PFAS in tap water database (Japan)TohokuChecked 2026.10.04
PFAS in tap water: Akita Prefecture
Highest, FY2020–202538 ng/L由利本荘市水道事業（2024）
Highest, FY2025 (to Aug)37 ng/L
Utilities with a year above 50 ng/L0
Utilities with values103 / 119
In Akita Prefecture’s water supplies, the highest combined PFOS and PFOA value for FY2020–FY2025 (FY2025 through the end of August) was 38 ng/L at the Yurihonjo City water utility (由利本荘市水道事業) (FY2024). It was measured only in raw water (water before treatment at the plant), and the FY2025 value was 37. No utility exceeded 50 ng/L.
Levels by utility (PFOS + PFOA combined, ng/L)
| Utility | FY2020 | FY2021 | FY2022 | FY2023 | FY2024 | FY2025* | Sampled at |
|---|---|---|---|---|---|---|---|
| 横手市水道事業Water supply · 横手市 | — | — | — | nd | nd | 11 | tap and raw |
| 秋田市上下水道局Water supply · 秋田市 | nd | nd | nd | nd | nd | nd | plant outlet and raw |
| 大館市水道事業Water supply · 大館市 | nd | — | nd | nd | nd | nd | raw water only |
| 由利本荘市水道事業Water supply · 由利本荘市 | — | nd | nd | nd | 38 | 37 | raw water only |
| 能代市水道事業Water supply · 能代市 | — | — | nd | nd | nd | nd | plant outlet and raw |
| 鹿角市水道事業Water supply · 鹿角市 | — | — | 6 | nd | nd | nd | tap and raw |
| 北秋田市（鷹巣上水道）Water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（森吉・合川上水道）Water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 大仙市（上水道）Water supply · 大仙市 | — | nd | nd | nd | nd | nd | tap and raw |
| 男鹿市企業局Water supply · 男鹿市 | — | — | — | — | nd | nd | tap only |
| 湯沢市（湯沢地区）水道事業Water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市（稲川地区）水道事業Water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 潟上市水道事業Water supply · 潟上市 | — | — | — | 14 | 11 | 8 | raw water only |
| 仙北市水道事業Water supply · 仙北市 | — | nd | nd | nd | nd | nd | tap and raw |
| 小坂町水道事業Water supply · 小坂町 | — | — | — | — | nd | nd | tap only |
| 五城目町水道事業Water supply · 五城目町 | — | — | — | — | nd | nd | raw water only |
| 井川町水道事業Water supply · 井川町 | — | nd | nd | nd | nd | nd | tap and raw |
| 八郎潟町水道事業Water supply · 八郎潟町 | — | — | — | — | nd | nd | raw water only |
| 三種町水道事業Water supply · 三種町 | — | — | — | — | — | nd | — |
| 美郷町水道事業Water supply · 美郷町 | — | — | — | 10 | 10 | 7 | tap and raw |
| にかほ市水道事業Water supply · にかほ市 | — | nd | nd | nd | nd | nd | raw water only |
| 羽後町水道事業Water supply · 羽後町 | — | — | — | nd | nd | — | raw water only |
| 藤里町簡易水道事業Small water supply · 藤里町 | — | — | — | — | — | nd | — |
| 八峰町（八森簡易水道）Small water supply · 八峰町 | — | — | — | — | — | nd | — |
| 八峰町（峰浜簡易水道）Small water supply · 八峰町 | — | — | — | — | — | nd | — |
| 石川簡易水道組合Small water supply | — | — | — | — | — | nd | — |
| 大潟村簡易水道Small water supply · 大潟村 | — | — | — | — | nd | nd | raw water only |
| 上台簡易水道組合Small water supply | — | — | — | — | — | nd | — |
| 上谷内簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 下谷内簡易水道組合Small water supply | — | — | — | — | — | nd | — |
| 長牛簡易水道組合Small water supply | — | — | — | — | — | nd | — |
| 大館市 新沢簡易水道組合Small water supply · 大館市 | — | — | — | — | — | nd | — |
| 大館市 大葛部落簡易水道施設利用組合Small water supply · 大館市 | — | — | — | — | — | planned | — |
| 大館市 独鈷水道組合Small water supply · 大館市 | — | — | — | — | — | 9 | — |
| 大館市 独鈷川久保地区水道組合Small water supply · 大館市 | — | — | — | — | — | nd | — |
| 北秋田市（綴子簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（向黒沢簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（摩当簡易水道Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（坊沢簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（七座簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（小猿部簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（阿仁合簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | 8 | raw water only |
| 北秋田市（根子簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（幸屋簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（萱草簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（比立内簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（打当簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 北秋田市（小渕簡易水道）Small water supply · 北秋田市 | — | — | — | — | nd | nd | raw water only |
| 能代市小繋簡易水道事業Small water supply · 能代市 | — | — | — | — | — | nd | — |
| 麻生中通り水道組合Small water supply | — | — | — | — | — | nd | — |
| 能代市種簡易水道事業Small water supply · 能代市 | — | — | — | — | — | nd | — |
| 梅内下地区水道組合Small water supply | — | — | — | — | — | nd | — |
| 切石堂ヶ沢水道組合Small water supply | — | — | — | — | — | nd | — |
| 能代市富根簡易水道事業Small water supply · 能代市 | — | — | — | — | — | nd | — |
| 能代市仁鮒簡易水道事業Small water supply · 能代市 | — | — | — | — | — | nd | — |
