Source Protection Zones England Wales
What are source protection zones in England and Wales?
Source protection zones (SPZs) are areas mapped around groundwater sources used for drinking water (wells, boreholes and springs). They show how much risk contamination poses to each source. The Environment Agency defines them for England and Natural Resources Wales (NRW) for Wales. The zones are based on how long groundwater takes to travel to the abstraction point. The Environment Agency's guidance describes them as "zones which show the level of risk to the source from contamination" (gov.uk SPZ guidance). NRW says their purpose is "to provide additional protection to safeguard drinking water quality through constraining the proximity of an activity that may impact upon a drinking water abstraction" (NRW SPZ dataset).
The zones
| Zone | England (Environment Agency) | Wales (NRW) |
|---|---|---|
| SPZ1, inner zone | Within 50 m of the abstraction point, or where groundwater takes up to 50 days to reach it, whichever area is larger | 50-day travel time or less from any point at or below the water table, with a minimum 50 m radius |
| SPZ2, outer zone | Within 250 m (abstraction under 2,000 m³/day) or 500 m (2,000 m³/day or more), or the 400-day travel time, whichever area is larger | 400-day travel time from a point below the water table, with a minimum radius of 250 or 500 m depending on abstraction size |
| SPZ3, total catchment | All the groundwater that flows to the abstraction point; it can reach a long way from the source | The total area needed to support the abstraction or discharge |
| SPZ4, zone of special interest | Areas that need extra local protection because of local conditions | Not listed in the NRW dataset description |
In England there are also "subsurface" zones (1c, 2c and 3c). These extend protection beneath confining layers such as clay, where deep drilling could open a pathway for contamination.
Where SPZs carry legal weight
- Definition in law: the Environmental Permitting (England and Wales) Regulations 2016 define only SPZ1 ("groundwater Source Protection Zone 1"). It is a zone within 50 m of a point where water is abstracted from underground strata for domestic or food production purposes, or the 50-day travel-time zone to such an abstraction, "whichever is larger" [1].
- Exemptions: in the 2016 Regulations, several exemptions only apply outside SPZ1, so being in SPZ1 rules them out:
- small sewage discharges must not put pollutants into groundwater within SPZ1;
- for closed-loop ground source heating and cooling, no part of the system may be within SPZ1;
- for open-loop systems in England, water must not be discharged within SPZ1;
- no part of a new cemetery or cemetery extension may be within SPZ1, and there are further limits on burial numbers for a principal aquifer outside SPZ2 [2].
- Permit conditions: for landspreading, operators "must not store or spread waste within" SPZ1 [3]. Sewage sludge must not be applied in SPZ1 in forestry [4]. Operators must consider sensitive locations within SPZ2 [5].
- Landfill: the Environment Agency treats SPZ2 and SPZ3 as sensitive groundwater locations, where risk assessments are needed. It "will normally object to any proposed landfill site within a SPZ 1", and an inert landfill permit there is unlikely to be granted [6].
Finding them: English SPZs are on the Magic map and the Defra Data Services Platform, where they are filed under non-statutory designations (gov.uk). Welsh SPZs are on NRW's DataMap Wales layer (DataMap Wales).
Approach: I searched the Environmental Permitting (England and Wales) Regulations 2016 and Environment Agency permitting guidance. I also opened the Environment Agency's SPZ guidance on gov.uk and NRW's SPZ dataset records.