Wales · Natural Resources Wales
Pwllheli
Avoid swimming
Active sewage discharge from Llannor WwTW Storm Overflow (4 active events within 5km, Welsh Water).
High confidence — an active discharge is being reported right now — the event itself is fresh evidence.
Status computed 26 Aug 2026, 23:28 UTC; statuses refresh every 15 minutes.
What we know
- Regulator classification
- Excellent
- Pollution risk forecast
- Not published for this spot
- Active discharges
- 4 within 5km right now
- Recent discharges (last 48 hours)
- 9 within 5km
- Upstream river network
- None reported affecting this spot’s river reaches
- Surrounding overflow coverage
- Within an ingested water company network
- Monitoring season
- Currently in regulator monitoring season
Last sampled 4 August 2026 · 7 weeks ago. Source: Natural Resources Wales.
Risk forecasts are published for 14% of Welsh spots only.
Llannor WwTW Storm Overflow (Welsh Water) — started 26 Aug 2026, 08:15 UTC.
Most recent at Llannor WwTW Storm Overflow (Welsh Water) — ended 26 Aug 2026, 10:45 UTC.
Discharges traced through the river network by sewage-map.
What this verdict means
Avoid swimming is driven by the strongest negative signals this map tracks: an active sewage discharge affecting this water, or a regulator classification of Poor or a closure. After a discharge ends, waiting at least 48 hours before swimming is the standard advice.
Every verdict here is computed from regulator classifications, sample dates, pollution-risk forecasts, and water-company discharge reports — it is not a water test. Absence of a negative signal is not positive confirmation of safety, and conditions on the day (rainfall, currents, cold) matter as much as water quality. Read how statuses are decided.