Overview of Anglian Water’s Catchment Management Strategy

11th July 2012

Simon Eyre

Water Resources Management Team

Contents

• Background Information

• AW catchments

• Nene drinking water catchments

• Work in the Nene

• Water Quality

• Activities

• Recent survey

• Next stages

Anglian Water

•Geographically the largest water company in England and Wales.

•4.2 million water customers and 5.6 million wastewater customers.

•Abstraction of c.1,200 Ml/d

Anglian WaterDrinking water sources

50% of our raw water comes from groundwater and 50% is from surface

water.

Groundwater:•226 sources, >500 boreholes

Surface water:

•9 reservoirs and 8 direct intakes

•Direct river abstraction into the treatment works •Pumping of water from a river into an impounding reservoir

•Natural flow from streams and storage in reservoirs

Pollution issues

• c.82% of AW region land agricultural

• Pesticides and nitrate • Diffuse and point source pollution

• Contrast surface water and groundwater catchments– Surface water; more vulnerable, larger

catchments, seasonal responses– Groundwater; variable vulnerability,

smaller catchments, less seasonal

Surface water catchments

Groundwater catchments

AW WTWs and theNene Catchment

73.45Tinwell) and Gwash)Morcott

123.891,215,190Nene (u/s of

Wansford)

(also Welland (u/s of

Rutland

reservoir

Wing

36.00101,643Nene (u/s of Duston

Mill)

Holcott, Scaldwell, Waldegrave

Pitsford

reservoir

Pitsford

7.0418,066Coton Mill

Crow Hill

Ravensthorpe

and Hollowellreservoirs

Ravensthorpe

Average Output (Ml/d)

PopulationFeeder streams/rivers

SourcesWTW

Pitsford – Natural catchments

These are small headwater catchments which feed directly into the reservoir. Detailed information on the catchment response is not

available.

Catchment response

Undifferentiated argillaceous rock overlain by interbedded limestone and sandstone

Catchment geology

Holcot Feeder Stream, Scaldwell Brook and Walgrave Brook combined: 47 km

2

Catchment area

Pitsford catchment

Catchment

These streams feed directly into PitsfordReservoir.

Nature of intake monitoring

SP793713SP776718

SP794701NGR

River River RiverSource Type

WalgraveBrook intake

ScaldwellBrook intake

HolcotFeeder Stream, intake

Source Name

Pitsford – Pumped catchment

Based on the flow gauge at Upton (a short distance upstream of the intake), the catchment response is affected by runoff

increased with effluent returns

Catchment response

Mostly clay (70%) with 30% superficial deposits, mainly Boulder Clay. Predominantly rural catchment with land use of

mixed farming

Catchment geology

280 km2

Catchment area

Water is pumped from intake to Pitsford Reservoir

Nature of intake monitoring

Upper NeneCatchment

SP729596NGR

RiverSource Type

River Nene/Duston Mill intakeSource Name

Ravensthorpe catchment

This is a small headwater catchment which feeds directly into the reservoir. Detailed information on the catchment

response is not available.

Catchment response

The geology of the catchment is Upper Lias overlain by Inferior Oolite

Catchment geology

9.9 km2

Catchment area

Water from this stream feeds into the Ravensthorpe

Reservoir

Nature of intake monitoring

RavensthorpeCatchment

SP683738NGR

Inflow from reservoir catchmentSource Type

Coton Mill Stream intakeSource Name

Hollowell catchment

This is a small headwater catchment which feeds directly into the reservoir. Detailed information on the catchment

response is not available.

Catchment response

The geology of the catchment is Upper Lias overlain by Inferior Oolite

Catchment geology

11.7 km2

Catchment area

Water from this stream feeds into the Hollowell Reservoir

Nature of intake monitoring

HollowellCatchment

SP672712NGR

Inflow from reservoir catchmentSource Type

Crow Hill Stream intakeSource Name

Drinking water standards

All water companies must supply water to defined drinking water standards

For example: Individual pesticide: 0.1 ug/l

Total pesticides: 0.5 ug/l

• If standards are exceeded the Drinking Water Inspectorate (DWI) requires solutions to be implemented

• Part of the Periodic Review Business Planning process

• Five year AMP periods• DWI Undertakings specify requirements

• Traditional solution has been treatment

Metaldehyde (2008-2012)

Pitsford Water Treatment Works - Metaldehyde

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Meta

ldeh

yd

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µg

/l)

Duston Mill intake

(river to reservoir)

Holcot Feeder Stream

(river to reservoir)

Scaldwell Brook

(river to reservoir)

Walgrave Brook

(river to reservoir)

Pitsford Raw Water

(reservoir to WTW)

Final Water

(12m max = 0.109µg/l)

Regulatory Standard

Go to Data

Metaldehyde (2008-2012)

Ravensthorpe Water Treatment Works - Metaldehyde

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Me

tald

eh

yd

e (

µg

/l)

Crow Hill

(river to Hollowell Reservoir)

Coton Mill

(river to Ravensthorpe Reservoir)

Hollowell Reservoir

(reservoir to WTW)

Ravensthorpe Reservoir

(reservoir to WTW)

Final Water

(12m max = 0.1µg/l)

