Drinking Water Labs Gain an Ally

Automated flow analyzer provides fast, cost-effective, and accurate results.

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By Brant Hoekstra

The United States Environmental Protection Agency’s National Primary Drinking Water Regulations (NPDWRs) list standards for over 100 chemical and microbial contaminants. Though this country has some of the safest water sources in the world, drinking water facilities must always be vigilant, as contaminants cannot always be seen, smelled, or tasted, and the consequences of contaminated water can be devastating.

Most drinking water facilities test for nitrates, nitrites, and phosphate on a daily or weekly basis, as they are very common contaminants found in groundwater aquifers and surface water. All three occur naturally in the environment, are also used in agriculture and industry, and are found in wastewater and solid waste as part of the process of decomposition. High levels of nitrates and nitrites have been linked to birth defects and methemoglobinemia (blue baby syndrome). Excess levels of phosphates accelerate plant growth and algal blooms, resulting in the spread of cyanobacteria and their toxins and making drinking water unsafe for human and animal consumption.

A drinking water treatment plant will typically perform dozens of tests throughout its facility over the course of any given day. On-site labs often find themselves working with limited resources, so it is critical that their testing be fast, accurate and cost-effective. One technique that has often been used is ion chromatography. Though accurate, ion chromatography is slow, running four to six samples per hour, which for a smaller facility can be adequate to get the job done. It is a difficult technique to master and the systems are usually quite complex. There are EPA methods for the technique, but the equipment can be quite expensive, with a high acquisition cost as well as cost per sample.

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The FS 3700 simplifies the automation of wet chemistries including ammonia/TKN, nitrate/nitrite, total phosphorus, and even the occasional cyanide test.

Utilizing segmented flow analysis (SFA) or flow injection analysis (FIA), continuous flow analyzers offer an efficient, reliable alternative to ion chromatography. The Flow Solution™ 3700 Automated Chemistry Analyzer from OI Analytical, a Xylem brand, is designed to improve laboratory productivity by automating wet chemistry procedures. With the ability to run upwards of 30-60 samples per hour, it provides a high-throughput solution for drinking water labs. With easy-to-use, icon-driven, Windows-compatible software that doesn’t require a PhD to run, the FS 3700 simplifies the automation of wet chemistries including ammonia/TKN, nitrate/nitrite, total phosphorus, and even the occasional cyanide test. Pre-configured, interchangeable chemistry cartridges take the guesswork out of set-up and plug-and-play photometric, amperometric, ion-selective, or third-party detectors provide additional flexibility for optimum results.

With reading accuracy equivalent to that of an ion chromatography system and an acquisition cost and cost per sample that are significantly less, the Flow Solution 3700 offers drinking water facilities an easy-to-use, reliable solution that will give them the results they need to stay in compliance, without going over their budget.

No matter what type of system on-site labs choose, what is important is accurate, consistent analysis. As the demand on drinking water sources continues to grow, it will be even more imperative to safeguard our limited water supply. Rapid, accurate testing helps drinking water facilities detect nutrient pollutants before they become a danger to the supply of clean water, protecting our health and our environment.


Brant Hoekstra is the analytical products manager for OI Analytical, a Xylem brand.

OI Analytical, a Xylem brand, is exhibiting at AWWA’s ACE16 expo in Booth 1866.

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