PFAS in tap water: Ehime Prefecture
In the national survey table, no water utility in Ehime Prefecture exceeded 50 ng/L (PFOS and PFOA combined) in FY2020–FY2025. The highest value in the prefecture was 25 ng/L (FY2024, tap water) for the Nakajima District small water supply system (中島地区簡易水道事業), run by the Matsuyama City Public Enterprise Bureau (松山市公営企業局). The highest value in the prefecture in FY2025 (through the end of August) was 8, in Masaki Town (松前町) and the privately run Shimoidai Umegumi small water supply system (下伊台梅組簡易水道).
Levels by utility (PFOS + PFOA combined, ng/L)
| Utility | FY2020 | FY2021 | FY2022 | FY2023 | FY2024 | FY2025* | Sampled at |
|---|---|---|---|---|---|---|---|
| 西条市水道事業Water supply · 西条市 | — | — | — | 7 | 6 | — | tap only |
| 四国中央市水道事業Water supply · 四国中央市 | nd | nd | nd | nd | nd | nd | tap, plant outlet and raw |
| 宇和島市水道事業Water supply · 宇和島市 | — | nd | nd | 9 | 8 | 7 | tap and raw |
| 新居浜市水道事業Water supply · 新居浜市 | — | 8 | 9 | 7 | 4 | 6 | tap, plant outlet and raw |
| 松山市公営企業局Water supply · 松山市 | — | 14 | 14 | 10 | 8 | 4 | plant outlet only |
| 今治市水道事業Water supply · 今治市 | 2 | 6 | 5 | 3 | 4 | nd | tap, plant outlet and raw |
| 今治市玉川水道事業Water supply · 今治市 | — | — | — | nd | nd | nd | tap only |
| 今治市菊間水道事業Water supply · 今治市 | — | — | — | nd | nd | nd | tap only |
| 今治市越智諸島水道事業Water supply · 今治市 | — | — | — | nd | nd | nd | tap only |
| 八幡浜市水道事業Water supply · 八幡浜市Also buys from: 南予水道企業団 | — | — | — | nd | 7 | 3 | raw water only |
| 大洲市水道事業Water supply · 大洲市 | — | nd | nd | nd | 1 | 5 | plant outlet only |
| 伊予市水道事業Water supply · 伊予市 | — | 10 | 5 | nd | 5 | — | tap and raw |
| 四国中央市土居地域水道事業Water supply · 四国中央市 | nd | nd | nd | nd | nd | nd | tap and raw |
| 西予市水道事業Water supply · 西予市 | — | — | — | — | 2 | 3 | tap only |
| 東温市水道事業Water supply · 東温市 | — | — | — | nd | 2 | 2 | raw water only |
| 上島町水道事業Water supply · 上島町buys all its water — Buys from 広島県水道広域連合企業団沼田川水道用水供給事業 | — | — | — | — | — | — | — |
| 松前町水道事業Water supply · 松前町 | — | 8 | 7 | 5 | 9 | 8 | tap and raw |
| 砥部町水道事業Water supply · 砥部町 | — | 5 | 8 | — | 13 | 5 | raw water only |
| 内子町上水道事業Water supply · 内子町 | — | — | — | — | 4 | — | — |
| 伊方町水道事業Water supply · 伊方町 | — | — | — | — | 5 | — | — |
| 鬼北町水道事業Water supply · 鬼北町 | — | — | — | nd | nd | nd | raw water only |
| 愛南町上水道事業Water supply · 愛南町 | — | — | — | — | 2 | 2 | tap only |
| 南予水道企業団Bulk supplierSupplies: 八幡浜市 | 1 | 1 | 2 | 1 | 1 | 1 | raw water only |
| 萩原簡易水道事業（松山市公営企業局）Small water supply · 松山市 | — | — | — | — | 5 | 5 | tap only |
| 院内簡易水道事業（松山市公営企業局）Small water supply · 松山市 | — | — | — | — | nd | nd | tap only |
| 米之野簡易水道事業（松山市公営企業局）Small water supply · 松山市 | — | — | — | — | nd | nd | tap only |
| 横谷簡易水道事業（松山市公営企業局）Small water supply · 松山市 | — | — | — | — | nd | nd | tap only |
| 客簡易水道事業（松山市公営企業局）Small water supply · 松山市 | — | — | — | — | 4 | 4 | tap only |
| 中島地区簡易水道事業（松山市公営企業局）Small water supply · 松山市 | — | — | — | — | 25 | 6 | tap only |
| 下伊台梅組簡易水道事業（民営）Small water supply | — | — | — | — | 8 | 8 | tap only |
| 関前簡易水道事業（今治市）Small water supply · 今治市 | — | — | — | nd | nd | nd | tap only |
| 釜倉簡易水道事業（八幡浜市）Small water supply · 八幡浜市 | — | — | — | — | nd | nd | tap only |
| 矢野畑簡易水道事業（八幡浜市）Small water supply · 八幡浜市 | — | — | — | — | nd | — | — |
| 日土簡易水道事業（八幡浜市）Small water supply · 八幡浜市 | — | — | — | — | 1 | 1 | tap only |
| 古薮簡易水道事業（八幡浜市）Small water supply · 八幡浜市 | — | — | — | — | nd | — | — |
| 今出簡易水道事業（八幡浜市）Small water supply · 八幡浜市 | — | — | — | — | nd | — | tap only |
| 梶谷岡簡易水道事業（八幡浜市）Small water supply · 八幡浜市 | — | — | — | — | 3 | 3 | tap only |
| 中山簡易水道事業（伊予市）Small water supply · 伊予市 | — | nd | nd | nd | nd | — | tap only |
| 佐礼谷簡易水道事業（伊予市）Small water supply · 伊予市 | — | nd | nd | nd | nd | — | tap only |
| 村中簡易水道事業（伊予市）Small water supply · 伊予市 | — | nd | nd | nd | nd | — | tap only |
| 永木簡易水道事業（伊予市）Small water supply · 伊予市 | — | nd | 1 | nd | nd | — | tap only |
| 豊田簡易水道事業（伊予市）Small water supply · 伊予市 | — | nd | nd | nd | nd | — | tap only |
| 新宮地区簡易水道事業（四国中央市）Small water supply · 四国中央市 | — | nd | nd | nd | nd | nd | tap and raw |
| 新宮地区北東部簡易水道事業（四国中央市）Small water supply · 四国中央市 | — | nd | nd | nd | nd | nd | tap and raw |