Regulatory Standard

Go to Data

Clopyralid (2008-2012)

Pitsford Water Treatment Works - Clopyralid

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Clo

py

rali

d (

µg

/l)

Duston Mill intake

(river to reservoir)

Holcot Feeder Stream

(river to reservoir)

Scaldwell Brook

(river to reservoir)

Walgrave Brook

(river to reservoir)

Pitsford Raw Water(reservoir to WTW)

Final Water (max = 0.139µg/l)

Regulatory Standard

Go to Data

Clopyralid (2008-2012)

Ravensthorpe Water Treatment Works - Clopyralid

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Clo

pyra

lid

(µ

g/l

)

Crow Hill

(river to Hollowell Reservoir)

Coton Mill

(river to Ravensthorpe Reservoir)

Hollowell Reservoir

(reservoir to WTW)

Ravensthorpe Reservoir

(reservoir to WTW)

Final Water

(max = 0.113µg/l)

Regulatory Standard

Go to Data

Business options

Solutions are costly:• Options:

– close source and find alternative– blend with better quality water (if available)– treat to remove/reduce pollutant

• Consequences of depending on treatment:– Capital and operational costs increase with number and complexity of

treatment stages– Embedded carbon cost of plant construction– Operational energy carbon cost– Disposal of process water by-product– Environmental and social impacts of asset construction and operation– Treatment options may not be completely effective – Technology may not be available to remove pollutants

Catchment ManagementRegulatory drivers

• Promoted by the WHO in 2001 and the Drinking Water Inspectorate

• Defra Water Strategy (2008): ‘We will encourage water companies to work with farmers to tackle pollution at source’

• AW Strategic Direction Statement (2007); sustainable approach to management of drinking water quality

• Opportunities given by DWI and Ofwat to invest in catchment management work

• Water Framework Directive Article 7: DrWPAs require catchment protection to avoid deterioration of raw water quality and the installation of additional treatment

Therefore, a regulatory shift of expectation from ‘traditional’ end-of-pipe solution to catchment management

Max. concentrations of selected pesticides from Pitsford reservoir(2005-10)

0.116Metazachlor

Pitsford Reservoir

1.7

0.133

0.604

0.786

0.369

0.195

0.18

0.827

0.236

Max. (ug/l)

Total pesticides

Simazine

Propyzamide

Metaldehyde

Mecoprop

Isoproturon

Clopyralid

Carbetamide

Bentazone

Pesticide

Max. concentrations of selected pesticides from Ravensthorpe and Hollowell reservoirs (2005-10)

0.1520.076Clopyralid

0.9950.17Simazine

HollowellRavensthorpe

1.472

0.173

0.594

0.994

0.307

0.142

0.675

0.306

Max. (ug/l)

2.178Total pesticides

0.045Quinmerac

1.14Propyzamide

1.47Metaldehyde

0.334Mecoprop

0.08Chlorotoluron

0.945Carbetamide

0.222Bentazone

Max. (ug/l)Pesticide

AW Nene work

• Improve understanding of catchment– Data Acquisition

– Catchment modelling

– Stakeholder meetings

– Hosting farmer and agronomist meetings at WTW

– MSG awareness

– ADAS farmer surveys

• Support initiatives– CSF Catchment Partnership

– WFD Pilot Catchment

– Nature Improvement Area

Catchment understanding

Key aspect of catchment management is to answer questions such as:

• What has caused the pollution problem?

• What needs to change?• What land use management practices to promote

and where?• What impacts on raw water quality would different

practices have?• How soon would the impacts be seen?• Can we do without treatment?

Survey work

Direct Engagement with farmers:

• Nov-11 to Feb-12

• Carried out by ADAS

• Gathered data on the use of metaldehyde and alternatives

• Raised awareness of drinking water issues

Process

• Invitation letters

• On-farm surveys (20 farms covering an area of 3,943 Ha)

• Collate data (for group not individual farms)

• Report

Key findings

• Willingness to consider ferric phosphate is an option to metaldehyde but need convincing

• Key factors in choice of slug control– Effectiveness of product

– Advice of agronomist

• Pellets rarely mixed

• Fairly consistent number of fields given an application 20-27% over the period 2008-2011

• Factors affecting slug presence– Wet weather

– Soil type

– Seed bed quality

Key findings (cont)

• Despite publicity some farmers not familiar with or not following best practice– Applications only carried out by trained operator

– No drains running at time of application

– Applications not exceeding 210g metaldehyde/ha during the restricted period (1st August to 31st December)

• Areas affected by breaches of guidelines (2008-11)– Untrained operators: 1292 ha

– Drains running at application: 4571 ha

– Restricted period applications exceeding max 210g/ha: 2672 ha

Next stages

Possible next steps:

• Discuss and review results

• Focussed group training

• Alternative product trialling

– Financial factors

– Agronomic factors

Conclusions

• Metaldehyde and clopyralid are still issues

• Catchment solutions are required to avoid:

– Expensive treatment, or

– Potential loss of product

• Planning mitigation measures has started

• Trials are needed to provide evidence that measures will work

• Opportunity to work together to ensure no detriment to either the farming or water businesses