Three types of fluoride chemicals are used in drinking water treatment. These are sodium fluoride, fluosilicic acid and what other type?
Hydrofluosilicic acid solution
What is the SDWA Primary Contaminant MCL for Fluoride?
4.0 mg/L
Mottling of a persons teeth (brown staining) occurs at fluoride levels of what?
1.5 mg/L
What is a major cause of over exposure to fluoride?
Breathing fluoride dust
What are obvious signs of fluoride poisoning by ingestion?
Vomiting, diarrhea
Which statement about gravimetric feeders is correct?
The amount fed is measured on the basis of the weight of the chemical
If significant overfeeding of fluoride occurs, what should the plant operator do?
Shut down the plant, begin flushing affected water mains and notify local and state health officials
What factors must the design of a fluoridation system incorporate?
Methods of preventing overfeeding and backsiphonage
What is the Secondary contaminant MCL for Fluoride?
2.0 mg/L
What is the pH value of hydrofluosilicic acid (H2SiF6)
1.2