SDR Appendix B Hammer Smith PS

8/3/2019 SDR Appendix B Hammer Smith PS

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Appendix B Hammersmith Pumping Station


B .1 Introduction

B.1.1 This appendix sets out the site selection process that we used and ourrationale for identifying our preferred phase one and phase twoconsultation sites to intercept the Hammersmith Pumping Station CSO.

Type of site

B.1.2 We need a worksite to connect the local combined sewer overflow (CSO),known as the Hammersmith Pumping Station CSO, to the main tunnel. Toenable the connection to be made the site needs to be as close aspossible to the line of the existing sewers.

Site selection process

B.1.3 All potential worksites have been identified in accordance with ourSite

selection methodology paper(SSM), which involved a sieving approach,commencing with identification of all potentially suitable areas of land(excluding concentrated residential sites and World Heritage Sites) andpassing these sites through increasingly detailed levels of assessment tomove from a long list to a draft short list, a final short list and finally a list ofpreferred sites for phase one consultation.

B.1.4 A plan showing all the sites considered for the interception of theHammersmith Pumping Station CSO and how they progressed during the

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B.2.2 In total, 11 sites were included on the long list. These sites wereassessed having regard to the high-level considerations set out in Table

2.2 of the SSM (hereafter referred to as Table 2.2) including (site size, sitefeatures, availability of jetty/wharf and access), planning and environment(heritage, landscape/townscape, open space and ecological) andcommunity and property (neighbouring land uses, site use, SpecialLand/Crown Land and acquisition costs) considerations.

B.2.3 The table below provides a summary of the outcome of the Table 2.2assessment in respect of the long list of sites considered for the

interception of this CSO. Sites which were assessed as being the leastconstrained when considered against Table 2.2 considerations passed tothe draft short list. This did not necessarily mean that these sites wouldultimately be judged as suitable, but that no significant constraints wereidentified in relation to the high-level considerations addressed at Table2.2. Sites that were judged to be more constrained were notrecommended to be retained on the short list for more detailedassessment. The main rationale for the exclusion of these sites at thisstage is summarised in the table.

Table B.1 Long list to draft short list for the interception of theHammersmith Pumping Station CSO (Table 2.2 assessment)

Site IDSite name/description

Recommendation and rationale

C04XA Foreshore adjacent Recommendation: To draft shortlist


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C04XHOld (abandoned)Pumping Station

Recommendation: Not to draft shortlist

Rationale: The works area is veryrestricted and the engineering connectionto the sewer is long and difficult

C04XJ

Adjacent toHammersmithPumping Station,

Chancellors Road

Recommendation: To draft shortlist

C04XLPart developmentsite to south east ofpumping station inlet


C04XMPart developmentsite to north east ofpumping station inlet


NB. The Site ID and Site name/description were used as an internal mechanismto record and describe the site but may be updated if necessary.

B.2.4 Of the 11 sites identified, five were assessed as potentially suitable andpassed to the draft short list while six sites were eliminated as beingunsuitable.

Assessment of draft short list sites


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retained on the short list to pass to the next stage of assessment. This didnot necessarily mean that a site would ultimately be judged as suitable,

but that no significant constraints were identified in relation to theconsiderations addressed at Table 2.3. Sites that were judged to be moreconstrained were not recommended to be retained on the short list formore detailed assessment.

Table B.2 Draft short list to final short list for the interception of theHammersmith Pumping Station CSO (Table 2.3 assessment)

Site IDSite name/description Recommendation and rationale

C04XAForeshore, adjacentto Chancellors Wharf

Recommendation: Retain on short list

C04XG Frank Banfield Park Recommendation: Retain on short list

C04XJHammersmithPumping Station (offChancellors Road)


C04XLNear HammersmithPumping Station off

Distillery Road



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and property considerations. At this stage in the process, sites wereassessed in isolation without comparison to other sites or regard to

tunnelling strategy. Sites were evaluated by each discipline usingtechnical knowledge and professional judgement as appropriate andassessed as eithersuitable, less suitable ornot suitable from thatdisciplines perspective.

B.2.12 A summary of the conclusions of each disciplines assessment from thesite suitability reports is provided below.

