Arun Horsham Water Body

Poor ecological status

Attributes

  • Water Body IDGB107041012310
  • Water Body TypeRiver
  • Hydromorphological designationnot designated artificial or heavily modified
  • NGRTQ1401131423
  • Surveillance Water BodyYes
  • Catchment area18.164 km2
  • Length7.274 km
  • Catchment area1816.42 ha

Classifications

Classification Item20192022
EcologicalPoorPoor
Biological quality elementsPoorPoor
FishGoodPoor
InvertebratesModerateModerate
Macrophytes and Phytobenthos CombinedPoorPoor
Macrophytes Sub ElementPoorPoor
Phytobenthos Sub ElementPoorPoor
Physico-chemical quality elementsModerateModerate
Acid Neutralising CapacityHighHigh
Ammonia (Phys-Chem)HighHigh
Dissolved oxygenHighGood
PhosphateModerateModerate
TemperatureHighHigh
pHHighHigh
Hydromorphological Supporting ElementsSupports goodSupports good
Hydrological RegimeSupports goodSupports good
MorphologySupports goodSupports good
Specific pollutantsHighHigh
ChlorothalonilHighHigh
Chromium (VI)HighHigh
CopperHighHigh
IronHighHigh
ManganeseHighHigh
PendimethalinHighHigh
TriclosanHighHigh
ZincHighHigh
ChemicalFailDoes not require assessment
Priority hazardous substancesFailDoes not require assessment
Benzo(a)pyreneGood
Benzo(b)fluorantheneGood
Benzo(g-h-i)peryleneFail
Benzo(k)fluorantheneGood
Cadmium and Its CompoundsGood
Dioxins and dioxin-like compoundsGood
Heptachlor and cis-Heptachlor epoxideGood
Hexabromocyclododecane (HBCDD)Good
HexachlorobenzeneGood
HexachlorobutadieneGood
HexachlorocyclohexaneGood
Mercury and Its CompoundsFail
NonylphenolGood
PentachlorobenzeneGood
Perfluorooctane sulphonate (PFOS)Fail
Polybrominated diphenyl ethers (PBDE)Fail
QuinoxyfenGood
Tributyltin CompoundsGood
Priority substancesGoodDoes not require assessment
1,2-dichloroethaneGood
AclonifenGood
AlachlorGood
BenzeneGood
BifenoxGood
CybutryneGood
Cypermethrin (Priority)Good
DichloromethaneGood
FluorantheneGood
Lead and Its CompoundsGood
Nickel and Its CompoundsGood
TrichloromethaneGood
Other PollutantsGoodDoes not require assessment
Carbon TetrachlorideGood
DDT TotalGood
para - para DDTGood

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

Investigations into classification status

Classification ElementCycleYearStatusOutcome
Macrophytes and Phytobenthos Combined22013PoorCertain there is not a problem
Triclosan22013ModerateUncertain there is a problem

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
RNAGUnknown (pending investigation)Unknown (pending investigation)Sector under investigationPerfluorooctane sulphonate (PFOS)Details
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsiblePolybrominated diphenyl ethers (PBDE)Details
RNAGPoint sourceSewage discharge (continuous)Water IndustryPhosphateDetails
RNAGDiffuse sourcePoor soil managementAgriculture and rural land managementPhosphateDetails
RNAGPoint sourceSewage discharge (continuous)Water IndustryInvertebratesDetails
RNAGUnknown (pending investigation)Unknown (pending investigation)Sector under investigationBenzo(g-h-i)peryleneDetails
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsibleMercury and Its CompoundsDetails
RNAGPoint sourceSewage discharge (continuous)Water IndustryMacrophytes and Phytobenthos CombinedDetails

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 transport0000000
Water Industry0300000
Local & central government0000000
Domestic general public0000000
Recreation0000000
Waste treatment and disposal0000000
Other0000000
No sector responsible0000000
Sector under investigation0000000
Total0300000

