PFAS in tap water: Fukushima Prefecture
In Fukushima Prefecture’s water supplies, the highest combined PFOS and PFOA value for FY2020–FY2025 (FY2025 through the end of August) was 12 ng/L at the Bandai Town water utility (磐梯町水道事業) (FY2024). The FY2025 maximum was 11 at the Kagamiishi Town water utility (鏡石町上水道事業) (treatment plant outlet). No utility exceeded 50 ng/L.
Levels by utility (PFOS + PFOA combined, ng/L)
| Utility | FY2020 | FY2021 | FY2022 | FY2023 | FY2024 | FY2025* | Sampled at |
|---|---|---|---|---|---|---|---|
| いわき市水道局Water supply · いわき市 | nd | nd | nd | nd | nd | — | tap and raw |
| 郡山市上下水道局Water supply · 郡山市 | nd | nd | nd | nd | nd | nd | tap, plant outlet and raw |
| 双葉地方水道事業Water supply | nd | nd | nd | nd | nd | — | tap and plant outlet |
| 会津若松市上下水道局Water supply · 会津若松市 | nd | nd | nd | nd | nd | nd | 浄水場出口水 |
| 福島市上水道事業Water supply · 福島市 | — | nd | nd | nd | nd | nd | raw water only |
| 白河市水道事業Water supply · 白河市 | — | nd | nd | nd | nd | nd | raw water only |
| 二本松市上水道Water supply · 二本松市 | — | — | — | nd | nd | — | raw water only |
| 本宮市水道事業Water supply · 本宮市 | — | — | — | — | nd | nd | — |
| 桑折町水道事業Water supply · 桑折町 | — | — | — | nd | — | nd | — |
| 国見町水道事業Water supply · 国見町 | — | nd | nd | nd | nd | — | raw water only |
| 川俣町水道事業Water supply · 川俣町 | — | — | — | — | nd | nd | raw water only |
| 大玉村水道事業Water supply · 大玉村 | — | — | — | nd | 1.2 | nd | — |
| 田村市水道事業Water supply · 田村市 | — | — | — | — | nd | nd | — |
| 鏡石町上水道事業Water supply · 鏡石町 | — | — | — | — | 11 | 11 | plant outlet only |
| 天栄村水道事業Water supply · 天栄村 | — | — | — | — | nd | nd | tap only |
| 石川町水道事業Water supply · 石川町 | — | nd | nd | nd | nd | nd | tap and raw |
| 玉川村上水道事業Water supply · 玉川村 | — | — | — | — | 1.3 | nd | raw water only |
| 浅川町上水道事業Water supply · 浅川町 | — | — | — | nd | — | — | plant outlet only |
| 三春町水道事業Water supply · 三春町 | — | — | — | — | nd | 3 | tap and raw |
| 小野町水道事業Water supply · 小野町 | — | — | — | nd | nd | nd | tap only |
| 泉崎村水道事業Water supply · 泉崎村 | — | — | — | — | nd | nd | raw water only |
| 矢祭町水道事業Water supply · 矢祭町 | — | — | — | — | 6 | — | — |
| 塙町上水道事業Water supply · 塙町 | — | — | — | — | nd | — | tap only |
| 西郷村上下水道事業Water supply · 西郷村 | — | — | — | nd | nd | nd | raw water only |
| 矢吹町水道事業Water supply · 矢吹町 | — | — | — | — | nd | nd | — |
| 棚倉町上水道事業Water supply · 棚倉町 | — | — | — | — | nd | nd | raw water only |
| 喜多方市水道事業Water supply · 喜多方市 | — | nd | nd | nd | nd | nd | raw water only |
| 猪苗代町水道事業Water supply · 猪苗代町 | — | — | — | — | nd | nd | — |
| 会津坂下町水道事業Water supply · 会津坂下町buys all its water — Buys from 会津若松地方水道用水供給事業 | — | — | — | — | — | nd | — |
| 浪江町水道事業Water supply · 浪江町 | — | — | — | — | nd | — | tap only |
| 会津美里町水道事業Water supply · 会津美里町 | — | — | — | — | — | nd | — |
