We're building an airport runway in Florida. Water from a local well is to be used as mixing water but it has a strong sulfur smell like rotten eggs. Will whatever is causing the smell affect concrete properties? Should we be looking for a different water supply? If the water is left in a glass overnight, the smell goes away.
The smell is hydrogen sulfide, a dissolved gas present in some well waters. Research Department Bulletin 119 from the Portland Cement Association says that quantities of hydrogen sulfide in industrial waters may vary from 0 to 15 parts per million (ppm). As little as 0.5 ppm can cause an odor. But the report states that it's hard to imagine even 15 ppm in mix water materially affecting the strength development of concrete. If you need test results to verify that there isn't a problem, have a testing laboratory make two sets of mortar cubes (ASTM C 109). Use the questionable water in one set and distilled water or water of known quality in the other set. The water is suitable if seven-day strengths of cubes made with it are at least 90% of the strengths for cubes made with known-quality water. If effect on setting time is a concern, you might also have the testing laboratory run time-of-set tests (ASTM C 191) using the questionable water.