Southwest Regional Water District, OH
Lead detected, under the action levels
Latest 90th-percentile lead: 1.4 ppb (monitoring period 2026-2026). 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.
Southwest Regional Water District at a glance
Southwest Regional Water District serves about 42,856 people through 15,875 service connections, which makes it a large system under EPA's size classes. It is under mixed public and private ownership and draws groundwater, in Butler County, Ohio. EPA system ID: OH0903912; phone on file: 513-896-3354. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Southwest Regional Water District's lead record
Against the period ending 2025 (1.3 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Southwest Regional Water District is 2 ppb across 11 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.4 ppb |
| 2025 | 1.3 ppb |
| 2024 | 1.3 ppb |
| 2023 | 1.5 ppb |
| 2022 | 1.9 ppb |
| 2022 | 2 ppb |
| 2021 | 1.9 ppb |
| 2020 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2018 | 0 (not detected) |
| 2016 | 0 (not detected) |
How Southwest Regional Water District compares
Of the 1,079 Ohio systems with a lead result, the median latest reading is 0.7 ppb; 1 are over 15 ppb right now and 27 have gone over at some point. Southwest Regional Water District's 1.4 ppb sits at the 67th percentile in Ohio and the 62nd nationally (higher means more lead).
Neighbouring systems
11 other systems share Butler County; 5 of them have a higher latest lead result than Southwest Regional Water District. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Butler Co. Water District 2 Pws | 116,572 | 3 ppb |
| Hamilton Public Water System | 62,447 | 0 (not detected) |
| Middletown City Pws | 51,229 | 1.14 ppb |
| Fairfield City Pws | 44,907 | 0 (not detected) |
| Oxford City Pws | 24,000 | 2.4 ppb |
| Monroe City Pws | 15,600 | 0.61 ppb |
| Trenton City Pws | 13,012 | 2.5 ppb |
| New Miami Village Pws | 3,200 | 1.1 ppb |
| Catalina Mobile Home Park | 1,280 | 0.7 ppb |
| Seven Mile Village Pws | 1,000 | 1.9 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Hamilton, OH 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 Southwest Regional Water District 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. Systems that went over once often dip back under; here is what that means.