Chlorate in Mississippi Drinking Water
Ranked by max chlorate detected (µg/L) · UCMR 3 data (2013–2015) · Data from EPA SDWIS & UCMR
Chlorate in Mississippi: what the data shows
Mississippi has 15 cities with chlorate data from the EPA's UCMR 3 program (2013–2015). Chlorate exceeded the 210 µg/L EPA lifetime health advisory in 4 of those cities. The state average max detected level is 166.5 µg/L. Chlorate is a disinfection byproduct that forms when chlorine dioxide or hypochlorite solutions are used to disinfect drinking water. It is most common in systems that use chlorine dioxide for taste-and-odor control or that store hypochlorite for extended periods. There is no federal MCL — the EPA lifetime health advisory is 210 µg/L. Chlorate can interfere with thyroid function by blocking iodide uptake, an effect of particular concern for pregnant women, infants, and people with thyroid conditions. Reverse osmosis and ion exchange (anion-specific) are effective at removing chlorate; standard activated carbon filters provide only modest reduction.
Cities exceeding 210 µg/L EPA lifetime HA (no MCL)
Chlorate data across Mississippi
Each dot is a city with UCMR 3 chlorate testing data. Cities where chlorate exceeds the 210 µg/L EPA lifetime health advisory are highlighted. Size reflects population served.
Top 10 cities by chlorate level in Mississippi
Highest Chlorate levels (µg/L)
All Mississippi cities ranked by chlorate level
| # | City | Level | Level | Over HA? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | West Point | 497.6 µg/L | Over HA | 4 | D | |
| 2 | Vicksburg | 470.2 µg/L | Over HA | 53 | D | |
| 3 | Oxford | 436.9 µg/L | Over HA | 22 | F | |
| 4 | Olive Branch | 249.7 µg/L | Over HA | 8 | B- | |
| 5 | Meridian | 127.3 µg/L | No | 5 | D+ | |
| 6 | Jackson | 111.2 µg/L | No | 75 | D | |
| 7 | Morton | 109.0 µg/L | No | 23 | D | |
| 8 | Southaven | 108.1 µg/L | No | 3 | B | |
| 9 | Hernando | 107.2 µg/L | No | 11 | D+ | |
| 10 | Horn Lake | 82.1 µg/L | No | 5 | B | |
| 11 | Columbus | 52.4 µg/L | No | 15 | D+ | |
| 12 | Philadelphia | 47.3 µg/L | No | 6 | C- | |
| 13 | Bailey | 40.5 µg/L | No | 5 | A | |
| 14 | Canton | 34.9 µg/L | No | 45 | D | |
| 15 | Corinth | 23.6 µg/L | No | 9 | D |
Frequently asked questions about chlorate in Mississippi
Is chlorate in Mississippi tap water dangerous?
Chlorate has no federal MCL. The EPA lifetime health advisory is 210 µg/L. 4 cities in Mississippi exceed this level. Chlorate can interfere with thyroid iodide uptake, which is a particular concern for infants, pregnant women, and people with hypothyroidism.
Where does chlorate in Mississippi water come from?
Chlorate is a byproduct of chlorine-based disinfectants — particularly chlorine dioxide and hypochlorite (bleach) solutions. Levels tend to be higher in systems that use chlorine dioxide for taste-and-odor treatment or store sodium hypochlorite at high concentrations or for long periods. Levels vary seasonally with disinfectant use.
How can I reduce chlorate exposure?
Reverse osmosis is the most effective home treatment for chlorate, typically removing 80–95%. Anion exchange systems also work but require regeneration. Standard activated carbon filters provide only limited chlorate reduction. Boiling does NOT remove chlorate.