| 明間簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 真土西簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 西山田簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 田苗簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 野田簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 松渓簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 鳥鹿野簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 旭簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 長谷簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 外場簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 内場簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 予子林簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 三島簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 天神簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 大野ヶ原簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 木落簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 植木簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 中筋簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 古市簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 魚成簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 土居簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 田穂簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 男河内成穂簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 下相上簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 今田簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 川津南簡易水道事業（西予市）Small water supply · 西予市 | — | — | — | — | — | planned | — |
| 魚島簡易水道事業（上島町）Small water supply · 上島町 | — | — | — | — | nd | — | plant outlet only |
| 久万簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | nd | nd | — |
| 畑野川簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 二名簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | planned | — |
| 露峰簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | planned | — |
| 直瀬簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | planned | — |
| 里成簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 御三戸簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 大川簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 古味簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 三和簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 二箆簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 黒藤川簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 成河簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 落出簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 永野簡易水道事業（久万高原町）Small water supply · 久万高原町 | — | — | — | — | — | nd | — |
| 松野町簡易水道事業Small water supply · 松野町 | — | — | — | — | nd | — | raw water only |
These are the highest values in each fiscal year reported by each utility to the national government (MLIT and the Ministry of the Environment). A utility with several sources or treatment plants can have different levels in different parts of its area. Samples are taken at the tap in principle, but some utilities only measured raw water (water before treatment), and raw-water values are not covered by the tap-water standard. nd = below the detection or quantification limit; — = no value reported. *FY2025 covers results up to the end of August 2025. Utility names are left in Japanese as in the official table.
>50 a year above 50 ng/L (for utilities that also sampled raw water, the value may be from raw water) raw above 50 ng/L, but measured in raw water only
Good to know
- Of the 87 rows in the national table, 30 have no testing records, and 29 of those are small water supply systems. With the move to a water quality standard in April 2026, small water supply systems are also now required to test (if past values were low, testing can be less frequent).
- The Matsuyama City Public Enterprise Bureau (public water supply) was 4–14 ng/L in FY2021–FY2025 (measured at the treatment plant outlet). The Nakajima District small water supply system was 6 in FY2025.
- There are 137 private water supplies (for a facility: in-house water systems for company housing, hospitals, schools and so on). None of the 98 that were tested exceeded 50 (FY2020 to August 2025).
Put it in terms of your own intake
- Intake from water
- — ng/kg/day
- Compared with Japan’s tolerable daily intake (PFOS and PFOA, 20 ng/kg bw/day each)
- —
- Compared with EFSA’s tolerable weekly intake (4 PFAS combined, 4.4 ng/kg bw/week ≈ 0.63 a day)
- —
- Compared with intake from 37 foods (MAFF estimate: PFOS 0.13 + PFOA 0.09 = 0.22 ng/kg bw/day; the 37 foods make up about half of what people eat by amount)
- —
The combined value is treated as a single substance (in reality it is split between PFOS and PFOA, so the share of Japan’s TDI would be smaller). EFSA’s value is for the sum of PFOA, PFNA, PFHxS and PFOS; tap-water values here do not include PFNA or PFHxS. This calculation shows how the same intake reads differently against different yardsticks; it does not judge health effects.
Related explainers
Sources
- Ministry of the Environment and MLIT: List of results of the follow-up survey of PFOS and PFOA in water supplies (published December 25, 2025)
- Ministry of the Environment and MLIT: Results of the follow-up survey (December 25, 2025)
- Ministry of the Environment: Notice of points to note on the revision of the Water Supply Act Enforcement Regulations (testing frequency)
Last checked 2026.10.04 (against the original government documents and papers, collected and cross-checked in Gemini Notebook). Utility values are as in the national table; Urayomi sorted and summarized them.