C04XA: Foreshore, adjacent to Chancellors WharfB.2.13 Site C04XA is situated on the foreshore of the River Thames within the

London Borough of Hammersmith and Fulham. The site is located directlyadjacent to properties located on Chancellors Wharf and can be accessedvia Chancellors Road.

B.2.14 A paved open space and public walkway separates Chancellors Wharfand the foreshore. The surrounding area is characterised by a range of

land uses, including residential, leisure, light industrial, warehousing andoffice developments. The nearest residential properties are at ChancellorsWharf.

B.2.15 Engineering: The site was assessed as less suitable for use as a CSOsite because it has poor access and is relatively small. However, being onthe foreshore, its size could be increased.

B.2.16 Planning: On balance, the site was assessed as being less suitable for

se as a site to intercept this CSO beca se of the pro imit of residential


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contains a number of residences and businesses. Charing Cross Hospitalis located to the southeast.

B.2.22 Engineering: The site was considered suitable for use as a CSO sitebecause it has good access and can facilitate all the site requirements.However, the site is situated more than 200m from the river.

B.2.23 Planning: On balance, the site was assessed as being less suitable foruse to intercept this CSO because the site is subject to several policydesignations, including being located within a conservation area.Furthermore, use of the site would result in the temporary loss of publicopen space and impacts on residential dwellings. Substantial mitigationwould be required for these impacts to be reduced.

B.2.24 Environment: Overall, the site was assessed as suitable for use as aCSO site. The site was considered likely to be suitable from theperspectives of transport, archaeology, built heritage, water resources,ecology, and flood risk. However, the site was considered less suitablefrom the perspective of townscape, air quality, noise and land quality,

although these impacts may be reduced by mitigation.

B.2.25 Socio-economic and community: The site was assessed as lesssuitable for use a CSO site due to impacts on Frank Banfield Park,specifically a play area, and residential properties. Permanent impactsmay also result from structures and hardstanding associated withoperations.

B.2.26 Property: The site was assessed as suitable for use as a CSO site asth i lik l t b t bl i iti t H i iti


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from the perspective of flood risk, air quality, noise and land quality,although these impacts may be reduced by appropriate mitigation.

B.2.32 Socio-economic and community: The site was assessed as suitablefor use a CSO site as the site is unlikely to have a significant impact on thelocal community as it is located on a brownfield site. While constructionrelated impacts may be experienced by adjacent residences andbusinesses, these can be reduced through appropriate mitigation.

B.2.33 Property: The site was assessed as suitable for use as a CSO site.However, this may change to less suitable if a proposed development onthe site commences.

C04XL: Near Hammersmith Pumping Station off Distillery Road

B.2.34 Site C04XL is situated within a vacant former industrial site known asHammersmith Embankment, within the London Borough of Hammersmithand Fulham.

B.2.35 The site is bounded to the north by Chancellors Road, and adjoins thesoutheast corner of an existing Thames Water pumping station. Thesurrounding area is predominantly residential with Frank Banfield Park tothe east and the River Thames to the west.

B.2.36 Engineering: The site was assessed as suitable for use as a CSO sitebecause it has good access and is adequate in size.

B.2.37 Planning: On balance, the site was assessed as being suitable for use

it t i t t thi CSO Th it i bj t t l l i d


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surrounding area is predominantly residential with Frank Banfield Park tothe east and the River Thames to the west.

B.2.43 Engineering: The site was considered suitable for use as a CSO sitebecause it has good access and is adequate in size.

B.2.44 Planning: On balance, the site was assessed as being suitable for useas a site to intercept this CSO. The site is subject to several planning andenvironmental policy designations. Furthermore, a number of residentialproperties are also in proximity. However, with appropriate mitigation, anyimpacts could be reduced.

B.2.45 Environment: Overall, the site was assessed as suitable for use as aCSO site. The site was considered likely to be suitable from theperspectives of archaeology, water resources, ecology, flood risk, andland quality. However, the site was considered less suitable from theperspective of transport, built heritage, townscape, air quality and noise,although these impacts may be reduced by appropriate mitigation.

