PFAS in tap water: Fukuoka Prefecture

Levels by utility (PFOS + PFOA combined, ng/L)

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

• In the November 2024 table, Miyama City’s testing points were a mix of tap and raw water (water before treatment), and the table does not say which one each value comes from. When the table was published in November 2024, the FY2024 value was 28 (through the end of September).
• Other relatively high values were in Okagaki Town (岡垣町) (45 in FY2020 → 19 in FY2025), Itoshima City (糸島市) (30 in FY2021 → nd in FY2025) and Chikugo City (筑後市) (22 in FY2023 → 27 in FY2025).
• The Fukuoka City water service (福岡市水道事業) and the Fukuoka District Water Supply Authority (福岡地区水道企業団) (a bulk water supplier) were nd (below the detection or quantification limit) in every year from FY2021 to FY2025, and the Kitakyushu City Water and Sewer Bureau (北九州市上下水道局) was 1–3 ng/L.
• Seven services “buy all their water” (they have no water source of their own and buy water): Okawa City (大川市), the Mii Water Supply Authority (三井水道企業団), Koga City (古賀市), Chikuzen Town (筑前町), Oki Town (大木町), Hirokawa Town (広川町) and Miyako Town (みやこ町). The values of the bulk water suppliers in the prefecture were nd–4 for the Fukuoka Kennan Wide-Area Water Supply Authority (福岡県南広域水道企業団), 10–14 for the Sanjin Water Supply Authority (山神水道企業団) and nd–13 for the Keichiku District Water Supply Authority (京築地区水道企業団). If you know which supplier your water comes from, check its values too. → How can I check PFAS in the tap water where I live?
• There are 427 private water supplies (for a facility: in-house water systems for company housing, hospitals, bases and so on). Of the 143 that were tested, 1 exceeded 50: the private water supply set up by the national government at JASDF Ashiya Air Base (航空自衛隊芦屋基地), 1,500 ng/L. A national document (December 2025) says, “Being handled with water purifiers as a stopgap. Removal equipment is planned to be installed.” (the December 2024 document said, “planned to switch to the public water supply in the future”). This is the value of the in-house water system inside the base, not the value of Ashiya Town’s (芦屋町) water supply.

Rivers and groundwater (environmental monitoring)

These measure rivers or groundwater themselves, not tap water. The water is not necessarily used for drinking.

• In the Ministry of the Environment’s nationwide survey for FY2019 (Reiwa 1), the Miyano River (宮の川) in Chikujo Town (築上町) (at Kawajiri Bridge (川尻橋)) had 145.9 ng/L of PFOS and PFOA combined. In the same survey, the Onga River (遠賀川) in Ashiya Town (at Ashiya Bridge (芦屋橋)) had 2.5, groundwater in Ashiya Town had 4.1, and the Mikasa River (御笠川) and Umi River (宇美川) in Fukuoka City had 7.3 and 6.4. These are river and groundwater measurements, not tap water values. The Chikujo Town water service had 12 in FY2020 and nd in FY2021–FY2025.

Put it in terms of your own intake

Related explainers

• How do you check PFAS in your local tap water? Reading the national tables and working out “what percent of the TDI”
• Do high PFAS values in rivers or groundwater mean high values in tap water? How guideline values differ from the tap water standard
• Japan’s PFAS standard for tap water, “50 ng/L”: how was it set, and how does it differ from the U.S. and EU?
• Water filters and PFAS

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: Results of the survey of PFOS and PFOA in water supplies (final summary, December 24, 2024; exceedances at private water supplies set up by the national government)
• Ministry of the Environment and MLIT: List of survey results (published November 29, 2024)
• Ministry of the Environment: List of results of the FY2019 (Reiwa 1) nationwide survey of PFOS and PFOA levels (published June 11, 2020)

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.

Other prefectures

• Saga Prefecture
• Nagasaki Prefecture
• Kumamoto Prefecture
• Oita Prefecture
• Miyazaki Prefecture
• Kagoshima Prefecture