lines, chemical scale, corrosion damage, use of mixing valves and leaky faucets. We found that these conditions biased the sampling results.
- The water well had a leaking pitless adapter and 40 ft of casing with intermittent cascading water. The well casing needed to be relined and pitless adapter repaired.
- The information water testing confirmed that the system had a problem with slime-forming bacteria, and trace levels of iron and manganese, and the raw water E. coli count was 3 colonies per 100 mL.
- There was a significant bacterial regrowth problem within the cold and hot water piping. The well and distribution system was shock disinfected, and the hot water system was pasteurized and flushed.
After we addressed the real problems, E. coli in the raw water was absent, and the facility was providing water that met drinking water standards. If we had used the approach recommended by the state, a 4-log treatment system would have been installed and the system would be required to hire an operator, but the system might not have been fixed.
We need all the tools in our toolbox, including field testing methods, field monitoring equipment and high-quality informational water testing. Certified water is critical, and we should use this testing to check our initial findings and benchmark the system.