Caernarfon Bay South at Settled Storm Overflow At Trefor Wastewater Treatment Works
This is a sewage discharge monitoring station, which is usually a type of Event Duration Monitor (EDM). These stations themselves are designed to mitigate the impact of heavy rainfall by discharging, under permitted conditions, any overflow into a water body. They are often actively discharging during flood events. This page presents the data acquired by the monitoring system for this discharge station.
Sewage Reports that include this Station
Operational Summary - 2021-2023
Caernarfon Bay South | 204 Spills | 2657.7 hours | 10.11
The declared body of water receiving this discharge is the "Caernarfon Bay South" This station has discharged sewage 204 time(s). The station has discharged for a total of 2657.7 hour(s). This is 10.11% of the time which we have data for. In total: 110 day(s)* of elapsed time.
66 | 8935.2 hours This monitor has been operational for 66% of its total time we have data for. There are 8935.2 hours unaccounted for due to downtime of the monitor.
The worst year in our records for the "Settled Storm Overflow At Trefor Wastewater Treatment Works" is 2023, discharging sewage for 2572 hours of the year.
Uptimes below 90% (red line) should be accompanied by a reason
*This is total time in days, not individual days.
Yearly Summary
Most Recent Year - 2023
Caernarfon Bay South | 175 Spills | 2572 hours | 29.36 The declared body of water receiving this discharge is the "Caernarfon Bay South" This station discharged sewage 175 time(s) during 2023. The station discharged for a total of 2572 hour(s). This is around 107 day(s)* or 29.36% of the year.
99.9 | 4.3 hours This monitor was operational for 99.9% of the year. Leaving 4.3 hours unaccounted for in the data.
*This is total time in days, not individual days of the year.
Permit & Governance
Attribute
Value
Governing Body
Natural Resources Wales
Operator
Dwr Cymru Welsh Water
Primary Permit #
CG0438901
Secondary Permit #
CG0438901
2022
Note: Data is potentially unreliable in 2022 Due to high unavailability of the monitor
Caernarfon Bay South | 0 Spills | 0 hours | 0 The declared body of water receiving this discharge is the "Caernarfon Bay South" This station discharged sewage 0 time(s) during 2022. The station discharged for a total of 0 hour(s). This is around 0 day(s)* or 0% of the year.
0 | 8760 hours This monitor was operational for 0% of the year. Leaving 8760 hours unaccounted for in the data. This falls below the 90% threshold where a reason should be given
The following reasons have been given for the downtime in 2022: Other – You Must Give Explanation In "Additional Comments" Box
*This is total time in days, not individual days of the year.
Permit & Governance
Attribute
Value
Governing Body
Natural Resources Wales
Operator
Dwr Cymru Welsh Water
Primary Permit #
CG0438901
Secondary Permit #
CG0438901
2021
Un-Named To Caernarfon Bay South | 29 Spills | 85.7 hours | 0.97 The declared body of water receiving this discharge is the "Un-Named To Caernarfon Bay South" This station discharged sewage 29 time(s) during 2021. The station discharged for a total of 85.7 hour(s). This is around 3 day(s)* or 0.97% of the year.
99.8 | 12.2 hours This monitor was operational for 99.8% of the year. Leaving 12.2 hours unaccounted for in the data.
*This is total time in days, not individual days of the year.
Permit & Governance
Attribute
Value
Governing Body
Natural Resources Wales
Operator
Dwr Cymru Welsh Water
Primary Permit #
CG0438901
Secondary Permit #
CG0438901
FloodMapper is not affiliated with this monitoring stations operator(s) or any other entities that may be mentioned on this page. All trademarks and registered trademarks are the property of their respective owners. Operator comments are presented, unedited, as they were received by us and do not reflect our views or position
Station overseen (meaning either provided, or regulated) by: Natural Resources Wales The information displayed here is used under license. We are not affiliated with any governing, or other, bodies. Nor do they necessarily endorse us, or us them. Please note that FloodMapper does not verify or check the accuracy of the data provided by third parties. The data is used as received from the source. Any underlying errors, inconsistencies, or inaccuracies in the original data will be reflected in the information presented on our platform. Users are advised to exercise their own judgment and caution when using the data for decision-making purposes. Information about our data sources and licenses can be found
FloodMapper is an independent site and is not associated with any government bodies (e.g. Environment Agency).