| 大仙市（宇留井谷地・船戸・戸月簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（神宮寺簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（刈和野簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（強首簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（川西簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（半道寺簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（心像小杉山簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（大沢郷簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（豊岡簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（極楽野・立石簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（入角簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（協和中央簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（協和南部簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（協和小種簡易水道）Small water supply · 大仙市 | — | — | — | — | 6 | nd | tap only |
| 大仙市（協和稲沢簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（協和淀川簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（協和沢庄簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（南外簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（戸地谷簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（仙北中央簡易水道）Small water supply · 大仙市 | — | — | — | — | nd | nd | tap only |
| 大仙市（下福田簡易水道）Small water supply · 大仙市 | — | — | — | — | — | planned | — |
| 大仙市（川戸賀簡易水道）Small water supply · 大仙市 | — | — | — | — | — | planned | — |
| 大仙市（下横堀簡易水道）Small water supply · 大仙市 | — | — | — | — | — | planned | — |
| 大仙市（上福田簡易水道）Small water supply · 大仙市 | — | — | — | — | — | planned | — |
| 大仙市（板見内簡易水道）Small water supply · 大仙市 | — | — | — | — | — | planned | — |
| 大仙市（中屋布簡易水道）Small water supply · 大仙市 | — | — | — | — | — | planned | — |
| 大仙市（谷地簡易水道）Small water supply · 大仙市 | — | — | — | — | — | planned | — |
| 長野駅前通簡易水道組合Small water supply | — | — | — | — | — | nd | — |
| 高梨東部簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 下田茂木簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 古舘簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 北野簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 中里簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 三本扇簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 本堂城回簡易水道組合Small water supply | — | — | — | — | nd | — | tap only |
| 上小阿仁村（沖田面簡易水道事業）Small water supply · 上小阿仁村 | — | — | — | nd | — | nd | — |
| 上小阿仁村（羽立簡易水道事業）Small water supply · 上小阿仁村 | — | — | — | nd | — | nd | — |
| 上小阿仁村（小沢田簡易水道事業）Small water supply · 上小阿仁村 | — | — | — | nd | — | nd | — |
| 上小阿仁村（五反沢簡易水道事業）Small water supply · 上小阿仁村 | — | — | — | nd | — | nd | — |
| 上到米簡易水道事業Small water supply | — | — | — | — | — | nd | — |
| 小坂清水簡易水道事業Small water supply | — | — | — | — | — | planned | — |
| 湯沢市山田簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市高松簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市高松東部簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市宇留院内簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市院内簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市横堀・小野簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市三ツ村簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市川井簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市湯ノ岱簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市野中簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市磯簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市真木簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市南沢簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市小沢簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市小安簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市湯元簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市羽場簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市板戸簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市長石田簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市貝沼・皿小屋簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市中生簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 湯沢市落合・沖ノ沢簡易水道事業Small water supply · 湯沢市 | — | — | — | nd | nd | nd | raw water only |
| 東成瀬村簡易水道事業Small water supply · 東成瀬村 | — | — | — | — | nd | 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
- Yurihonjo City was nd (below the detection or quantification limit) in FY2021–FY2023, then 38 and 37 from FY2024. These are raw water values, so they are not necessarily the values of tap water. The next highest were Katagami City (潟上市) (raw water; 14, 11 and 8), Yokote City (横手市) (11 in FY2025) and Misato Town (美郷町) (10, 10 and 7). The Akita City Water and Sewerage Bureau (秋田市上下水道局) was nd for all six years.
- Of the 119 rows in the table, 97 are small water supply systems, and 103 have a testing record. Small water supply systems in Kitaakita City (北秋田市) and elsewhere measure in raw water. → How to read the national table
- Private water supplies (for a facility) were tested at 48 of the 85 operators, and one exceedance of the provisional target value has been confirmed (FY2020 to the end of August 2025; it is not a national-government system, and its name is not given in the national documents).
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.
This page lists levels published by national and local government bodies and facts from standards, assessments and papers. It does not judge whether tap water is good or bad or whether it affects health. Check the latest values and measures with your local water utility.