BGS Hosted Metadata
Source Protection Zones [Merged]
Source Protection Zones [Merged] have been created as public facing outlines where common boundaries and overlaps (based on zone number) have been removed. Source Protection Zones (SPZs) are defined around large and public potable groundwater abstraction sites. The purpose of SPZs 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. This is part of an initial screening process in assessing impacts to groundwater resources. Zones around location sites are defined by groundwater travel time to an abstraction. This is determined through applying Environment Agency groundwater flow models run at the location of abstractions, inputting parameters such as flow direction, geology type, rainfall and hydrological boundaries. SPZs provide a visual representation of the increased risks as you get closer to the abstraction.
The following subdivisions are defined within SPZs:
Zone 1: (Inner Protection Zone) - This zone is defined by a travel time of 50-days or less from any point within the zone at, or below, the water table. Additionally, the zone has as a minimum a 50-metre radius. It is based principally on biological decay criteria and is designed to protect against the transmission of toxic chemicals and water-borne disease.
Zone 2: (Outer Protection Zone) - This zone is defined by the 400-day travel time from a point below the water table. Additionally this zone has a minimum radius of 250 or 500 metres, depending on the size of the abstraction. The travel time is derived from consideration of the minimum time required to provide delay, dilution and attenuation of slowly degrading pollutants.
Zone 3: (Total catchment) - This zone is defined as the total area needed to support the abstraction or discharge from the protected groundwater source.
We’ve 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 SPZ maps show them as zones 1c, 2c and 3c.
A further Zone 4, or ‘Zone of Special Interest’ is occasionally defined for some groundwater sources. These zones highlight areas (mainly on non-aquifers) where known local conditions mean that potentially polluting activities could impact on a groundwater source, even though the area is outside the normal catchment of that source. Attribution statement: © Environment Agency copyright and/or database right 2016. All rights reserved.
Simple
- Alternate title
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SPZs
- Alternate title
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source_protection_zones_50k
- Alternate title
-
SOURCE_PROTECTION_ZONES_50K
- Date (Creation)
- 1990-01-01
- Date (Revision)
- 2021-10-01
- Citation identifier
- DSTR04808
- Citation identifier
- 6fd0120f-d465-11e4-abee-f0def148f590
- Point of contact
-
Organisation name Individual name Electronic mail address Role Environment Agency
Point of contact
- Maintenance and update frequency
- Irregular
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GEMET Thesaurus version 2.1
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groundwater
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water resources management
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aquifer
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OpenData
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- Use limitation
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Open Government Licence
- Access constraints
- Other restrictions
- Access constraints
- License
- Access constraints
- Copyright
- Other constraints
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There are no public access constraints to this data. Use of this data is subject to the licence identified.
- Language
- English
- Character set
- UTF8
- Topic category
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- Environment
- Inland waters
- Extent type code
- Yes
- Geographic identifier
- http://data.ordnancesurvey.co.uk/doc/country/england
- Extent type code
- Yes
- Geographic identifier
- http://data.ordnancesurvey.co.uk/doc/country/wales
- Begin date
- 1990-01-01
))
- Reference system identifier
- http://www.opengis.net/def/crs/EPSG/0/27700
- Distribution format
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Name Version Open format | Shapefile (SHP)
Not Applicable
- OnLine resource
- Hierarchy level
- Dataset
- Statement
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Large potable groundwater abstractions are extracted from the National Abstraction Licence Database (NALD) and georeferenced as Source Protection Locations. A groundwater flow model for relevant aquifer is run and classified into zones defined by travel time. Individual Source Protection Zones are merged and dissolved by Zone number stripping out SPZ name. This is for National Security reasons.
Metadata
- File identifier
- 6fd0120f-d465-11e4-abee-f0def148f590 XML
- Metadata language
- English
- Character set
- UTF8
- Hierarchy level
- Dataset
- Date stamp
- 2024-06-11T14:35:06.940073Z
- Metadata standard name
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Gemini
- Metadata standard version
-
2.2
- Metadata author
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Organisation name Individual name Electronic mail address Role Environment Agency
Point of contact
)))