B.2.46 Socio-economic and community: The site was assessed as lesssuitable for use as a CSO site due to the proximity of Frank Banfield Park.Impacts may be experienced by adjacent residences and businesses butthese impacts may be reduced through appropriate mitigation.

B.2.47 Property: The site was assessed as suitable for use as a CSO site.However, this may change to less suitable if a proposed development onthe site commences.

Id tifi ti f th f d it


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main tunnel to cross much of this site thereby sterilising a greater partfor future development than a shaft on site C04XJ.

C04XM has a number of live, large diameter sewers under the groundwhich makes planning a large shaft and interception chamberscomplex, and also requires part use of Distillery Road, which wouldneed to be closed for an extended period. C04XL does not abut theexisting Hammersmith Pumping Station site and would lead to greaterfragmentation of the vacant land.

Site C04XJ has sufficient space and allows the permanent structuresto be located in close proximity to the existing pumping station. Thesite has good access and the size and location of the site would allowall works to be conducted off the carriageway reducing disruption.

Site C04XJ is primarily opposite business premises, located furtheraway from residential dwellings than the other sites, and would be anextension of the pumping station which would ease operational accessand maintenance.

B.2.50 C04XJ was therefore identified as the preferred site for the interception offlows from the Hammersmith Pumping Station CSO. As noted above, theHammersmith Pumping Station site had also been identified during thesite selection process as being suitable for use as a main tunnel site forthe construction of the main tunnel. The preferred tunnelling strategywhich was developed for phase one consultation proposed use of theHammersmith Pumping Station site to receive a tunnel boring machine

(TBM) b i d t d i th i t l f it t B El


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Design and visual impact of permanent structures.

B.3.3 The main comments received in support of the preferred site included:

good and logical choice for the function and the most obvious site

best site with regard to noise and traffic issues

the only viable option because it minimises disruption andinconvenience and uses derelict site which has been empty for manyyears.

B.3.4 More detail on the consultation responses relating to this site and ourresponse to the comments received are provided within the Report onphase one consultation.

B.3.5 Having taken all comments received into account, we still believe thatHammersmith Pumping Station is the most appropriate site to connect thelocal CSO to the main tunnel. Compared to the other shortlisted sites,Hammersmith Pumping Station has more limited impact on the residential

properties to the north side of Chancellors Road, reduces the potentialimpact on Frank Banfield Park and has good access.

B.3.6 However, due to the emergence of plans for the redevelopment of thecurrently vacant land on which we proposed to develop our worksite andadditional engineering design work, we began a review of our tunnellingstrategy for the construction of the western section of the main tunnel anda review of whether a main tunnel site is required at Hammersmith

P i St ti


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Hammersmith Pumping Station (off Chancellors Road C04XJ) as ourpreferred site to intercept the Hammersmith Pumping Station CSO.

B.3.11 This back-check involved a targeted repeat of each relevant stage of oursite selection process to reconsider which site would be most suitable forthe interception of the Hammersmith Pumping Station CSO. The followingoutlines the results from each stage of the back-check process.

B.3.12 The original long list of sites for Hammersmith Pumping Station CSOcontained eleven sites (see Table B.1). These sites were reviewed alongwith any new sites identified in the back-checking exercise (ie, a

reassessment to establish if there is any change of circumstances or newinformation has emerged).

B.3.13 All sites on the original long list were put on the back-check long list forthis CSO. In addition, the following new sites were added to theback-check long list:

C04XN: Hammersmith Pumping Station off Distillery Road (new site

incorporating sites C04XL and C04XM) C04XP: Thames Water Depot and Hammersmith Pumping Station,

Chancellors Road (new site which incorporated site C04XH and part ofC04XM).

B.3.14 Sites C04XH, C04XL and C04XM were subsequently withdrawn as thesewere replaced by the new sites detailed above.

B.3.15 It should be noted that consideration was also given to other alternativeit t d b lt h th th it


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Site IDSite

name/descriptionRecommendation and rationale

C04XBPaved areafronting River wall

Recommendation: Not to draft shortlistRationale: The site is thin and there arelikely to be restrictive working conditions.

