1. extensiveareasofbarepeatsoil.Heavyrainfall
wouldwashthepeatintoreservoirs,increasing
thecolourandturbidityofthereservoirwater
tolevelstraditionalwatertreatmentprocesses
couldnotfullyaddress(Figure1).
Phosphatefertilisersusedinfarmingcan
causealgalblooms:largefloatingmatsofalgae
thatcanblockfilters(reducingtheoutputofthe
workswhilethefiltersaremanuallycleaned)
andgivethewateramustytaste(leadingto
customercomplaints).
Many of the farms in United Utilities’
catchment also had waste management
facilities – slurry tanks or muck middens –
that were open to the elements. Agricultural
waste can pollute United Utilities’ water with
pathogens such as cryptosporidium and E.coli.
Water companies usually use chlorine
to kill pathogens. However, when the water
colour has been increasing from degrading
peat soils, as in United Utilities’ case, this can
have unwanted knock-on effects. Colour in
water mostly comes from dissolved organic
compounds (DOC), which can react with
chlorine to produce substances known as
disinfection by-products (DBP). Some DBP,
such as trihalomethanes, are potentially
harmful to humans, and regulators expect
tohelpensureasustainablefutureforthose
farmerswhooperatewithinitscatchment.
Overthelast30years,thewaterquality
inUnitedUtilities’catchmenthasbeen
deterioratingthankstotheeffectsofindustrial
airpollution,agriculturalactivities,wildfiresand
climatechange.
Themainmeasuresofwaterqualityare:
„„ colour:thischangesdependingonthe
amountofmaterialdissolvedinthewater,
andismeasuredinHazenunits(HU)
„„ turbidity:thischangesdependingon
howmuchsoilandothersolidmaterialis
suspendedinthewater.
14
To increase efficiency at its water treatment works, United Utilities is investing not just in
infrastructure but also in land management. Matthew Higginson explains why.
T
o protect the quality of the
water entering its drinking
water reservoirs, United Utilities
manages 56,385 hectares of land
in the north-west of England.
UnitedUtilitiescustomersexpecttheirwater
tobeclean,clearandfreefromunpleasant
taste.TheEuropeanUnion’sWaterFramework
Directivealsoimposeswaterqualitytargets
onEuropeanwaterandwastewatersuppliers,
withpenaltiesfororganisationsthatfailtomeet
them.
Ontopoftheseconsiderations,Sitesof
SpecialScientificInterest(SSSIs)makeup
about30percentofUnitedUtilitiesland
(about17,500hectares).TheUKgovernment
setatargetfor95percentofSSSIstobeina
“favourable”or“unfavourablerecovering”state
by2010.UnitedUtilitieshadactuallyachieved
thistargetaround2005,butfeltitcouldgoeven
further.
Finally,UnitedUtilitieshasaresponsibility
Upstream interventions
15May 2015May 2015
Toreducecolourandturbidity,improve
rawwaterqualityandmeetincreasingly
demandingdrinkingwaterqualitystandards,
thewaterindustryhasengineeredavarietyof
watertreatmentprocesses.Thesesolutions
arecapital-intensive,requiringadditional
chemicals,powerandwastehandlingfacilities.
Theyoftenresultinsignificantlyincreased
operatingcostsandincreasethecompany’s
carbonfootprint.
Natural filters
Recognisingtheneedtochallengethis
traditionofaddressingwaterqualityissues
withpurelyengineeringsolutions,United
UtilitiesdevelopedtheSustainableCatchment
ManagementProgramme(SCaMP)in2005.
Onelong-termobjectiveofthisinnovativeasset
managementsolutionistorestoretheland’s
“naturalwaterfilters”andensurethatcolour-
causingmaterialsstayonthemoors.
UnitedUtilities’catchmentcontained
“One objective is to
ensure that colour-
causing materials stay
on the moors”
“Many of the farms had
muck middens that were
open to the elements”
to find no more than 50 micrograms of these
substances per litre of water.
Raw water quality
Most water companies, including United
Utilities, reduce the formation of DBP by
separating the DOC from the water they are
processing. But United Utilities extended its
solution another step upstream, attempting
to reduce both DOC and pathogens in the raw
reservoir water as well.
One project set out in the SCaMP is to
revegetate the catchment’s bare peat areas
with heather brash, lime, grass seed and
fertiliser, turning them back into natural
moorland. Vegetation binds the soil in place
which stops rain from washing the particles
downhill into reservoirs. Not only that, but
when bound in place peat soil forms part of
a natural process of water filtration. When
operating effectively, these ecological
processes benefit water treatment works
considerably, helping them supply customers
with clean water more cost-effectively.
Several more SCaMP projects involve
working with the farmers in United Utilities’
catchment to manage livestock and improve
poor waste management facilities. Replacing
open-air tanks and middens with run-off
roofed facilities ensures muck and slurry stays
where it belongs even during heavy rain. There
is also a considerable carbon sequestration
benefit, where a carbon rich organic material
builds up over time.
Favourable state
More new buildings give farmers a place
to keep livestock during the wet winter
months and the lambing season. New
fences, hedgerows, drystone walls and
animal crossing points all exclude livestock
from the catchment’s watercourses. These
measures reduce the risk of pathogens
entering the raw water, which reduces the
demand for chlorine.
