As a rule, you probably don't give a lot of thought to your horses drinking water, but it does have a direct influence on his health and well-being. Dissolved in that clear liquid are minerals absorbed from the environment the water flows through, as well as chemical contaminants and bacteria picked up along the way.
Much as we'd like to believe that the water our horses consume is "pure," the truth is that water completely untouched by chemicals or minerals doesn't exist in nature. Water is, after all, the universal solvent, with a unique ability to pick up and dissolve virtually everything it comes in contact with. The substances contained in drinking water aren't necessarily bad; minerals dissolved in water impart much of its flavor, and many are beneficial, such as fluoride in city water supplies.
Instead of worrying about water purity, focus on whether it's safe for our horses to drink – that none of its contents are infectious or toxic.
Location Affects Water Supply
If you live in suburbia, your barn may draw its water from a public or municipal system that provides extensive purification and filtration services, and also regularly tests its water for contaminants. Worries are few with this type of system, but there are no guarantees. The testing is done at the source, but damage to the delivery line, or a problem with the plumbing on your property, could taint your water.
Living in the country is a different deal. More diligence is required if, like the majority of horse owners, you draw your barn's water from a well. An annual Total Coliform test is a good idea for all wells. The test checks the water for bacteria that normally are found in the soil, in surface water and in human and animal waste.
A few coliform bacteria are not, in themselves, considered harmful, but their presence in your water supply is an indication that your well may be contaminated by run-off from your manure pile or a nearby septic bed tank. Coliform levels rise in drought conditions, when there's a sudden heavy rainfall or when there is any unusual change in weather patterns. It's also possible to have high coliform levels when the well has physical defects, such as a broken or missing cap that could allow debris, surface water, insects, or rodents inside.
When To Do Bacterial Testing
Wells that are correctly drilled, well protected, and more than 50 feet deep generally have less chance of becoming contaminated with bacteria. If you have such a well and several previous bacterial tests have come back negative, you may need to test every 2 to 3 years. Water from an old or shallow well should be tested more frequently.
An agricultural extension agent or an agricultural university can conduct water testing for coliform bacteria. Some private labs also offer water testing. When you contact a lab about water testing make sure you follow its instructions for collecting your sample meticulously. Incorrect collection procedures can easily contaminate your water sample and lead to false test results.
Minerals: Good News or Bad?
Bacteria aren't the only concern with drinking water. The mineral content can influence its taste, smell, and palatability. The classic example is "sulfur water," which has that characteristic rotten-egg odor. Minerals are rarely toxic from water. However, if you have a concern, a lab can test your water for levels of calcium, magnesium, manganese, iron, copper, zinc, sodium, chloride, and lead, as well as sulfates and nitrates. Concentrations of these minerals, if sufficiently high, can have an impact on your horse's dietary balance because levels of one mineral in his system often can influence his ability to absorb another. Water can provide all the iodide, and from 4 to 20 percent of the daily requirements for salt, calcium, magnesium, manganese, cobalt, and sulfur, but less than 1 percent of other minerals.
What To Do If You Have Contamination