| 南会津町水道事業Water supply · 南会津町 | — | — | — | — | nd | — | raw water only |
| 南相馬市原町水道事業Water supply · 南相馬市 | — | — | — | nd | nd | — | — |
| 須賀川市水道事業Water supply · 須賀川市 | 2 | nd | nd | nd | nd | nd | plant outlet and raw |
| 相馬地方広域水道企業団Water supply | — | 5 | nd | nd | 5 | — | tap and raw |
| 伊達市水道事業Water supply · 伊達市buys all its water — Buys from 福島地方水道用水供給企業団 | — | — | — | — | — | — | — |
| 会津若松地方水道用水供給事業Bulk supplierSupplies: 会津若松市、会津坂下町、会津美里町 | nd | nd | nd | nd | nd | nd | raw water only |
| 白河地方広域市町村圏整備組合Bulk supplierSupplies: 白河市、西郷村、泉崎村、中島村、矢吹町、棚倉町 | — | nd | nd | nd | nd | nd | raw water only |
| 福島地方水道用水供給企業団Bulk supplierSupplies: 福島市、伊達市、二本松市、桑折町、国見町、川俣町 | nd | nd | nd | nd | nd | nd | raw water only |
| いわき市遠野簡易水道事業Small water supply · いわき市 | nd | nd | nd | nd | nd | — | tap and raw |
| いわき市川前簡易水道事業Small water supply · いわき市 | nd | nd | nd | nd | nd | — | tap and raw |
| いわき市田人簡易水道事業Small water supply · いわき市 | nd | nd | nd | nd | nd | — | tap and raw |
| 佐原第一簡易水道組合Small water supply | — | — | — | — | nd | — | raw water only |
| 土船簡易水道組合Small water supply | — | — | — | — | nd | — | plant outlet only |
| 二本松市岩代小浜地区簡易水道Small water supply · 二本松市 | — | — | — | 0.6 | 0.6 | — | — |
| 二本松市岩代西新殿地区簡易水道Small water supply · 二本松市 | — | — | — | nd | 0.5 | — | — |
| 二本松市東和簡易水道Small water supply · 二本松市 | — | — | — | nd | 0.5 | — | — |
| 御免町簡易水道組合Small water supply | — | — | — | — | — | 5 | — |
| 栗和田簡易水道組合Small water supply | — | — | — | — | — | nd | — |
| 郡山市簡易水道事業Small water supply · 郡山市 · 3 systems | — | — | — | nd | nd | nd | tap and raw |
| 田村市都路地区簡易水道Small water supply · 田村市 | — | — | — | — | nd | nd | — |
| 高柴簡易水道Small water supply | — | — | — | — | — | planned | — |
| 天栄村簡易水道事業Small water supply · 天栄村 | — | — | — | — | nd | nd | tap only |
| 平田村簡易水道事業Small water supply · 平田村 | — | — | — | — | nd | nd | raw water only |
| 古殿町簡易水道事業Small water supply · 古殿町 | — | — | — | — | 1.7 | — | raw water only |
| 中島村簡易水道事業Small water supply · 中島村 | — | — | — | — | nd | nd | raw water only |
| 鮫川村簡易水道事業Small water supply · 鮫川村 | — | — | — | — | nd | — | raw water only |
| 棚倉町山岡簡易水道事業Small water supply · 棚倉町 | — | — | — | — | nd | nd | — |
| 棚倉町瀬ヶ野簡易水道事業Small water supply · 棚倉町 | — | — | — | — | nd | nd | — |
| 棚倉町高野西部簡易水道事業Small water supply · 棚倉町 | — | — | — | — | nd | nd | — |
| 会津若松市湊町簡易水道事業（下馬渡地区）Small water supply · 会津若松市 | — | — | — | — | nd | nd | tap only |
| 会津若松市湊町簡易水道事業（東田面地区）Small water supply · 会津若松市 | — | — | — | — | nd | nd | tap only |
| 会津若松市湊町簡易水道事業（西田面地区）Small water supply · 会津若松市 | — | — | — | — | nd | nd | tap only |
| 上馬渡簡易水道事業Small water supply | — | — | — | — | — | planned | — |
| 赤井簡易水道事業Small water supply | — | — | — | — | — | planned | — |
| 原簡易水道事業Small water supply | — | — | — | — | — | planned | — |
| 北塩原簡易水道Small water supply · 北塩原村 | — | — | — | — | nd | — | — |
