Harrison County Water Quality: 4 Cities Ranked by the Records
Harrison County, Mississippi: 4 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.
Highest result for each contaminant
One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.
LithiumDetected in 4 systems10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest21.5 µg/L
- CITY OF PASS CHRISTIAN21.5 µg/LSample date: 2023-05-08 to 2023-11-13
- CITY OF BILOXI17.4 µg/LSample date: 2024-06-04 to 2024-12-03
- CITY OF GULFPORT15.9 µg/LSample date: 2024-12-10 to 2025-06-26
- CITY OF LONG BEACH15.7 µg/LSample date: 2023-12-20 to 2025-03-17
Total trihalomethanes (TTHM)Detected in 1 system80 ppb federal MCL · US EPAHighest48.2 ppb
- CITY OF BILOXI48.2 ppbReporting year: 2025
Haloacetic acids (HAA5)Detected in 1 system60 ppb federal MCL · US EPAHighest26.6 ppb
- CITY OF BILOXI26.6 ppbReporting year: 2025
ArsenicDetected in 1 system0.010 mg/L · US EPAHighest0.0029 mg/L
- CITY OF BILOXI0.0029 mg/LReporting year: 2025
Lead (90th percentile)Detected in 4 systems15 µg/L federal action level · US EPAHighest2.9 µg/L
- CITY OF LONG BEACH2.9 µg/LMonitoring period: 2022–2024
- CITY OF GULFPORT1.5 µg/LMonitoring period: 2021–2023
- CITY OF BILOXI1 µg/LMonitoring period: 2022–2024
- CITY OF PASS CHRISTIAN1 µg/LMonitoring period: 2022–2024
CopperDetected in 1 system1.3 mg/L (action level) · US EPAHighest0.2 mg/L
- CITY OF BILOXI0.2 mg/LReporting year: 2025
FluorideDetected in 1 system4.0 mg/L · US EPAHighest0.43 mg/L
- CITY OF BILOXI0.43 mg/LReporting year: 2025
29 PFAS tested, none detected in any systemShow
Tested in these 4 systems: CITY OF BILOXI, CITY OF GULFPORT, CITY OF LONG BEACH, CITY OF PASS CHRISTIAN
- 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
- 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
- 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
- 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
- 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
- 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
- Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
- N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
- N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
- Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
- Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
- Perfluoro-3-methoxypropanoic acid (PFMPA)
- Perfluoro-4-methoxybutanoic acid (PFMBA)
- Perfluorobutanesulfonic acid (PFBS)
- Perfluorobutanoic acid (PFBA)
- Perfluorodecanoic acid (PFDA)
- Perfluorododecanoic acid (PFDoA)
- Perfluoroheptanesulfonic acid (PFHpS)
- Perfluoroheptanoic acid (PFHpA)
- Perfluorohexanesulfonic acid (PFHxS)
- Perfluorohexanoic acid (PFHxA)
- Perfluorononanoic acid (PFNA)
- Perfluorooctanesulfonic acid (PFOS)
- Perfluorooctanoic acid (PFOA)
- Perfluoropentanesulfonic acid (PFPeS)
- Perfluoropentanoic acid (PFPeA)
- Perfluorotetradecanoic acid (PFTA)
- Perfluorotridecanoic acid (PFTrDA)
- Perfluoroundecanoic acid (PFUnA)
Cities ranked by the records
Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.
0of 4 cities above the 15 µg/L action level
Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.
Lead in MississippiLargest water systems
- GulfportCITY OF GULFPORT · MS024000375,056 served
- BiloxiCITY OF BILOXI · MS024000123,310 served
- Long BeachCITY OF LONG BEACH · MS024000518,514 served
- Pass ChristianCITY OF PASS CHRISTIAN · MS024000910,436 served
Frequently asked
How does Harrison County tap water compare across cities?
PurityMap ranks 4 cities in Harrison County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Pass Christian's main water system: CITY OF PASS CHRISTIAN · PWSID MS0240009 · Purity Score 99 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.
How many Harrison County cities had a PFAS sample above a 2024 EPA limit?
None of the 4 Harrison County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing. PFAS were detected below the limit in 0.
Is there lead in Harrison County tap water?
Utilities report lead as a 90th-percentile result from home taps. 4 of 4 Harrison County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.
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