These initiatives all lead to more consistent
water quality, reducing United Utilities’
operational costs and the need to upgrade its
wastewater treatment assets.
Revegetation, watercourse fencing and
improving agricultural waste management
are also effective ways of enhancing and
protecting biodiversity – so as well as
improving the efficiency of United Utilities’
water treatment works and the quality of its
product, the SCaMP projects brought the
SSSIs within the catchment closer to the
“favourable” or “unfavourable recovering”
state required by the government.
0
90
06
95
07
00
08
05
09
10
10
Date
Date
Colour(Hazen)
Colour(Hazen)
Colour ColourAnnualAverage
ColourTrendProcessMaximum
15
11
20
12
25
13
30
5
10
0
15
100
20
200
25
300
30
400
35
500
40
600
45
RawWaterColour Monthlymean Non-ScientificlineindicatingPeakReduction
Figure 1: Colour in a Cumbrian reservoir exceeded the limit at which it could be treated
Figure 2: Daily raw water colour from a Pennine river. Note the downward trend in seasonal peaks

2. 16
MatthewHigginsongraduatedfromLeeds
UniversitywithaBScinPhysicalGeography.
SincejoiningUnitedUtilitieshehascarriedouta
cost-benefitanalysisoftheSCaMPinitiativeand
implementedregulatorychangestothecompany’s
DrinkingWaterSafetyPlan.Heiscurrentlyworking
onanRCMproject.
Author’s biography
DevelopingandimplementingSCaMP
involvedamassiveculturalshiftforUnited
Utilities,whereinvestmentdecisionsare
usuallycapital-driven.Butaseriesofcost-
benefitanalyses(seebox)predictedbenefitsfor
UnitedUtilitiescustomersundereventhemost
pessimisticscenariosovera60yearperiod.
Stakeholdermanagementandpartnership
workingarekeytothesuccessoftheSCaMP:
throughcommunicationandcollaboration,
commongoalswereestablishedwith
interestedparties(includingNaturalEngland
andNationalTrust),whichthenassistedwith
fundingfortheprogramme.
Continuing downstream
In2010,NaturalEnglandfound98.6percent
oftheSSSIsinUnitedUtilities’catchmentto
beina“favourable”or“unfavourablerecover-
ing”state,exceedingthegovernment’starget.
Today,thefigureis99.4percent.
Severalyearsaftercatchmentinterventions
began,thedatafromsomeofUnitedUtilities’
monitoringsitesisstartingtoshowslightly
–butstatisticallysignificantly–improved
rawwatercolour(Figure2).Streamturbidity
hasdecreasedatmanyreservoirs,reducing
chemicalandcoagulantusage.
Boththepre-andpost-interventiondata
setsareoftenlimited,butindicationssofar
arepositiveandlonger-termtrends–and
theirimpactonwatertreatmentassets–will
becomeapparentovertime.Thenextreview
ofSCaMPprogresswilltakeplaceattheendof
2015.
Meanwhile,UnitedUtilitieshasstarted
CatchmentWise:anewprojectintendedtodo
forwatercoursesdownstreamofitswastewater
treatmentworkswhatSCaMPdoesforthose
upstream.
The colour of the raw water supplying a
major Cumbrian water treatment works,
serving over a million customers, has
been steadily increasing from 1990 to
2013. There has also been increased
seasonal variability, with levels tending
to peak during the autumn.
The main treatment process for colour at
this works is direct filtration, which can
treat up to 26 HU. Colour levels at the
inlet peaked at 26 HU in 1998 and 2004,
and have exceeded 26 HU a number
of times since 2009. When these peaks
occur, the works has to increase its
use of a chemical coagulant (incurring
additional costs and carbon emissions)
and reduce its maximum throughput
(reducing efficiency).
As the average colour increases, these
peaks are likely to occur more often.
If sustainable catchment management
fails to check the increase in raw water
colour, United Utilities would either
need to reduce the output from the
works when colour is high or invest
approximately £60 million in additional
treatment. The capital investment,
together with increased operational
costs, power consumption and carbon
impact, would increase customers’ bills.
The analysis indicates that some
additional capital expenditure is
inevitable, although it predicts
United Utilities can significantly delay
investment and possibly reduce the
investment needed (Table 1).
Cost-benefit analysis
“Stream turbidity has
decreased, reducing
chemical and coagulant
usage”
Description Pessimistic
estate(£M)
Central
estate(£M)
Optimistic
estate(£M)
Benefits
against
business
asusual
prediction
Water
treatment
opexsavings
0 2 9
Water
treatment
capexsavings
0 8 27
Biodiversity
benefits 1 6 12
Recreation
benefits
0 1 3
Greenhouse
gasesbenefits 5 18 40
Totalbenefits 6 35 90
UU+partner UU+partner
costs 4 4 4
Netpresent
value
2 31 87
Benefit:
costratio
1.59 9.52 24.82
UUonly UsingUUcosts
only 3 3 3
Netpresent
value 3 32 87
Benefit:
costratio
1.89 11.33 29.52
Table 1: Cost-benefit analysis for a Cumbrian water treatment works, showing savings against a
counterfactual scenario of increasing costs over 60 years
May 2015