GovWire

Groundwater supplies a third of our drinking water. In some areas of southern England, up to 80% of the water you get from your taps is from groundwater. It also keeps many of our rivers flowing.

The Environment Agency must protect groundwater sources used to supply drinking water from pollution. Sources include wells, boreholes and springs. Weve defined SPZs theyre zones which show the level of risk to the source from contamination. This could be from any activity that might cause pollution in the area. For example, storing pollutants like petrol underground, soakaways from septic tanks to the ground. The closer the activity, the greater the risk.

We use our approach to groundwater protection to:

• put in pollution prevention measures in areas of high risk
• monitor the activities of nearby potential polluters

Find groundwater SPZs

The maps show 3 main zones:

• inner SPZ1
• outer SPZ2
• total catchment SPZ3

We sometimes apply a fourth zone of special interest.

See the section how weve defined the zones.

You can view the Environment Agencys groundwater SPZs on Magicmap.

To find the SPZs, from the table of contents on the left hand side, select in this order:

• designations
• land-based designations
• non-statutory
• source protection zones merged (England) tick the box

Enter your postcode and size the map. You can use the transparency slider bar under the designations sub heading to adjust visibility of place names within the zones.

You can also download groundwater SPZs or view them as a geographic information system (GIS) layer from the Department for Environment Food & Rural Affairs (Defra) data services portal.

When you need to find a groundwater SPZ

You may need to find out if youre in a SPZ if:

• your property is not connected to mains drainage your septic tank or small sewage discharge treatment plant has a soakaway to the ground this can be a major cause of pollution
• youre applying for an environmental permit or other permission and your business carries out activities that may affect groundwater for example spreading waste to land
• your business produces bottled water
• youre a developer and your proposals have the potential to pollute or harm groundwater
• youre a landowner and your land is within a SPZ
• youre a source operator, for example youre a water company
• you need to define a new SPZ
• you have an interest in drinking water quality

How we defined the zones

We have used models to estimate:

• how long it will take for groundwater to travel below ground (any point below the water table) to the source (the point where water is taken)
• the area around the source which needs protecting from potential pollutants

Inner zone SPZ1

A groundwaterSPZ1is the area immediately around an abstraction point for domestic supply or for food production purposes. Groundwater in a SPZ1 is most vulnerable to pollution given the close proximity of the abstraction point and the waters intended use for human consumption. It is defined within the Environmental Permitting (England and Wales) Regulations 2016 as one of the following.

1. The area within 50 metres of a point where the groundwater is abstracted for domestic supply or food production purposes.
2. The area where it takes groundwater that is intended to be used to supply water for domestic or food production purposes up to 50 days to travel to the groundwater abstraction point.

For any given abstraction point, whichever area is largest applies.

Outer zone SPZ2

A groundwaterSPZ2is the area around an abstraction point for domestic supply or for food production purposes that meets one of the following definitions.

1. The area within 250 metres of the abstraction point if the maximum allowable annual volume, divided by 365, is less than 2,000 cubic metres per day. This is when this is authorised by either:

• an abstraction licence under section 24 of the Water Resources Act 1991
• the right to abstract small quantities under section 27 of the Water Resources Act 1991

2. The area within 500 metres of the abstraction point if the maximum allowable annual volume, divided by 365, is equal to or greater than 2,000 cubic metres per day. This is when this is authorised by an abstraction licence under section 24 of the Water Resources Act 1991

3. The area where it takes groundwater that is used to supply water for domestic or food production purposes up to 400 days to travel to the groundwater abstraction point.

For any given abstraction point, whichever area is largest applies.

Total catchment SPZ3

This is the area around a supply source within which all the groundwater ends up at the abstraction point. This is the point from where the water is taken. This could extend some distance from the source point.

Extended zones beneath protective cover

Weve extended some zones to include areas where there is protective geology cover, such as clay. This is because activities below the surface, such as deep drilling, could create pathways for pollutants to enter the groundwater. The maps show them as zones 1c, 2c and 3c.

Zone of special interest SPZ4

This zone is where local conditions require additional protection.

Technical guidance

You can use the Manual for the production of groundwater source protection zones to find out:

• how the Environment Agency produced the zones
• technical details of the methods used
• how the Environment Agency keeps the zones up to date
• case studies of using particular methods in different geological settings