| 西会津町簡易水道事業Small water supply · 西会津町 | — | — | — | — | nd | — | — |
| 磐梯町水道事業Small water supply · 磐梯町 | — | — | — | — | 12 | — | — |
| 三島町宮下簡易水道事業Small water supply · 三島町 | — | — | — | — | nd | — | tap only |
| 三島町西方地区簡易水道事業Small water supply · 三島町 | — | — | — | — | nd | — | tap only |
| 三島町滝谷簡易水道事業Small water supply · 三島町 | — | — | — | — | — | planned | — |
| 三島町大石田簡易水道事業Small water supply · 三島町 | — | — | — | — | — | planned | — |
| 金山町統合簡易水道事業Small water supply · 金山町 | — | — | — | — | — | nd | — |
| 昭和村松山地区簡易水道事業Small water supply · 昭和村 | — | — | — | — | nd | — | raw water only |
| 昭和村昭和地区簡易水道事業Small water supply · 昭和村 | — | — | — | — | nd | — | raw water only |
| 昭和村大芦地区簡易水道事業Small water supply · 昭和村 | — | — | — | — | nd | — | raw water only |
| 下郷町統合簡易水道Small water supply · 下郷町 | — | — | — | — | nd | — | — |
| 只見統合簡易水道事業Small water supply | — | — | — | — | 3 | — | tap only |
| 檜枝岐村簡易水道事業Small water supply · 檜枝岐村 | — | — | — | — | — | nd | — |
| 玉野簡易水道Small water supply | — | — | — | — | — | nd | — |
| 山上坂下簡易水道Small water supply | — | — | — | — | — | nd | — |
| 南相馬市小高簡易水道事業Small water supply · 南相馬市 | — | — | — | nd | nd | — | — |
| 飯舘村簡易水道事業Small water supply · 飯舘村 | — | — | — | nd | — | nd | plant outlet only |
| 葛尾村簡易水道事業Small water supply · 葛尾村 | — | — | — | — | nd | — | tap only |
| 柳津町簡易水道事業Small water supply · 柳津町 | — | — | — | — | nd | — | — |
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
- The Koriyama City Water and Sewerage Bureau (郡山市上下水道局), the Iwaki City Waterworks Bureau (いわき市水道局) and the Fukushima City water utility (福島市上水道事業) were nd (below the detection or quantification limit) in every year they measured. The three bulk water suppliers (Aizuwakamatsu area (会津若松地方), Shirakawa area (白河地方) and Fukushima area (福島地方)) were also nd, but these values were measured only in raw water (water before treatment at the plant).
- In the November 2024 table, the Bandai Town row showed “none” for testing record, and its value appeared for the first time in the 2025 table. The table does not say where it was sampled (tap or treatment plant). → How to read the national table
- Private water supplies (for a facility) were tested at 85 of the 170 operators, and no exceedance of the provisional target value has been confirmed (through the end of 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, “Results of the follow-up survey on PFOS and PFOA in water supplies” (December 25, 2025)
- Same, list of survey results (updated), Excel (annual maximums, FY2020–FY2025)
- Ministry of the Environment and MLIT, list of survey results, Excel (published November 29, 2024; sampling point column)
- Same, follow-up survey annex (status of private water supplies by prefecture)
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.