Castalian W/A, MS
Lead detected, under the action levels
Latest 90th-percentile lead: 0.3 ppb (monitoring period 2025-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
Who runs the water here
Castalian W/A serves about 321 people through 119 service connections, which makes it a very small system under EPA's size classes. It is under mixed public and private ownership and draws groundwater, in Holmes County, Mississippi. EPA system ID: MS0260003; phone on file: 662-582-7739. They can tell you what your service line is made of and whether they pay to replace it.
Castalian W/A's lead record
Against the period ending 2024 (0.6 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Castalian W/A is 1.7 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0.3 ppb |
| 2024 | 0.6 ppb |
| 2023 | 0 (not detected) |
| 2022 | 0.4 ppb |
| 2018 | 1.7 ppb |
| 2016 | 0 (not detected) |
How Castalian W/A compares
Of the 973 Mississippi systems with a lead result, the median latest reading is 1 ppb; 9 are over 15 ppb right now and 44 have gone over at some point. Castalian W/A's 0.3 ppb sits at the 19th percentile in Mississippi and the 41st nationally (higher means more lead).
Nearby utilities
19 other systems share Holmes County; 18 of them have a higher latest lead result than Castalian W/A. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| City Of Durant | 2,932 | 0.6 ppb |
| Lebanon W/A-West | 1,742 | 0.8 ppb |
| Sweet Home Water & Sewer Dist | 1,695 | 2.7 ppb |
| Town Of Tchula | 1,642 | 1.3 ppb |
| City Of Lexington | 1,600 | 0.7 ppb |
| Town Of Pickens | 1,587 | 0.9 ppb |
| Acona Water Association #1 | 1,373 | 0.8 ppb |
| West Holmes Water Association | 1,245 | 2.1 ppb |
| Town Of Goodman | 1,188 | 1.5 ppb |
| Harland Creek Community W/A-B | 1,177 | 2.3 ppb |
Your move
Test your own tap with a certified lab first-draw sample; West, MS may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Castalian W/A whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. What a 90th-percentile result does and does not tell you: how to read a lead result. Size matters more than most people expect: small vs large water systems.