PFAS in tap water: Tokushima Prefecture
In the national survey table, no water utility in Tokushima Prefecture exceeded 50 ng/L (PFOS and PFOA combined) in FY2020–FY2025. The highest value in the prefecture was 14 ng/L (FY2024, tap water) for the Awa City water service (阿波市水道事業). The highest value in the prefecture in FY2025 (through the end of August) was 7 in Anan City (阿南市).
Levels by utility (PFOS + PFOA combined, ng/L)
| Utility | FY2020 | FY2021 | FY2022 | FY2023 | FY2024 | FY2025* | Sampled at |
|---|---|---|---|---|---|---|---|
| 徳島市上下水道事業Water supply · 徳島市 | nd | nd | nd | nd | nd | nd | tap, plant outlet and raw |
| 鳴門市企業局Water supply · 鳴門市 | nd | nd | nd | 2 | nd | nd | tap and raw |
| 上板町水道事業Water supply · 上板町 | — | — | — | 7 | — | — | plant outlet only |
| 北島町水道事業Water supply · 北島町 | nd | nd | nd | nd | nd | nd | plant outlet and raw |
| 藍住町水道事業Water supply · 藍住町 | nd | nd | nd | nd | nd | nd | tap and raw |
| 阿南市水道事業Water supply · 阿南市 | nd | nd | nd | nd | 5 | 7 | tap and raw |
| 吉野川市水道事業Water supply · 吉野川市 | 2.8 | nd | — | — | 2 | nd | tap and raw |
| 小松島市水道事業Water supply · 小松島市 | nd | nd | nd | nd | nd | 2 | tap and raw |
| 松茂町 水道事業Water supply · 松茂町 | nd | nd | nd | nd | nd | 2 | tap only |
| 石井町水道事業Water supply · 石井町buys all its water — Buys from 徳島市上下水道事業 | — | — | — | — | nd | nd | 給水栓水 |
| つるぎ町水道事業Water supply · つるぎ町 | — | — | — | — | — | nd | — |
| 板野町水道事業Water supply · 板野町 | — | nd | nd | nd | nd | nd | tap only |
| 三好市水道事業Water supply · 三好市 | — | — | — | — | nd | nd | raw water only |
| 海陽町水道事業Water supply · 海陽町 | nd | nd | nd | nd | nd | 2 | tap and raw |
| 美波町水道事業Water supply · 美波町 | nd | nd | nd | nd | nd | nd | tap only |
| 阿波市水道事業Water supply · 阿波市 | — | 9 | 9 | — | 14 | — | tap only |
| 美馬市水道事業Water supply · 美馬市 | nd | nd | nd | nd | nd | — | tap only |
| 東みよし町水道事業Water supply · 東みよし町 | — | — | — | — | nd | — | — |
| 飯谷町沖野簡易水道事業Small water supply | — | — | — | — | 2 | — | — |
| 徳島市名東町末広簡易水道組合Small water supply · 徳島市 | — | — | — | — | — | 2 | — |
| 飯谷長柱簡易水道組合Small water supply | — | — | — | — | — | 2 | — |
| 八多町五滝簡易水道組合Small water supply | — | — | — | — | — | planned | — |
| 飯谷沖野簡易水道組合Small water supply | — | — | — | — | — | 4 | — |
| 名東町３丁目簡易水道組合Small water supply | — | — | — | — | — | 2 | — |
| 共栄簡易水道組合Small water supply | — | — | — | — | — | nd | — |
| 若葉団地親和簡易須藤組合Small water supply | — | — | — | — | — | nd | — |
| 桑野簡易水道組合Small water supply | — | — | — | — | — | 2 | — |
| 勝浦町簡易水道事業Small water supply · 勝浦町 | — | — | — | — | 3 | 3 | tap only |
| 神山町簡易水道Small water supply · 神山町 | — | — | — | — | nd | — | tap only |
| 阿南市水道事業Small water supply · 阿南市 · 2 systems | — | — | nd | nd | nd | nd | raw water only |
| 那賀町鷲敷簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町中山簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町西納野下原簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町大久保簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町延野簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町平谷簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町海川簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町小浜簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町桜谷簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町市宇簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町出羽簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町坂州簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町六地蔵簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町北川簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町南宇簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町出原和無田簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 那賀町横石簡易水道事業Small water supply · 那賀町 | — | — | — | — | nd | — | tap and plant outlet |
| 牟岐町簡易水道事業Small water supply · 牟岐町 | — | — | — | — | nd | 2 | raw water only |
| 佐那河内村府能簡易水道事業Small water supply · 佐那河内村 | — | — | — | — | nd | — | — |
| 上勝町簡易水道事業Small water supply · 上勝町 | — | — | — | — | 2 | nd | tap 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
- The national table has 50 rows for Tokushima Prefecture (including small water supply systems), and 49 of them have testing records. Most are nd (below the detection or quantification limit) or single-digit values.
- Awa City had 9 in FY2021 and FY2022 and 14 in FY2024. The national table has no values for FY2023 or FY2025.
- There are 55 private water supplies (for a facility: in-house water systems for company housing, hospitals, schools and so on). None of the 16 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 and MLIT: List of survey results (published November 29, 2024)
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.