C04XCVacant lot adjacentto the River

Recommendation: Not to draft shortlistRationale: The engineering connectionto the sewer is long and difficult

C04XDParking areabetween offices

Recommendation: Not to draft shortlistRationale: The site is thin and there arelikely to be restrictive working conditions.

C04XE Crisp RoadRecommendation: Not to draft shortlistRationale: The site is too thin and toosmall.

C04XFAdjacent toHammersmithPumping Station,Chancellor's Road

Recommendation: To draft shortlist tobe considered with C04XJ

C04XGFrank BanfieldPark


Hammersmith

P i St ti R d ti T d ft h tli t t


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B.3.21 The table below summarises the outcome of the back-check assessmentof the draft short list of sites. Sites which were assessed as being the

least constrained when considered against Table 2.3 considerations wereretained on the back-check short list to pass to the next stage ofassessment. This did not necessarily mean that a site would ultimately bejudged as suitable, but that no significant constraints were identified inrelation to the considerations addressed at Table 2.3. Sites that werejudged to be more constrained were not recommended to be retained onthe short list for more detailed assessment.

B.3.22 The main rationale for the exclusion of these sites at this stage issummarised below.

Table B.4 Draft short list to final short list for the interception of theHammersmith Pumping Station CSO (Table 2.3 assessment)



C04XAForeshore, adjacentto Chancellors Wharf


C04XG Frank Banfield Park Recommendation: Retain on short list

C04XJ /Hammersmith

S ( ff R d i R i h li


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C04XJ/C04XF: Adjacent to Hammersmith Pumping Station (offChancellors Road)

C04XN: Hammersmith Pumping Station (off Distillery Road)

C04XP: TW Depot and Pumping Station, Chancellors Road.

B.3.26 A site suitability report (SSR) was prepared for the new back-check finalshort list site and the SSRs for the phase one shortlisted sites werere-evaluated.

C04XA: Foreshore, adjacent to Chancellors WharfB.3.27 All discipline recommendations remain unchanged.

C04XG: Frank Banfield Park

B.3.28 There are likely to be high acquisition costs if replacement land isrequired. Therefore, the property recommendation becomes lesssuitable.

B.3.29 All other discipline recommendations remain unchanged.

C04XJ/C04XF: Adjacent to Hammersmith Pumping Station (offChancellors Road)

B.3.30 Because these two sites are adjoining, we reviewed the conclusions fromthe original C04XJ SSR and consider these would be valid for thecombined site.

B 3 31 If d l t th it l b il bl hi h


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minimum. There will be impacts on residential amenity but these are likelyto be able to be reduced by appropriate mitigation. Further negotiations

with the land owner will be required in order to agree the use of the site forthe temporary and permanent Thames Tunnel project works and phasingof the redevelopment proposals.

B.3.37 Environment: Overall, the site was assessed as suitable for use as aCSO site. The site was considered likely to be suitable from theperspective of transport, archaeology, built heritage, townscape, waterresources (hydrogeology and surface water), ecology and flood risk.

However, the site was considered less suitable from the perspective ofair quality, noise and land quality although these impacts may be reducedby appropriate mitigation.

B.3.38 Socio-economic and community: The site was assessed as lesssuitable for use a CSO site due to the proximity of Frank Banfield Park, avaluable area of community open space. The area has been identified asreasonably quiet and therefore, there may be construction noise impacts

on the park and also on residential properties opposite the site.B.3.39 Property: The site was assessed as less suitable for use as a CSO site.

The site is in private ownership and therefore there should be noprocedural difficulty in acquiring the land in its current state. Furthermore,the acquisition cost is likely to be high but acceptable. However, ifdevelopment commences, the site may no longer be available, whichrepresents a risk to the project. Furthermore, if Thames Tunnel project

k j di d l t i iti t lik l t i


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B.3.45 Planning: On balance, both options were assessed as being notsuitable for use as a site to intercept this CSO. The construction works

are likely to directly impact on a large number of existing residents andthere is unlikely to be acceptable mitigation measures to protect theamenity of these residences.