Objectives

Classification ItemStatusYearReasons
EcologicalModerate2033Natural conditions: Ecological recovery time;
Technically infeasible: No known technical solution is available
Biological quality elementsModerate2033Natural conditions: Ecological recovery time;
Technically infeasible: No known technical solution is available
FishGood2015
InvertebratesGood2033Natural conditions: Ecological recovery time
Macrophytes and Phytobenthos CombinedModerate2033Natural conditions: Ecological recovery time;
Technically infeasible: No known technical solution is available
Physico-chemical quality elementsModerate2015Technically infeasible: No known technical solution is available
Acid Neutralising CapacityGood2015
Ammonia (Phys-Chem)Good2015
Dissolved oxygenGood2015
PhosphateModerate2021Technically infeasible: No known technical solution is available
TemperatureGood2015
pHGood2015
Hydromorphological Supporting ElementsSupports good2015
Hydrological RegimeSupports good2015
Supporting elements (Surface Water)Not assessed2015
Specific pollutantsHigh2015
ChlorothalonilHigh2015
Chromium (VI)High2015
CopperHigh2015
IronHigh2015
ManganeseHigh2015
PendimethalinHigh2015
TriclosanHigh2015
ZincHigh2015
ChemicalGood2063Natural conditions: Chemical status recovery time;
Technically infeasible: No known technical solution is available
Priority hazardous substancesGood2063Natural conditions: Chemical status recovery time;
Technically infeasible: No known technical solution is available
Benzo(a)pyreneGood2015
Benzo(b)fluorantheneGood2015
Benzo(g-h-i)peryleneGood2033Technically infeasible: No known technical solution is available
Benzo(k)fluorantheneGood2015
Cadmium and Its CompoundsGood2015
Dioxins and dioxin-like compoundsGood2015
Heptachlor and cis-Heptachlor epoxideGood2015
Hexabromocyclododecane (HBCDD)Good2015
HexachlorobenzeneGood2015
HexachlorobutadieneGood2015
HexachlorocyclohexaneGood2015
Mercury and Its CompoundsGood2040Natural conditions: Chemical status recovery time
NonylphenolGood2015
PentachlorobenzeneGood2015
Perfluorooctane sulphonate (PFOS)Good2039Technically infeasible: No known technical solution is available
Polybrominated diphenyl ethers (PBDE)Good2063Natural conditions: Chemical status recovery time
QuinoxyfenGood2015
Tributyltin CompoundsGood2015
Priority substancesGood2015
1,2-dichloroethaneGood2015
AclonifenGood2015
AlachlorGood2015
BenzeneGood2015
BifenoxGood2015
CybutryneGood2015
Cypermethrin (Priority)Good2015
DichloromethaneGood2015
FluorantheneGood2015
Lead and Its CompoundsGood2015
Nickel and Its CompoundsGood2015
TrichloromethaneGood2015
Other PollutantsGood2015
Carbon TetrachlorideGood2015
DDT TotalGood2015
para - para DDTGood2015

Protected areas

PA NameIdDirectiveMore information
ArunSWSGZ4317Safeguard Zone
River Arun (u/s Pallingham) NVZS523Nitrates Directive
River ArunUKENRI109Urban Waste Water Treatment Directive

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
ARUN/HORSHAM STW/ 81352010, 2009, 20132019, 2015, 20162022, 2019
ARUN/HORSHAM-BY-PASS SQ/ 167312010, 2009, 2011
144094 1440942013, 20142014, 2013, 2016, 2015
42793 427932009, 2010, 2013, 2014, 2011, 20122016, 2019, 2015, 2014, 20132019
R ARUN WELLCROSS BRIDGE F00027972009, 2011, 2010, 2013, 2012, 20142019, 2015, 2016, 2013, 20142019, 2022
42207 422072009, 2010
R ARUN D/S HORSHAM BYPASS A24 F00028042013, 2014, 2009, 20122016, 2015, 2014, 2019, 20132019, 2022
ARUN/WELLCROSS BRIDGE Q/ 283632012, 2010, 2009, 2013, 20112013
ARUN/WELLCROSS BRIDGE/ 167102010, 2009, 2011
42903 429032013, 2014
144093 1440932013, 2011, 2014
ARUN/THEALE FARM/ 601232019, 2015, 20162019

Upstream water bodies

Downstream water bodies