Robin Salverson, South Dakota State University Extension Cow/Calf Field Specialist
(Previously published with South Dakota State University Extension: November 18, 2021)
Water 
sources that are often assumed to be safe, such as spring fed reservoirs and clear appearing water, can still be high in salts/sulfates. The visual appearance of water should not be used to determine if the water is good or bad. The only way to know if water is suitable for livestock is through testing.
Health Considerations
Poor-quality water will cause an animal to drink less. As a result, they also consume less forage and feed, which leads to weight loss, decreased milk production, and lower fertility.
Polio
Sporadic cases of polio can be seen when high levels of sulfates are present in the water. A common symptom of polio is blindness, but other signs include: lethargy, anorexia, muscle tremor, exaggerated response to sound and touch, incoordination, staggering, weakness, head pressing, and eventually convulsions and inability to get up. Polio can be successfully treated if caught early. Thiamine injections and anti-inflammatories are important components of treatment. Antibiotics will not solve the problem. Contact your veterinarian to determine your treatment plan if you have any concern of potential losses due to polio.
Sulfates
Research conducted at the South Dakota Agricultural Experiment Station Cottonwood Range and Livestock Field Station near Philip, SD has evaluated the effect of high sulfate on both cow-calf pairs and yearling steers grazing pastures. Both classes of livestock were negatively impacted. Cows consuming high sulfate water (2608 ppm) lost 36 pounds, while cows on low sulfate water (388 ppm) gained 15 pounds during the treatment period (June 3 to August 26). Yearling steers grazing pastures with high-sulfate water had a decreased average daily gain and a few cases of polio at levels of 3900 ppm and 4600 ppm.
Mineral Nutrition
Minerals in the water can also tie-up trace minerals, especially copper. High levels of sulfur and molybdenum (found in forages) binds with copper to form thiomolybdate, which is unavailable to the animal. Iron also binds to copper and decreases the amount the animal can utilize. Having adequate copper in the diet is critical for reproduction and immune function.
Summary
Be proactive and monitor your water and your livestock. Just because your neighbor does not have problems does not mean you will not.