B.3.46 Environment: Overall, Option 1 was assessed as suitable for use as aCSO site. The site was considered likely to be suitable from theperspectives of transport, archaeology, water resources (hydrogeologyand surface water), flood risk and ecology. However, the site was

considered less suitable from the perspective of built heritage,townscape, air quality, noise and land quality, although these impacts maybe reduced by appropriate mitigation.

B.3.47 Overall, Option 2 was assessed as less suitable for use as a CSO site.The site was considered likely to be suitable from the perspectives ofarchaeology, water resources (surface water and hydrogeology), flood riskand ecology. However, the site was considered less suitable from the

perspectives of transport, built heritage, townscape, air quality, noise andland quality.

B.3.48 Socio-economic and community: Both options were assessed as notsuitable for use as a CSO site. Construction works are likely to directlyimpact on a number of residential properties and given their closeproximity to the site, effective mitigation may be difficult to achieve.Furthermore, site layout option one is in close proximity to twoplaygrounds and site layout option two requires a large amount of


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B.4.2 This workshop took into account the findings of all the SSRs, newinformation and the feedback received during the phase one consultation.

On the basis of the assessments described above and professionaljudgement, it was agreed by all disciplines that Hammersmith PumpingStation (off Distillery Road C04XN) should become therecommended phase two consultation preferred site for theinterception of the Hammersmith Pumping Station CSO. This meantthat we believed this to be the most appropriate site, subject to furtherengagement with stakeholders and further design development to verifythis conclusion prior to phase two consultation. For the purposes ofphase two consultation, this site will be referred to as HammersmithPumping Station.

B.4.3 In summary, Hammersmith Pumping Station (off Distillery Road C04XN)was identified as the most suitable site because:

the site is within the footprint of our phase one consultationconstruction layout plan, but the site is much smaller as it is only

needed to intercept the CSO. Due to the advanced stages of theredevelopment proposal for this site for a major residentialdevelopment, it was concluded that the larger site required for a maintunnel reception site would not be available and would therefore posea significant risk to the project if it were selected as a main tunnel site

technically a suitable location to intercept this CSO

location of the CSO fits in with the developers proposed

d l t f th it d k b di t d


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to developing the design and construction of our works and the scope ofour environmental assessments. To ensure our design process is

transparent, we undertook a series of design reviews, hosted and chairedby the Design Council CABE (formerly the Commission for Architectureand the Built Environment). The review for Hammersmith PumpingStation was attended by the London Borough of Hammersmith andFulham and our pan-London stakeholders.

B.5.4 Furthermore, we have also had regular meetings with the landowner of theadjacent development site in order to mitigate the projects impact on their

interests.

Construction layout

B.5.5 In response to stakeholder engagement, phase one consultationresponses and scheme development, the construction layout of the sitehas been altered to minimise impact on the local community andenvironment and is guided by operational and functional requirements.

Particular factors at this site that have influenced the layout are as follows: We have arranged the site offices so that they would be positioned

along the northern boundary of the site to act as a screen from theconstruction activities for the residents on Chancellors Road.

Effects of construction works on adjacent land uses have beenminimised by siting as much of the works as possible within theexisting Hammersmith Pumping Station site.


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B .6 Confirmation of the preferred site for phase twoconsultation

B.6.1 A final preferred sites workshop was held in summer 2011 to verify thechoice of preferred sites and to consider any outcomes of furtherengagement and scheme development. The conclusion reached was thatHammersmith Pumping Station should become the phase twoconsultation preferred site for the interception of the HammersmithPumping Station CSO.

B.6.2 Phase two consultation will provide an opportunity for the public tocomment on our revised preferred site and scheme for the Thames Tunnelproject, before we publicise our proposed application.


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Annex B.1


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C04XP

C04XC

C04XD

C04XB

C04XN

C04XG

C04XP

C04XA

C04XJ

C04XF

CS04X

C04XE

Hammersmith Pumping Station

Preferred List: CSO SitesCS04X

Hammersmith Pumping Station

The Point, 7thFloor,

37NorthWharf Road,Paddington,LondonW21AF

Thames Water Utilities

Legend

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Documents

SDR Appendix B Hammer Smith PS