While some regulatory compliance monitoring is required at entry points, other monitoring must be completed in the distribution system. Samples for testing of microbiological contaminants, disinfection by-products, and disinfectants are collected throughout the distribution system.

Results of Microbiological Testing in the Distribution System

The Safe Drinking Water Act requires water systems to meet standards for total and fecal coliform bacteria. Because most water systems in the United States disinfect their water supplies, waterborne diseases caused by bacteria are rare in this country.

Each month, samples are collected from sample points throughout the distribution system and tested for total and fecal coliform bacteria. Many customers have allowed us to use water taps at their homes and businesses to collect samples. In 2007, a total of 2,546 samples were collected and tested for total and fecal coliform bacteria.

Results of Disinfection Byproduct Testing in the Distribution System

During disinfection, disinfection byproducts form as a result of chemical reactions between chlorine and naturally occurring organic matter in the water. USEPA has set standards for two kinds of disinfection byproducts: Total Trihalomethanes and Haloacetic Acids.

The New Mexico Environment Department (NMED) has directed the Utility to collect one sample every three months at six locations in the distribution system. Each sample is tested for Total Trihalomethanes and Haloacetic Acids. The results for the entire distribution system for 2007 are shown below.

Results of Disinfectant Testing in the Distribution System

The water supply is disinfected with sodium hypochlorite. Generated on-site from table salt and water, sodium hypochlorite is like weak household bleach.

Each time a sample for microbiological testing is collected, the level of chlorine in the sample is measured.

Seen any of these in your neighborhood?

New Sample Hydrants

For many years, many of you have allowed Water Quality Specialists access to water taps outside your homes for collection of water samples. We thank you. However, like the mailman or the meter reader, Water Quality Specialists often encounter difficult circumstances. A new dog, a new fence, or a broken or frozen faucet make a sample site unusable. Line Maintenance crews have installed the first of many sample hydrants dedicated to the collection of samples with better quality control, and easier access. The hydrants are enclosed in kelly green boxes that look much like a cable T.V. box. Made especially for the Water Authority, each box is marked with our logo and should have a lock on the side. For more information about the sample hydrants call the Water Systems Division at 857-8260 or email This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .