Surrey Ash Water Body

Moderate ecological status

Attributes

  • Water Body IDGB106039023480
  • Water Body TypeRiver
  • Hydromorphological designationheavily modified
  • NGRTQ0618969337
  • Catchment area19.015 km2
  • Surveillance Water BodyNo
  • Catchment area1901.497 ha
  • Length11.127 km

Classifications

Classification Item2019
EcologicalModerate
Biological quality elementsModerate
FishModerate
InvertebratesHigh
Macrophytes and Phytobenthos Combined
Macrophytes Sub ElementGood
Physico-chemical quality elementsModerate
Ammonia (Phys-Chem)High
Dissolved oxygenGood
PhosphateModerate
TemperatureHigh
pHHigh
Hydromorphological Supporting ElementsSupports good
Hydrological RegimeSupports good
Supporting elements (Surface Water)Moderate
Mitigation Measures AssessmentModerate or less
Specific pollutantsHigh
IronHigh
TriclosanHigh
ChemicalFail
Priority hazardous substancesFail
Benzo(a)pyreneGood
Di(2-ethylhexyl)phthalate (Priority hazardous)Good
Dioxins and dioxin-like compoundsGood
Heptachlor and cis-Heptachlor epoxideGood
Hexabromocyclododecane (HBCDD)Good
HexachlorobenzeneGood
HexachlorobutadieneGood
Mercury and Its CompoundsGood
NonylphenolGood
Perfluorooctane sulphonate (PFOS)Good
Polybrominated diphenyl ethers (PBDE)Fail
Priority substancesGood
Cypermethrin (Priority)Good
FluorantheneGood
Other PollutantsDoes not require assessment

Why do all water bodies have a chemical status of fail?

Investigations into classification status

No data to show

Reasons for not achieving good (RNAG) and reasons for deterioration (RFD)

All reasons (RFDs and RNAGs) attributed to the classification elements in this water body.

Reason TypeSWMIActivityCategoryClassification ElementMore information
RNAGPoint sourceMisconnectionsDomestic General PublicPhosphateDetails
RNAGPoint sourceSewage discharge (continuous)Water IndustryPhosphateDetails
RNAGPhysical modificationOther (not in list, must add details in comments)Urban and transportMitigation Measures AssessmentDetails
RNAGPhysical modificationOther (not in list, must add details in comments)Local and Central GovernmentMitigation Measures AssessmentDetails
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsiblePolybrominated diphenyl ethers (PBDE)Details
RNAGDiffuse sourceUrbanisation - urban developmentUrban and transportPhosphateDetails

Reasons for not achieving good status by business sector

The issues preventing waters reaching good status and the sectors identified as contributing to them. The numbers in the table are individual counts of the reasons for not achieving good status with a confidence status of 'confirmed' and 'probable', where the latest classification is less than good status. There may be more than one reason in a single water body. Note, table does not include reasons for deterioration.

Significant water management issuePhysical modificationsPollution from waste waterPollution from towns, cities and transportChanges to the natural flow and level of waterInvasive non-native speciesPollution from rural areasPollution from abandoned mines
Agriculture and rural land management0000000
Industry0000000
Mining and quarrying0000000
Navigation0000000
Urban and transport1010000
Water Industry0100000
Local & central government1000000
Domestic general public0000000
Recreation0000000
Waste treatment and disposal0000000
Other0000000
No sector responsible0000000
Sector under investigation0000000
Total2110000

Objectives

Classification ItemStatusYearReasons
EcologicalModerate2015Disproportionately expensive: Disproportionate burdens;
Disproportionately expensive: Unfavourable balance of costs and benefits
Biological quality elementsGood2015
FishGood2015
InvertebratesGood2015
Macrophytes and Phytobenthos CombinedNot assessed2015
Physico-chemical quality elementsModerate2015Disproportionately expensive: Unfavourable balance of costs and benefits
Ammonia (Phys-Chem)Good2015
Dissolved oxygenGood2015
PhosphateModerate2015Disproportionately expensive: Unfavourable balance of costs and benefits
TemperatureGood2015
pHGood2015
Hydromorphological Supporting ElementsSupports good2015
Hydrological RegimeSupports good2015
Supporting elements (Surface Water)Good2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Mitigation Measures AssessmentGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Specific pollutantsHigh2015
IronHigh2015
TriclosanHigh2015
ChemicalGood2063Natural conditions: Chemical status recovery time
Priority hazardous substancesGood2063Natural conditions: Chemical status recovery time
Benzo(a)pyreneGood2015
Di(2-ethylhexyl)phthalate (Priority hazardous)Good2015
Dioxins and dioxin-like compoundsGood2015
Heptachlor and cis-Heptachlor epoxideGood2015
Hexabromocyclododecane (HBCDD)Good2015
HexachlorobenzeneGood2015
HexachlorobutadieneGood2015
Mercury and Its CompoundsGood2015
NonylphenolGood2015
Perfluorooctane sulphonate (PFOS)Good2015
Polybrominated diphenyl ethers (PBDE)Good2063Natural conditions: Chemical status recovery time
Priority substancesGood2015
Cypermethrin (Priority)Good2015
FluorantheneGood2015
Other PollutantsDoes not require assessment2015

Protected areas

PA NameIdDirectiveMore information
Lower Thames (Cookham Egham Teddington)SWSGZ4016Safeguard Zone
South West London WaterbodiesUK9012171Special Protection AreaNatural England
South West London WaterbodiesUK11065Ramsar SiteNatural England

Monitoring sites which have been used to classify this water body

Shows which sites were used for classification for which years within each cycle.

Monitoring SiteCycle 1Cycle 2Cycle 3
DUKE OF NORTHUMBERLAND/HATTON ROAD/ 163902014, 2012, 2010, 2013, 2009, 20112016, 2014, 2015, 2013
DUKE OF NORTHUMBERLAND/MOOR LANE/ 146202010
34257 342572014, 2010, 20092014, 2016
ASH ABOVE THAMES PTHR00052014, 2010, 2013, 2011, 2009, 20122014, 2015, 2016, 20192019
ASH ABOVE ASHFORD COMMON WATERWORKS PTHR00042014, 20092014, 2015, 2016, 20192019
CRANE ABOVE DUKE OF NORTHUMBERLANDS RIVE PCRR00202009
ASH (THAMES)/GASTON BRIDGE/ 163382014, 2012, 2010, 2013, 2009, 20112016, 2019, 2014, 2015, 20132019
RIVER THAMES/THAMES JUVENILE SURVEY/LALEHAM ABBEY/LALEHAM ABBEY 9A/ 290422009
COLNE/PINN/ROBBIE BELL BRIDGE/ 191382012
ASH (THAMES)/FORD BRIDGE ROUNDABOUT/ 191362014, 2012, 2013, 20112016, 2019, 2014, 2015, 20132019
34021 340212011, 2014, 2013, 2012, 2010, 20092014, 2015, 2013, 2019, 20162019

Upstream water bodies

    Downstream water bodies