Aqua Ohio - Tiffin, OH
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Aqua Ohio - Tiffin at a glance
Aqua Ohio - Tiffin serves about 20,279 people through 8,311 service connections, which makes it a large system under EPA's size classes. It is privately owned and draws surface water, in Seneca County, Ohio. EPA system ID: OH7400614; phone on file: 740-383-0939. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
That is down 5.4 ppb from 5.4 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Aqua Ohio - Tiffin is 13 ppb across 10 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 5.4 ppb |
| 2024 | 4.7 ppb |
| 2023 | 0 (not detected) |
| 2022 | 9.2 ppb |
| 2021 | 10 ppb |
| 2020 | 13 ppb over 10 |
| 2019 | 9.9 ppb |
| 2018 | 6.6 ppb |
| 2016 | 7.3 ppb |
How Aqua Ohio - Tiffin 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. Aqua Ohio - Tiffin's reported as 0 (not detected) sits at the 41st percentile in Ohio and the 39th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Seneca County
10 other systems share Seneca County; 4 of them have a higher latest lead result than Aqua Ohio - Tiffin. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Fostoria City | 13,441 | 0 (not detected) |
| Green Springs Village Pws | 1,592 | 1.8 ppb |
| Attica Village | 1,148 | 0 (not detected) |
| Bloomville Village Pws | 956 | 0 (not detected) |
| Bettsville Village | 692 | 2.2 ppb |
| Republic Village | 550 | 2.5 ppb |
| Fostoria Mobile Estates | 281 | 0 (not detected) |
| Evergreen Poplar Village Mhp Pws | 128 | 2.85 ppb |
| Brook Park Estates Mhp Pws | 75 | 0 (not detected) |
| Brightstar Fostoria East Mhp Pws | 65 | 0 (not detected) |
Next steps for Marion, OH
Look up your address in Aqua Ohio - Tiffin's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Aqua Ohio - Tiffin 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. A zero today does not rule out a jump later - the rules are tightening in 2027.